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| author | Shaohua Li <shaohua.li@intel.com> | 2010-07-27 16:06:34 +0800 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2010-08-06 12:19:15 -0400 |
| commit | 575570f02761bd680ba5731c1dfd4701062e7fb2 (patch) | |
| tree | 7789ba121ae95af2705fe9053fa1ae9e9fb04a5b /kernel | |
| parent | 8a4fd31e0e8dc33f00b8949a12ac56310bac57bc (diff) | |
| download | linux-575570f02761bd680ba5731c1dfd4701062e7fb2.tar.gz linux-575570f02761bd680ba5731c1dfd4701062e7fb2.tar.bz2 linux-575570f02761bd680ba5731c1dfd4701062e7fb2.zip | |
tracing: Fix an unallocated memory access in function_graph
With CONFIG_DEBUG_PAGEALLOC, I observed an unallocated memory access in
function_graph trace. It appears we find a small size entry in ring buffer,
but we access it as a big size entry. The access overflows the page size
and touches an unallocated page.
Cc: <stable@kernel.org>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
LKML-Reference: <1280217994.32400.76.camel@sli10-desk.sh.intel.com>
[ Added a comment to explain the problem - SDR ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_functions_graph.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 79f4bac99a94..b4c179ae4e45 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -507,7 +507,15 @@ get_return_for_leaf(struct trace_iterator *iter, * if the output fails. */ data->ent = *curr; - data->ret = *next; + /* + * If the next event is not a return type, then + * we only care about what type it is. Otherwise we can + * safely copy the entire event. + */ + if (next->ent.type == TRACE_GRAPH_RET) + data->ret = *next; + else + data->ret.ent.type = next->ent.type; } } |