Ard Biesheuvel [Thu, 10 Mar 2022 16:24:45 +0000 (17:24 +0100)]
ARM: entry: fix unwinder problems caused by IRQ stacks
The IRQ stacks series made some changes to the unwinder, to permit
unwinding across different stacks. This is needed because otherwise, the
call stack would terminate at the point where the stack switch between
the task stack and the IRQ stack occurs, which would defeat any
diagnostics that rely on timer interrupts, such as RCU stall detection.
Unfortunately, getting the unwind annotations correct turns out to be
difficult, given that this now involves a frame pointer which needs to
point into the right location in the task stack when unwinding from the
IRQ stack. Getting this wrong for an exception handling routine results
in the stack pointer to be unwound from the wrong location, causing any
subsequent unwind attempts to cause all kinds of issues, as reported by
Naresh here [0].
So let's simplify this, by deferring the stack switch to
call_with_stack(), which already has the correct unwind annotations, and
removing all the complicated handling of the stack frame from the IRQ
exception entrypoint itself.
[0] https://lore.kernel.org/all/CA+G9fYtpy8VgK+ag6OsA9TDrwi5YGU4hu7GM8xwpO7v6LrCD4Q@mail.gmail.com/
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Russell King (Oracle) [Wed, 9 Mar 2022 12:06:02 +0000 (12:06 +0000)]
ARM: unwind: set frame.pc correctly for current-thread unwinding
When e.g. a WARN_ON() is encountered, we attempt to unwind the current
thread. To do this, we set frame.pc to unwind_backtrace, which means it
points at the beginning of the function. However, the rest of the state
is initialised from within the function, which means the function
prologue has already been run.
This can be confusing, and with a recent patch from Ard, can result in
the unwinder misbehaving if we want to be strict about the PC value.
If we correctly initialise the state so it is self-consistent (in other
words, set frame.pc to the location we are initialising it) then we
eliminate this confusion, and avoid possible future issues.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Ard Biesheuvel [Wed, 2 Mar 2022 11:38:18 +0000 (12:38 +0100)]
ARM: 9184/1: return_address: disable again for CONFIG_ARM_UNWIND=y
Commit
41918ec82eb6 ("ARM: ftrace: enable the graph tracer with the EABI
unwinder") removed the dummy version of return_address() that was
provided for the CONFIG_ARM_UNWIND=y case, on the assumption that the
removal of the kernel_text_address() call from unwind_frame() in the
preceding patch made it safe to do so.
However, this turns out not to be the case: Corentin reports warnings
about suspicious RCU usage and other strange behavior that seems to
originate in the stack unwinding that occurs in return_address().
Given that the function graph tracer (which is what these changes were
enabling for CONFIG_ARM_UNWIND=y builds) does not appear to care about
this distinction, let's revert return_address() to the old state.
Cc: Corentin Labbe <clabbe.montjoie@gmail.com>
Fixes:
41918ec82eb6 ("ARM: ftrace: enable the graph tracer with the EABI unwinder")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reported-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Ard Biesheuvel [Wed, 2 Mar 2022 11:36:56 +0000 (12:36 +0100)]
ARM: 9183/1: unwind: avoid spurious warnings on bogus code addresses
Corentin reports that since commit
538b9265c063 ("ARM: unwind: track
location of LR value in stack frame"), numerous spurious warnings are
emitted into the kernel log:
[ 0.000000] unwind: Index not found
c0f0c440
[ 0.000000] unwind: Index not found
00000000
[ 0.000000] unwind: Index not found
c0f0c440
[ 0.000000] unwind: Index not found
00000000
This is due to the fact that the commit in question removes a check
whether the PC value in the unwound frame is actually a kernel text
address, on the assumption that such an address will not be associated
with valid unwind data to begin with, which is checked right after.
The reason for removing this check was that unwind_frame() will be
called by the ftrace graph tracer code, which means that it can no
longer be safely instrumented itself, or any code that it calls, as it
could cause infinite recursion.
In order to prevent the spurious diagnostics, let's add back the call to
kernel_text_address(), but this time, only call it if no unwind data
could be found for the address in question. This is more efficient for
the common successful case, and should avoid any unintended recursion,
considering that kernel_text_address() will only be called if no unwind
data was found.
Cc: Corentin Labbe <clabbe.montjoie@gmail.com>
Fixes:
538b9265c063 ("ARM: unwind: track location of LR value in stack frame")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Russell King (Oracle) [Mon, 28 Feb 2022 13:53:48 +0000 (13:53 +0000)]
Merge tag 'arm-ftrace-for-rmk' of git://git./linux/kernel/git/ardb/linux into devel-stable
ARM: ftrace fixes and cleanups
Make all flavors of ftrace available on all builds, regardless of ISA
choice, unwinder choice or compiler:
- use ADD not POP where possible
- fix a couple of Thumb2 related issues
- enable HAVE_FUNCTION_GRAPH_FP_TEST for robustness
- enable the graph tracer with the EABI unwinder
- avoid clobbering frame pointer registers to make Clang happy
Link: https://lore.kernel.org/linux-arm-kernel/20220203082204.1176734-1-ardb@kernel.org/
Ard Biesheuvel [Wed, 26 Jan 2022 10:43:39 +0000 (11:43 +0100)]
Revert "ARM: 9144/1: forbid ftrace with clang and thumb2_kernel"
This reverts commit
ecb108e3e3f7c692082b7c6fce41779c3835854a.
Clang + Thumb2 with ftrace is now supported.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Ard Biesheuvel [Tue, 1 Feb 2022 10:56:44 +0000 (11:56 +0100)]
ARM: mach-bcm: disable ftrace in SMC invocation routines
The SMC calling convention uses R7 as an argument register, which
conflicts with its use as a frame pointer when building in Thumb2 mode.
Given that Clang with ftrace does not permit frame pointers to be
disabled, let's omit this compilation unit from ftrace instrumentation.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Ard Biesheuvel [Wed, 26 Jan 2022 10:40:02 +0000 (11:40 +0100)]
ARM: cacheflush: avoid clobbering the frame pointer
Thumb2 uses R7 rather than R11 as the frame pointer, and even if we
rarely use a frame pointer to begin with when building in Thumb2 mode,
there are cases where it is required by the compiler (Clang when
inserting profiling hooks via -pg)
However, preserving and restoring the frame pointer is risky, as any
unhandled exceptions raised in the mean time will produce a bogus
backtrace, and it would be better not to touch the frame pointer at all.
This is the case even when CONFIG_FRAME_POINTER is not set, as the
unwind directive used by the unwinder may also use R7 or R11 as the
unwind anchor, even if the frame pointer is not managed strictly
according to the frame pointer ABI.
So let's tweak the cacheflush asm code not to clobber R7 or R11 at all,
so that we can drop R7 from the clobber lists of the inline asm blocks
that call these routines, and remove the code that preserves/restores
R11.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Ard Biesheuvel [Wed, 26 Jan 2022 10:27:21 +0000 (11:27 +0100)]
ARM: kprobes: treat R7 as the frame pointer register in Thumb2 builds
Thumb2 code uses R7 as the frame pointer rather than R11, because the
opcodes to access it are generally shorter.
This means that there are cases where we cannot simply add it to the
clobber list of an asm() block, but need to preserve/restore it
explicitly, or the compiler may complain in some cases (e.g., Clang
builds with ftrace enabled).
Since R11 is not special in that case, clobber it instead, and use it to
preserve/restore the value of R7.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Ard Biesheuvel [Tue, 25 Jan 2022 14:55:24 +0000 (15:55 +0100)]
ARM: ftrace: enable the graph tracer with the EABI unwinder
Enable the function graph tracer in combination with the EABI unwinder,
so that Thumb2 builds or Clang ARM builds can make use of it.
This involves using the unwinder to locate the return address of an
instrumented function on the stack, so that it can be overridden and
made to refer to the ftrace handling routines that need to be called at
function return.
Given that for these builds, it is not guaranteed that the value of the
link register is stored on the stack, fall back to the stack slot that
will be used by the ftrace exit code to restore LR in the instrumented
function's execution context.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Ard Biesheuvel [Mon, 24 Jan 2022 15:49:09 +0000 (16:49 +0100)]
ARM: unwind: track location of LR value in stack frame
The ftrace graph tracer needs to override the return address of an
instrumented function, in order to install a hook that gets invoked when
the function returns again.
Currently, we only support this when building for ARM using GCC with
frame pointers, as in this case, it is guaranteed that the function will
reload LR from [FP, #-4] in all cases, and we can simply pass that
address to the ftrace code.
In order to support this for configurations that rely on the EABI
unwinder, such as Thumb2 builds, make the unwinder keep track of the
address from which LR was unwound, permitting ftrace to make use of this
in a subsequent patch.
Drop the call to is_kernel_text_address(), which is problematic in terms
of ftrace recursion, given that it may be instrumented itself. The call
is redundant anyway, as no unwind directives will be found unless the PC
points to memory that is known to contain executable code.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Ard Biesheuvel [Tue, 25 Jan 2022 10:20:49 +0000 (11:20 +0100)]
ARM: ftrace: enable HAVE_FUNCTION_GRAPH_FP_TEST
Fix the frame pointer handling in the function graph tracer entry and
exit code so we can enable HAVE_FUNCTION_GRAPH_FP_TEST. Instead of using
FP directly (which will have different values between the entry and exit
pieces of the function graph tracer), use the value of SP at entry and
exit, as we can derive the former value from the frame pointer.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Ard Biesheuvel [Tue, 7 Dec 2021 18:50:35 +0000 (19:50 +0100)]
ARM: ftrace: avoid unnecessary literal loads
Avoid explicit literal loads and instead, use accessor macros that
generate the optimal sequence depending on the architecture revision
being targeted.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Ard Biesheuvel [Sun, 23 Jan 2022 19:18:33 +0000 (20:18 +0100)]
ARM: ftrace: avoid redundant loads or clobbering IP
Tweak the ftrace return paths to avoid redundant loads of SP, as well as
unnecessary clobbering of IP.
This also fixes the inconsistency of using MOV to perform a function
return, which is sub-optimal on recent micro-architectures but more
importantly, does not perform an interworking return, unlike compiler
generated function returns in Thumb2 builds.
Let's fix this by popping PC from the stack like most ordinary code
does.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Ard Biesheuvel [Sun, 23 Jan 2022 19:28:39 +0000 (20:28 +0100)]
ARM: ftrace: use trampolines to keep .init.text in branching range
Kernel images that are large in comparison to the range of a direct
branch may fail to work as expected with ftrace, as patching a direct
branch to one of the core ftrace routines may not be possible from the
.init.text section, if it is emitted too far away from the normal .text
section.
This is more likely to affect Thumb2 builds, given that its range is
only -/+ 16 MiB (as opposed to ARM which has -/+ 32 MiB), but may occur
in either ISA.
To work around this, add a couple of trampolines to .init.text and
swap these in when the ftrace patching code is operating on callers in
.init.text.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Ard Biesheuvel [Wed, 8 Dec 2021 07:42:03 +0000 (08:42 +0100)]
ARM: ftrace: use ADD not POP to counter PUSH at entry
The compiler emitted hook used for ftrace consists of a PUSH {LR} to
preserve the link register, followed by a branch-and-link (BL) to
__gnu_mount_nc. Dynamic ftrace patches away the latter to turn the
combined sequence into a NOP, using a POP {LR} instruction.
