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 8F7263B6BFA for ; Mon, 20 Jul 2026 08:55:06 +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=1784537707; cv=none; b=RyX8Af1lYKT22ejkYQHF6SHd8NVv/JGaqaqkh7SiiyVArGuXeGd/fZJomodYFSh1k+PeK4Ehd0abVcg3Bx3+1VSVa8XK8svwUXTdjtxZSlk+FSZT85mh4Xxfm0sgy8e2YbKu20hBuBz7QTSzl42TCU0JcqoNvuU3mxVG0YxH9zQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784537707; c=relaxed/simple; bh=BIfjCWMStcPBouEgBE1sbsNlNp0zzMeE8/XYDxr4tdI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QOdK1MZgu8rcJzUCARvXbT0v9qVCKv8TEAJ6ZDflRl/D8R+FCjIh3tn96Lgu4TpyC0D42meOULmT+uEsOYLtsfxf3YGt/vznRogIFGu3csWXK4xw9rtv0ZxLEWtz6UPAF+qncc4y6jcA9+V5hM61T234L/vw9LHMDgCUt6yRjMo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jqJ33m1R; 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="jqJ33m1R" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B004F1F000E9; Mon, 20 Jul 2026 08:55:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784537706; bh=swSrEkSbY8KimggYoTVtul+Mo5FXEDsx470MSFv0gBQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jqJ33m1R27rk11zNpfCTz3RSkRRXe8WUq0PQ90BG6S68lhUBt6V8+w3pBpSDnoCvc 09M4gAEFrC1rccsr5dhFSdNSzWTWFkoXYnyQk1TdSg0bQnuNcPRJy3DAfroeyA7y0u q3z+1N09nSC6QaoGtRoqviAbYj3R4Dx71eNTGBascNbBA5sGJ+bd6zwXk1TMCgsIRK 9xsv2nV+n1/1f1a8WYl1c6FiN3KVwTGrclbOZuTo+nUOZQYcdiE9/ZCp1oHRIJ+WJP NsNH9ItOzHVAXfffkHx2af3dI2aolfOqVSGFVegSMyHZUd12TMr1l4ssBmA6Ejwmbo Gvz7F1gPyM1Gg== 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 Subject: [PATCH bpf-next 7/9] bpf: Factor callchain_finalize function from __bpf_get_stack Date: Mon, 20 Jul 2026 10:53:49 +0200 Message-ID: <20260720085351.655075-8-jolsa@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260720085351.655075-1-jolsa@kernel.org> References: <20260720085351.655075-1-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 The new callchain_finalize function calls the build-id retrieval (if needed) and zeroes the buffer. Signed-off-by: Jiri Olsa --- kernel/bpf/stackmap.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index b990643f25cd..eea7b781300c 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -770,16 +770,29 @@ static u32 callchain_store(struct perf_callchain_entry *trace, void *buf, u32 si return trace_nr; } +static long callchain_finalize(void *buf, u32 size, u32 trace_nr, u32 elem_size, + bool user_build_id, bool user, bool may_fault) +{ + u32 copy_len = trace_nr * elem_size; + + if (user_build_id) + stack_map_get_build_id_offset(buf, trace_nr, user, may_fault); + + if (size > copy_len) + memset(buf + copy_len, 0, size - copy_len); + return copy_len; +} + static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, struct perf_callchain_entry *trace_in, void *buf, u32 size, u64 flags, bool may_fault) { - u32 trace_nr, copy_len, elem_size, max_depth; bool user_build_id = flags & BPF_F_USER_BUILD_ID; bool crosstask = task && task != current; u32 skip = flags & BPF_F_SKIP_FIELD_MASK; bool user = flags & BPF_F_USER_STACK; struct perf_callchain_entry *trace; + u32 trace_nr, elem_size, max_depth; bool kernel = !user; int err = -EINVAL; @@ -827,18 +840,12 @@ static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, } trace_nr = callchain_store(trace, buf, size, elem_size, flags); - copy_len = trace_nr * elem_size; /* trace should not be dereferenced after this point */ if (may_fault) rcu_read_unlock(); - if (user_build_id) - stack_map_get_build_id_offset(buf, trace_nr, user, may_fault); - - if (size > copy_len) - memset(buf + copy_len, 0, size - copy_len); - return copy_len; + return callchain_finalize(buf, size, trace_nr, elem_size, user_build_id, user, may_fault); err_fault: err = -EFAULT; -- 2.54.0