Yonghong Song
f371b304f1
bpf/tracing: allow user space to query prog array on the same tp
...
Commit e87c6bc385 ("bpf: permit multiple bpf attachments
for a single perf event") added support to attach multiple
bpf programs to a single perf event.
Although this provides flexibility, users may want to know
what other bpf programs attached to the same tp interface.
Besides getting visibility for the underlying bpf system,
such information may also help consolidate multiple bpf programs,
understand potential performance issues due to a large array,
and debug (e.g., one bpf program which overwrites return code
may impact subsequent program results).
Commit 2541517c32 ("tracing, perf: Implement BPF programs
attached to kprobes") utilized the existing perf ioctl
interface and added the command PERF_EVENT_IOC_SET_BPF
to attach a bpf program to a tracepoint. This patch adds a new
ioctl command, given a perf event fd, to query the bpf program
array attached to the same perf tracepoint event.
The new uapi ioctl command:
PERF_EVENT_IOC_QUERY_BPF
The new uapi/linux/perf_event.h structure:
struct perf_event_query_bpf {
__u32 ids_len;
__u32 prog_cnt;
__u32 ids[0];
};
User space provides buffer "ids" for kernel to copy to.
When returning from the kernel, the number of available
programs in the array is set in "prog_cnt".
The usage:
struct perf_event_query_bpf *query =
malloc(sizeof(*query) + sizeof(u32) * ids_len);
query.ids_len = ids_len;
err = ioctl(pmu_efd, PERF_EVENT_IOC_QUERY_BPF, query);
if (err == 0) {
/* query.prog_cnt is the number of available progs,
* number of progs in ids: (ids_len == 0) ? 0 : query.prog_cnt
*/
} else if (errno == ENOSPC) {
/* query.ids_len number of progs copied,
* query.prog_cnt is the number of available progs
*/
} else {
/* other errors */
}
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12 08:46:40 -08:00
..
bpf
bpf/tracing: allow user space to query prog array on the same tp
2017-12-12 08:46:40 -08:00
cgroup
Merge branch 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2017-11-15 14:29:44 -08:00
configs
debug
events
bpf/tracing: allow user space to query prog array on the same tp
2017-12-12 08:46:40 -08:00
gcov
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
irq
Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2017-11-26 14:39:20 -08:00
livepatch
Merge branch 'for-linus' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
2017-11-15 10:21:58 -08:00
locking
kmemcheck: remove annotations
2017-11-15 18:21:04 -08:00
power
mm: remove __GFP_COLD
2017-11-15 18:21:06 -08:00
printk
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
2017-11-21 05:28:13 -10:00
rcu
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2017-11-13 17:56:58 -08:00
sched
Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2017-11-17 11:54:55 -08:00
time
- final batch of "non trivial" timer conversions (multi-tree dependencies,
2017-11-23 16:29:05 +01:00
trace
bpf/tracing: allow user space to query prog array on the same tp
2017-12-12 08:46:40 -08:00
.gitignore
acct.c
Merge branch 'linus' into locking/core, to resolve conflicts
2017-11-07 10:32:44 +01:00
async.c
audit.c
Audit: remove unused audit_log_secctx function
2017-11-10 16:08:47 -05:00
audit.h
audit/stable-4.15 PR 20171113
2017-11-15 13:28:48 -08:00
audit_fsnotify.c
audit_tree.c
Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
2017-11-14 14:08:20 -08:00
audit_watch.c
auditfilter.c
audit: filter PATH records keyed on filesystem magic
2017-11-10 16:08:56 -05:00
auditsc.c
audit/stable-4.15 PR 20171113
2017-11-15 13:28:48 -08:00
backtracetest.c
bounds.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
capability.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
compat.c
sched_rr_get_interval(): move compat to native, get rid of set_fs()
2017-09-20 00:30:57 -04:00
configs.c
context_tracking.c
cpu.c
cpu/hotplug: Reset node state after operation
2017-10-21 16:11:30 +02:00
cpu_pm.c
crash_core.c
kdump: print a message in case parse_crashkernel_mem resulted in zero bytes
2017-11-17 16:10:03 -08:00
crash_dump.c
cred.c
delayacct.c
dma.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
elfcore.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
