| Message ID | 20190814084712.28188-9-tz.stoyanov@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Steven Rostedt |
| Headers | show |
| Series | Separate trace-cmd and libtracecmd code | expand |
On Wed, 14 Aug 2019 11:47:08 +0300 "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote: > tracecmd_stack_tracer_status() function reads the stack tracer status > from the proc file system. It does not depend on trace-cmd context and > can be used standalone. The function is moved from trace-cmd application > into libtracecmd. > > Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> > --- > lib/trace-cmd/trace-util.c | 49 +++++++++++++++++++++++++++++++++ > tracecmd/trace-stack.c | 56 ++------------------------------------ > 2 files changed, 51 insertions(+), 54 deletions(-) > > diff --git a/lib/trace-cmd/trace-util.c b/lib/trace-cmd/trace-util.c > index 8c1a0a0..d16a018 100644 > --- a/lib/trace-cmd/trace-util.c > +++ b/lib/trace-cmd/trace-util.c > @@ -25,6 +25,7 @@ > #define LOCAL_PLUGIN_DIR ".trace-cmd/plugins" > #define TRACEFS_PATH "/sys/kernel/tracing" > #define DEBUGFS_PATH "/sys/kernel/debug" > +#define PROC_STACK_FILE "/proc/sys/kernel/stack_tracer_enabled" > > int tracecmd_disable_sys_plugins; > int tracecmd_disable_plugins; > @@ -1787,3 +1788,51 @@ int trace_set_log_file(char *logfile) > return 0; > } > > +/** > + * tracecmd_stack_tracer_status - Check stack trace status > + * @status: Returned stack trace status: > + * 0 - not configured, disabled > + * non 0 - enabled > + * > + * Returns -1 in case of an error, 0 if file does not exist > + * (stack tracer not enabled) or 1 on successful completion. "(stack tracer not configured in kernel)" Saying "enabled" is ambiguous. > + */ > +int tracecmd_stack_tracer_status(int *status) If we are making this a library function, shouldn't it be declared in the trace-cmd.h file? -- Steve
Hi Steven, On Wed, Aug 28, 2019 at 11:21 PM Steven Rostedt <rostedt@goodmis.org> wrote: > ... > > +/** > > + * tracecmd_stack_tracer_status - Check stack trace status > > + * @status: Returned stack trace status: > > + * 0 - not configured, disabled > > + * non 0 - enabled > > + * > > + * Returns -1 in case of an error, 0 if file does not exist > > + * (stack tracer not enabled) or 1 on successful completion. > > "(stack tracer not configured in kernel)" > > Saying "enabled" is ambiguous. > > > + */ > > +int tracecmd_stack_tracer_status(int *status) > > If we are making this a library function, shouldn't it be declared in > the trace-cmd.h file? > It is already part of trace-cmd.h, that was one of the problems - it was defined as library API, but implemented in the trace-cmd application. This patch moves the implementation in the library, the declaration in trace-cmd.h remains the same. > -- Steve
diff --git a/lib/trace-cmd/trace-util.c b/lib/trace-cmd/trace-util.c index 8c1a0a0..d16a018 100644 --- a/lib/trace-cmd/trace-util.c +++ b/lib/trace-cmd/trace-util.c @@ -25,6 +25,7 @@ #define LOCAL_PLUGIN_DIR ".trace-cmd/plugins" #define TRACEFS_PATH "/sys/kernel/tracing" #define DEBUGFS_PATH "/sys/kernel/debug" +#define PROC_STACK_FILE "/proc/sys/kernel/stack_tracer_enabled" int tracecmd_disable_sys_plugins; int tracecmd_disable_plugins; @@ -1787,3 +1788,51 @@ int trace_set_log_file(char *logfile) return 0; } +/** + * tracecmd_stack_tracer_status - Check stack trace status + * @status: Returned stack trace status: + * 0 - not configured, disabled + * non 0 - enabled + * + * Returns -1 in case of an error, 0 if file does not exist + * (stack tracer not enabled) or 1 on successful completion. + */ +int tracecmd_stack_tracer_status(int *status) +{ + struct stat stat_buf; + char buf[64]; + long num; + int fd; + int n; + + if (stat(PROC_STACK_FILE, &stat_buf) < 0) { + /* stack tracer not configured on running kernel */ + *status = 0; /* not configured means disabled */ + return 0; + } + + fd = open(PROC_STACK_FILE, O_RDONLY); + + if (fd < 0) + return -1; + + n = read(fd, buf, sizeof(buf)); + close(fd); + + if (n <= 0) + return -1; + + if (n >= sizeof(buf)) + return -1; + + buf[n] = 0; + errno = 0; + num = strtol(buf, NULL, 10); + + /* Check for various possible errors */ + if (num > INT_MAX || num < INT_MIN || (!num && errno)) + return -1; + + *status = num; + return 1; /* full success */ +} diff --git a/tracecmd/trace-stack.c b/tracecmd/trace-stack.c index 34b3b58..bb002c0 100644 --- a/tracecmd/trace-stack.c +++ b/tracecmd/trace-stack.c @@ -36,58 +36,6 @@ static void test_available(void) die("stack tracer not configured on running kernel"); } -/* - * Returns: - * -1 - Something went wrong - * 0 - File does not exist (stack tracer not enabled) - * 1 - Success - */ -static int read_proc(int *status) -{ - struct stat stat_buf; - char buf[64]; - long num; - int fd; - int n; - - if (stat(PROC_FILE, &stat_buf) < 0) { - /* stack tracer not configured on running kernel */ - *status = 0; /* not configured means disabled */ - return 0; - } - - fd = open(PROC_FILE, O_RDONLY); - - if (fd < 0) - return -1; - - n = read(fd, buf, sizeof(buf)); - close(fd); - - if (n <= 0) - return -1; - - if (n >= sizeof(buf)) - return -1; - - buf[n] = 0; - errno = 0; - num = strtol(buf, NULL, 10); - - /* Check for various possible errors */ - if (num > INT_MAX || num < INT_MIN || (!num && errno)) - return -1; - - *status = num; - return 1; /* full success */ -} - -/* Public wrapper of read_proc() */ -int tracecmd_stack_tracer_status(int *status) -{ - return read_proc(status); -} - /* NOTE: this implementation only accepts new_status in the range [0..9]. */ static void change_stack_tracer_status(unsigned new_status) { @@ -102,7 +50,7 @@ static void change_stack_tracer_status(unsigned new_status) return; } - ret = read_proc(&status); + ret = tracecmd_stack_tracer_status(&status); if (ret < 0) die("error reading %s", PROC_FILE); @@ -160,7 +108,7 @@ static void read_trace(void) size_t n; int r; - if (read_proc(&status) <= 0) + if (tracecmd_stack_tracer_status(&status) <= 0) die("Invalid stack tracer state"); if (status > 0)
tracecmd_stack_tracer_status() function reads the stack tracer status from the proc file system. It does not depend on trace-cmd context and can be used standalone. The function is moved from trace-cmd application into libtracecmd. Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> --- lib/trace-cmd/trace-util.c | 49 +++++++++++++++++++++++++++++++++ tracecmd/trace-stack.c | 56 ++------------------------------------ 2 files changed, 51 insertions(+), 54 deletions(-)