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Date: Wed, 5 Feb 2025 09:46:12 +0900 Message-ID: <20250205004615.1253389-1-hyesoo.yu@samsung.com> X-Mailer: git-send-email 2.48.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrMJsWRmVeSWpSXmKPExsWy7bCmma7u1kXpBptuGFlM7DGwmLN+DZvF 9W9vGC3+dl5gtVjZ3cxmsXlOscXlXXPYLO6t+c9q0fb5H5BYspHJYuIaUYvZjX2MDjweO2fd ZfdYsKnUY9OqTjaPTZ8msXt0vb3C5HFixm8WjydXpjN5LGyYyuzRt2UVo8eZBUfYPT5vkgvg jsq2yUhNTEktUkjNS85PycxLt1XyDo53jjc1MzDUNbS0MFdSyEvMTbVVcvEJ0HXLzAG6XEmh LDGnFCgUkFhcrKRvZ1OUX1qSqpCRX1xiq5RakJJTYF6gV5yYW1yal66Xl1piZWhgYGQKVJiQ nXHixS3GggkiFTOurWRuYPzK38XIySEhYCLRtvItUxcjF4eQwA5GiWfTH7FBOJ8YJY7s+gmV +cYo8aJ5BQtMy/03X9khEnsZJY5/ncgM4XxmlHg/t58JpIpNQF3ixJZljCC2iACLxMrv38G6 mQVWMUv0vjAHsYUFPCReb7vADGKzCKhK7H78mg3E5hWwkdj1+CUTxDZ5idtrTrJAxAUlTs58 AjVHXqJ562ywxRICMzkkNq2axgbR4CJxbt51qGZhiVfHt7BD2FISL/vboOxiiW2LDzNBNDcw SmzuuM8MkTCWmPWsHehqDqANmhLrd+mDmBICyhJHbkHt5ZPoOPyXHSLMK9HRJgTRqCyxf9k8 aABJSjxa284KYXtIHJn9DewyIYFYifX/D7FNYJSfheSbWUi+mYWwdwEj8ypGsdSC4tz01GKj AhN4rCbn525iBKdeLY8djLPfftA7xMjEwXiIUYKDWUmE9/T2BelCvCmJlVWpRfnxRaU5qcWH GE2B4TuRWUo0OR+Y/PNK4g1NLA1MzMwMzY1MDcyVxHmrd7SkCwmkJ5akZqemFqQWwfQxcXBK NTBFTc0/wcng9OyGgWCS4Ord/JVdPFHms2VYLt5RvZVtU8a3XOn4z2imtiLmZSm5kgmVlnW5 s5s+HEgsPTZp3z2P4Cj9kocP2K7oCrN/8jsjbfb59Sb/A3/PXbol8EqBc4XZIqaj031urmhI V2xMCb/oVBuZ2JA5Y0/AcpPUP/c+hr0/kn5QfmkqR0gq/5dze067Sc8NOXdH/9kr0WDNO/fq r8Qav9o0ueABo8/VmndZ4leOWptHxmx9dSvzXF5hyMy/AR/M48s6z54/9fpSkqeAy1GvhWbB 09/N+PDOn3nN/b0H6ir5E691l5tPs8iUWWKwYXeGnmeb3i8t57/GwoZxn7sNg5ZweWvdWRJV +U6JpTgj0VCLuag4EQB8SLG2RgQAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrMLMWRmVeSWpSXmKPExsWy7bCSnK7u1kXpBjuPMVpM7DGwmLN+DZvF 9W9vGC3+dl5gtVjZ3cxmsXlOscXlXXPYLO6t+c9q0fb5H5BYspHJYuIaUYvZjX2MDjweO2fd ZfdYsKnUY9OqTjaPTZ8msXt0vb3C5HFixm8WjydXpjN5LGyYyuzRt2UVo8eZBUfYPT5vkgvg juKySUnNySxLLdK3S+DKOPHiFmPBBJGKGddWMjcwfuXvYuTkkBAwkbj/5it7FyMXh5DAbkaJ 2Q172SESkhKzPp9kgrCFJe63HGGFKPrIKPFsyn5GkASbgLrEiS3LwGwRARaJld+/s4AUMQts Y5a4cXAeG0hCWMBD4vW2C8wgNouAqsTux6/B4rwCNhK7Hr+E2iAvcXvNSRaIuKDEyZlPwGxm oHjz1tnMExj5ZiFJzUKSWsDItIpRMrWgODc9t9iwwDAvtVyvODG3uDQvXS85P3cTIzgetDR3 MG5f9UHvECMTB+MhRgkOZiUR3tPbF6QL8aYkVlalFuXHF5XmpBYfYpTmYFES5xV/0ZsiJJCe WJKanZpakFoEk2Xi4JRqYIp84rJKml3///dZd7P2XI6fObFr7b6U6R+fZBTPOz9tnadfqc5K hdfxvDMrel+7LJbh9rJbxKF7ov/7hg0n0jcdPBgZ1VcVoNL8zdmuuvWdZmQjmxeLd+y3o3qa /AuKrXSVP+85f/neh0lHBBav2zN5ZqV+ge5czTbTLTmT13Hr2oneLn/zZzk399WTZdYJa0pj 9su7Xq1ZM3vx8Ud7PqfOTuFzf5Pwc/nRlLtBsocvnOVPucQw43zA1e0T+pZ86yublSGsUiBT zXM9g3vNQwEVtYdTp5t/9ZjybsO0Yn19FovaNxPdPnrKPQsRyzbq4dzO+HFNeeiP7blnfv54 +XMpc2Za/+cohpKDP9gj92kpsRRnJBpqMRcVJwIAQPTDjPYCAAA= X-CMS-MailID: 