From e441a2ae0e9e9bb12fd3fbe2d59d923fadfe8ef7 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 27 Feb 2020 15:24:29 +0100 Subject: [PATCH] x86/entry/32: Remove the 0/-1 distinction from exception entries Nothing cares about the -1 "mark as interrupt" in the errorcode of exception entries. It's only used to fill the error code when a signal is delivered, but this is already inconsistent vs. 64 bit as there all exceptions which do not have an error code set it to 0. So if 32 bit applications would care about this, then they would have noticed more than a decade ago. Just use 0 for all excpetions which do not have an errorcode consistently. This does neither break /proc/$PID/syscall because this interface examines the error code / syscall number which is on the stack and that is set to -1 (no syscall) in common_exception unconditionally for all exceptions. The push in the entry stub is just there to fill the hardware error code slot on the stack for consistency of the stack layout. A transient observation of 0 is possible, but that's true for the other exceptions which use 0 already as well and that interface is an unreliable snapshot of dubious correctness anyway. Signed-off-by: Thomas Gleixner Reviewed-by: Alexandre Chartre Link: https://lkml.kernel.org/r/87mu94m7ky.fsf@nanos.tec.linutronix.de --- arch/x86/entry/entry_32.S | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 0753f4879a80..ddc87f232877 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -1290,7 +1290,7 @@ SYM_CODE_END(simd_coprocessor_error) SYM_CODE_START(device_not_available) ASM_CLAC - pushl $-1 # mark this as an int + pushl $0 pushl $do_device_not_available jmp common_exception SYM_CODE_END(device_not_available) @@ -1531,7 +1531,7 @@ SYM_CODE_START(debug) * Entry from sysenter is now handled in common_exception */ ASM_CLAC - pushl $-1 # mark this as an int + pushl $0 pushl $do_debug jmp common_exception SYM_CODE_END(debug) @@ -1682,7 +1682,7 @@ SYM_CODE_END(nmi) SYM_CODE_START(int3) ASM_CLAC - pushl $-1 # mark this as an int + pushl $0 pushl $do_int3 jmp common_exception SYM_CODE_END(int3)