kprobes/x86: Disable optimizing on the function jumps to indirect thunk
authorMasami Hiramatsu <mhiramat@kernel.org>
Thu, 18 Jan 2018 16:15:20 +0000 (01:15 +0900)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 23 Jan 2018 18:58:20 +0000 (19:58 +0100)
commit4fb8368bb6a0b7a50974722ddc16419b5a4c4559
treeccc27b67a32b6507034cb513a9e6699b5d3fe13d
parentaaadccc92ba402b32cbdd72694dc12f6dd4e9ecf
kprobes/x86: Disable optimizing on the function jumps to indirect thunk

commit c86a32c09f8ced67971a2310e3b0dda4d1749007 upstream.

Since indirect jump instructions will be replaced by jump
to __x86_indirect_thunk_*, those jmp instruction must be
treated as an indirect jump. Since optprobe prohibits to
optimize probes in the function which uses an indirect jump,
it also needs to find out the function which jump to
__x86_indirect_thunk_* and disable optimization.

Add a check that the jump target address is between the
__indirect_thunk_start/end when optimizing kprobe.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Link: https://lkml.kernel.org/r/151629212062.10241.6991266100233002273.stgit@devbox
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/x86/kernel/kprobes/opt.c