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perf: Stop stack frame walking off kernel addresses boundaries

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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>
This commit is contained in:
Frederic Weisbecker 2009-12-31 03:52:25 +01:00 committed by Ingo Molnar
parent 7284ce6c9f
commit c2c5d45d46
1 changed files with 8 additions and 6 deletions
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14
arch/x86/kernel/dumpstack.c
View file

@ -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);