TencentOS-kernel/kernel
Yonghong Song dfaec15bb0 bpf: Add bpf_for_each_map_elem() helper
[upstream commit 69c087ba6225b574afb6e505b72cb75242a3d844]

The bpf_for_each_map_elem() helper is introduced which
iterates all map elements with a callback function. The
helper signature looks like
  long bpf_for_each_map_elem(map, callback_fn, callback_ctx, flags)
and for each map element, the callback_fn will be called. For example,
like hashmap, the callback signature may look like
  long callback_fn(map, key, val, callback_ctx)

There are two known use cases for this. One is from upstream ([1]) where
a for_each_map_elem helper may help implement a timeout mechanism
in a more generic way. Another is from our internal discussion
for a firewall use case where a map contains all the rules. The packet
data can be compared to all these rules to decide allow or deny
the packet.

For array maps, users can already use a bounded loop to traverse
elements. Using this helper can avoid using bounded loop. For other
type of maps (e.g., hash maps) where bounded loop is hard or
impossible to use, this helper provides a convenient way to
operate on all elements.

For callback_fn, besides map and map element, a callback_ctx,
allocated on caller stack, is also passed to the callback
function. This callback_ctx argument can provide additional
input and allow to write to caller stack for output.

If the callback_fn returns 0, the helper will iterate through next
element if available. If the callback_fn returns 1, the helper
will stop iterating and returns to the bpf program. Other return
values are not used for now.

Currently, this helper is only available with jit. It is possible
to make it work with interpreter with so effort but I leave it
as the future work.

[1]: https://lore.kernel.org/bpf/20210122205415.113822-1-xiyou.wangcong@gmail.com/

