Commit-ID: 0d2b8579add41e08aa1110da864f1071d58e6048
Gitweb: http://git.kernel.org/tip/0d2b8579add41e08aa1110da864f1071d58e6048
Author: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Wed, 26 Oct 2016 10:41:50 -0500
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 27 Oct 2016 08:32:38 +0200
x86/dumpstack: Warn on stack recursion
Print a warning if stack recursion is detected.
Use printk_deferred_once() because the unwinder can be called with the
console lock by lockdep via save_stack_trace().
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/def18247aafaab480844484398e793f552b79bda.1477496147.git.jpoimboe@xxxxxxxxxx
[ Unbroke the lines. ]
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/kernel/dumpstack_32.c | 4 +++-
arch/x86/kernel/dumpstack_64.c | 4 +++-
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index 90cf460..d7d20999 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -109,8 +109,10 @@ recursion_check:
* just break out and report an unknown stack type.
*/
if (visit_mask) {
- if (*visit_mask & (1UL << info->type))
+ if (*visit_mask & (1UL << info->type)) {
+ printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
goto unknown;
+ }
*visit_mask |= 1UL << info->type;
}
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 310abf4..ab0f8b9 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -128,8 +128,10 @@ recursion_check:
* just break out and report an unknown stack type.
*/
if (visit_mask) {
- if (*visit_mask & (1UL << info->type))
+ if (*visit_mask & (1UL << info->type)) {
+ printk_deferred_once(KERN_WARNING "WARNING: stack recursion on stack type %d\n", info->type);
goto unknown;
+ }
*visit_mask |= 1UL << info->type;
}
--
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