This is not necessary, since the link register does not get clobbered in
this case, and simply adding #4 to the stack pointer is sufficient, and
avoids a memory access that may take a few cycles to resolve depending
on the micro-architecture.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Ard Biesheuvel [Mon, 24 Jan 2022 09:38:15 +0000 (10:38 +0100)]
ARM: ftrace: ensure that ADR takes the Thumb bit into account
Using ADR to take the address of 'ftrace_stub' via a local label
produces an address that has the Thumb bit cleared, which means the
subsequent comparison is guaranteed to fail. Instead, use the badr
macro, which forces the Thumb bit to be set.
Fixes:
a3ba87a61499 ("ARM: 6316/1: ftrace: add Thumb-2 support")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Russell King (Oracle) [Mon, 31 Jan 2022 15:26:45 +0000 (15:26 +0000)]
Merge tag 'arm-vmap-stacks-v6' of git://git./linux/kernel/git/ardb/linux into devel-stable
ARM: support for IRQ and vmap'ed stacks [v6]
This tag covers the changes between the version of vmap'ed + IRQ stacks
support pulled into rmk/devel-stable [0] (which was dropped from v5.17
due to issues discovered too late in the cycle), and my v5 proposed for
the v5.18 cycle [1].
[0] git://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git arm-irq-and-vmap-stacks-for-rmk
[1] https://lore.kernel.org/linux-arm-kernel/
20220124174744.1054712-1-ardb@kernel.org/
Ard Biesheuvel [Mon, 24 Jan 2022 22:32:51 +0000 (23:32 +0100)]
ARM: make get_current() and __my_cpu_offset() __always_inline
The get_current() and __my_cpu_offset() accessors evaluate to only a
single instruction emitted inline, but due to the size of the asm string
that is created for SMP+v6 configurations, the compiler assumes
otherwise, and may emit the functions out of line instead.
So use __always_inline to avoid this.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Ard Biesheuvel [Mon, 24 Jan 2022 22:29:59 +0000 (23:29 +0100)]
ARM: drop pointless SMP check on secondary startup path
Only SMP systems use the secondary startup path by definition, so there
is no need for SMP conditionals there.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Mon, 24 Jan 2022 19:55:10 +0000 (20:55 +0100)]
ARM: iop: make iop_handle_irq() static
The build bots complain about iop_handle_irq() not being declared so
let's make it static instead.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Mon, 10 Jan 2022 08:54:22 +0000 (09:54 +0100)]
ARM: mm: make vmalloc_seq handling SMP safe
Rework the vmalloc_seq handling so it can be used safely under SMP, as
we started using it to ensure that vmap'ed stacks are guaranteed to be
mapped by the active mm before switching to a task, and here we need to
ensure that changes to the page tables are visible to other CPUs when
they observe a change in the sequence count.
Since LPAE needs none of this, fold a check against it into the
vmalloc_seq counter check after breaking it out into a separate static
inline helper.
Given that vmap'ed stacks are now also supported on !SMP configurations,
let's drop the WARN() that could potentially now fire spuriously.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Mon, 24 Jan 2022 18:36:03 +0000 (19:36 +0100)]
ARM: entry: avoid clobbering R9 in IRQ handler
Avoid using R9 in the IRQ handler code, as the entry code uses it for
tsk, and expects it to remain untouched between the IRQ entry and exit
code.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Mon, 24 Jan 2022 18:28:58 +0000 (19:28 +0100)]
ARM: smp: elide HWCAP_TLS checks or __entry_task updates on SMP+v6
Use the SMP_ON_UP patching framework to elide HWCAP_TLS tests from the
context switch and return to userspace code paths, as SMP systems are
guaranteed to have this h/w capability.
At the same time, omit the update of __entry_task if the system is
detected to be UP at runtime, as in that case, the value is never used.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Mon, 24 Jan 2022 18:16:58 +0000 (19:16 +0100)]
ARM: assembler: define a Kconfig symbol for group relocation support
Nathan reports the group relocations go out of range in pathological
cases such as allyesconfig kernels, which have little chance of actually
booting but are still used in validation.
So add a Kconfig symbol for this feature, and make it depend on
!COMPILE_TEST.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Mon, 24 Jan 2022 18:51:58 +0000 (19:51 +0100)]
ARM: mm: switch to swapper_pg_dir early for vmap'ed stack
When onlining a CPU, switch to swapper_pg_dir as soon as possible so
that it is guaranteed that the vmap'ed stack is mapped before it is
used.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Fri, 24 Dec 2021 09:31:00 +0000 (10:31 +0100)]
ARM: 9176/1: avoid literal references in inline assembly
Nathan reports that the new get_current() and per-CPU offset accessors
may cause problems at build time due to the use of a literal to hold the
address of the respective variables. This is due to the fact that LLD
before v14 does not support the PC-relative group relocations that are
normally used for this, and the fallback relies on literals but does not
emit the literal pools explictly using the .ltorg directive.
./arch/arm/include/asm/current.h:53:6: error: out of range pc-relative fixup value
asm(LOAD_SYM_ARMV6(%0, __current) : "=r"(cur));
^
./arch/arm/include/asm/insn.h:25:2: note: expanded from macro 'LOAD_SYM_ARMV6'
" ldr " #reg ", =" #sym " nt"
^
<inline asm>:1:3: note: instantiated into assembly here
ldr r0, =__current
^
Since emitting a literal pool in this particular case is not possible,
let's avoid the LOAD_SYM_ARMV6() entirely, and use the ordinary C
assigment instead.
As it turns out, there are other such cases, and here, using .ltorg to
emit the literal pool within range of the LDR instruction would be
possible due to the presence of an unconditional branch right after it.
Unfortunately, putting .ltorg directives in subsections appears to
confuse the Clang inline assembler, resulting in similar errors even
though the .ltorg is most definitely within range.
So let's fix this by emitting the literal explicitly, and not rely on
the assembler to figure this out. This means we have move the fallback
out of the LOAD_SYM_ARMV6() macro and into the callers.
Link: https://github.com/ClangBuiltLinux/linux/issues/1551
Fixes:
9c46929e7989 ("ARM: implement THREAD_INFO_IN_TASK for uniprocessor systems")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Ard Biesheuvel [Wed, 5 Jan 2022 14:45:26 +0000 (15:45 +0100)]
ARM: 9177/1: disable vmap'ed stacks on suspend-capable SMP configs
There are several reports about the new vmap'ed stacks code breaking
suspend/resume on Exynos, Renesas and Tegra SMP platforms. While this is
under investigation, let's disable the vmap'ed stacks feature for the
time being for SMP configurations that have suspend/resume enabled.
[0] https://lore.kernel.org/linux-arm-kernel/
20211122092816.2865873-8-ardb@kernel.org/
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Russell King (Oracle) [Fri, 17 Dec 2021 11:48:13 +0000 (11:48 +0000)]
Merge tag 'arm-irq-and-vmap-stacks-for-rmk' of git://git./linux/kernel/git/ardb/linux into devel-stable
ARM: support for IRQ and vmap'ed stacks
This PR covers all the work related to implementing IRQ stacks and
vmap'ed stacks for all 32-bit ARM systems that are currently supported
by the Linux kernel, including RiscPC and Footbridge. It has been
submitted for review in three different waves:
- IRQ stacks support for v7 SMP systems [0],
- vmap'ed stacks support for v7 SMP systems[1],
- extending support for both IRQ stacks and vmap'ed stacks for all
remaining configurations, including v6/v7 SMP multiplatform kernels
and uniprocessor configurations including v7-M [2]
[0] https://lore.kernel.org/linux-arm-kernel/
20211115084732.3704393-1-ardb@kernel.org/
[1] https://lore.kernel.org/linux-arm-kernel/
20211122092816.2865873-1-ardb@kernel.org/
[2] https://lore.kernel.org/linux-arm-kernel/
20211206164659.1495084-1-ardb@kernel.org/
Ard Biesheuvel [Thu, 2 Dec 2021 08:36:59 +0000 (09:36 +0100)]
ARM: v7m: enable support for IRQ stacks
Enable support for IRQ stacks on !MMU, and add the code to the IRQ entry
path to switch to the IRQ stack if not running from it already.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Wed, 24 Nov 2021 13:08:11 +0000 (14:08 +0100)]
ARM: implement THREAD_INFO_IN_TASK for uniprocessor systems
On UP systems, only a single task can be 'current' at the same time,
which means we can use a global variable to track it. This means we can
also enable THREAD_INFO_IN_TASK for those systems, as in that case,
thread_info is accessed via current rather than the other way around,
removing the need to store thread_info at the base of the task stack.
This, in turn, permits us to enable IRQ stacks and vmap'ed stacks on UP
systems as well.
To partially mitigate the performance overhead of this arrangement, use
a ADD/ADD/LDR sequence with the appropriate PC-relative group
relocations to load the value of current when needed. This means that
accessing current will still only require a single load as before,
avoiding the need for a literal to carry the address of the global
variable in each function. However, accessing thread_info will now
require this load as well.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Thu, 25 Nov 2021 22:21:45 +0000 (23:21 +0100)]
ARM: smp: defer TPIDRURO update for SMP v6 configurations too
Defer TPIDURO updates for user space until exit also for CPU_V6+SMP
configurations so that we can decide at runtime whether to use it to
carry the current pointer, provided that we are running on a CPU that
actually implements this register. This is needed for
THREAD_INFO_IN_TASK support for UP systems, which requires that all SMP
capable systems use the TPIDRURO based access to 'current' as the only
remaining alternative will be a global variable which only works on UP.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Fri, 26 Nov 2021 09:13:06 +0000 (10:13 +0100)]
ARM: use TLS register for 'current' on !SMP as well
Enable the use of the TLS register to hold the 'current' pointer also on
non-SMP configurations that target v6k or later CPUs. This will permit
the use of THREAD_INFO_IN_TASK as well as IRQ stacks and vmap'ed stacks
for such configurations.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Thu, 25 Nov 2021 09:26:44 +0000 (10:26 +0100)]
ARM: percpu: add SMP_ON_UP support
Permit the use of the TPIDRPRW system register for carrying the per-CPU
offset in generic SMP configurations that also target non-SMP capable
ARMv6 cores. This uses the SMP_ON_UP code patching framework to turn all
TPIDRPRW accesses into reads/writes of entry #0 in the __per_cpu_offset
array.
While at it, switch over some existing direct TPIDRPRW accesses in asm
code to invocations of a new helper that is patched in the same way when
necessary.
Note that CPU_V6+SMP without SMP_ON_UP results in a kernel that does not
boot on v6 CPUs without SMP extensions, so add this dependency to
Kconfig as well.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Fri, 26 Nov 2021 18:37:27 +0000 (19:37 +0100)]
ARM: assembler: add optimized ldr/str macros to load variables from memory
We will be adding variable loads to various hot paths, so it makes sense
to add a helper macro that can load variables from asm code without the
use of literal pool entries. On v7 or later, we can simply use MOVW/MOVT
pairs, but on earlier cores, this requires a bit of hackery to emit a
instruction sequence that implements this using a sequence of ADD/LDR
instructions.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Wed, 24 Nov 2021 17:56:22 +0000 (18:56 +0100)]
ARM: module: implement support for PC-relative group relocations
Add support for the R_ARM_ALU_PC_Gn_NC and R_ARM_LDR_PC_G2 group
relocations [0] so we can use them in modules. These will be used to
load the current task pointer from a global variable without having to
rely on a literal pool entry to carry the address of this variable,
which may have a significant negative impact on cache utilization for
variables that are used often and in many different places, as each
occurrence will result in a literal pool entry and therefore a line in
the D-cache.
