From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CA44B5540B4 for ; Tue, 8 Sep 2026 13:12:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788873142; cv=none; b=B1Pr1itahtY8vKe4T60nnTCjp3yV7Pv6fffCdyFyXEhpr8JZgzOCxtbD1LsF7DBTYU2IqoKsR55Pc39W6Q6AuYJjKaURVI5BZ0g7sS8C+lJzOHrOQth1KG301XN+sC28J0eT2R3ekOdn/Q0aUGZ00nFAAB3+6CDcF9YuA6zDLx4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788873142; c=relaxed/simple; bh=95/Hw8ELypd5RnI8NROCKds2QvyK9oG8RGb8LH9Em3Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DqQPtsX4dRP9Lft2T91xreurIguwIKC9EeCAs9eAym53AXtTPZOluCAftscr3UsX119W0eXWaeVIoP+gKUO7BQpngr2+XRoevKBJNMvOVJlSTYJDWmXhyRJ/n3Ye2W6r8JVeS0FcHkajhxCzkQ8unnX0XmFJrRxxt2bA4L0M3JU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=V2mBOYzs; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="V2mBOYzs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 098E11F00A3D; Tue, 8 Sep 2026 13:12:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788873133; bh=dWJ64UyfhSFw0Ibx/3y1RIc7DidvwGjlGerxA4AU04I=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=V2mBOYzsQtzyJW8IbJ9g+exR55tY75ke3xI3VkU3tqFj2Qjz8iV3L4uSDPN9OW09h l8q9y1MGFdfxpWhpE9l3e6VmwP1OCJKBvpK9WFECFQ2ntUJDqGLFrx+cSvkh82N9Bm V1pU2S1UlR1VTnglMvuGNv1XZ6DJmYnD6JJEvafRu0WSOrO356Ub4sdN3Xnvhyt0Hy 1mx7jQcDwLd4KVEdjn5Tt6IXWXDYmhhrbY+c+yv7BudB3oH00r/4vL1N6/IBckerWX HTefhlQin+K2soentR8UdAJMe5iTmZeyPXnBT+fHZOLMK2lTBcSeYDrEZC9YYXMvdR LecY9XpzD6a9g== From: Sasha Levin To: stable@vger.kernel.org Cc: Jiri Olsa , Andrii Nakryiko , Sasha Levin Subject: [PATCH 6.18.y 4/5] bpf: Use stack id functions instead of __bpf_get_stackid Date: Tue, 8 Sep 2026 09:12:08 -0400 Message-ID: <20260908131209.2236373-4-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260908131209.2236373-1-sashal@kernel.org> References: <2026090347-bodacious-studio-93ee@gregkh> <20260908131209.2236373-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Jiri Olsa [ Upstream commit 09b3fd6caa0b57f8a39254ee5db3af30bdd53c18 ] 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 Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20260803210149.296496-5-jolsa@kernel.org Stable-dep-of: 15f1bd857466 ("bpf: Disable preemption in bpf_get_stackid") Signed-off-by: Sasha Levin --- 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 cd3b91a726336..0634eaae48702 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -326,22 +326,13 @@ 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; @@ -371,10 +362,12 @@ 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))) @@ -388,7 +381,15 @@ 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 = { @@ -416,6 +417,7 @@ 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; @@ -443,7 +445,6 @@ 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; @@ -452,12 +453,22 @@ 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; } -- 2.53.0