From nobody Tue Apr 7 14:36:48 2026 Received: from mail-dl1-f74.google.com (mail-dl1-f74.google.com [74.125.82.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7B84A3FF1 for ; Thu, 12 Mar 2026 22:31:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773354697; cv=none; b=QcVI8Bosu4+t9tZFOQ8kjdbm80lwFuBvtXwpIshekf/Ie7yZjXVNaAxr7wVZJx/Rd1+e/3i5uH8EL1w7dXaMUTs+X5IYU7lNaaDySA/PbZOStkZAw2nsk93nChl8MlwYD6Zj3GCnSWIj0L3XXOv5jgkBB6J66igrg61h/5rgCo0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773354697; c=relaxed/simple; bh=QQ3dviOlS/QKwOAue1T9KEs16UskwW92wS4vygLVkM0=; h=Date:Mime-Version:Message-ID:Subject:From:To:Content-Type; b=PVdwxRDcMYlz/rl0anclil2lzfdBPXYLa9QYSeK+Z60/gChtmu6PJKAX6Nb1HtQQteg4zOlGgCSk1ws+mkT6uZMI54m6TW8/ZFaTshL9q3M7NKs2AcNOGlew/sWJ93ACfs8teR+cxL5witWGrLd+fgH1RwmCIEK4a4EBO4ES/bE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=GVzy63zS; arc=none smtp.client-ip=74.125.82.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="GVzy63zS" Received: by mail-dl1-f74.google.com with SMTP id a92af1059eb24-127133794b6so2415490c88.1 for ; Thu, 12 Mar 2026 15:31:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1773354696; x=1773959496; darn=vger.kernel.org; h=to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=48/JBhfRTYkQbuu3k/IhRnah6yiGvJ46CDfj9rjG1jo=; b=GVzy63zSAUo1nMAGwaF6sq0WVkrCH1Wd2lgJE5+CS3RtXeKoLhDYDN2R96aDEg/s0Q EM7O1V80P5QOIzenCY1Aog4oJY0wLLjT2dNM8gsoumJr6oMJJ75KSmZrVxWR8d4vuYG5 gwfObqvnyWmd4rknjJeyuXS1CEqATiu4MwYGHq2PNWiTwdDObBvWFPE7GDS2xoMv5rkA ZVI93gGQe9uCoIvElDBUy9rSaMKqeyYf0wZFuC1/0x8Tep7Dhcu0/FYY7Wg2U+3tYOFT YcY0tlRv2fLwU9dCwuLAUChmAjJIusC0e/QVn+8U8nW6dUv156+C+zVdgKBdyHj277Z5 y94A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1773354696; x=1773959496; h=to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=48/JBhfRTYkQbuu3k/IhRnah6yiGvJ46CDfj9rjG1jo=; b=mtzr+R3fWRnXV+/KZY3zz49UXWxiQ/NeMsIojdmueuq4uaxEkU3Snb+djqxi/8j0JF 3UHqEszJOAuiSsjLBRiM59H17OS+F+1/6krhTGBYmXyfZqUNn4/xy9AN3aDMG4kpEFte WMSpgvzNJYhtU1WvHgLQAm4Uif0ezYWGCbLmd+4+cfuFol09qGy3m40aYPyMywWLLx1o uEI7/w9dxCI77lMQWzjOX01aIUobgpFSVwj0Gc0uFlxmIH5Re3Kab1+Lqb2yEc8RnvTk 0b6ScRCJmlMpI1uzTz8sfo3E2NOy5mpa9fbYKJ2ZJpOoZ18a6h3AA/XADO/JKmBlmL/v 3/9Q== X-Forwarded-Encrypted: i=1; AJvYcCVleB3VpTnZicWEQt1ZWl/QEeotRXM5JCVsTBr5lMYY2fYlzQ0u+F00JtU7oqdjOmZdVCBCpV3ptMsulHI=@vger.kernel.org X-Gm-Message-State: AOJu0Yzry3CoGk9Fwzwx4Zv6sIKpUxr9UFL0SA9pZ6LeFyUwZ60WlxO+ AOBHq83Cy2q85dCxpD87poyhTbnnpwyM1us/DxTrldT7tFcFE0b14ohw5Nr562xmDikuVDdoVpv Uw5E6EVvJ3w== X-Received: from dldz19-n1.prod.google.com ([2002:a05:701b:4193:10b0:128:d282:5eec]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7022:459e:b0:128:ced9:93ef with SMTP id a92af1059eb24-128f3e128femr572510c88.39.1773354695382; Thu, 12 Mar 2026 15:31:35 -0700 (PDT) Date: Thu, 12 Mar 2026 15:31:31 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.53.0.851.ga537e3e6e9-goog Message-ID: <20260312223131.2184095-1-irogers@google.com> Subject: [PATCH v1] perf branch: Avoid incrementing NULL From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , James Clark , Kan Liang , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" If the entry is NULL the value is meaningless so early return NULL to avoid an increment of NULL. This was happening in calls from has_stitched_lbr when running the "perf record LBR tests". The return value isn't used in that case, so returning NULL as no effect. Fixes: 42bbabed09ce ("perf tools: Add hw_idx in struct branch_stack") Signed-off-by: Ian Rogers --- tools/perf/util/branch.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/perf/util/branch.h b/tools/perf/util/branch.h index 7429530fa774..a1d4736497c4 100644 --- a/tools/perf/util/branch.h +++ b/tools/perf/util/branch.h @@ -66,6 +66,9 @@ static inline struct branch_entry *perf_sample__branch_en= tries(struct perf_sampl { u64 *entry =3D (u64 *)sample->branch_stack; =20 + if (entry =3D=3D NULL) + return NULL; + entry++; if (sample->no_hw_idx) return (struct branch_entry *)entry; --=20 2.53.0.851.ga537e3e6e9-goog