From: Jiri Olsa <jolsa@kernel.org> mainline inclusion from mainline-v7.3-rc1 commit 09b3fd6caa0b57f8a39254ee5db3af30bdd53c18 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/19054 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Replacing __bpf_get_stackid calls with sequence of following functions: stackid_fastpath stackid_new_bucket stackid_install This makes code more structured and allows us to easily disable preemption only in bpf_get_stackid in following changes. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260803210149.296496-5-jolsa@kernel.org Signed-off-by: Pu Lehui <pulehui@huawei.com> --- kernel/bpf/stackmap.c | 43 +++++++++++++++++++++++++++---------------- 1 file changed, 27 insertions(+), 16 deletions(-) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index efdda87e51ca..7094e5a12b87 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -514,22 +514,13 @@ stackid_new_bucket(struct stackid *stackid, struct bpf_map *map) return bucket; } -static long __bpf_get_stackid(struct stackid *stackid, struct bpf_map *map, - struct perf_callchain_entry *trace, u64 flags) +static long stackid_install(struct stackid *stackid, struct bpf_map *map, + struct stack_map_bucket *new_bucket, u64 flags) { struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map); - struct stack_map_bucket *new_bucket, *old_bucket; bool user = flags & BPF_F_USER_STACK; + struct stack_map_bucket *old_bucket; u32 trace_len; - int err; - - err = stackid_fastpath(stackid, map, trace, flags); - if (err != -ENOENT) - return err; - - new_bucket = stackid_new_bucket(stackid, map); - if (!new_bucket) - return -ENOMEM; if (stack_map_use_build_id(map)) { struct bpf_stack_build_id *id_offs; @@ -559,10 +550,12 @@ BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map, { u32 elem_size = stack_map_data_size(map); bool user = flags & BPF_F_USER_STACK; + struct stack_map_bucket *new_bucket; struct perf_callchain_entry *trace; struct stackid stackid; bool kernel = !user; u32 max_depth; + int err; if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK | BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID))) @@ -576,7 +569,15 @@ BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map, /* couldn't fetch the stack trace */ return -EFAULT; - return __bpf_get_stackid(&stackid, map, trace, flags); + err = stackid_fastpath(&stackid, map, trace, flags); + if (err != -ENOENT) + return err; + + new_bucket = stackid_new_bucket(&stackid, map); + if (!new_bucket) + return -ENOMEM; + + return stackid_install(&stackid, map, new_bucket, flags); } const struct bpf_func_proto bpf_get_stackid_proto = { @@ -604,6 +605,7 @@ BPF_CALL_3(bpf_get_stackid_pe, struct bpf_perf_event_data_kern *, ctx, struct bpf_map *, map, u64, flags) { struct perf_event *event = ctx->event; + struct stack_map_bucket *new_bucket; struct perf_callchain_entry *trace; struct stackid stackid; bool kernel, user; @@ -631,7 +633,6 @@ BPF_CALL_3(bpf_get_stackid_pe, struct bpf_perf_event_data_kern *, ctx, if (kernel) { trace->nr = nr_kernel; - ret = __bpf_get_stackid(&stackid, map, trace, flags); } else { /* user */ u64 skip = flags & BPF_F_SKIP_FIELD_MASK; @@ -640,12 +641,22 @@ BPF_CALL_3(bpf_get_stackid_pe, struct bpf_perf_event_data_kern *, ctx, return -EFAULT; flags = (flags & ~BPF_F_SKIP_FIELD_MASK) | skip; - ret = __bpf_get_stackid(&stackid, map, trace, flags); } + ret = stackid_fastpath(&stackid, map, trace, flags); + if (ret != -ENOENT) + goto out; + + new_bucket = stackid_new_bucket(&stackid, map); + if (new_bucket) { + trace->nr = nr; + return stackid_install(&stackid, map, new_bucket, flags); + } + ret = -ENOMEM; + +out: /* restore nr */ trace->nr = nr; - return ret; } -- 2.34.1