summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel
diff options
context:
space:
mode:
authorHugh Dickins <hughd@google.com>2012-03-23 14:02:55 -0700
committerIngo Molnar <mingo@kernel.org>2012-03-24 08:15:04 +0100
commit65c0ff4079c011232e795e62c74a0a95512b7ac3 (patch)
treef578bc91f8e241c23b068bec2ecd0f58b0a322fb /arch/x86/kernel
parent4da7072ad6831a35a11341097ce477e18651bedd (diff)
x86: Stop recursive fault in print_context_stack after stack overflow
After printing out the first line of a stack backtrace, print_context_stack() calls print_ftrace_graph_addr() to check if it's making a graph of function calls, usually not the case. But unfortunate ordering of assignments causes this to oops if an earlier stack overflow corrupted threadinfo->task. Reorder to avoid that irritation. ( The fact that there was a stack overflow may often be more interesting than the stack that can now be shown; but integrating that information with this stacktrace is awkward, so leave it to overflow reporting. ) Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20120323225648.15DD5A033B@akpm.mtv.corp.google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/dumpstack.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 4025fe4f928..90bf130f09b 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -37,13 +37,16 @@ print_ftrace_graph_addr(unsigned long addr, void *data,
const struct stacktrace_ops *ops,
struct thread_info *tinfo, int *graph)
{
- struct task_struct *task = tinfo->task;
+ struct task_struct *task;
unsigned long ret_addr;
- int index = task->curr_ret_stack;
+ int index;
if (addr != (unsigned long)return_to_handler)
return;
+ task = tinfo->task;
+ index = task->curr_ret_stack;
+
if (!task->ret_stack || index < *graph)
return;