[0] 'ELF for the ARM architecture'
https://github.com/ARM-software/abi-aa/releases
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Wed, 24 Nov 2021 11:09:48 +0000 (12:09 +0100)]
ARM: entry: preserve thread_info pointer in switch_to
Tweak the UP stack protector handling code so that the thread info
pointer is preserved in R7 until set_current is called. This is needed
for a subsequent patch that implements THREAD_INFO_IN_TASK and
set_current for UP as well.
This also means we will prefer the per-task protector on UP systems that
implement the thread ID registers, so tweak the preprocessor
conditionals to reflect this.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Vladimir Murzin [Wed, 1 Dec 2021 11:02:59 +0000 (11:02 +0000)]
irqchip: nvic: Use GENERIC_IRQ_MULTI_HANDLER
Rather then restructuring the ARMv7M entrly logic per TODO, just move
NVIC to GENERIC_IRQ_MULTI_HANDLER.
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Arnd Bergmann [Fri, 26 Nov 2021 21:36:06 +0000 (22:36 +0100)]
ARM: remove old-style irq entry
The last user of arch_irq_handler_default is gone now, so the
entry-macro-multi.S file and all references to mach/entry-macro.S can
be removed, as well as the asm_do_IRQ() entrypoint into the interrupt
handling routines implemented in C.
Note: The ARMv7-M entry still uses its own top-level IRQ entry, calling
nvic_handle_irq() from assembly. This could be changed to go through
generic_handle_arch_irq() as well, but it's unclear to me if there are
any benefits.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[ardb: keep irq_handler macro as it carries all the IRQ stack handling]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Arnd Bergmann [Tue, 30 Nov 2021 10:21:49 +0000 (11:21 +0100)]
ARM: iop32x: use GENERIC_IRQ_MULTI_HANDLER
iop32x uses the entry-macro.S file for both the IRQ entry and for
hooking into the arch_ret_to_user code path. This is done because the
cp6 registers have to be enabled before accessing any of the interrupt
controller registers but have to be disabled when running in user space.
There is also a lazy-enable logic in cp6.c, but during a hardirq, we
know it has to be enabled.
Both the cp6-enable code and the code to read the IRQ status can be
lifted into the normal generic_handle_arch_irq() path, but the
cp6-disable code has to remain in the user return code. As nothing
other than iop32x uses this hook, just open-code it there with an
ifdef for the platform that can eventually be removed when iop32x
has reached the end of its life.
The cp6-enable path in the IRQ entry has an extra cp_wait barrier that
the trap version does not have, but it is harmless to do it in both
cases to simplify the logic here at the cost of a few extra cycles
for the trap.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Arnd Bergmann [Tue, 30 Nov 2021 10:16:41 +0000 (11:16 +0100)]
ARM: iop32x: offset IRQ numbers by 1
iop32x is one of the last platforms to use IRQ 0, and this has apparently
stopped working in a 2014 cleanup without anyone noticing. This interrupt
is used for the DMA engine, so most likely this has not actually worked
in the past 7 years, but it's also not essential for using this board.
I'm splitting out this change from my GENERIC_IRQ_MULTI_HANDLER
conversion so it can be backported if anyone cares.
Fixes:
a71b092a9c68 ("ARM: Convert handle_IRQ to use __handle_domain_irq")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[ardb: take +1 offset into account in mask/unmask and init as well]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Arnd Bergmann [Mon, 29 Nov 2021 13:43:14 +0000 (14:43 +0100)]
ARM: footbridge: use GENERIC_IRQ_MULTI_HANDLER
Footbridge still uses the classic IRQ entry path in assembler,
but this is easily converted into an equivalent C version.
In this case, the correlation between IRQ numbers and bits in
the status register is non-obvious, and the priorities are
handled by manually checking each bit in a static order,
re-reading the status register after each handled event.
I moved the code into the new file and edited the syntax without
changing this sequence to keep the behavior as close as possible
to what it traditionally did.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Arnd Bergmann [Tue, 30 Nov 2021 07:19:13 +0000 (08:19 +0100)]
ARM: riscpc: use GENERIC_IRQ_MULTI_HANDLER
This is one of the last platforms using the old entry path.
While this code path is spread over a few files, it is fairly
straightforward to convert it into an equivalent C version,
leaving the existing algorithm and all the priority handling
the same.
Unlike most irqchip drivers, this means reading the status
register(s) in a loop and always handling the highest-priority
irq first.
The IOMD_IRQREQC and IOMD_IRQREQD registers are not actaully
used here, but I left the code in place for the time being,
to keep the conversion as direct as possible. It could be
removed in a cleanup on top.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[ardb: drop obsolete IOMD_IRQREQC/IOMD_IRQREQD handling]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Fri, 3 Dec 2021 16:11:36 +0000 (17:11 +0100)]
ARM: riscpc: drop support for IOMD_IRQREQC/IOMD_IRQREQD IRQ groups
IOMD_IRQREQC nor IOMD_IRQREQD are ever defined, so any conditionally
compiled code that depends on them is dead code, and can be removed.
Suggested-by: Russell King <linux@armlinux.org.uk>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Thu, 23 Sep 2021 07:15:53 +0000 (09:15 +0200)]
ARM: implement support for vmap'ed stacks
Wire up the generic support for managing task stack allocations via vmalloc,
and implement the entry code that detects whether we faulted because of a
stack overrun (or future stack overrun caused by pushing the pt_regs array)
While this adds a fair amount of tricky entry asm code, it should be
noted that it only adds a TST + branch to the svc_entry path. The code
implementing the non-trivial handling of the overflow stack is emitted
out-of-line into the .text section.
Since on ARM, we rely on do_translation_fault() to keep PMD level page
table entries that cover the vmalloc region up to date, we need to
ensure that we don't hit such a stale PMD entry when accessing the
stack. So we do a dummy read from the new stack while still running from
the old one on the context switch path, and bump the vmalloc_seq counter
when PMD level entries in the vmalloc range are modified, so that the MM
switch fetches the latest version of the entries.
Note that we need to increase the per-mode stack by 1 word, to gain some
space to stash a GPR until we know it is safe to touch the stack.
However, due to the cacheline alignment of the struct, this does not
actually increase the memory footprint of the struct stack array at all.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Sun, 17 Oct 2021 15:23:47 +0000 (17:23 +0200)]
ARM: entry: rework stack realignment code in svc_entry
The original Thumb-2 enablement patches updated the stack realignment
code in svc_entry to work around the lack of a STMIB instruction in
Thumb-2, by subtracting 4 from the frame size, inverting the sense of
the misaligment check, and changing to a STMIA instruction and a final
stack push of a 4 byte quantity that results in the stack becoming
aligned at the end of the sequence. It also pushes and pops R0 to the
stack in order to have a temp register that Thumb-2 allows in general
purpose ALU instructions, as TST using SP is not permitted.
Both are a bit problematic for vmap'ed stacks, as using the stack is
only permitted after we decide that we did not overflow the stack, or
have already switched to the overflow stack.
As for the alignment check: the current approach creates a corner case
where, if the initial SUB of SP ends up right at the start of the stack,
we will end up subtracting another 8 bytes and overflowing it. This
means we would need to add the overflow check *after* the SUB that
deliberately misaligns the stack. However, this would require us to keep
local state (i.e., whether we performed the subtract or not) across the
overflow check, but without any GPRs or stack available.
So let's switch to an approach where we don't use the stack, and where
the alignment check of the stack pointer occurs in the usual way, as
this is guaranteed not to result in overflow. This means we will be able
to do the overflow check first.
While at it, switch to R1 so the mode stack pointer in R0 remains
accessible.
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Sat, 16 Oct 2021 16:00:01 +0000 (18:00 +0200)]
ARM: switch_to: clean up Thumb2 code path
The load-multiple instruction that essentially performs the switch_to
operation in ARM mode, by loading all callee save registers as well the
stack pointer and the program counter, is split into 3 separate loads
for Thumb-2, with the IP register used as a temporary to capture the
value of R4 before it gets overwritten.
We can clean this up a bit, by sticking with a single LDMIA instruction,
but one that pops SP and PC into IP and LR, respectively, and by using
ordinary move register and branch instructions to get those values into
SP and PC. This also allows us to move the set_current call closer to
the assignment of SP, reducing the window where those are mutually out
of sync. This is especially relevant for CONFIG_VMAP_STACK, which is
being introduced in a subsequent patch, where we need to issue a load
that might fault from the new stack while running from the old one, to
ensure that stale PMD entries in the VMALLOC space are synced up.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Mon, 4 Oct 2021 06:46:38 +0000 (08:46 +0200)]
ARM: unwind: disregard unwind info before stack frame is set up
When unwinding the stack from a stack overflow, we are likely to start
from a stack push instruction, given that this is the most common way to
grow the stack for compiler emitted code. This push instruction rarely
appears anywhere else than at offset 0x0 of the function, and if it
doesn't, the compiler tends to split up the unwind annotations, given
that the stack frame layout is apparently not the same throughout the
function.
This means that, in the general case, if the frame's PC points at the
first instruction covered by a certain unwind entry, there is no way the
stack frame that the unwind entry describes could have been created yet,
and so we are still on the stack frame of the caller in that case. So
treat this as a special case, and return with the new PC taken from the
frame's LR, without applying the unwind transformations to the virtual
register set.
This permits us to unwind the call stack on stack overflow when the
overflow was caused by a stack push on function entry.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Mon, 4 Oct 2021 09:34:05 +0000 (11:34 +0200)]
ARM: memset: clean up unwind annotations
The memset implementation carves up the code in different sections, each
covered with their own unwind info. In this case, it is done in a way
similar to how the compiler might do it, to disambiguate between parts
where the return address is in LR and the SP is unmodified, and parts
where a stack frame is live, and the unwinder needs to know the size of
the stack frame and the location of the return address within it.
Only the placement of the unwind directives is slightly odd: the stack
pushes are placed in the wrong sections, which may confuse the unwinder
when attempting to unwind with PC pointing at the stack push in
question.
So let's fix this up, by reordering the directives and instructions as
appropriate.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Mon, 4 Oct 2021 09:29:11 +0000 (11:29 +0200)]
ARM: memmove: use frame pointer as unwind anchor
The memmove routine is a bit unusual in the way it manages the stack
pointer: depending on the execution path through the function, the SP
assumes different values as different subsets of the register file are
preserved and restored again. This is problematic when it comes to EHABI
unwind info, as it is not instruction accurate, and does not allow
tracking the SP value as it changes.
Commit
207a6cb06990c ("ARM: 8224/1: Add unwinding support for memmove
function") addressed this by carving up the function in different chunks
as far as the unwinder is concerned, and keeping a set of unwind
directives for each of them, each corresponding with the state of the
stack pointer during execution of the chunk in question. This not only
duplicates unwind info unnecessarily, but it also complicates unwinding
the stack upon overflow.
