diff options
Diffstat (limited to 'kernel/bpf/stackmap.c')
| -rw-r--r-- | kernel/bpf/stackmap.c | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 8f0f3ff1a869..a839041e0d00 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -414,8 +414,7 @@ static void stack_map_get_build_id_offset_sleepable(struct bpf_stack_build_id *i static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, u32 trace_nr, bool user, bool may_fault) { - struct mmap_unlock_irq_work *work = NULL; - bool irq_work_busy = bpf_mmap_unlock_get_irq_work(&work); + struct mmap_unlock_irq_work *work; bool has_user_ctx = user && current && current->mm; struct stack_map_build_id_cache cache = {}; struct vm_area_struct *vma; @@ -426,15 +425,16 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, return; } - /* If the irq_work is in use, fall back to report ips. Same - * fallback is used for kernel stack (!user) on a stackmap with - * build_id. - */ - if (!has_user_ctx || irq_work_busy || !mmap_read_trylock(current->mm)) { - /* cannot access current->mm, fall back to ips */ - for (i = 0; i < trace_nr; i++) - stack_map_build_id_set_ip(&id_offs[i]); - return; + if (!has_user_ctx) + goto fallback; + + work = bpf_mmap_unlock_guard_get(); + if (IS_ERR(work)) + goto fallback; + + if (!mmap_read_trylock(current->mm)) { + bpf_mmap_unlock_guard_put(work); + goto fallback; } for (i = 0; i < trace_nr; i++) { @@ -465,6 +465,12 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, vma->vm_pgoff); } bpf_mmap_unlock_mm(work, current->mm); + return; + +fallback: + /* cannot access current->mm, fall back to ips */ + for (i = 0; i < trace_nr; i++) + stack_map_build_id_set_ip(&id_offs[i]); } static struct perf_callchain_entry * |