exec_domain.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
exit.c
locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE()
2017-10-25 11:01:08 +02:00
extable.c
kprobes, x86/alternatives: Use text_mutex to protect smp_alt_modules
2017-11-07 12:20:09 +01:00
fork.c
pid: remove pidhash
2017-11-17 16:10:04 -08:00
freezer.c
futex.c
Merge branch 'linus' into core/urgent, to pick up dependent commits
2017-11-04 08:53:04 +01:00
futex_compat.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
groups.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
hung_task.c
irq_work.c
Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2017-11-13 17:33:11 -08:00
jump_label.c
jump_label: Invoke jump_label_test() via early_initcall()
2017-11-14 08:41:41 +01:00
kallsyms.c
kallsyms: take advantage of the new '%px' format
2017-11-29 10:30:13 -08:00
kcmp.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c
kcov: support comparison operands collection
2017-11-17 16:10:04 -08:00
kexec.c
kexec_core.c
kexec_file.c
resource: Provide resource struct in resource walk callback
2017-11-07 15:35:57 +01:00
kexec_internal.h
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
kmod.c
kmod: move #ifdef CONFIG_MODULES wrapper to Makefile
2017-09-08 18:26:51 -07:00
kprobes.c
kprobes: Disable the jprobes APIs
2017-10-20 11:02:29 +02:00
ksysfs.c
kthread.c
treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE casts
2017-11-21 16:35:54 -08:00
latencytop.c
Makefile
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
memremap.c
memremap: add scheduling point to devm_memremap_pages
2017-10-03 17:54:25 -07:00
module-internal.h
module.c
kallsyms: take advantage of the new '%px' format
2017-11-29 10:30:13 -08:00
module_signing.c
notifier.c
nsproxy.c
padata.c
treewide: setup_timer() -> timer_setup()
2017-11-21 15:57:07 -08:00
panic.c
kernel/panic.c: add TAINT_AUX
2017-11-17 16:10:04 -08:00
params.c
kernel/params.c: improve STANDARD_PARAM_DEF readability
2017-10-03 17:54:26 -07:00
pid.c
pid: remove pidhash
2017-11-17 16:10:04 -08:00
pid_namespace.c
pid: remove pidhash
2017-11-17 16:10:04 -08:00
profile.c
ptrace.c
range.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
reboot.c
kernel/reboot.c: add devm_register_reboot_notifier()
2017-11-17 16:10:04 -08:00
relay.c
resource.c
x86/mm, resource: Use PAGE_KERNEL protection for ioremap of memory pages
2017-11-07 15:35:58 +01:00
seccomp.c
Merge branch 'linus' into locking/core, to resolve conflicts
2017-11-07 10:32:44 +01:00
signal.c
Merge branch 'akpm' (patches from Andrew)
2017-11-17 16:56:17 -08:00
smp.c
smp/core: Use lockdep to assert IRQs are disabled/enabled
2017-11-08 11:13:50 +01:00
smpboot.c
watchdog/core, powerpc: Lock cpus across reconfiguration
2017-10-04 10:53:54 +02:00
smpboot.h
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
softirq.c
kmemcheck: rip it out
2017-11-15 18:21:05 -08:00
stacktrace.c
stop_machine.c
sys.c
arm64 updates for 4.15
2017-11-15 10:56:56 -08:00
sys_ni.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
sysctl.c
kernel/sysctl.c: code cleanups
2017-11-17 16:10:03 -08:00
sysctl_binary.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
task_work.c
Merge branch 'linus' into locking/core, to resolve conflicts
2017-11-07 10:32:44 +01:00
taskstats.c
test_kprobes.c
kprobes: Disable the jprobes test code
2017-10-20 11:02:54 +02:00
torture.c
tracepoint.c
tsacct.c
ucount.c
uid16.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
umh.c
kernel/umh.c: optimize 'proc_cap_handler()'
2017-11-17 16:10:01 -08:00
up.c
user-return-notifier.c
user.c
userns: use union in {g,u}idmap struct
2017-10-31 17:22:58 -05:00
user_namespace.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
2017-11-16 12:20:15 -08:00
utsname.c
utsname_sysctl.c
watchdog.c
Merge branch 'linus' into sched/core, to pick up fixes
2017-11-08 10:17:15 +01:00
watchdog_hld.c
Merge branch 'linus' into core/urgent, to pick up dependent commits
2017-11-04 08:53:04 +01:00
workqueue.c
treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE casts
2017-11-21 16:35:54 -08:00
workqueue_internal.h
Merge branch 'for-4.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
2017-11-06 12:26:49 -08:00