20250205004741epcas2p3081bc2c97b7c1c27a9797cd498c4bc64 X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-Sendblock-Type: AUTO_CONFIDENTIAL CMS-TYPE: 102P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20250205004741epcas2p3081bc2c97b7c1c27a9797cd498c4bc64 References: If a slab object is corrupted or an error occurs in its internal value, continuing after restoration may cause other side effects. At this point, it is difficult to debug because the problem occurred in the past. It is better to use WARN() instead of pr_err to catch errors at the point of issue because WARN() could trigger panic for system debugging when panic_on_warn is enabled. WARN() should be called prior to fixing the value because when a panic is triggered by WARN(= ), it allows us to check corrupted data. Changes in v2: - Replace direct calling with BUG_ON with the use of WARN in slab_fix. Signed-off-by: Hyesoo Yu --- mm/slub.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 1f50129dcfb3..ea956cb4b8be 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1043,7 +1043,7 @@ static void slab_fix(struct kmem_cache *s, char *fmt,= ...) va_start(args, fmt); vaf.fmt =3D fmt; vaf.va =3D &args; - pr_err("FIX %s: %pV\n", s->name, &vaf); + WARN(1, "FIX %s: %pV\n", s->name, &vaf); va_end(args); } =20 @@ -1106,8 +1106,8 @@ static bool freelist_corrupted(struct kmem_cache *s, = struct slab *slab, if ((s->flags & SLAB_CONSISTENCY_CHECKS) && !check_valid_pointer(s, slab, nextfree) && freelist) { object_err(s, slab, *freelist, "Freechain corrupt"); - *freelist =3D NULL; slab_fix(s, "Isolate corrupted freechain"); + *freelist =3D NULL; return true; } =20 @@ -1445,9 +1445,9 @@ static int on_freelist(struct kmem_cache *s, struct s= lab *slab, void *search) set_freepointer(s, object, NULL); } else { slab_err(s, slab, "Freepointer corrupt"); + slab_fix(s, "Freelist cleared"); slab->freelist =3D NULL; slab->inuse =3D slab->objects; - slab_fix(s, "Freelist cleared"); return 0; } break; @@ -1464,14 +1464,14 @@ static int on_freelist(struct kmem_cache *s, struct= slab *slab, void *search) if (slab->objects !=3D max_objects) { slab_err(s, slab, "Wrong number of objects. Found %d but should be %d", slab->objects, max_objects); - slab->objects =3D max_objects; slab_fix(s, "Number of objects adjusted"); + slab->objects =3D max_objects; } if (slab->inuse !=3D slab->objects - nr) { slab_err(s, slab, "Wrong object count. Counter is %d but counted were %d= ", slab->inuse, slab->objects - nr); - slab->inuse =3D slab->objects - nr; slab_fix(s, "Object count adjusted"); + slab->inuse =3D slab->objects - nr; } return search =3D=3D NULL; } --=20 2.48.0