x86/entry/64: Migrate 64-bit and compat syscalls to the new exit handlers and remove...

These need to be migrated together, as the compat case used to
jump into the middle of the 64-bit exit code.

Remove the old assembly code.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/d4d1d70de08ac3640badf50048a9e8f18fe2497f.1435952415.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index ccfcba9..4ca5b78 100644 (file)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -229,6 +229,11 @@ entry_SYSCALL_64_fastpath:
         */
        USERGS_SYSRET64
 
+GLOBAL(int_ret_from_sys_call_irqs_off)
+       TRACE_IRQS_ON
+       ENABLE_INTERRUPTS(CLBR_NONE)
+       jmp int_ret_from_sys_call
+
        /* Do syscall entry tracing */
 tracesys:
        movq    %rsp, %rdi
@@ -272,69 +277,11 @@ tracesys_phase2:
  * Has correct iret frame.
  */
 GLOBAL(int_ret_from_sys_call)
-       DISABLE_INTERRUPTS(CLBR_NONE)
-int_ret_from_sys_call_irqs_off: /* jumps come here from the irqs-off SYSRET path */
-       TRACE_IRQS_OFF
-       movl    $_TIF_ALLWORK_MASK, %edi
-       /* edi: mask to check */
-GLOBAL(int_with_check)
-       LOCKDEP_SYS_EXIT_IRQ
-       GET_THREAD_INFO(%rcx)
-       movl    TI_flags(%rcx), %edx
-       andl    %edi, %edx
-       jnz     int_careful
-       andl    $~TS_COMPAT, TI_status(%rcx)
-       jmp     syscall_return
-
-       /*
-        * Either reschedule or signal or syscall exit tracking needed.
-        * First do a reschedule test.
-        * edx: work, edi: workmask
-        */
-int_careful:
-       bt      $TIF_NEED_RESCHED, %edx
-       jnc     int_very_careful
-       TRACE_IRQS_ON
-       ENABLE_INTERRUPTS(CLBR_NONE)
-       pushq   %rdi
-       SCHEDULE_USER
-       popq    %rdi
-       DISABLE_INTERRUPTS(CLBR_NONE)
-       TRACE_IRQS_OFF
-       jmp     int_with_check
-
-       /* handle signals and tracing -- both require a full pt_regs */
-int_very_careful:
-       TRACE_IRQS_ON
-       ENABLE_INTERRUPTS(CLBR_NONE)
        SAVE_EXTRA_REGS
-       /* Check for syscall exit trace */
-       testl   $_TIF_WORK_SYSCALL_EXIT, %edx
-       jz      int_signal
-       pushq   %rdi
-       leaq    8(%rsp), %rdi                   /* &ptregs -> arg1 */
-       call    syscall_trace_leave
-       popq    %rdi
-       andl    $~(_TIF_WORK_SYSCALL_EXIT|_TIF_SYSCALL_EMU), %edi
-       jmp     int_restore_rest
-
-int_signal:
-       testl   $_TIF_DO_NOTIFY_MASK, %edx
-       jz      1f
-       movq    %rsp, %rdi                      /* &ptregs -> arg1 */
-       xorl    %esi, %esi                      /* oldset -> arg2 */
-       call    do_notify_resume
-1:     movl    $_TIF_WORK_MASK, %edi
-int_restore_rest:
+       movq    %rsp, %rdi
+       call    syscall_return_slowpath /* returns with IRQs disabled */
        RESTORE_EXTRA_REGS
-       DISABLE_INTERRUPTS(CLBR_NONE)
-       TRACE_IRQS_OFF
-       jmp     int_with_check
-
-syscall_return:
-       /* The IRETQ could re-enable interrupts: */
-       DISABLE_INTERRUPTS(CLBR_ANY)
-       TRACE_IRQS_IRETQ
+       TRACE_IRQS_IRETQ                /* we're about to change IF */
 
        /*
         * Try to use SYSRET instead of IRET if we're returning to

diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index e5ebdd9..d9bbd31 100644 (file)
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -210,10 +210,10 @@ sysexit_from_sys_call:
        .endm
 
        .macro auditsys_exit exit
-       testl   $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
-       jnz     ia32_ret_from_sys_call
        TRACE_IRQS_ON
        ENABLE_INTERRUPTS(CLBR_NONE)
+       testl   $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
+       jnz     ia32_ret_from_sys_call
        movl    %eax, %esi              /* second arg, syscall return value */
        cmpl    $-MAX_ERRNO, %eax       /* is it an error ? */
        jbe     1f
@@ -232,7 +232,7 @@ sysexit_from_sys_call:
        movq    %rax, R10(%rsp)
        movq    %rax, R9(%rsp)
        movq    %rax, R8(%rsp)
-       jmp     int_with_check
+       jmp     int_ret_from_sys_call_irqs_off
        .endm
 
 sysenter_auditsys: