Messages in this thread Patch in this message | | | Date | Wed, 13 Jan 2010 10:30:19 GMT | From | tip-bot for Frederic Weisbecker <> | Subject | [tip:perf/core] perf: Stop stack frame walking off kernel addresses boundaries |
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Commit-ID: c2c5d45d46c8c0fd34291dec958670ad4816796f Gitweb: http://git.kernel.org/tip/c2c5d45d46c8c0fd34291dec958670ad4816796f Author: Frederic Weisbecker <fweisbec@gmail.com> AuthorDate: Thu, 31 Dec 2009 03:52:25 +0100 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Wed, 13 Jan 2010 09:32:54 +0100
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> --- arch/x86/kernel/dumpstack.c | 14 ++++++++------ 1 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index c56bc28..6d81755 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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