leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

perf augmented_syscalls: Use pid_filter

Browse Source 
Just to test filtering a bunch of pids, now its time to go and get that
hooked up in 'perf trace', right after we load the bpf program, if we
find a "pids_filtered" map defined, we'll populate it with the filtered
pids.

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-1i9s27wqqdhafk3fappow84x@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo
2018-11-06 16:09:06 -03:00
parent 77ecb64050
commit ed9a77ba77
1 changed files with 32 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
tools/perf/examples/bpf/augmented_raw_syscalls.c
View File

@@ -16,6 +16,7 @@
#include <stdio.h> #include <stdio.h>
#include <unistd.h> #include <unistd.h>
#include <pid_filter.h>
/* bpf-output associated map */ /* bpf-output associated map */
struct bpf_map SEC("maps") __augmented_syscalls__ = { struct bpf_map SEC("maps") __augmented_syscalls__ = {
@@ -48,6 +49,29 @@ struct augmented_filename {
#define SYS_POLL 7 #define SYS_POLL 7
#define SYS_OPENAT 257 #define SYS_OPENAT 257
pid_filter(pids_filtered);
static void pid_filter__init(void)
{
/*
* Filter a bunch of pids: gnome-shell, kvm, firefox threads,
* avahi-daemon, etc, just for testing as we go along.
*
* These will come from 'perf trace --filter-pids' in a explicit way
* and also it will filter out itself, to avoid the feedback loop:
* syscalls 'perf trace' does gets caught, reported, causing new
* syscalls to get emitted, rinse repeat forever.
*/
if (pid_filter__add(&pids_filtered, 2971))
return; /* pid_filter__init() was already called, bail out */
pid_filter__add(&pids_filtered, 20016);
pid_filter__add(&pids_filtered, 12018);
pid_filter__add(&pids_filtered, 2310);
pid_filter__add(&pids_filtered, 3759);
pid_filter__add(&pids_filtered, 25978);
pid_filter__add(&pids_filtered, 883);
}
SEC("raw_syscalls:sys_enter") SEC("raw_syscalls:sys_enter")
int sys_enter(struct syscall_enter_args *args) int sys_enter(struct syscall_enter_args *args)
{ {
@@ -57,8 +81,14 @@ int sys_enter(struct syscall_enter_args *args)
} augmented_args; } augmented_args;
unsigned int len = sizeof(augmented_args); unsigned int len = sizeof(augmented_args);
const void *filename_arg = NULL; const void *filename_arg = NULL;
/*
* We still don't have a "main()" called first and only once
* call it always, it will exit as soon as it realizes the
* first hard coded filtered pid was already added.
*/
pid_filter__init();
if (getpid() == 2971) if (pid_filter__has(&pids_filtered, getpid()))
return 0; return 0;
probe_read(&augmented_args.args, sizeof(augmented_args.args), args); probe_read(&augmented_args.args, sizeof(augmented_args.args), args);
@@ -132,7 +162,7 @@ int sys_enter(struct syscall_enter_args *args)
SEC("raw_syscalls:sys_exit") SEC("raw_syscalls:sys_exit")
int sys_exit(struct syscall_exit_args *args) int sys_exit(struct syscall_exit_args *args)
{ {
return getpid() != 2971; return !pid_filter__has(&pids_filtered, getpid());
} }
license(GPL); license(GPL);