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authorArnaldo Carvalho de Melo <acme@redhat.com>2018-11-06 15:23:40 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2018-11-21 12:00:31 -0300
commit55f127b43143363d000165c7cb72e4b95de1380d (patch)
treedf0387f70dfc0153b74dd1b7f07d44500f3e314c /tools/perf/examples
parent1475d35c4a6174d4ec633b9af5713e9770b3ac0d (diff)
perf augmented_syscalls: Filter on a hard coded pid
Just to show where we'll hook pid based filters, and what we use to obtain the current pid, using a BPF getpid() equivalent. Now we need to remove that hardcoded PID with a BPF hash map, so that we start by filtering 'perf trace's own PID, implement the --filter-pid functionality, etc. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: https://lkml.kernel.org/n/tip-oshrcgcekiyhd0whwisxfvtv@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/examples')
-rw-r--r--tools/perf/examples/bpf/augmented_raw_syscalls.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/tools/perf/examples/bpf/augmented_raw_syscalls.c b/tools/perf/examples/bpf/augmented_raw_syscalls.c
index 90a19336310b..2feb00018f79 100644
--- a/tools/perf/examples/bpf/augmented_raw_syscalls.c
+++ b/tools/perf/examples/bpf/augmented_raw_syscalls.c
@@ -15,6 +15,7 @@
*/
#include <stdio.h>
+#include <unistd.h>
#include <linux/socket.h>
/* bpf-output associated map */
@@ -56,6 +57,9 @@ int sys_enter(struct syscall_enter_args *args)
unsigned int len = sizeof(augmented_args);
const void *filename_arg = NULL;
+ if (getpid() == 2971)
+ return 0;
+
probe_read(&augmented_args.args, sizeof(augmented_args.args), args);
/*
* Yonghong and Edward Cree sayz:
@@ -125,7 +129,7 @@ int sys_enter(struct syscall_enter_args *args)
SEC("raw_syscalls:sys_exit")
int sys_exit(struct syscall_exit_args *args)
{
- return 1; /* 0 as soon as we start copying data returned by the kernel, e.g. 'read' */
+ return getpid() != 2971;
}
license(GPL);