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 2181A306B08 for ; Mon, 3 Aug 2026 21:02:35 +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=1785790957; cv=none; b=sne/Le/SpeX5etnyrNNzI6dHqNNEeuglgNcGmhCj0+qb3W5VeeoNslcHeViLdLk/oXUdff7DLLfbXp9qOaFNiRn7ZqGvaPoe8NivlSlQha3wWDOVHcwPkDjTldYpmyA1v2cRi1Ab6tEEBFq4guACSIWcqdNrBILlPj5Z0EHHU3c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785790957; c=relaxed/simple; bh=HvtNCDj49dgFvhp3wom9wsy9zpflN1CxtCBa7W0JESo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HkRxZ+VOzywfvR7hEDUgfRWCGiQWvYkkK09JbiW4jcXh6BcYyexcwYSVhyYoVv60sKbqYlMX9xc3PBA71pSSKnvuhop2IqfkzO8EqVNowww6gbf9COHNuSJIJ3NXFe8bCP8cLzvldc9Lgh5lIrtXrz3ZchgD1YyTvVdFJs/cMFE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TPSAAQrj; 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="TPSAAQrj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D83F91F000E9; Mon, 3 Aug 2026 21:02:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785790955; bh=Lp9lWB4MpbVcAxvqIWu5ifkaYSpYAw1xzolskJ6j4Zg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TPSAAQrjIwkPOp/N1hUzt0xJ9N4PpqszgQ1FMyybGafeBH28DwH2dwfJkyCX7yZpW RsB3QpHveGE+vFdFjbYKafeT4QlvzKyhivGzvJELvaCwuvpuvKi39PUJf7lw1NMLp6 gnl0eTBBxcBHF1NAvVHhtPdW2UWoWBfxKOIDphtkYwISU35/V5OrY4J8v7ymhlqDCH B9fSGtAIbyLQYvA+nEbwpNbkkVJm3G7jI+Jon2cPPIuWxbtHwNB5xlHOXXpj5Y5WF/ k9pAFj3ZnVzHxi4nbv+0koLuHNE5x5/LSWQy89SRfeTHyOsBC6zmnYDNRpTGFau2U+ Mcd5CAj2dtRvw== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: bpf@vger.kernel.org, Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , Quentin Monnet , Tao Chen , STAR Labs SG , Arnaud Lecomte Subject: [PATCHv3 bpf-next 04/12] bpf: Use stack id functions instead of __bpf_get_stackid Date: Mon, 3 Aug 2026 23:01:41 +0200 Message-ID: <20260803210149.296496-5-jolsa@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260803210149.296496-1-jolsa@kernel.org> References: <20260803210149.296496-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 --- 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 d930d9754d7d..3ee0034daf52 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -584,22 +584,13 @@ 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; @@ -629,10 +620,12 @@ 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))) @@ -646,7 +639,15 @@ 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 = { @@ -674,6 +675,7 @@ 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; @@ -701,7 +703,6 @@ 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; @@ -710,12 +711,22 @@ 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; } -- 2.54.0