From cf8517cf905b5cd31d5790250b9ac39f7cb8aa53 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Fri, 23 Oct 2009 19:36:16 -0400 Subject: tracing: Update *ppos instead of filp->f_pos Instead of directly updating filp->f_pos we should update the *ppos argument. The filp->f_pos gets updated within the file_pos_write() function called from sys_write(). Signed-off-by: Jiri Olsa Signed-off-by: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <20091023233646.399670810@goodmis.org> Signed-off-by: Ingo Molnar diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 37ba67e..9c451a1 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -740,7 +740,7 @@ ftrace_profile_write(struct file *filp, const char __user *ubuf, out: mutex_unlock(&ftrace_profile_lock); - filp->f_pos += cnt; + *ppos += cnt; return cnt; } diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index c820b03..b20d3ec 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2440,7 +2440,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf, return ret; } - filp->f_pos += cnt; + *ppos += cnt; return cnt; } @@ -2582,7 +2582,7 @@ tracing_ctrl_write(struct file *filp, const char __user *ubuf, } mutex_unlock(&trace_types_lock); - filp->f_pos += cnt; + *ppos += cnt; return cnt; } @@ -2764,7 +2764,7 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf, if (err) return err; - filp->f_pos += ret; + *ppos += ret; return ret; } @@ -3299,7 +3299,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, } } - filp->f_pos += cnt; + *ppos += cnt; /* If check pages failed, return ENOMEM */ if (tracing_disabled) -- cgit v0.10.2 From 3e69533b51930a7169235db2caf703884e6e3bbb Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Fri, 23 Oct 2009 19:36:17 -0400 Subject: tracing: Fix trace_seq_printf() return value trace_seq_printf() return value is a little ambiguous. It currently returns the length of the space available in the buffer. printf usually returns the amount written. This is not adequate here, because: trace_seq_printf(s, ""); is perfectly legal, and returning 0 would indicate that it failed. We can always see the amount written by looking at the before and after values of s->len. This is not quite the same use as printf. We only care if the string was successfully written to the buffer or not. Make trace_seq_printf() return 0 if the trace oversizes the buffer's free space, 1 otherwise. Signed-off-by: Jiri Olsa Signed-off-by: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <20091023233646.631787612@goodmis.org> Signed-off-by: Ingo Molnar diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index ed17565..b6c12c6 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -69,6 +69,9 @@ enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter) * @s: trace sequence descriptor * @fmt: printf format string * + * It returns 0 if the trace oversizes the buffer's free + * space, 1 otherwise. + * * The tracer may use either sequence operations or its own * copy to user routines. To simplify formating of a trace * trace_seq_printf is used to store strings into a special @@ -95,7 +98,7 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...) s->len += ret; - return len; + return 1; } EXPORT_SYMBOL_GPL(trace_seq_printf); -- cgit v0.10.2 From 67b394f7f26d84edb7294cc6528ab7ca6daa2ad1 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Fri, 23 Oct 2009 19:36:18 -0400 Subject: tracing: Fix comment typo and documentation example Trivial patch to fix a documentation example and to fix a comment. Signed-off-by: Jiri Olsa Signed-off-by: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <20091023233646.871719877@goodmis.org> Signed-off-by: Ingo Molnar diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index 957b22f..8179692 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -1231,6 +1231,7 @@ something like this simple program: #include #include #include +#include #define _STR(x) #x #define STR(x) _STR(x) @@ -1265,6 +1266,7 @@ const char *find_debugfs(void) return NULL; } + strcat(debugfs, "/tracing/"); debugfs_found = 1; return debugfs; diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index d4ff019..217f699 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2681,7 +2681,7 @@ unsigned long ring_buffer_entries(struct ring_buffer *buffer) EXPORT_SYMBOL_GPL(ring_buffer_entries); /** - * ring_buffer_overrun_cpu - get the number of overruns in buffer + * ring_buffer_overruns - get the number of overruns in buffer * @buffer: The ring buffer * * Returns the total number of overruns in the ring buffer -- cgit v0.10.2 From 6d3f1e12f46a2f9a1bb7e7aa433df8dd31ce5647 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Fri, 23 Oct 2009 19:36:19 -0400 Subject: tracing: Remove cpu arg from the rb_time_stamp() function The cpu argument is not used inside the rb_time_stamp() function. Plus fix a typo. Signed-off-by: Jiri Olsa Signed-off-by: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <20091023233647.118547500@goodmis.org> Signed-off-by: Ingo Molnar diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h index c134dd1..09077f6 100644 --- a/include/linux/trace_seq.h +++ b/include/linux/trace_seq.h @@ -7,7 +7,7 @@ /* * Trace sequences are used to allow a function to call several other functions - * to create a string of data to use (up to a max of PAGE_SIZE. + * to create a string of data to use (up to a max of PAGE_SIZE). */ struct trace_seq { diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 217f699..3ffa502 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -483,7 +483,7 @@ struct ring_buffer_iter { /* Up this if you want to test the TIME_EXTENTS and normalization */ #define DEBUG_SHIFT 0 -static inline u64 rb_time_stamp(struct ring_buffer *buffer, int cpu) +static inline u64 rb_time_stamp(struct ring_buffer *buffer) { /* shift to debug/test normalization and TIME_EXTENTS */ return buffer->clock() << DEBUG_SHIFT; @@ -494,7 +494,7 @@ u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu) u64 time; preempt_disable_notrace(); - time = rb_time_stamp(buffer, cpu); + time = rb_time_stamp(buffer); preempt_enable_no_resched_notrace(); return time; @@ -599,7 +599,7 @@ static struct list_head *rb_list_head(struct list_head *list) } /* - * rb_is_head_page - test if the give page is the head page + * rb_is_head_page - test if the given page is the head page * * Because the reader may move the head_page pointer, we can * not trust what the head page is (it may be pointing to @@ -1868,7 +1868,7 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer, * Nested commits always have zero deltas, so * just reread the time stamp */ - *ts = rb_time_stamp(buffer, cpu_buffer->cpu); + *ts = rb_time_stamp(buffer); next_page->page->time_stamp = *ts; } @@ -2111,7 +2111,7 @@ rb_reserve_next_event(struct ring_buffer *buffer, if (RB_WARN_ON(cpu_buffer, ++nr_loops > 1000)) goto out_fail; - ts = rb_time_stamp(cpu_buffer->buffer, cpu_buffer->cpu); + ts = rb_time_stamp(cpu_buffer->buffer); /* * Only the first commit can update the timestamp. -- cgit v0.10.2