Steven Rostedt (Red Hat) 70c8217acd tracing: Handle NULL formats in hold_module_trace_bprintk_format() ... If a task uses a non constant string for the format parameter in trace_printk(), then the trace_printk_fmt variable is set to NULL. This variable is then saved in the __trace_printk_fmt section. The function hold_module_trace_bprintk_format() checks to see if duplicate formats are used by modules, and reuses them if so (saves them to the list if it is new). But this function calls lookup_format() that does a strcmp() to the value (which is now NULL) and can cause a kernel oops. This wasn't an issue till 3debb0a9dd ("tracing: Fix trace_printk() to print when not using bprintk()") which added "__used" to the trace_printk_fmt variable, and before that, the kernel simply optimized it out (no NULL value was saved). The fix is simply to handle the NULL pointer in lookup_format() and have the caller ignore the value if it was NULL. Link: http://lkml.kernel.org/r/1464769870-18344-1-git-send-email-zhengjun.xing@intel.com Reported-by: xingzhen <zhengjun.xing@intel.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Fixes: 3debb0a9dd ("tracing: Fix trace_printk() to print when not using bprintk()") Cc: stable@vger.kernel.org # v3.5+ Signed-off-by: Steven Rostedt <rostedt@goodmis.org>		2016-06-20 09:46:12 -04:00
..
blktrace.c	blktrace: add missed mask name	2016-05-10 08:41:36 -06:00
bpf_trace.c	bpf, trace: use READ_ONCE for retrieving file ptr	2016-06-07 14:48:03 -07:00
ftrace.c	Three more changes.	2016-05-22 19:40:39 -07:00
Kconfig	tracing: Add 'hist' event trigger command	2016-04-19 12:16:14 -04:00
Makefile	tracing: Add 'hist' event trigger command	2016-04-19 12:16:14 -04:00
power-traces.c	cpufreq: schedutil: New governor based on scheduler utilization data	2016-04-02 01:09:12 +02:00
ring_buffer.c	ring-buffer: Prevent overflow of size in ring_buffer_resize()	2016-05-13 16:44:20 -04:00
ring_buffer_benchmark.c
rpm-traces.c
trace.c	tracing: Use temp buffer when filtering events	2016-05-03 17:59:24 -04:00
trace.h	tracing: Use temp buffer when filtering events	2016-05-03 17:59:24 -04:00
trace_benchmark.c
trace_benchmark.h
trace_branch.c
trace_clock.c
trace_entries.h
trace_event_perf.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2016-05-17 16:26:30 -07:00
trace_events.c	This includes two new updates for the ftrace infrastructure.	2016-05-18 18:55:19 -07:00
trace_events_filter.c	tracing: Use temp buffer when filtering events	2016-05-03 17:59:24 -04:00
trace_events_filter_test.h
trace_events_hist.c	tracing: Add check for NULL event field when creating hist field	2016-04-26 09:40:29 -04:00
trace_events_trigger.c	tracing: Add support for named triggers	2016-04-19 18:56:00 -04:00
trace_export.c
trace_functions.c
trace_functions_graph.c	arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections	2016-03-25 16:37:42 -07:00
trace_irqsoff.c	tracing: Remove redundant reset per-CPU buff in irqsoff tracer	2016-03-18 16:39:11 -04:00
trace_kdb.c
trace_kprobe.c	perf: split perf_trace_buf_prepare into alloc and update parts	2016-04-07 21:04:26 -04:00
trace_mmiotrace.c	kernel/...: convert pr_warning to pr_warn	2016-03-22 15:36:02 -07:00
trace_nop.c
trace_output.c	tracing: Record and show NMI state	2016-03-22 18:04:10 -04:00
trace_output.h
trace_printk.c	tracing: Handle NULL formats in hold_module_trace_bprintk_format()	2016-06-20 09:46:12 -04:00
trace_probe.c	kernel/...: convert pr_warning to pr_warn	2016-03-22 15:36:02 -07:00
trace_probe.h
trace_sched_switch.c
trace_sched_wakeup.c
trace_selftest.c
trace_selftest_dynamic.c
trace_seq.c
trace_stack.c
trace_stat.c	kernel/...: convert pr_warning to pr_warn	2016-03-22 15:36:02 -07:00
trace_stat.h
trace_syscalls.c	perf: split perf_trace_buf_prepare into alloc and update parts	2016-04-07 21:04:26 -04:00
trace_uprobe.c	perf: split perf_trace_buf_prepare into alloc and update parts	2016-04-07 21:04:26 -04:00
tracing_map.c	tracing: Handle tracing_map_alloc_elts() error path correctly	2016-04-26 09:40:30 -04:00
tracing_map.h	tracing: Update some tracing_map constants and comments	2016-04-19 12:16:06 -04:00