evie/android_kernel_oneplus_msm8998
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

x86/asm/traps: Disable tracing and kprobes in fixup_bad_iret and sync_regs

Browse source 
These functions can be executed on the int3 stack, so kprobes
are dangerous. Tracing is probably a bad idea, too.

Fixes: b645af2d59 ("x86_64, traps: Rework bad_iret")
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: <stable@vger.kernel.org> # Backport as far back as it would apply
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/50e33d26adca60816f3ba968875801652507d0c4.1416870125.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Andy Lutomirski 2014-11-24 17:39:06 -08:00 • committed by Ingo Molnar
parent 5d01410fe4
commit 7ddc6a2199
1 changed files with 3 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
arch/x86/kernel/traps.c
View file

@ -387,7 +387,7 @@ NOKPROBE_SYMBOL(do_int3);
* for scheduling or signal handling. The actual stack switch is done in * for scheduling or signal handling. The actual stack switch is done in
* entry.S * 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; struct pt_regs *regs = eregs;
/* Did already sync */ /* Did already sync */
@ -413,7 +413,7 @@ struct bad_iret_stack {
struct pt_regs regs; struct pt_regs regs;
}; };
asmlinkage __visible asmlinkage __visible notrace
struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) 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)); BUG_ON(!user_mode_vm(&new_stack->regs));
return new_stack; return new_stack;
} }
NOKPROBE_SYMBOL(fixup_bad_iret);
#endif #endif
/* /*