From 234e340582901211f40d8c732afc49f0630ecf05 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Thu, 5 Apr 2012 14:25:11 -0700 Subject: simple_open: automatically convert to simple_open() Many users of debugfs copy the implementation of default_open() when they want to support a custom read/write function op. This leads to a proliferation of the default_open() implementation across the entire tree. Now that the common implementation has been consolidated into libfs we can replace all the users of this function with simple_open(). This replacement was done with the following semantic patch: @ open @ identifier open_f != simple_open; identifier i, f; @@ -int open_f(struct inode *i, struct file *f) -{ ( -if (i->i_private) -f->private_data = i->i_private; | -f->private_data = i->i_private; ) -return 0; -} @ has_open depends on open @ identifier fops; identifier open.open_f; @@ struct file_operations fops = { ... -.open = open_f, +.open = simple_open, ... }; [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Stephen Boyd Cc: Greg Kroah-Hartman Cc: Al Viro Cc: Julia Lawall Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/trace/blktrace.c | 18 ++---------------- 1 file changed, 2 insertions(+), 16 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index cdea7b56b0c..c0bd0308741 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -311,13 +311,6 @@ int blk_trace_remove(struct request_queue *q) } EXPORT_SYMBOL_GPL(blk_trace_remove); -static int blk_dropped_open(struct inode *inode, struct file *filp) -{ - filp->private_data = inode->i_private; - - return 0; -} - static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos) { @@ -331,18 +324,11 @@ static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, static const struct file_operations blk_dropped_fops = { .owner = THIS_MODULE, - .open = blk_dropped_open, + .open = simple_open, .read = blk_dropped_read, .llseek = default_llseek, }; -static int blk_msg_open(struct inode *inode, struct file *filp) -{ - filp->private_data = inode->i_private; - - return 0; -} - static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, size_t count, loff_t *ppos) { @@ -371,7 +357,7 @@ static ssize_t blk_msg_write(struct file *filp, const char __user *buffer, static const struct file_operations blk_msg_fops = { .owner = THIS_MODULE, - .open = blk_msg_open, + .open = simple_open, .write = blk_msg_write, .llseek = noop_llseek, }; -- cgit v1.2.3-70-g09d2 From 6e48b550d1f5f1919e6500547ae14a73fbf66c7b Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Fri, 13 Apr 2012 09:52:59 +0100 Subject: tracing: Fix build breakage without CONFIG_PERF_EVENTS (again) Today's -next fails to link for me: kernel/built-in.o:(.data+0x178e50): undefined reference to `perf_ftrace_event_register' It looks like multiple fixes have been merged for the issue fixed by commit fa73dc9 (tracing: Fix build breakage without CONFIG_PERF_EVENTS) though I can't identify the other changes that have gone in at the minute, it's possible that the changes which caused the breakage fixed by the previous commit got dropped but the fix made it in. Link: http://lkml.kernel.org/r/1334307179-21255-1-git-send-email-broonie@opensource.wolfsonmicro.com Cc: Frederic Weisbecker Cc: Ingo Molnar Signed-off-by: Mark Brown Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 95059f091a2..f95d65da6db 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -836,11 +836,11 @@ extern const char *__stop___trace_bprintk_fmt[]; filter) #include "trace_entries.h" -#ifdef CONFIG_FUNCTION_TRACER +#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_FUNCTION_TRACER) int perf_ftrace_event_register(struct ftrace_event_call *call, enum trace_reg type, void *data); #else #define perf_ftrace_event_register NULL -#endif /* CONFIG_FUNCTION_TRACER */ +#endif #endif /* _LINUX_KERNEL_TRACE_H */ -- cgit v1.2.3-70-g09d2 From 348f0fc238efb441a28e7644c51f9fd3001b228a Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 16 Apr 2012 15:41:28 -0400 Subject: tracing: Fix regression with tracing_on The change to make tracing_on affect only the ftrace ring buffer, caused a bug where it wont affect any ring buffer. The problem was that the buffer of the trace_array was passed to the write function and not the trace array itself. The trace_array can change the buffer when running a latency tracer. If this happens, then the buffer being disabled may not be the buffer currently used by ftrace. This will cause the tracing_on file to become useless. The simple fix is to pass the trace_array to the write function instead of the buffer. Then the actual buffer may be changed. Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ed7b5d1e12f..2a22255c101 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4629,7 +4629,8 @@ static ssize_t rb_simple_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { - struct ring_buffer *buffer = filp->private_data; + struct trace_array *tr = filp->private_data; + struct ring_buffer *buffer = tr->buffer; char buf[64]; int r; @@ -4647,7 +4648,8 @@ static ssize_t rb_simple_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { - struct ring_buffer *buffer = filp->private_data; + struct trace_array *tr = filp->private_data; + struct ring_buffer *buffer = tr->buffer; unsigned long val; int ret; @@ -4734,7 +4736,7 @@ static __init int tracer_init_debugfs(void) &trace_clock_fops); trace_create_file("tracing_on", 0644, d_tracer, - global_trace.buffer, &rb_simple_fops); + &global_trace, &rb_simple_fops); #ifdef CONFIG_DYNAMIC_FTRACE trace_create_file("dyn_ftrace_total_info", 0444, d_tracer, -- cgit v1.2.3-70-g09d2 From db4c75cbebd7e5910cd3bcb6790272fcc3042857 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 19 Apr 2012 10:31:47 -0400 Subject: tracing: Fix stacktrace of latency tracers (irqsoff and friends) While debugging a latency with someone on IRC (mirage335) on #linux-rt (OFTC), we discovered that the stacktrace output of the latency tracers (preemptirqsoff) was empty. This bug was caused by the creation of the dynamic length stack trace again (like commit 12b5da3 "tracing: Fix ent_size in trace output" was). This bug is caused by the latency tracers requiring the next event to determine the time between the current event and the next. But by grabbing the next event, the iter->ent_size is set to the next event instead of the current one. As the stacktrace event is the last event, this makes the ent_size zero and causes nothing to be printed for the stack trace. The dynamic stacktrace uses the ent_size to determine how much of the stack can be printed. The ent_size of zero means no stack. The simple fix is to save the iter->ent_size before finding the next event. Note, mirage335 asked to remain anonymous from LKML and git, so I will not add the Reported-by and Tested-by tags, even though he did report the issue and tested the fix. Cc: stable@vger.kernel.org # 3.1+ Signed-off-by: Steven Rostedt --- kernel/trace/trace_output.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel/trace') diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 859fae6b182..df611a0e76c 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -652,6 +652,8 @@ int trace_print_lat_context(struct trace_iterator *iter) { u64 next_ts; int ret; + /* trace_find_next_entry will reset ent_size */ + int ent_size = iter->ent_size; struct trace_seq *s = &iter->seq; struct trace_entry *entry = iter->ent, *next_entry = trace_find_next_entry(iter, NULL, @@ -660,6 +662,9 @@ int trace_print_lat_context(struct trace_iterator *iter) unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start); unsigned long rel_usecs; + /* Restore the original ent_size */ + iter->ent_size = ent_size; + if (!next_entry) next_ts = iter->ts; rel_usecs = ns2usecs(next_ts - iter->ts); -- cgit v1.2.3-70-g09d2