path: root/kernel
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2021-04-20 14:38:35 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-04-20 14:38:35 -0700
commit1fe5501ba1abf2b7e78295df73675423bd6899a0 (patch)
treeade207f81b2d916f131e636b114cf37b27b08f94 /kernel
parentdb2e718a47984b9d71ed890eb2ea36ecf150de18 (diff)
parent0e1e71d34901a633825cd5ae78efaf8abd9215c6 (diff)
Merge tag 'trace-v5.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-traceHEADmaster
Pull tracing fix from Steven Rostedt: "Fix tp_printk command line and trace events Masami added a wrapper to be able to unhash trace event pointers as they are only read by root anyway, and they can also be extracted by the raw trace data buffers. But this wrapper utilized the iterator to have a temporary buffer to manipulate the text with. tp_printk is a kernel command line option that will send the trace output of a trace event to the console on boot up (useful when the system crashes before finishing the boot). But the code used the same wrapper that Masami added, and its iterator did not have a buffer, and this caused the system to crash. Have the wrapper just print the trace event normally if the iterator has no temporary buffer" * tag 'trace-v5.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix checking event hash pointer logic when tp_printk is enabled
Diffstat (limited to 'kernel')
1 files changed, 7 insertions, 3 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5c777627212f..c0c9aa5cd8e2 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3545,7 +3545,11 @@ static char *trace_iter_expand_format(struct trace_iterator *iter)
char *tmp;
- if (iter->fmt == static_fmt_buf)
+ /*
+ * iter->tr is NULL when used with tp_printk, which makes
+ * this get called where it is not safe to call krealloc().
+ */
+ if (!iter->tr || iter->fmt == static_fmt_buf)
return NULL;
tmp = krealloc(iter->fmt, iter->fmt_size + STATIC_FMT_BUF_SIZE,
@@ -3566,7 +3570,7 @@ const char *trace_event_format(struct trace_iterator *iter, const char *fmt)
if (WARN_ON_ONCE(!fmt))
return fmt;
- if (iter->tr->trace_flags & TRACE_ITER_HASH_PTR)
+ if (!iter->tr || iter->tr->trace_flags & TRACE_ITER_HASH_PTR)
return fmt;
p = fmt;
@@ -9692,7 +9696,7 @@ void __init early_trace_init(void)
if (tracepoint_printk) {
tracepoint_print_iter =
- kmalloc(sizeof(*tracepoint_print_iter), GFP_KERNEL);
+ kzalloc(sizeof(*tracepoint_print_iter), GFP_KERNEL);
if (MEM_FAIL(!tracepoint_print_iter,
"Failed to allocate trace iterator\n"))
tracepoint_printk = 0;