From: Andy Lutomirski Date: Tue, 25 Nov 2014 01:39:06 +0000 (-0800) Subject: x86/asm/traps: Disable tracing and kprobes in fixup_bad_iret and sync_regs X-Git-Tag: firefly_0821_release~176^2~2620^2~7 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=7ddc6a2199f1da405a2fb68c40db8899b1a8cd87;p=firefly-linux-kernel-4.4.55.git x86/asm/traps: Disable tracing and kprobes in fixup_bad_iret and sync_regs These functions can be executed on the int3 stack, so kprobes are dangerous. Tracing is probably a bad idea, too. Fixes: b645af2d5905 ("x86_64, traps: Rework bad_iret") Signed-off-by: Andy Lutomirski Cc: # Backport as far back as it would apply Cc: Linus Torvalds Cc: Steven Rostedt Link: http://lkml.kernel.org/r/50e33d26adca60816f3ba968875801652507d0c4.1416870125.git.luto@amacapital.net Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index de801f22128a..07ab8e9733c5 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -387,7 +387,7 @@ NOKPROBE_SYMBOL(do_int3); * for scheduling or signal handling. The actual stack switch is done in * entry.S */ -asmlinkage __visible struct pt_regs *sync_regs(struct pt_regs *eregs) +asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs) { struct pt_regs *regs = eregs; /* Did already sync */ @@ -413,7 +413,7 @@ struct bad_iret_stack { struct pt_regs regs; }; -asmlinkage __visible +asmlinkage __visible notrace struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) { /* @@ -436,6 +436,7 @@ struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) BUG_ON(!user_mode_vm(&new_stack->regs)); return new_stack; } +NOKPROBE_SYMBOL(fixup_bad_iret); #endif /*