From 7717c6be699975f6733d278b13b7c4295d73caf6 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 13 Jan 2016 15:48:54 -0500 Subject: [PATCH 1/3] tracing: Fix stacktrace skip depth in trace_buffer_unlock_commit_regs() While cleaning the stacktrace code I unintentially changed the skip depth of trace_buffer_unlock_commit_regs() from 0 to 6. kprobes uses this function, and with skipping 6 call backs, it can easily produce no stack. Here's how I tested it: # echo 'p:ext4_sync_fs ext4_sync_fs ' > /sys/kernel/debug/tracing/kprobe_events # echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable # cat /sys/kernel/debug/trace sync-2394 [005] 502.457060: ext4_sync_fs: (ffffffff81317650) sync-2394 [005] 502.457063: kernel_stack: sync-2394 [005] 502.457086: ext4_sync_fs: (ffffffff81317650) sync-2394 [005] 502.457087: kernel_stack: sync-2394 [005] 502.457091: ext4_sync_fs: (ffffffff81317650) After putting back the skip stack to zero, we have: sync-2270 [000] 748.052693: ext4_sync_fs: (ffffffff81317650) sync-2270 [000] 748.052695: kernel_stack: => iterate_supers (ffffffff8126412e) => sys_sync (ffffffff8129c4b6) => entry_SYSCALL_64_fastpath (ffffffff8181f0b2) sync-2270 [000] 748.053017: ext4_sync_fs: (ffffffff81317650) sync-2270 [000] 748.053019: kernel_stack: => iterate_supers (ffffffff8126412e) => sys_sync (ffffffff8129c4b6) => entry_SYSCALL_64_fastpath (ffffffff8181f0b2) sync-2270 [000] 748.053381: ext4_sync_fs: (ffffffff81317650) sync-2270 [000] 748.053383: kernel_stack: => iterate_supers (ffffffff8126412e) => sys_sync (ffffffff8129c4b6) => entry_SYSCALL_64_fastpath (ffffffff8181f0b2) Cc: stable@vger.kernel.org # v4.4+ Fixes: 73dddbb57bb0 "tracing: Only create stacktrace option when STACKTRACE is configured" Reported-by: Brendan Gregg Tested-by: Brendan Gregg Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 87fb9801bd9e..d9293402ee68 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1751,7 +1751,7 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr, { __buffer_unlock_commit(buffer, event); - ftrace_trace_stack(tr, buffer, flags, 6, pc, regs); + ftrace_trace_stack(tr, buffer, flags, 0, pc, regs); ftrace_trace_userstack(buffer, flags, pc); } EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit_regs); From b7522056ec1a62a5f3246627e12ef48e6274c21c Mon Sep 17 00:00:00 2001 From: Dmitry Safonov <0x7f454c46@gmail.com> Date: Wed, 13 Jan 2016 18:39:58 +0300 Subject: [PATCH 2/3] ftrace: Remove unused nr_trampolines var It's not needed & not used since introducing old_hash: commit fef5aeeee9e371 ("ftrace: Replace tramp_hash with old_*_hash to save space"). Link: http://lkml.kernel.org/r/1452699598-27610-1-git-send-email-0x7f454c46@gmail.com Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> Signed-off-by: Steven Rostedt --- include/linux/ftrace.h | 1 - 1 file changed, 1 deletion(-) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 60048c50404e..65460ad93c7b 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -164,7 +164,6 @@ struct ftrace_ops { ftrace_func_t saved_func; int __percpu *disabled; #ifdef CONFIG_DYNAMIC_FTRACE - int nr_trampolines; struct ftrace_ops_hash local_hash; struct ftrace_ops_hash *func_hash; struct ftrace_ops_hash old_hash; From 7fd13615992ae0fc132c9abb24511be43f3b5d9d Mon Sep 17 00:00:00 2001 From: Gustavo Padovan Date: Thu, 21 Jan 2016 09:48:14 -0200 Subject: [PATCH 3/3] tracing/dma-buf/fence: Fix timeline str value on fence_annotate_wait_on timeline was wrongly assigned with ->get_driver_name(). Link: http://lkml.kernel.org/r/1453376895-30747-1-git-send-email-gustavo@padovan.org Signed-off-by: Gustavo Padovan Signed-off-by: Steven Rostedt --- include/trace/events/fence.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/trace/events/fence.h b/include/trace/events/fence.h index 98feb1b82896..d6dfa05ba322 100644 --- a/include/trace/events/fence.h +++ b/include/trace/events/fence.h @@ -17,7 +17,7 @@ TRACE_EVENT(fence_annotate_wait_on, TP_STRUCT__entry( __string(driver, fence->ops->get_driver_name(fence)) - __string(timeline, fence->ops->get_driver_name(fence)) + __string(timeline, fence->ops->get_timeline_name(fence)) __field(unsigned int, context) __field(unsigned int, seqno)