From 7fbbd5cbebf118a9e09f5453f686656a167c3d1c Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Mon, 4 Dec 2017 15:07:27 +0100 Subject: x86/entry/64: Remove the SYSENTER stack canary Now that the SYSENTER stack has a guard page, there's no need for a canary to detect overflow after the fact. Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Reviewed-by: Thomas Gleixner Reviewed-by: Borislav Petkov Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Dave Hansen Cc: David Laight Cc: Denys Vlasenko Cc: Eduardo Valentin Cc: Greg KH Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rik van Riel Cc: Will Deacon Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Link: https://lkml.kernel.org/r/20171204150606.572577316@linutronix.de Signed-off-by: Ingo Molnar --- arch/x86/kernel/traps.c | 7 ------- 1 file changed, 7 deletions(-) (limited to 'arch/x86/kernel/traps.c') diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 3e29aad5c7cc..5ade4f89a6d1 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -814,13 +814,6 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code) debug_stack_usage_dec(); exit: - /* - * This is the most likely code path that involves non-trivial use - * of the SYSENTER stack. Check that we haven't overrun it. - */ - WARN(this_cpu_read(cpu_tss.SYSENTER_stack_canary) != STACK_END_MAGIC, - "Overran or corrupted SYSENTER stack\n"); - ist_exit(regs); } NOKPROBE_SYMBOL(do_debug); -- cgit v1.2.3