Re: [RFC PATCH] arm64: perf test: Improbe bp_signal

From: Jiri Olsa
Date: Tue Jan 05 2016 - 04:00:39 EST


On Tue, Jan 05, 2016 at 04:58:00AM +0000, Wang Nan wrote:

SNIP

> + * - SIGUSR1 is delivered -> overflows_2 == 1 (nested signal)
> + * - sig_handler_2 return
> + * - sig_handler return
> + * - fd3 event watchpoint hit -> count3 == 1 (wp and bp in one insn)
> + * - SIGIO is delivered -> overflows == 2
> + * - fd2 event breakpoint hit -> count2 == 2
> + * - SIGUSR1 is delivered -> overflows_2 == 2
> + * - sig_handler_2 return
> + * - sig_handler return
> + * - fd3 event watchpoint hit -> count3 == 2 (standalone wp)
> + * - SIGIO is delivered -> overflows = 3
> + * - fd2 event breakpoint hit -> count2 == 3
> + * - SIGUSR1 is delivered -> overflows_2 == 3
> + * - sig_handler_2 return
> + * - sig_handler return
> *
> * The test case check following error conditions:
> * - we get stuck in signal handler because of debug
> @@ -152,11 +229,13 @@ int test__bp_signal(int subtest __maybe_unused)
> *
> */
>
> - fd1 = bp_event(test_function, 1);
> - fd2 = bp_event(sig_handler, 0);
> + fd1 = bp_event(__test_function, 1);
> + fd2 = __xp_event(true, sig_handler, 1, SIGUSR1);
> + fd3 = wp_event((void *)&the_var, 1);
>

spent some time to figure this out.. would attached change be more readable?

thanks,
jirka


---
diff --git a/tools/perf/tests/bp_signal.c b/tools/perf/tests/bp_signal.c
index 0bc4f76c22ca..e5349616ac3f 100644
--- a/tools/perf/tests/bp_signal.c
+++ b/tools/perf/tests/bp_signal.c
@@ -99,7 +99,7 @@ static void sig_handler(int signum __maybe_unused,
}
}

-static int __xp_event(bool is_bp, void *addr, int setup_signal, int signal)
+static int __event(bool is_x, void *addr, int signal)
{
struct perf_event_attr pe;
int fd;
@@ -109,7 +109,7 @@ static int __xp_event(bool is_bp, void *addr, int setup_signal, int signal)
pe.size = sizeof(struct perf_event_attr);

pe.config = 0;
- pe.bp_type = is_bp ? HW_BREAKPOINT_X : HW_BREAKPOINT_W;
+ pe.bp_type = is_x ? HW_BREAKPOINT_X : HW_BREAKPOINT_W;
pe.bp_addr = (unsigned long) addr;
pe.bp_len = sizeof(long);

@@ -128,25 +128,23 @@ static int __xp_event(bool is_bp, void *addr, int setup_signal, int signal)
return TEST_FAIL;
}

- if (setup_signal) {
- fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
- fcntl(fd, F_SETSIG, signal);
- fcntl(fd, F_SETOWN, getpid());
- }
+ fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
+ fcntl(fd, F_SETSIG, signal);
+ fcntl(fd, F_SETOWN, getpid());

ioctl(fd, PERF_EVENT_IOC_RESET, 0);

return fd;
}

-static int bp_event(void *addr, int setup_signal)
+static int bp_event(void *addr, int signal)
{
- return __xp_event(true, addr, setup_signal, SIGIO);
+ return __event(true, addr, signal);
}

-static int wp_event(void *addr, int setup_signal)
+static int wp_event(void *addr, int signal)
{
- return __xp_event(false, addr, setup_signal, SIGIO);
+ return __event(false, addr, signal);
}

static long long bp_count(int fd)
@@ -229,9 +227,9 @@ int test__bp_signal(int subtest __maybe_unused)
*
*/

- fd1 = bp_event(__test_function, 1);
- fd2 = __xp_event(true, sig_handler, 1, SIGUSR1);
- fd3 = wp_event((void *)&the_var, 1);
+ fd1 = bp_event(__test_function, SIGIO);
+ fd2 = bp_event(sig_handler, SIGUSR1);
+ fd3 = wp_event((void *)&the_var, SIGIO);

ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0);
ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0);
--
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