Instead, let's do what the compiler does when the SP is updated halfway
through a function, which is to use a frame pointer and emit the
appropriate unwind directives to communicate this to the unwinder.
Note that Thumb-2 uses R7 for this, while ARM uses R11 aka FP. So let's
avoid touching R7 in the body of the function, so that Thumb-2 can use
it as the frame pointer. R11 was not modified in the first place.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Sun, 3 Oct 2021 17:05:53 +0000 (19:05 +0200)]
ARM: memcpy: use frame pointer as unwind anchor
The memcpy template is a bit unusual in the way it manages the stack
pointer: depending on the execution path through the function, the SP
assumes different values as different subsets of the register file are
preserved and restored again. This is problematic when it comes to EHABI
unwind info, as it is not instruction accurate, and does not allow
tracking the SP value as it changes.
Commit
279f487e0b471 ("ARM: 8225/1: Add unwinding support for memory
copy functions") addressed this by carving up the function in different
chunks as far as the unwinder is concerned, and keeping a set of unwind
directives for each of them, each corresponding with the state of the
stack pointer during execution of the chunk in question. This not only
duplicates unwind info unnecessarily, but it also complicates unwinding
the stack upon overflow.
Instead, let's do what the compiler does when the SP is updated halfway
through a function, which is to use a frame pointer and emit the
appropriate unwind directives to communicate this to the unwinder.
Note that Thumb-2 uses R7 for this, while ARM uses R11 aka FP. So let's
avoid touching R7 in the body of the template, so that Thumb-2 can use
it as the frame pointer. R11 was not modified in the first place.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Tue, 5 Oct 2021 07:15:42 +0000 (09:15 +0200)]
ARM: run softirqs on the per-CPU IRQ stack
Now that we have enabled IRQ stacks, any softIRQs that are handled over
the back of a hard IRQ will run from the IRQ stack as well. However, any
synchronous softirq processing that happens when re-enabling softIRQs
from task context will still execute on that task's stack.
Since any call to local_bh_enable() at any level in the task's call
stack may trigger a softIRQ processing run, which could potentially
cause a task stack overflow if the combined stack footprints exceed the
stack's size, let's run these synchronous invocations of do_softirq() on
the IRQ stack as well.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Tue, 5 Oct 2021 07:15:41 +0000 (09:15 +0200)]
ARM: call_with_stack: add unwind support
Restructure the code and add the unwind annotations so that both the
frame pointer unwinder as well as the EHABI unwind info based unwinder
will be able to follow the call stack through call_with_stack().
Since GCC and Clang use different formats for the stack frame, two
methods are implemented: a GCC version that pushes fp, sp, lr and pc for
compatibility with the frame pointer unwinder, and a second version that
works with Clang, as well as with the EHABI unwinder both in ARM and
Thumb2 modes.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Tue, 5 Oct 2021 07:15:40 +0000 (09:15 +0200)]
ARM: implement IRQ stacks
Now that we no longer rely on the stack pointer to access the current
task struct or thread info, we can implement support for IRQ stacks
cleanly as well.
Define a per-CPU IRQ stack and switch to this stack when taking an IRQ,
provided that we were not already using that stack in the interrupted
context. This is never the case for IRQs taken from user space, but ones
taken while running in the kernel could fire while one taken from user
space has not completed yet.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Fri, 15 Oct 2021 14:27:09 +0000 (16:27 +0200)]
ARM: backtrace-clang: avoid crash on bogus frame pointer
The Clang backtrace code dereferences the link register value pulled
from the stack to decide whether the caller was a branch-and-link
instruction, in order to subsequently decode the offset to find the
start of the calling function. Unlike other loads in this routine, this
one is not protected by a fixup, and may therefore cause a crash if the
address in question is bogus.
So let's fix this, by treating the fault as a failure to decode the 'bl'
instruction. To avoid a label renum, reuse a fixup label that guards an
instruction that cannot fault to begin with.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Tue, 5 Oct 2021 07:15:39 +0000 (09:15 +0200)]
ARM: unwind: dump exception stack from calling frame
The existing code that dumps the contents of the pt_regs structure
passed to __entry routines does so while unwinding the callee frame, and
dereferences the stack pointer as a struct pt_regs*. This will no longer
work when we enable support for IRQ or overflow stacks, because the
struct pt_regs may live on the task stack, while we are executing from
another stack.
The unwinder has access to this information, but only while unwinding
the calling frame. So let's combine the exception stack dumping code
with the handling of the calling frame as well. By printing it before
dumping the caller/callee addresses, the output order is preserved.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Tue, 5 Oct 2021 07:15:38 +0000 (09:15 +0200)]
ARM: export dump_mem() to other objects
The unwind info based stack unwinder will make its own call to
dump_mem() to dump the exception stack, so give it external linkage.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Tue, 5 Oct 2021 07:15:37 +0000 (09:15 +0200)]
ARM: unwind: support unwinding across multiple stacks
Implement support in the unwinder for dealing with multiple stacks.
This will be needed once we add support for IRQ stacks, or for the
overflow stack used by the vmap'ed stacks code.
This involves tracking the unwind opcodes that either update the virtual
stack pointer from another virtual register, or perform an explicit
subtract on the virtual stack pointer, and updating the low and high
bounds that we use to sanitize the stack pointer accordingly.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Tue, 5 Oct 2021 07:15:35 +0000 (09:15 +0200)]
ARM: assembler: introduce bl_r macro
Add a bl_r macro that abstract the difference between the ways indirect
calls are performed on older and newer ARM architecture revisions.
The main difference is to prefer blx instructions over explicit LR
assignments when possible, as these tend to confuse the prediction logic
in out-of-order cores when speculating across a function return.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Tue, 5 Oct 2021 07:15:34 +0000 (09:15 +0200)]
ARM: remove some dead code
This code appears to be no longer used so let's get rid of it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Keith Packard <keithpac@amazon.com>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Thu, 21 Oct 2021 14:16:47 +0000 (16:16 +0200)]
ARM: stackprotector: prefer compiler for TLS based per-task protector
Currently, we implement the per-task stack protector for ARM using a GCC
plugin, due to lack of native compiler support. However, work is
underway to get this implemented in the compiler, which means we will be
able to deprecate the GCC plugin at some point.
In the meantime, we will need to support both, where the native compiler
implementation is obviously preferred. So let's wire this up in Kconfig
and the Makefile.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARMv7M
Ard Biesheuvel [Tue, 26 Oct 2021 08:23:31 +0000 (10:23 +0200)]
ARM: decompressor: disable stack protector
Enabling the stack protector in the decompressor is of dubious value,
given that it uses a fixed value for the canary, cannot print any output
unless CONFIG_DEBUG_LL is enabled (which relies on board specific build
time settings), and is already disabled for a good chunk of the code
(libfdt).
So let's just disable it in the decompressor. This will make it easier
in the future to manage the command line options that would need to be
removed again in this context for the TLS register based stack
protector.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Linus Torvalds [Sun, 14 Nov 2021 21:56:52 +0000 (13:56 -0800)]
Linux 5.16-rc1
Gustavo A. R. Silva [Sun, 14 Nov 2021 00:57:25 +0000 (18:57 -0600)]
kconfig: Add support for -Wimplicit-fallthrough
Add Kconfig support for -Wimplicit-fallthrough for both GCC and Clang.
The compiler option is under configuration CC_IMPLICIT_FALLTHROUGH,
which is enabled by default.
Special thanks to Nathan Chancellor who fixed the Clang bug[1][2]. This
bugfix only appears in Clang 14.0.0, so older versions still contain
the bug and -Wimplicit-fallthrough won't be enabled for them, for now.
This concludes a long journey and now we are finally getting rid
of the unintentional fallthrough bug-class in the kernel, entirely. :)
Link: https://github.com/llvm/llvm-project/commit/9ed4a94d6451046a51ef393cd62f00710820a7e8
Link: https://bugs.llvm.org/show_bug.cgi?id=51094
Link: https://github.com/KSPP/linux/issues/115
Link: https://github.com/ClangBuiltLinux/linux/issues/236
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Sun, 14 Nov 2021 20:18:22 +0000 (12:18 -0800)]
Merge tag 'xfs-5.16-merge-5' of git://git./fs/xfs/xfs-linux
Pull xfs cleanups from Darrick Wong:
"The most 'exciting' aspect of this branch is that the xfsprogs
maintainer and I have worked through the last of the code
discrepancies between kernel and userspace libxfs such that there are
no code differences between the two except for #includes.
IOWs, diff suffices to demonstrate that the userspace tools behave the
same as the kernel, and kernel-only bits are clearly marked in the
/kernel/ source code instead of just the userspace source.
Summary:
- Clean up open-coded swap() calls.
- A little bit of #ifdef golf to complete the reunification of the
kernel and userspace libxfs source code"
* tag 'xfs-5.16-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: sync xfs_btree_split macros with userspace libxfs
xfs: #ifdef out perag code for userspace
xfs: use swap() to make dabtree code cleaner
Linus Torvalds [Sun, 14 Nov 2021 19:53:59 +0000 (11:53 -0800)]
Merge tag 'for-5.16/parisc-3' of git://git./linux/kernel/git/deller/parisc-linux
Pull more parisc fixes from Helge Deller:
"Fix a build error in stracktrace.c, fix resolving of addresses to
function names in backtraces, fix single-stepping in assembly code and
flush userspace pte's when using set_pte_at()"
* tag 'for-5.16/parisc-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc/entry: fix trace test in syscall exit path
parisc: Flush kernel data mapping in set_pte_at() when installing pte for user page
parisc: Fix implicit declaration of function '__kernel_text_address'
parisc: Fix backtrace to always include init funtion names
Linus Torvalds [Sun, 14 Nov 2021 19:37:49 +0000 (11:37 -0800)]
Merge tag 'sh-for-5.16' of git://git.libc.org/linux-sh
Pull arch/sh updates from Rich Felker.