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210226204925.3884923-1-yhs@fb.com
2022-06-21 10:27:16 +08:00
..
bpf bpf: Add bpf_for_each_map_elem() helper 2022-06-21 10:27:16 +08:00
cgroup bpf: Refactor bpf_link update handling 2022-06-21 10:27:09 +08:00
configs Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
debug kdb: Make memory allocations more robust 2021-04-12 12:52:10 +08:00
dma swiotlb: fix "x86: Don't panic if can not alloc buffer for swiotlb" 2021-03-16 16:40:57 +08:00
events perf: Expose get/put_callchain_entry() 2022-06-21 10:27:13 +08:00
gcov gcov: re-fix clang-11+ support 2021-05-20 16:06:55 +08:00
irq genirq/matrix: Prevent allocation counter corruption 2021-05-20 16:07:24 +08:00
livepatch Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
locking locking/qspinlock: Introduce llc aware spinlock 2021-12-20 11:43:06 +08:00
power PM: EM: postpone creating the debugfs dir till fs_initcall 2021-04-12 12:53:30 +08:00
printk printk: fix deadlock when kernel panic 2021-04-12 12:52:39 +08:00
rcu rcu/nocb: Perform deferred wake up before last idle's need_resched() check 2021-04-12 12:52:37 +08:00
sched cgroupfs: support stat based on cpuacct 2022-05-18 14:43:14 +08:00
time posix-timers: Preserve return value in clock_adjtime32() 2021-05-20 16:07:22 +08:00
tkernel Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
trace bpf: Add bpf_for_each_map_elem() helper 2022-06-21 10:27:16 +08:00
.gitignore kbuild: update config_data.gz only when the content of .config is changed 2021-05-20 16:07:35 +08:00
Kconfig.freezer Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Kconfig.hz Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Kconfig.locks Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Kconfig.preempt Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Makefile kbuild: update config_data.gz only when the content of .config is changed 2021-05-20 16:07:35 +08:00
acct.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
async.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
audit.c audit: fix a net reference leak in audit_list_rules_send() 2021-03-16 16:29:25 +08:00
audit.h audit: fix a net reference leak in audit_list_rules_send() 2021-03-16 16:29:25 +08:00
audit_fsnotify.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
audit_tree.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
audit_watch.c audit: CONFIG_CHANGE don't log internal bookkeeping as an event 2021-03-16 16:36:51 +08:00
auditfilter.c audit: fix a net reference leak in audit_list_rules_send() 2021-03-16 16:29:25 +08:00
auditsc.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
backtracetest.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
bounds.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
capability.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
compat.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
configs.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
context_tracking.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
cpu.c kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling 2021-03-16 16:42:28 +08:00
cpu_pm.c kernel/cpu_pm: Fix uninitted local in cpu_pm 2021-03-16 16:29:48 +08:00
crash_core.c x86, arm64: Add ARCH_WANT_RESERVE_CRASH_KERNEL config 2022-06-06 13:52:03 +08:00
crash_dump.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
cred.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
delayacct.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
dma.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
exec_domain.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
exit.c don't dump the threads that had been already exiting when zapped. 2021-03-16 16:40:57 +08:00
extable.c bpf: Add support for BTF pointers to x86 JIT 2022-06-21 10:27:03 +08:00
fail_function.c fail_function: Remove a redundant mutex unlock 2021-03-16 16:41:23 +08:00
fork.c exec: Transform exec_update_mutex into a rw_semaphore 2021-04-12 12:51:05 +08:00
freezer.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
futex.c Revert 337f13046ff0 ("futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op") 2021-05-20 16:07:35 +08:00
gen_kheaders.sh kbuild: add variables for compression tools 2021-03-16 16:35:19 +08:00
groups.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
hung_task.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
iomem.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
irq_work.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
jump_label.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kallsyms.c kallsyms: Refactor kallsyms_show_value() to take cred 2021-03-16 16:31:37 +08:00
kcmp.c exec: Transform exec_update_mutex into a rw_semaphore 2021-04-12 12:51:05 +08:00
kcov.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kexec.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kexec_core.c x86: kdump: move reserve_crashkernel[_low]() into crash_core.c 2022-06-06 13:50:12 +08:00
kexec_elf.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kexec_file.c ima: Free IMA measurement buffer after kexec syscall 2021-04-12 12:52:21 +08:00
kexec_internal.h Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kheaders.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kmod.c kmod: make request_module() return an error when autoloading is disabled 2021-03-16 16:26:15 +08:00
kprobes.c tracing/kprobe: Fix to support kretprobe events on unloaded modules 2021-04-12 12:51:58 +08:00
ksysfs.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
kthread.c kthread: Fix PF_KTHREAD vs to_kthread() race 2022-01-05 14:51:53 +08:00
latencytop.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
module-internal.h Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
module.c kabi: check modver major version and features 2021-06-23 07:24:18 +00:00
module_signature.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
module_signing.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
notifier.c kernel/notifier.c: intercept duplicate registrations to avoid infinite loops 2021-03-16 16:36:43 +08:00
nsproxy.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
padata.c padata: add separate cpuhp node for CPUHP_PADATA_DEAD 2021-03-16 16:28:57 +08:00
panic.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
params.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
pid.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
pid_namespace.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
profile.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
ptrace.c ptrace: Set PF_SUPERPRIV when checking capability 2021-03-16 16:41:32 +08:00
range.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
reboot.c reboot: fix overflow parsing reboot cpu number 2021-03-16 16:40:55 +08:00
relay.c kernel/relay.c: fix memleak on destroy relay channel 2021-03-16 16:34:28 +08:00
resource.c /dev/mem: Revoke mappings when a driver claims the region 2021-03-16 16:30:25 +08:00
rseq.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
seccomp.c seccomp: Add missing return in non-void function 2021-04-12 12:52:36 +08:00
signal.c ptrace: fix task_join_group_stop() for the case when current is traced 2021-03-16 16:40:18 +08:00
smp.c smp: Fix smp_call_function_single_async prototype 2021-05-20 16:08:01 +08:00
smpboot.c kthread: Extract KTHREAD_IS_PER_CPU 2021-04-12 12:51:51 +08:00
smpboot.h Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
softirq.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
stackleak.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
stacktrace.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
stop_machine.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
sys.c kernel/sys.c: avoid copying possible padding bytes in copy_to_user 2021-03-16 16:36:43 +08:00
sys_ni.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
sysctl-test.c kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec() 2021-03-16 16:36:31 +08:00
sysctl.c bpf: Sharing bpf runtime stats with BPF_ENABLE_STATS 2022-06-21 10:27:12 +08:00
sysctl_binary.c net: change TCP_TIMEWAIT_LEN on runtime 2021-03-16 16:43:58 +08:00
task_work.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
taskstats.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
test_kprobes.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
torture.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
tracepoint.c tracepoint: Do not fail unregistering a probe due to memory failure 2021-04-12 12:52:27 +08:00
tsacct.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
ucount.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
uid16.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
uid16.h Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
umh.c usermodehelper: reset umask to default before executing user process 2021-03-16 16:37:54 +08:00
up.c smp: Fix smp_call_function_single_async prototype 2021-05-20 16:08:01 +08:00
user-return-notifier.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
user.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
user_namespace.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
utsname.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
utsname_sysctl.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
watchdog.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
watchdog_hld.c Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
workqueue.c workqueue: Move the position of debug_work_activate() in __queue_work() 2021-05-20 16:07:02 +08:00
workqueue_internal.h Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00