leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

x86/unwind: Prevent KASAN false positive warnings in guess unwinder

Browse Source 
The guess unwinder scans the entire stack, which can cause KASAN
"stack-out-of-bounds" false positive warnings.  Tell KASAN to ignore it.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: davej@codemonkey.org.uk
Cc: dvyukov@google.com
Link: http://lkml.kernel.org/r/61939c0b2b2d63ce97ba59cba3b00fd47c2962cf.1479398226.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Josh Poimboeuf 2016-11-17 09:57:23 -06:00 committed by Ingo Molnar
parent 553bbc11aa
commit c2d75e03d6
1 changed files with 6 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
arch/x86/kernel/unwind_guess.c
View File

@ -7,11 +7,13 @@
unsigned long unwind_get_return_address(struct unwind_state *state) unsigned long unwind_get_return_address(struct unwind_state *state)
{ {
unsigned long addr = READ_ONCE_NOCHECK(*state->sp);
if (unwind_done(state)) if (unwind_done(state))
return 0; return 0;
return ftrace_graph_ret_addr(state->task, &state->graph_idx, return ftrace_graph_ret_addr(state->task, &state->graph_idx,
*state->sp, state->sp); addr, state->sp);
} }
EXPORT_SYMBOL_GPL(unwind_get_return_address); EXPORT_SYMBOL_GPL(unwind_get_return_address);
@ -23,8 +25,10 @@ bool unwind_next_frame(struct unwind_state *state)
return false; return false;
do { do {
unsigned long addr = READ_ONCE_NOCHECK(*state->sp);
for (state->sp++; state->sp < info->end; state->sp++) for (state->sp++; state->sp < info->end; state->sp++)
if (__kernel_text_address(*state->sp)) if (__kernel_text_address(addr))
return true; return true;
state->sp = info->next_sp; state->sp = info->next_sp;