* tag 'sh-for-5.16' of git://git.libc.org/linux-sh:
sh: pgtable-3level: Fix cast to pointer from integer of different size
sh: fix READ/WRITE redefinition warnings
sh: define __BIG_ENDIAN for math-emu
sh: math-emu: drop unused functions
sh: fix kconfig unmet dependency warning for FRAME_POINTER
sh: Cleanup about SPARSE_IRQ
sh: kdump: add some attribute to function
maple: fix wrong return value of maple_bus_init().
sh: boot: avoid unneeded rebuilds under arch/sh/boot/compressed/
sh: boot: add intermediate vmlinux.bin* to targets instead of extra-y
sh: boards: Fix the cacography in irq.c
sh: check return code of request_irq
sh: fix trivial misannotations
Linus Torvalds [Sun, 14 Nov 2021 19:30:50 +0000 (11:30 -0800)]
Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm
Pull ARM fixes from Russell King:
- Fix early_iounmap
- Drop cc-option fallbacks for architecture selection
* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
ARM: 9156/1: drop cc-option fallbacks for architecture selection
ARM: 9155/1: fix early early_iounmap()
Linus Torvalds [Sun, 14 Nov 2021 19:11:51 +0000 (11:11 -0800)]
Merge tag 'devicetree-fixes-for-5.16-1' of git://git./linux/kernel/git/robh/linux
Pull devicetree fixes from Rob Herring:
- Two fixes due to DT node name changes on Arm, Ltd. boards
- Treewide rename of Ingenic CGU headers
- Update ST email addresses
- Remove Netlogic DT bindings
- Dropping few more cases of redundant 'maxItems' in schemas
- Convert toshiba,tc358767 bridge binding to schema
* tag 'devicetree-fixes-for-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
dt-bindings: watchdog: sunxi: fix error in schema
bindings: media: venus: Drop redundant maxItems for power-domain-names
dt-bindings: Remove Netlogic bindings
clk: versatile: clk-icst: Ensure clock names are unique
of: Support using 'mask' in making device bus id
dt-bindings: treewide: Update @st.com email address to @foss.st.com
dt-bindings: media: Update maintainers for st,stm32-hwspinlock.yaml
dt-bindings: media: Update maintainers for st,stm32-cec.yaml
dt-bindings: mfd: timers: Update maintainers for st,stm32-timers
dt-bindings: timer: Update maintainers for st,stm32-timer
dt-bindings: i2c: imx: hardware do not restrict clock-frequency to only 100 and 400 kHz
dt-bindings: display: bridge: Convert toshiba,tc358767.txt to yaml
dt-bindings: Rename Ingenic CGU headers to ingenic,*.h
Linus Torvalds [Sun, 14 Nov 2021 18:43:38 +0000 (10:43 -0800)]
Merge tag 'timers-urgent-2021-11-14' of git://git./linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
"A single fix for POSIX CPU timers to address a problem where POSIX CPU
timer delivery stops working for a new child task because
copy_process() copies state information which is only valid for the
parent task"
* tag 'timers-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-cpu-timers: Clear task::posix_cputimers_work in copy_process()
Linus Torvalds [Sun, 14 Nov 2021 18:38:27 +0000 (10:38 -0800)]
Merge tag 'irq-urgent-2021-11-14' of git://git./linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
"A set of fixes for the interrupt subsystem
Core code:
- A regression fix for the Open Firmware interrupt mapping code where
a interrupt controller property in a node caused a map property in
the same node to be ignored.
Interrupt chip drivers:
- Workaround a limitation in SiFive PLIC interrupt chip which
silently ignores an EOI when the interrupt line is masked.
- Provide the missing mask/unmask implementation for the CSKY MP
interrupt controller.
PCI/MSI:
- Prevent a use after free when PCI/MSI interrupts are released by
destroying the sysfs entries before freeing the memory which is
accessed in the sysfs show() function.
- Implement a mask quirk for the Nvidia ION AHCI chip which does not
advertise masking capability despite implementing it. Even worse
the chip comes out of reset with all MSI entries masked, which due
to the missing masking capability never get unmasked.
- Move the check which prevents accessing the MSI[X] masking for XEN
back into the low level accessors. The recent consolidation missed
that these accessors can be invoked from places which do not have
that check which broke XEN. Move them back to he original place
instead of sprinkling tons of these checks all over the code"
* tag 'irq-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
of/irq: Don't ignore interrupt-controller when interrupt-map failed
irqchip/sifive-plic: Fixup EOI failed when masked
irqchip/csky-mpintc: Fixup mask/unmask implementation
PCI/MSI: Destroy sysfs before freeing entries
PCI: Add MSI masking quirk for Nvidia ION AHCI
PCI/MSI: Deal with devices lying about their MSI mask capability
PCI/MSI: Move non-mask check back into low level accessors
Linus Torvalds [Sun, 14 Nov 2021 18:30:17 +0000 (10:30 -0800)]
Merge tag 'locking-urgent-2021-11-14' of git://git./linux/kernel/git/tip/tip
Pull x86 static call update from Thomas Gleixner:
"A single fix for static calls to make the trampoline patching more
robust by placing explicit signature bytes after the call trampoline
to prevent patching random other jumps like the CFI jump table
entries"
* tag 'locking-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
static_call,x86: Robustify trampoline patching
Linus Torvalds [Sun, 14 Nov 2021 17:39:03 +0000 (09:39 -0800)]
Merge tag 'sched_urgent_for_v5.16_rc1' of git://git./linux/kernel/git/tip/tip
Pull scheduler fixes from Borislav Petkov:
- Avoid touching ~100 config files in order to be able to select the
preemption model
- clear cluster CPU masks too, on the CPU unplug path
- prevent use-after-free in cfs
- Prevent a race condition when updating CPU cache domains
- Factor out common shared part of smp_prepare_cpus() into a common
helper which can be called by both baremetal and Xen, in order to fix
a booting of Xen PV guests
* tag 'sched_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
preempt: Restore preemption model selection configs
arch_topology: Fix missing clear cluster_cpumask in remove_cpu_topology()
sched/fair: Prevent dead task groups from regaining cfs_rq's
sched/core: Mitigate race cpus_share_cache()/update_top_cache_domain()
x86/smp: Factor out parts of native_smp_prepare_cpus()
Linus Torvalds [Sun, 14 Nov 2021 17:33:12 +0000 (09:33 -0800)]
Merge tag 'perf_urgent_for_v5.16_rc1' of git://git./linux/kernel/git/tip/tip
Pull perf fixes from Borislav Petkov:
- Prevent unintentional page sharing by checking whether a page
reference to a PMU samples page has been acquired properly before
that
- Make sure the LBR_SELECT MSR is saved/restored too
- Reset the LBR_SELECT MSR when resetting the LBR PMU to clear any
residual data left
* tag 'perf_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Avoid put_page() when GUP fails
perf/x86/vlbr: Add c->flags to vlbr event constraints
perf/x86/lbr: Reset LBR_SELECT during vlbr reset
Linus Torvalds [Sun, 14 Nov 2021 17:29:03 +0000 (09:29 -0800)]
Merge tag 'x86_urgent_for_v5.16_rc1' of git://git./linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Add the model number of a new, Raptor Lake CPU, to intel-family.h
- Do not log spurious corrected MCEs on SKL too, due to an erratum
- Clarify the path of paravirt ops patches upstream
- Add an optimization to avoid writing out AMX components to sigframes
when former are in init state
* tag 'x86_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu: Add Raptor Lake to Intel family
x86/mce: Add errata workaround for Skylake SKX37
MAINTAINERS: Add some information to PARAVIRT_OPS entry
x86/fpu: Optimize out sigframe xfeatures when in init state
Linus Torvalds [Sun, 14 Nov 2021 17:25:01 +0000 (09:25 -0800)]
Merge tag 'perf-tools-for-v5.16-2021-11-13' of git://git./linux/kernel/git/acme/linux
Pull more perf tools updates from Arnaldo Carvalho de Melo:
"Hardware tracing:
- ARM:
* Print the size of the buffer size consistently in hexadecimal in
ARM Coresight.
* Add Coresight snapshot mode support.
* Update --switch-events docs in 'perf record'.
* Support hardware-based PID tracing.
* Track task context switch for cpu-mode events.
- Vendor events:
* Add metric events JSON file for power10 platform
perf test:
- Get 'perf test' unit tests closer to kunit.
- Topology tests improvements.
- Remove bashisms from some tests.
perf bench:
- Fix memory leak of perf_cpu_map__new() in the futex benchmarks.
libbpf:
- Add some more weak libbpf functions o allow building with the
libbpf versions, old ones, present in distros.
libbeauty:
- Translate [gs]setsockopt 'level' argument integer values to
strings.
tools headers UAPI:
- Sync futex_waitv, arch prctl, sound, i195_drm and msr-index files
with the kernel sources.
Documentation:
- Add documentation to 'struct symbol'.
- Synchronize the definition of enum perf_hw_id with code in
tools/perf/design.txt"
* tag 'perf-tools-for-v5.16-2021-11-13' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (67 commits)
perf tests: Remove bash constructs from stat_all_pmu.sh
perf tests: Remove bash construct from record+zstd_comp_decomp.sh
perf test: Remove bash construct from stat_bpf_counters.sh test
perf bench futex: Fix memory leak of perf_cpu_map__new()
tools arch x86: Sync the msr-index.h copy with the kernel sources
tools headers UAPI: Sync drm/i915_drm.h with the kernel sources
tools headers UAPI: Sync sound/asound.h with the kernel sources
tools headers UAPI: Sync linux/prctl.h with the kernel sources
tools headers UAPI: Sync arch prctl headers with the kernel sources
perf tools: Add more weak libbpf functions
perf bpf: Avoid memory leak from perf_env__insert_btf()
perf symbols: Factor out annotation init/exit
perf symbols: Bit pack to save a byte
perf symbols: Add documentation to 'struct symbol'
tools headers UAPI: Sync files changed by new futex_waitv syscall
perf test bpf: Use ARRAY_CHECK() instead of ad-hoc equivalent, addressing array_size.cocci warning
perf arm-spe: Support hardware-based PID tracing
perf arm-spe: Save context ID in record
perf arm-spe: Update --switch-events docs in 'perf record'
perf arm-spe: Track task context switch for cpu-mode events
...
Thomas Gleixner [Sun, 14 Nov 2021 12:59:05 +0000 (13:59 +0100)]
Merge tag 'irqchip-fixes-5.16-1' of git://git./linux/kernel/git/maz/arm-platforms into irq/urgent
Pull irqchip fixes from Marc Zyngier:
- Address an issue with the SiFive PLIC being unable to EOI
a masked interrupt
- Move the disable/enable methods in the CSky mpintc to
mask/unmask
- Fix a regression in the OF irq code where an interrupt-controller
property in the same node as an interrupt-map property would get
ignored
Link: https://lore.kernel.org/all/20211112173459.4015233-1-maz@kernel.org
Linus Torvalds [Sat, 13 Nov 2021 23:32:30 +0000 (15:32 -0800)]
Merge tag 'zstd-for-linus-v5.16' of git://github.com/terrelln/linux
Pull zstd update from Nick Terrell:
"Update to zstd-1.4.10.
Add myself as the maintainer of zstd and update the zstd version in
the kernel, which is now 4 years out of date, to a much more recent
zstd release. This includes bug fixes, much more extensive fuzzing,
and performance improvements. And generates the kernel zstd
automatically from upstream zstd, so it is easier to keep the zstd
verison up to date, and we don't fall so far out of date again.
This includes 5 commits that update the zstd library version:
- Adds a new kernel-style wrapper around zstd.
This wrapper API is functionally equivalent to the subset of the
current zstd API that is currently used. The wrapper API changes to
be kernel style so that the symbols don't collide with zstd's
symbols. The update to zstd-1.4.10 maintains the same API and
preserves the semantics, so that none of the callers need to be
updated. All callers are updated in the commit, because there are
zero functional changes.
- Adds an indirection for `lib/decompress_unzstd.c` so it doesn't
depend on the layout of `lib/zstd/` to include every source file.
This allows the next patch to be automatically generated.
- Imports the zstd-1.4.10 source code. This commit is automatically
generated from upstream zstd (https://github.com/facebook/zstd).
- Adds me (terrelln@fb.com) as the maintainer of `lib/zstd`.
- Fixes a newly added build warning for clang.
The discussion around this patchset has been pretty long, so I've
included a FAQ-style summary of the history of the patchset, and why
we are taking this approach.
Why do we need to update?
