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authorKaixu Xia <xiakaixu@huawei.com>2015-08-12 09:37:53 +0000
committerDavid S. Miller <davem@davemloft.net>2015-08-12 16:39:12 -0700
commit5ed3ccbd5ac11414d61c16182718e68868becc16 (patch)
treedf41b5ddd7767528d1a26b204dca9586c9008524 /samples
parent47b344b27a003fcdaccbdc07b3d558a7ccdfec04 (diff)
downloadleg-kernel-5ed3ccbd5ac11414d61c16182718e68868becc16.tar.gz
bpf: fix build warnings and add function read_trace_pipe()
There are two improvements in this patch: 1. Fix the build warnings; 2. Add function read_trace_pipe() to print the result on the screen; Before this patch, we can get the result through /sys/kernel/de bug/tracing/trace_pipe and get nothing on the screen. By applying this patch, the result can be printed on the screen. $ ./tracex6 ... tracex6-705 [003] d..1 131.428593: : CPU-3 19981414 sshd-683 [000] d..1 131.428727: : CPU-0 221682321 sshd-683 [000] d..1 131.428821: : CPU-0 221808766 sshd-683 [000] d..1 131.428950: : CPU-0 221982984 sshd-683 [000] d..1 131.429045: : CPU-0 222111851 tracex6-705 [003] d..1 131.429168: : CPU-3 20757551 sshd-683 [000] d..1 131.429170: : CPU-0 222281240 sshd-683 [000] d..1 131.429261: : CPU-0 222403340 sshd-683 [000] d..1 131.429378: : CPU-0 222561024 ... Signed-off-by: Kaixu Xia <xiakaixu@huawei.com> Acked-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'samples')
-rw-r--r--samples/bpf/tracex6_kern.c1
-rw-r--r--samples/bpf/tracex6_user.c22
2 files changed, 14 insertions, 9 deletions
diff --git a/samples/bpf/tracex6_kern.c b/samples/bpf/tracex6_kern.c
index 23d1cffaf249..be479c4af9e2 100644
--- a/samples/bpf/tracex6_kern.c
+++ b/samples/bpf/tracex6_kern.c
@@ -1,3 +1,4 @@
+#include <linux/ptrace.h>
#include <linux/version.h>
#include <uapi/linux/bpf.h>
#include "bpf_helpers.h"
diff --git a/samples/bpf/tracex6_user.c b/samples/bpf/tracex6_user.c
index 928f05eaa304..8ea4976cfcf1 100644
--- a/samples/bpf/tracex6_user.c
+++ b/samples/bpf/tracex6_user.c
@@ -17,8 +17,7 @@ static void test_bpf_perf_event(void)
{
int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
int *pmu_fd = malloc(nr_cpus * sizeof(int));
- unsigned long value;
- int i;
+ int status, i;
struct perf_event_attr attr_insn_pmu = {
.freq = 0,
@@ -32,22 +31,26 @@ static void test_bpf_perf_event(void)
for (i = 0; i < nr_cpus; i++) {
pmu_fd[i] = perf_event_open(&attr_insn_pmu, -1/*pid*/, i/*cpu*/, -1/*group_fd*/, 0);
- if (pmu_fd[i] < 0)
+ if (pmu_fd[i] < 0) {
printf("event syscall failed\n");
+ goto exit;
+ }
bpf_update_elem(map_fd[0], &i, &pmu_fd[i], BPF_ANY);
ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0);
}
- system("ls");
- system("pwd");
- system("sleep 2");
+ status = system("ls > /dev/null");
+ if (status)
+ goto exit;
+ status = system("sleep 2");
+ if (status)
+ goto exit;
+exit:
for (i = 0; i < nr_cpus; i++)
close(pmu_fd[i]);
-
- close(map_fd);
-
+ close(map_fd[0]);
free(pmu_fd);
}
@@ -63,6 +66,7 @@ int main(int argc, char **argv)
}
test_bpf_perf_event();
+ read_trace_pipe();
return 0;
}