diff options
| author |   Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2025-07-03 13:48:14 -0700 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2025-07-03 19:30:07 -0700 |
| commit | ecec5b5743bf964f3e2bb5486daee058344d9066 (patch) | |
| tree | d894163a7159e56eb701a4d1e6031783562f8e5c | |
| parent | bpf: Report may_goto timeout to BPF stderr (diff) | |
| download | wireguard-linux-ecec5b5743bf964f3e2bb5486daee058344d9066.tar.xz wireguard-linux-ecec5b5743bf964f3e2bb5486daee058344d9066.zip | |
bpf: Report rqspinlock deadlocks/timeout to BPF stderr
Begin reporting rqspinlock deadlocks and timeout to BPF program's
stderr.
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250703204818.925464-9-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | kernel/bpf/rqspinlock.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/kernel/bpf/rqspinlock.c b/kernel/bpf/rqspinlock.c index 338305c8852c..5ab354d55d82 100644 --- a/kernel/bpf/rqspinlock.c +++ b/kernel/bpf/rqspinlock.c @@ -666,6 +666,27 @@ EXPORT_SYMBOL_GPL(resilient_queued_spin_lock_slowpath); __bpf_kfunc_start_defs(); +static void bpf_prog_report_rqspinlock_violation(const char *str, void *lock, bool irqsave) +{ + struct rqspinlock_held *rqh = this_cpu_ptr(&rqspinlock_held_locks); + struct bpf_stream_stage ss; + struct bpf_prog *prog; + + prog = bpf_prog_find_from_stack(); + if (!prog) + return; + bpf_stream_stage(ss, prog, BPF_STDERR, ({ + bpf_stream_printk(ss, "ERROR: %s for bpf_res_spin_lock%s\n", str, irqsave ? "_irqsave" : ""); + bpf_stream_printk(ss, "Attempted lock = 0x%px\n", lock); + bpf_stream_printk(ss, "Total held locks = %d\n", rqh->cnt); + for (int i = 0; i < min(RES_NR_HELD, rqh->cnt); i++) + bpf_stream_printk(ss, "Held lock[%2d] = 0x%px\n", i, rqh->locks[i]); + bpf_stream_dump_stack(ss); + })); +} + +#define REPORT_STR(ret) ({ (ret) == -ETIMEDOUT ? "Timeout detected" : "AA or ABBA deadlock detected"; }) + __bpf_kfunc int bpf_res_spin_lock(struct bpf_res_spin_lock *lock) { int ret; @@ -676,6 +697,7 @@ __bpf_kfunc int bpf_res_spin_lock(struct bpf_res_spin_lock *lock) preempt_disable(); ret = res_spin_lock((rqspinlock_t *)lock); if (unlikely(ret)) { + bpf_prog_report_rqspinlock_violation(REPORT_STR(ret), lock, false); preempt_enable(); return ret; } @@ -698,6 +720,7 @@ __bpf_kfunc int bpf_res_spin_lock_irqsave(struct bpf_res_spin_lock *lock, unsign local_irq_save(flags); ret = res_spin_lock((rqspinlock_t *)lock); if (unlikely(ret)) { + bpf_prog_report_rqspinlock_violation(REPORT_STR(ret), lock, true); local_irq_restore(flags); preempt_enable(); return ret; |