-------------------------
The zstd version in the kernel is based off of zstd-1.3.1, which is
was released August 20, 2017. Since then zstd has seen many bug fixes
and performance improvements. And, importantly, upstream zstd is
continuously fuzzed by OSS-Fuzz, and bug fixes aren't backported to
older versions. So the only way to sanely get these fixes is to keep
up to date with upstream zstd.
There are no known security issues that affect the kernel, but we need
to be able to update in case there are. And while there are no known
security issues, there are relevant bug fixes. For example the problem
with large kernel decompression has been fixed upstream for over 2
years [1]
Additionally the performance improvements for kernel use cases are
significant. Measured for x86_64 on my Intel i9-9900k @ 3.6 GHz:
- BtrFS zstd compression at levels 1 and 3 is 5% faster
- BtrFS zstd decompression+read is 15% faster
- SquashFS zstd decompression+read is 15% faster
- F2FS zstd compression+write at level 3 is 8% faster
- F2FS zstd decompression+read is 20% faster
- ZRAM decompression+read is 30% faster
- Kernel zstd decompression is 35% faster
- Initramfs zstd decompression+build is 5% faster
On top of this, there are significant performance improvements coming
down the line in the next zstd release, and the new automated update
patch generation will allow us to pull them easily.
How is the update patch generated?
----------------------------------
The first two patches are preparation for updating the zstd version.
Then the 3rd patch in the series imports upstream zstd into the
kernel. This patch is automatically generated from upstream. A script
makes the necessary changes and imports it into the kernel. The
changes are:
- Replace all libc dependencies with kernel replacements and rewrite
includes.
- Remove unncessary portability macros like: #if defined(_MSC_VER).
- Use the kernel xxhash instead of bundling it.
This automation gets tested every commit by upstream's continuous
integration. When we cut a new zstd release, we will submit a patch to
the kernel to update the zstd version in the kernel.
The automated process makes it easy to keep the kernel version of zstd
up to date. The current zstd in the kernel shares the guts of the
code, but has a lot of API and minor changes to work in the kernel.
This is because at the time upstream zstd was not ready to be used in
the kernel envrionment as-is. But, since then upstream zstd has
evolved to support being used in the kernel as-is.
Why are we updating in one big patch?
-------------------------------------
The 3rd patch in the series is very large. This is because it is
restructuring the code, so it both deletes the existing zstd, and
re-adds the new structure. Future updates will be directly
proportional to the changes in upstream zstd since the last import.
They will admittidly be large, as zstd is an actively developed
project, and has hundreds of commits between every release. However,
there is no other great alternative.
One option ruled out is to replay every upstream zstd commit. This is
not feasible for several reasons:
- There are over 3500 upstream commits since the zstd version in the
kernel.
- The automation to automatically generate the kernel update was only
added recently, so older commits cannot easily be imported.
- Not every upstream zstd commit builds.
- Only zstd releases are "supported", and individual commits may have
bugs that were fixed before a release.
Another option to reduce the patch size would be to first reorganize
to the new file structure, and then apply the patch. However, the
current kernel zstd is formatted with clang-format to be more
"kernel-like". But, the new method imports zstd as-is, without
additional formatting, to allow for closer correlation with upstream,
and easier debugging. So the patch wouldn't be any smaller.
It also doesn't make sense to import upstream zstd commit by commit
going forward. Upstream zstd doesn't support production use cases
running of the development branch. We have a lot of post-commit
fuzzing that catches many bugs, so indiviudal commits may be buggy,
but fixed before a release. So going forward, I intend to import every
(important) zstd release into the Kernel.
So, while it isn't ideal, updating in one big patch is the only patch
I see forward.
Who is responsible for this code?
---------------------------------
I am. This patchset adds me as the maintainer for zstd. Previously,
there was no tree for zstd patches. Because of that, there were
several patches that either got ignored, or took a long time to merge,
since it wasn't clear which tree should pick them up. I'm officially
stepping up as maintainer, and setting up my tree as the path through
which zstd patches get merged. I'll make sure that patches to the
kernel zstd get ported upstream, so they aren't erased when the next
version update happens.
How is this code tested?
------------------------
I tested every caller of zstd on x86_64 (BtrFS, ZRAM, SquashFS, F2FS,
Kernel, InitRAMFS). I also tested Kernel & InitRAMFS on i386 and
aarch64. I checked both performance and correctness.
Also, thanks to many people in the community who have tested these
patches locally.
Lastly, this code will bake in linux-next before being merged into
v5.16.
Why update to zstd-1.4.10 when zstd-1.5.0 has been released?
------------------------------------------------------------
This patchset has been outstanding since 2020, and zstd-1.4.10 was the
latest release when it was created. Since the update patch is
automatically generated from upstream, I could generate it from
zstd-1.5.0.
However, there were some large stack usage regressions in zstd-1.5.0,
and are only fixed in the latest development branch. And the latest
development branch contains some new code that needs to bake in the
fuzzer before I would feel comfortable releasing to the kernel.
Once this patchset has been merged, and we've released zstd-1.5.1, we
can update the kernel to zstd-1.5.1, and exercise the update process.
You may notice that zstd-1.4.10 doesn't exist upstream. This release
is an artifical release based off of zstd-1.4.9, with some fixes for
the kernel backported from the development branch. I will tag the
zstd-1.4.10 release after this patchset is merged, so the Linux Kernel
is running a known version of zstd that can be debugged upstream.
Why was a wrapper API added?
----------------------------
The first versions of this patchset migrated the kernel to the
upstream zstd API. It first added a shim API that supported the new
upstream API with the old code, then updated callers to use the new
shim API, then transitioned to the new code and deleted the shim API.
However, Cristoph Hellwig suggested that we transition to a kernel
style API, and hide zstd's upstream API behind that. This is because
zstd's upstream API is supports many other use cases, and does not
follow the kernel style guide, while the kernel API is focused on the
kernel's use cases, and follows the kernel style guide.
Where is the previous discussion?
---------------------------------
Links for the discussions of the previous versions of the patch set
below. The largest changes in the design of the patchset are driven by
the discussions in v11, v5, and v1. Sorry for the mix of links, I
couldn't find most of the the threads on lkml.org"
Link: https://lkml.org/lkml/2020/9/29/27
Link: https://www.spinics.net/lists/linux-crypto/msg58189.html
Link: https://lore.kernel.org/linux-btrfs/20210430013157.747152-1-nickrterrell@gmail.com/
Link: https://lore.kernel.org/lkml/20210426234621.870684-2-nickrterrell@gmail.com/
Link: https://lore.kernel.org/linux-btrfs/20210330225112.496213-1-nickrterrell@gmail.com/
Link: https://lore.kernel.org/linux-f2fs-devel/20210326191859.1542272-1-nickrterrell@gmail.com/
Link: https://lkml.org/lkml/2020/12/3/1195
Link: https://lkml.org/lkml/2020/12/2/1245
Link: https://lore.kernel.org/linux-btrfs/20200916034307.2092020-1-nickrterrell@gmail.com/
Link: https://www.spinics.net/lists/linux-btrfs/msg105783.html
Link: https://lkml.org/lkml/2020/9/23/1074
Link: https://www.spinics.net/lists/linux-btrfs/msg105505.html
Link: https://lore.kernel.org/linux-btrfs/20200916034307.2092020-1-nickrterrell@gmail.com/
Signed-off-by: Nick Terrell <terrelln@fb.com>
Tested By: Paul Jones <paul@pauljones.id.au>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v13.0.0 on x86-64
Tested-by: Jean-Denis Girard <jd.girard@sysnux.pf>
* tag 'zstd-for-linus-v5.16' of git://github.com/terrelln/linux:
lib: zstd: Add cast to silence clang's -Wbitwise-instead-of-logical
MAINTAINERS: Add maintainer entry for zstd
lib: zstd: Upgrade to latest upstream zstd version 1.4.10
lib: zstd: Add decompress_sources.h for decompress_unzstd
lib: zstd: Add kernel-specific API
Linus Torvalds [Sat, 13 Nov 2021 21:14:05 +0000 (13:14 -0800)]
Merge tag 'virtio-mem-for-5.16' of git://github.com/davidhildenbrand/linux
Pull virtio-mem update from David Hildenbrand:
"Support the VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE feature in virtio-mem,
now that "accidential" access to logically unplugged memory inside
added Linux memory blocks is no longer possible, because we:
- Removed /dev/kmem in commit
bbcd53c96071 ("drivers/char: remove
/dev/kmem for good")
- Disallowed access to virtio-mem device memory via /dev/mem in
commit
2128f4e21aa ("virtio-mem: disallow mapping virtio-mem memory
via /dev/mem")
- Sanitized access to virtio-mem device memory via /proc/kcore in
commit
0daa322b8ff9 ("fs/proc/kcore: don't read offline sections,
logically offline pages and hwpoisoned pages")
- Sanitized access to virtio-mem device memory via /proc/vmcore in
commit
ce2814622e84 ("virtio-mem: kdump mode to sanitize
/proc/vmcore access")
The new VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE feature that will be
required by some hypervisors implementing virtio-mem in the near
future, so let's support it now that we safely can"
* tag 'virtio-mem-for-5.16' of git://github.com/davidhildenbrand/linux:
virtio-mem: support VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE
James Clark [Thu, 28 Oct 2021 13:48:27 +0000 (14:48 +0100)]
perf tests: Remove bash constructs from stat_all_pmu.sh
The tests were passing but without testing and were printing the
following:
$ ./perf test -v 90
90: perf all PMU test :
--- start ---
test child forked, pid 51650
Testing cpu/branch-instructions/
./tests/shell/stat_all_pmu.sh: 10: [:
Performance counter stats for 'true':
137,307 cpu/branch-instructions/
0.
001686672 seconds time elapsed
0.
001376000 seconds user
0.
000000000 seconds sys: unexpected operator
Changing the regexes to a grep works in sh and prints this:
$ ./perf test -v 90
90: perf all PMU test :
--- start ---
test child forked, pid 60186
[...]
Testing tlb_flush.stlb_any
test child finished with 0
---- end ----
perf all PMU test: Ok
Signed-off-by: James Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/20211028134828.65774-4-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
James Clark [Thu, 28 Oct 2021 13:48:26 +0000 (14:48 +0100)]
perf tests: Remove bash construct from record+zstd_comp_decomp.sh
Commit
463538a383a2 ("perf tests: Fix test 68 zstd compression for
s390") inadvertently removed the -g flag from all platforms rather than
just s390, because the [[ ]] construct fails in sh. Changing to single
brackets restores testing of call graphs and removes the following error
from the output:
$ ./perf test -v 85
85: Zstd perf.data compression/decompression :
--- start ---
test child forked, pid 50643
Collecting compressed record file:
./tests/shell/record+zstd_comp_decomp.sh: 15: [[: not found
Fixes:
463538a383a2 ("perf tests: Fix test 68 zstd compression for s390")
Signed-off-by: James Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/20211028134828.65774-3-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
James Clark [Thu, 28 Oct 2021 13:48:25 +0000 (14:48 +0100)]
perf test: Remove bash construct from stat_bpf_counters.sh test
Currently the test skips with an error because == only works in bash:
$ ./perf test 91 -v
Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
91: perf stat --bpf-counters test :
--- start ---
test child forked, pid 44586
./tests/shell/stat_bpf_counters.sh: 26: [: -v: unexpected operator
test child finished with -2
---- end ----
perf stat --bpf-counters test: Skip
Changing == to = does the same thing, but doesn't result in an error:
./perf test 91 -v
Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
91: perf stat --bpf-counters test :
--- start ---
test child forked, pid 45833
Skipping: --bpf-counters not supported
Error: unknown option `bpf-counters'
[...]
test child finished with -2
---- end ----
perf stat --bpf-counters test: Skip
Signed-off-by: James Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/20211028134828.65774-2-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Sohaib Mohamed [Fri, 12 Nov 2021 20:11:33 +0000 (22:11 +0200)]
perf bench futex: Fix memory leak of perf_cpu_map__new()
ASan reports memory leaks while running:
$ sudo ./perf bench futex all
The leaks are caused by perf_cpu_map__new not being freed.
