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authorFrederic Weisbecker <fweisbec@gmail.com>2009-12-31 03:52:25 +0100
committerIngo Molnar <mingo@elte.hu>2010-01-13 09:32:54 +0100
commitc2c5d45d46c8c0fd34291dec958670ad4816796f (patch)
tree3d65ac0b76107abb6cf30982f69ccb9120de5be7 /arch/x86/kernel/dumpstack.c
parent7284ce6c9f6153d1777df5f310c959724d1bd446 (diff)
downloadblackbird-op-linux-c2c5d45d46c8c0fd34291dec958670ad4816796f.tar.gz
blackbird-op-linux-c2c5d45d46c8c0fd34291dec958670ad4816796f.zip
perf: Stop stack frame walking off kernel addresses boundaries
While processing kernel perf callchains, an bad entry can be considered as a valid stack pointer but not as a kernel address. In this case, we hang in an endless loop. This can happen in an x86-32 kernel after processing the last entry in a kernel stacktrace. Just stop the stack frame walking after we encounter an invalid kernel address. This fixes a hard lockup in x86-32. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1262227945-27014-1-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/dumpstack.c')
-rw-r--r--arch/x86/kernel/dumpstack.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index c56bc2873030..6d817554780a 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -123,13 +123,15 @@ print_context_stack_bp(struct thread_info *tinfo,
while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) {
unsigned long addr = *ret_addr;
- if (__kernel_text_address(addr)) {
- ops->address(data, addr, 1);
- frame = frame->next_frame;
- ret_addr = &frame->return_address;
- print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
- }
+ if (!__kernel_text_address(addr))
+ break;
+
+ ops->address(data, addr, 1);
+ frame = frame->next_frame;
+ ret_addr = &frame->return_address;
+ print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
}
+
return (unsigned long)frame;
}
EXPORT_SYMBOL_GPL(print_context_stack_bp);
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