From c4a5923055c9e0c87dfc0387f7cda5ee2bbac3c1 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 10 Dec 2015 12:50:45 -0600 Subject: tracing: Add event record param to trigger_ops.func() Some triggers may need access to the trace event, so pass it in. Also fix up the existing trigger funcs and their callers. Link: http://lkml.kernel.org/r/543e31e9fc445ef61077421ab219033401c39846.1449767187.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- include/linux/trace_events.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 925730bc9fc1..0d6930e941e8 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -430,7 +430,8 @@ extern int call_filter_check_discard(struct trace_event_call *call, void *rec, extern enum event_trigger_type event_triggers_call(struct trace_event_file *file, void *rec); extern void event_triggers_post_call(struct trace_event_file *file, - enum event_trigger_type tt); + enum event_trigger_type tt, + void *rec); bool trace_event_ignore_this_pid(struct trace_event_file *trace_file); @@ -517,7 +518,7 @@ event_trigger_unlock_commit(struct trace_event_file *file, trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc); if (tt) - event_triggers_post_call(file, tt); + event_triggers_post_call(file, tt, entry); } /** @@ -550,7 +551,7 @@ event_trigger_unlock_commit_regs(struct trace_event_file *file, irq_flags, pc, regs); if (tt) - event_triggers_post_call(file, tt); + event_triggers_post_call(file, tt, entry); } #ifdef CONFIG_BPF_EVENTS -- cgit v1.2.3 From 3debb0a9ddb16526de8b456491b7db60114f7b5e Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Tue, 22 Mar 2016 17:30:58 -0400 Subject: tracing: Fix trace_printk() to print when not using bprintk() The trace_printk() code will allocate extra buffers if the compile detects that a trace_printk() is used. To do this, the format of the trace_printk() is saved to the __trace_printk_fmt section, and if that section is bigger than zero, the buffers are allocated (along with a message that this has happened). If trace_printk() uses a format that is not a constant, and thus something not guaranteed to be around when the print happens, the compiler optimizes the fmt out, as it is not used, and the __trace_printk_fmt section is not filled. This means the kernel will not allocate the special buffers needed for the trace_printk() and the trace_printk() will not write anything to the tracing buffer. Adding a "__used" to the variable in the __trace_printk_fmt section will keep it around, even though it is set to NULL. This will keep the string from being printed in the debugfs/tracing/printk_formats section as it is not needed. Reported-by: Vlastimil Babka Fixes: 07d777fe8c398 "tracing: Add percpu buffers for trace_printk()" Cc: stable@vger.kernel.org # v3.5+ Signed-off-by: Steven Rostedt --- include/linux/kernel.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index f31638c6e873..95452f72349a 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -635,7 +635,7 @@ do { \ #define do_trace_printk(fmt, args...) \ do { \ - static const char *trace_printk_fmt \ + static const char *trace_printk_fmt __used \ __attribute__((section("__trace_printk_fmt"))) = \ __builtin_constant_p(fmt) ? fmt : NULL; \ \ @@ -679,7 +679,7 @@ int __trace_printk(unsigned long ip, const char *fmt, ...); */ #define trace_puts(str) ({ \ - static const char *trace_printk_fmt \ + static const char *trace_printk_fmt __used \ __attribute__((section("__trace_printk_fmt"))) = \ __builtin_constant_p(str) ? str : NULL; \ \ @@ -701,7 +701,7 @@ extern void trace_dump_stack(int skip); #define ftrace_vprintk(fmt, vargs) \ do { \ if (__builtin_constant_p(fmt)) { \ - static const char *trace_printk_fmt \ + static const char *trace_printk_fmt __used \ __attribute__((section("__trace_printk_fmt"))) = \ __builtin_constant_p(fmt) ? fmt : NULL; \ \ -- cgit v1.2.3