This patch adds the missing perf_cpu_map__put since it calls
cpu_map_delete implicitly.
Fixes:
9c3516d1b850ea93 ("libperf: Add perf_cpu_map__new()/perf_cpu_map__read() functions")
Signed-off-by: Sohaib Mohamed <sohaib.amhmd@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: André Almeida <andrealmeid@collabora.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sohaib Mohamed <sohaib.amhmd@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20211112201134.77892-1-sohaib.amhmd@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Arnaldo Carvalho de Melo [Fri, 7 Aug 2020 11:45:47 +0000 (08:45 -0300)]
tools arch x86: Sync the msr-index.h copy with the kernel sources
To pick up the changes in:
dae1bd58389615d4 ("x86/msr-index: Add MSRs for XFD")
Addressing these tools/perf build warnings:
diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h
Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h'
That makes the beautification scripts to pick some new entries:
$ diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h
--- tools/arch/x86/include/asm/msr-index.h 2021-07-15 16:17:01.
819817827 -0300
+++ arch/x86/include/asm/msr-index.h 2021-11-06 15:49:33.
738517311 -0300
@@ -625,6 +625,8 @@
#define MSR_IA32_BNDCFGS_RSVD 0x00000ffc
+#define MSR_IA32_XFD 0x000001c4
+#define MSR_IA32_XFD_ERR 0x000001c5
#define MSR_IA32_XSS 0x00000da0
#define MSR_IA32_APICBASE 0x0000001b
$ tools/perf/trace/beauty/tracepoints/x86_msr.sh > /tmp/before
$ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h
$ tools/perf/trace/beauty/tracepoints/x86_msr.sh > /tmp/after
$ diff -u /tmp/before /tmp/after
--- /tmp/before 2021-11-13 11:10:39.
964201505 -0300
+++ /tmp/after 2021-11-13 11:10:47.
902410873 -0300
@@ -93,6 +93,8 @@
[0x000001b0] = "IA32_ENERGY_PERF_BIAS",
[0x000001b1] = "IA32_PACKAGE_THERM_STATUS",
[0x000001b2] = "IA32_PACKAGE_THERM_INTERRUPT",
+ [0x000001c4] = "IA32_XFD",
+ [0x000001c5] = "IA32_XFD_ERR",
[0x000001c8] = "LBR_SELECT",
[0x000001c9] = "LBR_TOS",
[0x000001d9] = "IA32_DEBUGCTLMSR",
$
And this gets rebuilt:
CC /tmp/build/perf/trace/beauty/tracepoints/x86_msr.o
INSTALL trace_plugins
LD /tmp/build/perf/trace/beauty/tracepoints/perf-in.o
LD /tmp/build/perf/trace/beauty/perf-in.o
LD /tmp/build/perf/perf-in.o
LINK /tmp/build/perf/perf
Now one can trace systemwide asking to see backtraces to where those
MSRs are being read/written with:
# perf trace -e msr:*_msr/max-stack=32/ --filter="msr==IA32_XFD || msr==IA32_XFD_ERR"
^C#
#
If we use -v (verbose mode) we can see what it does behind the scenes:
# perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr==IA32_XFD || msr==IA32_XFD_ERR"
<SNIP>
New filter for msr:read_msr: (msr==0x1c4 || msr==0x1c5) && (common_pid != 4448951 && common_pid != 8781)
New filter for msr:write_msr: (msr==0x1c4 || msr==0x1c5) && (common_pid != 4448951 && common_pid != 8781)
<SNIP>
^C#
Example with a frequent msr:
# perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr==IA32_SPEC_CTRL" --max-events 2
Using CPUID AuthenticAMD-25-21-0
0x48
New filter for msr:read_msr: (msr==0x48) && (common_pid != 3738351 && common_pid != 3564)
0x48
New filter for msr:write_msr: (msr==0x48) && (common_pid != 3738351 && common_pid != 3564)
mmap size 528384B
Looking at the vmlinux_path (8 entries long)
symsrc__init: build id mismatch for vmlinux.
Using /proc/kcore for kernel data
Using /proc/kallsyms for symbols
0.000 pipewire/2479 msr:write_msr(msr: IA32_SPEC_CTRL, val: 6)
do_trace_write_msr ([kernel.kallsyms])
do_trace_write_msr ([kernel.kallsyms])
__switch_to_xtra ([kernel.kallsyms])
__switch_to ([kernel.kallsyms])
__schedule ([kernel.kallsyms])
schedule ([kernel.kallsyms])
schedule_hrtimeout_range_clock ([kernel.kallsyms])
do_epoll_wait ([kernel.kallsyms])
__x64_sys_epoll_wait ([kernel.kallsyms])
do_syscall_64 ([kernel.kallsyms])
entry_SYSCALL_64_after_hwframe ([kernel.kallsyms])
epoll_wait (/usr/lib64/libc-2.33.so)
[0x76c4] (/usr/lib64/spa-0.2/support/libspa-support.so)
[0x4cf0] (/usr/lib64/spa-0.2/support/libspa-support.so)
0.027 :0/0 msr:write_msr(msr: IA32_SPEC_CTRL, val: 2)
do_trace_write_msr ([kernel.kallsyms])
do_trace_write_msr ([kernel.kallsyms])
__switch_to_xtra ([kernel.kallsyms])
__switch_to ([kernel.kallsyms])
__schedule ([kernel.kallsyms])
schedule_idle ([kernel.kallsyms])
do_idle ([kernel.kallsyms])
cpu_startup_entry ([kernel.kallsyms])
start_kernel ([kernel.kallsyms])
secondary_startup_64_no_verify ([kernel.kallsyms])
#
Cc: Borislav Petkov <bp@suse.de>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/YY%2FJdb6on7swsn+C@kernel.org/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Arnaldo Carvalho de Melo [Sat, 13 Nov 2021 14:08:31 +0000 (11:08 -0300)]
tools headers UAPI: Sync drm/i915_drm.h with the kernel sources
To pick up the changes in:
e5e32171a2cf1e43 ("drm/i915/guc: Connect UAPI to GuC multi-lrc interface")
9409eb35942713d0 ("drm/i915: Expose logical engine instance to user")
ea673f17ab763879 ("drm/i915/uapi: Add comment clarifying purpose of I915_TILING_* values")
d3ac8d42168a9be7 ("drm/i915/pxp: interfaces for using protected objects")
cbbd3764b2399ad8 ("drm/i915/pxp: Create the arbitrary session after boot")
That don't add any new ioctl, so no changes in tooling.
This silences this perf build warning:
Warning: Kernel ABI header at 'tools/include/uapi/drm/i915_drm.h' differs from latest version at 'include/uapi/drm/i915_drm.h'
diff -u tools/include/uapi/drm/i915_drm.h include/uapi/drm/i915_drm.h
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Huang, Sean Z <sean.z.huang@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Arnaldo Carvalho de Melo [Sat, 13 Nov 2021 14:04:55 +0000 (11:04 -0300)]
tools headers UAPI: Sync sound/asound.h with the kernel sources
To pick up the changes in:
5aec579e08e4f2be ("ALSA: uapi: Fix a C++ style comment in asound.h")
That is just changing a // style comment to /* */.
This silences this perf build warning:
Warning: Kernel ABI header at 'tools/include/uapi/sound/asound.h' differs from latest version at 'include/uapi/sound/asound.h'
diff -u tools/include/uapi/sound/asound.h include/uapi/sound/asound.h
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Arnaldo Carvalho de Melo [Thu, 11 Feb 2021 15:50:52 +0000 (12:50 -0300)]
tools headers UAPI: Sync linux/prctl.h with the kernel sources
To pick the changes in:
61bc346ce64a3864 ("uapi/linux/prctl: provide macro definitions for the PR_SCHED_CORE type argument")
That don't result in any changes in tooling:
$ tools/perf/trace/beauty/prctl_option.sh > before
$ cp include/uapi/linux/prctl.h tools/include/uapi/linux/prctl.h
$ tools/perf/trace/beauty/prctl_option.sh > after
$ diff -u before after
$
Just silences this perf tools build warning:
Warning: Kernel ABI header at 'tools/include/uapi/linux/prctl.h' differs from latest version at 'include/uapi/linux/prctl.h'
diff -u tools/include/uapi/linux/prctl.h include/uapi/linux/prctl.h
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Eugene Syromiatnikov <esyr@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Arnaldo Carvalho de Melo [Sat, 13 Nov 2021 13:43:52 +0000 (10:43 -0300)]
tools headers UAPI: Sync arch prctl headers with the kernel sources
To pick the changes in this cset:
db8268df0983adc2 ("x86/arch_prctl: Add controls for dynamic XSTATE components")
This picks these new prctls:
$ tools/perf/trace/beauty/x86_arch_prctl.sh > /tmp/before
$ cp arch/x86/include/uapi/asm/prctl.h tools/arch/x86/include/uapi/asm/prctl.h
$ tools/perf/trace/beauty/x86_arch_prctl.sh > /tmp/after
$ diff -u /tmp/before /tmp/after
--- /tmp/before 2021-11-13 10:42:52.
787308809 -0300
+++ /tmp/after 2021-11-13 10:43:02.
295558837 -0300
@@ -6,6 +6,9 @@
[0x1004 - 0x1001]= "GET_GS",
[0x1011 - 0x1001]= "GET_CPUID",
[0x1012 - 0x1001]= "SET_CPUID",
+ [0x1021 - 0x1001]= "GET_XCOMP_SUPP",
+ [0x1022 - 0x1001]= "GET_XCOMP_PERM",
+ [0x1023 - 0x1001]= "REQ_XCOMP_PERM",
};
#define x86_arch_prctl_codes_2_offset 0x2001
$
With this 'perf trace' can translate those numbers into strings and use
the strings in filter expressions:
# perf trace -e prctl
0.000 ( 0.011 ms): DOM Worker/3722622 prctl(option: SET_NAME, arg2: 0x7f9c014b7df5) = 0
0.032 ( 0.002 ms): DOM Worker/3722622 prctl(option: SET_NAME, arg2: 0x7f9bb6b51580) = 0
5.452 ( 0.003 ms): StreamT~ns #30/3722623 prctl(option: SET_NAME, arg2: 0x7f9bdbdfeb70) = 0
5.468 ( 0.002 ms): StreamT~ns #30/3722623 prctl(option: SET_NAME, arg2: 0x7f9bdbdfea70) = 0
24.494 ( 0.009 ms): IndexedDB #556/3722624 prctl(option: SET_NAME, arg2: 0x7f562a32ae28) = 0
24.540 ( 0.002 ms): IndexedDB #556/3722624 prctl(option: SET_NAME, arg2: 0x7f563c6d4b30) = 0
670.281 ( 0.008 ms): systemd-userwo/3722339 prctl(option: SET_NAME, arg2: 0x564be30805c8) = 0
670.293 ( 0.002 ms): systemd-userwo/3722339 prctl(option: SET_NAME, arg2: 0x564be30800f0) = 0
^C#
This addresses these perf build warnings:
Warning: Kernel ABI header at 'tools/arch/x86/include/uapi/asm/prctl.h' differs from latest version at 'arch/x86/include/uapi/asm/prctl.h'
diff -u tools/arch/x86/include/uapi/asm/prctl.h arch/x86/include/uapi/asm/prctl.h
Cc: Borislav Petkov <bp@suse.de>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/YY%2FER104k852WOTK@kernel.org/T/#u
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Jiri Olsa [Tue, 9 Nov 2021 14:07:06 +0000 (15:07 +0100)]
perf tools: Add more weak libbpf functions
We hit the window where perf uses libbpf functions, that did not make it
to the official libbpf release yet and it's breaking perf build with
dynamicly linked libbpf.
