linux-kernel - [PATCH] Enable the enable_on_exec flag if record forks the target

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Wed,  3 Mar 2010 22:06:27 +0000
From:	Eric B Munson <ebmunson@...ibm.com>
To:	a.p.zijlstra@...llo.nl
Cc:	paulus@...ba.org, mingo@...e.hu, acme@...hat.com,
	linux-kernel@...r.kernel.org, Eric B Munson <ebmunson@...ibm.com>
Subject: [PATCH] Enable the enable_on_exec flag if record forks the target

When forking its target, perf record can capture data from before the target
application is started.  Perf stat uses the enable_on_exec flag in the event
attributes to keep from displaying events from before the target program
starts, this patch adds the same functionality to perf record when it is will
fork the target process.

Signed-off-by: Eric B Munson <ebmunson@...ibm.com>
---
 tools/perf/builtin-record.c |   13 ++++++++-----
 1 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 771533c..625076e 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -224,7 +224,7 @@ static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int n
 	return h_attr;
 }
 
-static void create_counter(int counter, int cpu, pid_t pid)
+static void create_counter(int counter, int cpu, pid_t pid, bool forks)
 {
 	char *filter = filters[counter];
 	struct perf_event_attr *attr = attrs + counter;
@@ -273,6 +273,9 @@ static void create_counter(int counter, int cpu, pid_t pid)
 	attr->inherit		= inherit;
 	attr->disabled		= 1;
 
+	if (forks)
+		attr->enable_on_exec = 1;
+
 try_again:
 	fd[nr_cpu][counter] = sys_perf_event_open(attr, pid, cpu, group_fd, 0);
 
@@ -376,13 +379,13 @@ try_again:
 	ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_ENABLE);
 }
 
-static void open_counters(int cpu, pid_t pid)
+static void open_counters(int cpu, pid_t pid, bool forks)
 {
 	int counter;
 
 	group_fd = -1;
 	for (counter = 0; counter < nr_counters; counter++)
-		create_counter(counter, cpu, pid);
+		create_counter(counter, cpu, pid, forks);
 
 	nr_cpu++;
 }
@@ -542,10 +545,10 @@ static int __cmd_record(int argc, const char **argv)
 
 
 	if ((!system_wide && !inherit) || profile_cpu != -1) {
-		open_counters(profile_cpu, target_pid);
+		open_counters(profile_cpu, target_pid, forks);
 	} else {
 		for (i = 0; i < nr_cpus; i++)
-			open_counters(i, target_pid);
+			open_counters(i, target_pid, forks);
 	}
 
 	if (file_new) {
-- 
1.6.3.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/