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author | Vaibhav Nagarnaik <vnagarnaik@google.com> | 2014-02-13 19:51:48 -0800 |
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committer | Steven Rostedt <rostedt@goodmis.org> | 2014-03-20 13:21:05 -0400 |
commit | 87291347c49dc40aa339f587b209618201c2e527 (patch) | |
tree | 2681b2e84bb9d67cd20f85b0efa62397027b7994 /include/linux/ftrace_event.h | |
parent | dcb99fd9b08cfe1afe426af4d8d3cbc429190f15 (diff) | |
download | linux-stable-87291347c49dc40aa339f587b209618201c2e527.tar.gz linux-stable-87291347c49dc40aa339f587b209618201c2e527.tar.bz2 linux-stable-87291347c49dc40aa339f587b209618201c2e527.zip |
tracing: Fix array size mismatch in format string
In event format strings, the array size is reported in two locations.
One in array subscript and then via the "size:" attribute. The values
reported there have a mismatch.
For e.g., in sched:sched_switch the prev_comm and next_comm character
arrays have subscript values as [32] where as the actual field size is
16.
name: sched_switch
ID: 301
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1;signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:char prev_comm[32]; offset:8; size:16; signed:1;
field:pid_t prev_pid; offset:24; size:4; signed:1;
field:int prev_prio; offset:28; size:4; signed:1;
field:long prev_state; offset:32; size:8; signed:1;
field:char next_comm[32]; offset:40; size:16; signed:1;
field:pid_t next_pid; offset:56; size:4; signed:1;
field:int next_prio; offset:60; size:4; signed:1;
After bisection, the following commit was blamed:
92edca0 tracing: Use direct field, type and system names
This commit removes the duplication of strings for field->name and
field->type assuming that all the strings passed in
__trace_define_field() are immutable. This is not true for arrays, where
the type string is created in event_storage variable and field->type for
all array fields points to event_storage.
Use __stringify() to create a string constant for the type string.
Also, get rid of event_storage and event_storage_mutex that are not
needed anymore.
also, an added benefit is that this reduces the overhead of events a bit more:
text data bss dec hex filename
8424787 2036472 1302528 11763787 b3804b vmlinux
8420814 2036408 1302528 11759750 b37086 vmlinux.patched
Link: http://lkml.kernel.org/r/1392349908-29685-1-git-send-email-vnagarnaik@google.com
Cc: Laurent Chavey <chavey@google.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include/linux/ftrace_event.h')
-rw-r--r-- | include/linux/ftrace_event.h | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index 4e4cc28623ad..4cdb3a17bcb5 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -495,10 +495,6 @@ enum { FILTER_TRACE_FN, }; -#define EVENT_STORAGE_SIZE 128 -extern struct mutex event_storage_mutex; -extern char event_storage[EVENT_STORAGE_SIZE]; - extern int trace_event_raw_init(struct ftrace_event_call *call); extern int trace_define_field(struct ftrace_event_call *call, const char *type, const char *name, int offset, int size, |