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| author | Alexei Starovoitov <ast@kernel.org> | 2022-10-25 23:11:47 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-10-25 23:11:47 -0700 |
| commit | fdf457871e7c070416403efd1533ba49adc20a87 (patch) | |
| tree | fdf22af5765c1f3c2e0c31b61f25e4e249459a20 /kernel/bpf/syscall.c | |
| parent | f3c51fe02c55bd944662714e5b91b96dc271ad9f (diff) | |
| parent | 387b532138eed5b12e1afa68cafb6a389507310f (diff) | |
Merge branch 'bpf: Avoid unnecessary deadlock detection and failure in task storage'
Martin KaFai Lau says:
====================
From: Martin KaFai Lau <martin.lau@kernel.org>
The commit bc235cdb423a ("bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete]")
added deadlock detection to avoid a tracing program from recurring
on the bpf_task_storage_{get,delete}() helpers. These helpers acquire
a spin lock and it will lead to deadlock.
It is unnecessary for the bpf_lsm and bpf_iter programs which do
not recur. The situation is the same as the existing
bpf_pid_task_storage_{lookup,delete}_elem() which are
used in the syscall and they also do not have deadlock detection.
This set is to add new bpf_task_storage_{get,delete}() helper proto
without the deadlock detection. The set also removes the prog->active
check from the bpf_lsm and bpf_iter program. Please see the individual
patch for details.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 7b373a5e861f..a0b4266196a8 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -5133,13 +5133,14 @@ int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) run_ctx.bpf_cookie = 0; run_ctx.saved_run_ctx = NULL; - if (!__bpf_prog_enter_sleepable(prog, &run_ctx)) { + if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { /* recursion detected */ bpf_prog_put(prog); return -EBUSY; } attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); - __bpf_prog_exit_sleepable(prog, 0 /* bpf_prog_run does runtime stats */, &run_ctx); + __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, + &run_ctx); bpf_prog_put(prog); return 0; #endif |