Fixing this by providing the new interface as weak functions which calls
the original libbpf functions. Fortunatelly the changes were just
renames.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20211109140707.1689940-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Fri, 12 Nov 2021 07:45:25 +0000 (23:45 -0800)]
perf bpf: Avoid memory leak from perf_env__insert_btf()
perf_env__insert_btf() doesn't insert if a duplicate BTF id is
encountered and this causes a memory leak. Modify the function to return
a success/error value and then free the memory if insertion didn't
happen.
v2. Adds a return -1 when the insertion error occurs in
perf_env__fetch_btf. This doesn't affect anything as the result is
never checked.
Fixes:
3792cb2ff43b1b19 ("perf bpf: Save BTF in a rbtree in perf_env")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: http://lore.kernel.org/lkml/20211112074525.121633-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Fri, 12 Nov 2021 03:51:24 +0000 (19:51 -0800)]
perf symbols: Factor out annotation init/exit
The exit function fixes a memory leak with the src field as detected by
leak sanitizer. An example of which is:
Indirect leak of
25133184 byte(s) in 207 object(s) allocated from:
#0 0x7f199ecfe987 in __interceptor_calloc libsanitizer/asan/asan_malloc_linux.cpp:154
#1 0x55defe638224 in annotated_source__alloc_histograms util/annotate.c:803
#2 0x55defe6397e4 in symbol__hists util/annotate.c:952
#3 0x55defe639908 in symbol__inc_addr_samples util/annotate.c:968
#4 0x55defe63aa29 in hist_entry__inc_addr_samples util/annotate.c:1119
#5 0x55defe499a79 in hist_iter__report_callback tools/perf/builtin-report.c:182
#6 0x55defe7a859d in hist_entry_iter__add util/hist.c:1236
#7 0x55defe49aa63 in process_sample_event tools/perf/builtin-report.c:315
#8 0x55defe731bc8 in evlist__deliver_sample util/session.c:1473
#9 0x55defe731e38 in machines__deliver_event util/session.c:1510
#10 0x55defe732a23 in perf_session__deliver_event util/session.c:1590
#11 0x55defe72951e in ordered_events__deliver_event util/session.c:183
#12 0x55defe740082 in do_flush util/ordered-events.c:244
#13 0x55defe7407cb in __ordered_events__flush util/ordered-events.c:323
#14 0x55defe740a61 in ordered_events__flush util/ordered-events.c:341
#15 0x55defe73837f in __perf_session__process_events util/session.c:2390
#16 0x55defe7385ff in perf_session__process_events util/session.c:2420
...
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin Liška <mliska@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20211112035124.94327-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Fri, 12 Nov 2021 03:51:23 +0000 (19:51 -0800)]
perf symbols: Bit pack to save a byte
Use a bit field alongside the earlier bit fields.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin Liška <mliska@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20211112035124.94327-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Fri, 12 Nov 2021 03:51:22 +0000 (19:51 -0800)]
perf symbols: Add documentation to 'struct symbol'
Refactor some existing comments and then infer the rest.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin Liška <mliska@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20211112035124.94327-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Arnaldo Carvalho de Melo [Wed, 8 Sep 2021 19:09:08 +0000 (16:09 -0300)]
tools headers UAPI: Sync files changed by new futex_waitv syscall
To pick the changes in these csets:
039c0ec9bb77446d ("futex,x86: Wire up sys_futex_waitv()")
bf69bad38cf63d98 ("futex: Implement sys_futex_waitv()")
That add support for this new syscall in tools such as 'perf trace'.
For instance, this is now possible:
# perf trace -e futex_waitv
^C#
# perf trace -v -e futex_waitv
Using CPUID AuthenticAMD-25-21-0
event qualifier tracepoint filter: (common_pid != 807333 && common_pid != 3564) && (id == 449)
mmap size 528384B
^C#
# perf trace -v -e futex* --max-events 10
Using CPUID AuthenticAMD-25-21-0
event qualifier tracepoint filter: (common_pid != 812168 && common_pid != 3564) && (id == 202 || id == 449)
mmap size 528384B
? ( ): Timer/219310 ... [continued]: futex()) = -1 ETIMEDOUT (Connection timed out)
0.012 ( 0.002 ms): Timer/219310 futex(uaddr: 0x7fd0b152d3c8, op: WAKE|PRIVATE_FLAG, val: 1) = 0
0.024 ( 0.060 ms): Timer/219310 futex(uaddr: 0x7fd0b152d420, op: WAIT_BITSET|PRIVATE_FLAG, utime: 0x7fd0b1657840, val3: MATCH_ANY) = 0
0.086 ( 0.001 ms): Timer/219310 futex(uaddr: 0x7fd0b152d3c8, op: WAKE|PRIVATE_FLAG, val: 1) = 0
0.088 ( ): Timer/219310 futex(uaddr: 0x7fd0b152d424, op: WAIT_BITSET|PRIVATE_FLAG, utime: 0x7fd0b1657840, val3: MATCH_ANY) ...
0.075 ( 0.005 ms): Web Content/219299 futex(uaddr: 0x7fd0b152d420, op: WAKE|PRIVATE_FLAG, val: 1) = 1
0.169 ( 0.004 ms): Web Content/219299 futex(uaddr: 0x7fd0b152d424, op: WAKE|PRIVATE_FLAG, val: 1) = 1
0.088 ( 0.089 ms): Timer/219310 ... [continued]: futex()) = 0
0.179 ( 0.001 ms): Timer/219310 futex(uaddr: 0x7fd0b152d3c8, op: WAKE|PRIVATE_FLAG, val: 1) = 0
0.181 ( ): Timer/219310 futex(uaddr: 0x7fd0b152d420, op: WAIT_BITSET|PRIVATE_FLAG, utime: 0x7fd0b1657840, val3: MATCH_ANY) ...
#
That is the filter expression attached to the raw_syscalls:sys_{enter,exit}
tracepoints.
$ grep futex_waitv tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
449 common futex_waitv sys_futex_waitv
$
This addresses these perf build warnings:
Warning: Kernel ABI header at 'tools/include/uapi/asm-generic/unistd.h' differs from latest version at 'include/uapi/asm-generic/unistd.h'
diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
Warning: Kernel ABI header at 'tools/perf/arch/x86/entry/syscalls/syscall_64.tbl' differs from latest version at 'arch/x86/entry/syscalls/syscall_64.tbl'
diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
Cc: André Almeida <andrealmeid@collabora.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Guo Zhengkui [Mon, 8 Nov 2021 07:07:52 +0000 (15:07 +0800)]
perf test bpf: Use ARRAY_CHECK() instead of ad-hoc equivalent, addressing array_size.cocci warning
Address following coccicheck warnings:
./tools/perf/tests/bpf.c:316:22-23: WARNING: Use ARRAY_SIZE.
Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: kernel@vivo.com
Cc: netdev@vger.kernel.org
Link: http://lore.kernel.org/lkml/20211108070801.5540-1-guozhengkui@vivo.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
German Gomez [Thu, 11 Nov 2021 13:36:25 +0000 (13:36 +0000)]
perf arm-spe: Support hardware-based PID tracing
If ARM SPE traces contains CONTEXT packets with TID info, use these
values for tracking the TID of samples. Otherwise fall back to using
context switch events and display a message warning to the user of
possible timing inaccuracies [1].
[1] https://lore.kernel.org/lkml/
f877cfa6-9b25-6445-3806-
ca44a4042eaf@arm.com/
Signed-off-by: German Gomez <german.gomez@arm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20211111133625.193568-5-german.gomez@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
German Gomez [Thu, 11 Nov 2021 13:36:24 +0000 (13:36 +0000)]
perf arm-spe: Save context ID in record
This patch is to save context ID in record, this will be used to set TID
for samples.
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: German Gomez <german.gomez@arm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20211111133625.193568-4-german.gomez@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
German Gomez [Thu, 11 Nov 2021 13:36:23 +0000 (13:36 +0000)]
perf arm-spe: Update --switch-events docs in 'perf record'
Update 'perf record' docs and ARM SPE recording options so that they are
consistent. This includes supporting the --no-switch-events flag in ARM
SPE as well.
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: German Gomez <german.gomez@arm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20211111133625.193568-3-german.gomez@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Namhyung Kim [Thu, 11 Nov 2021 13:36:22 +0000 (13:36 +0000)]
perf arm-spe: Track task context switch for cpu-mode events
When perf report synthesize events from ARM SPE data, it refers to
current cpu, pid and tid in the machine. But there's no place to set
them in the ARM SPE decoder. I'm seeing all pid/tid is set to -1 and
user symbols are not resolved in the output.
# perf record -a -e arm_spe_0/ts_enable=1/ sleep 1
# perf report -q | head
8.77% 8.77% :-1 [kernel.kallsyms] [k] format_decode
7.02% 7.02% :-1 [kernel.kallsyms] [k] seq_printf
7.02% 7.02% :-1 [unknown] [.] 0x0000ffff9f687c34
5.26% 5.26% :-1 [kernel.kallsyms] [k] vsnprintf
3.51% 3.51% :-1 [kernel.kallsyms] [k] string
3.51% 3.51% :-1 [unknown] [.] 0x0000ffff9f66ae20
3.51% 3.51% :-1 [unknown] [.] 0x0000ffff9f670b3c
3.51% 3.51% :-1 [unknown] [.] 0x0000ffff9f67c040
1.75% 1.75% :-1 [kernel.kallsyms] [k] ___cache_free
1.75% 1.75% :-1 [kernel.kallsyms] [k] __count_memcg_events
Like Intel PT, add context switch records to track task info. As ARM
SPE support was added later than PERF_RECORD_SWITCH_CPU_WIDE, I think
we can safely set the attr.context_switch bit and use it.
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: German Gomez <german.gomez@arm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20211111133625.193568-2-german.gomez@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Kajol Jain [Mon, 8 Nov 2021 06:00:10 +0000 (11:30 +0530)]
perf vendor events power10: Add metric events JSON file for power10 platform
Add PMU metric JSON file for power10 platform.
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Reviewed-by: Paul Clarke <pc@us.ibm.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lore.kernel.org/lkml/20211108060010.177517-1-kjain@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>