aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86
diff options
context:
space:
mode:
authorFrederic Weisbecker <fweisbec@gmail.com>2009-12-30 21:52:25 -0500
committerIngo Molnar <mingo@elte.hu>2010-01-13 03:32:54 -0500
commitc2c5d45d46c8c0fd34291dec958670ad4816796f (patch)
tree3d65ac0b76107abb6cf30982f69ccb9120de5be7 /arch/x86
parent7284ce6c9f6153d1777df5f310c959724d1bd446 (diff)
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')
-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,
123 while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) { 123 while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) {
124 unsigned long addr = *ret_addr; 124 unsigned long addr = *ret_addr;
125 125
126 if (__kernel_text_address(addr)) { 126 if (!__kernel_text_address(addr))
127 ops->address(data, addr, 1); 127 break;
128 frame = frame->next_frame; 128
129 ret_addr = &frame->return_address; 129 ops->address(data, addr, 1);
130 print_ftrace_graph_addr(addr, data, ops, tinfo, graph); 130 frame = frame->next_frame;
131 } 131 ret_addr = &frame->return_address;
132 print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
132 } 133 }
134
133 return (unsigned long)frame; 135 return (unsigned long)frame;
134} 136}
135EXPORT_SYMBOL_GPL(print_context_stack_bp); 137EXPORT_SYMBOL_GPL(print_context_stack_bp);