From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) (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 AA05B10E5 for ; Fri, 2 Sep 2022 04:06:18 +0000 (UTC) Received: from omf02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 1E25A1C6992; Thu, 1 Sep 2022 23:19:58 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: joe@perches.com) by omf02.hostedemail.com (Postfix) with ESMTPA id A9ECF8000E; Thu, 1 Sep 2022 23:19:36 +0000 (UTC) Message-ID: Subject: Re: [RFC PATCH 28/30] Improved symbolic error names From: Joe Perches To: Suren Baghdasaryan , akpm@linux-foundation.org Cc: kent.overstreet@linux.dev, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, roman.gushchin@linux.dev, mgorman@suse.de, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, void@manifault.com, peterz@infradead.org, juri.lelli@redhat.com, ldufour@linux.ibm.com, peterx@redhat.com, david@redhat.com, axboe@kernel.dk, mcgrof@kernel.org, masahiroy@kernel.org, nathan@kernel.org, changbin.du@intel.com, ytcoode@gmail.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, bristot@redhat.com, vschneid@redhat.com, cl@linux.com, penberg@kernel.org, iamjoonsoo.kim@lge.com, 42.hyeyoo@gmail.com, glider@google.com, elver@google.com, dvyukov@google.com, shakeelb@google.com, songmuchun@bytedance.com, arnd@arndb.de, jbaron@akamai.com, rientjes@google.com, minchan@google.com, kaleshsingh@google.com, kernel-team@android.com, linux-mm@kvack.org, iommu@lists.linux.dev, kasan-dev@googlegroups.com, io-uring@vger.kernel.org, linux-arch@vger.kernel.org, xen-devel@lists.xenproject.org, linux-bcache@vger.kernel.org, linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 01 Sep 2022 16:19:35 -0700 In-Reply-To: <20220830214919.53220-29-surenb@google.com> References: <20220830214919.53220-1-surenb@google.com> <20220830214919.53220-29-surenb@google.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.44.4 (3.44.4-1.fc36) Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Server: rspamout03 X-Rspamd-Queue-Id: A9ECF8000E X-Spam-Status: No, score=0.64 X-Stat-Signature: iwqjhu65bfnp7s38he58qcgfcrx3mruu X-Session-Marker: 6A6F6540706572636865732E636F6D X-Session-ID: U2FsdGVkX18FfjZ7BuRv/DHsUMYX6e6vN/rFvSwIdRQ= X-HE-Tag: 1662074376-819350 On Tue, 2022-08-30 at 14:49 -0700, Suren Baghdasaryan wrote: > From: Kent Overstreet >=20 > This patch adds per-error-site error codes, with error strings that > include their file and line number. >=20 > To use, change code that returns an error, e.g. > return -ENOMEM; > to > return -ERR(ENOMEM); >=20 > Then, errname() will return a string that includes the file and line > number of the ERR() call, for example > printk("Got error %s!\n", errname(err)); > will result in > Got error ENOMEM at foo.c:1234 Why? Something wrong with just using %pe ? printk("Got error %pe at %s:%d!\n", ERR_PTR(err), __FILE__, __LINE__); Likely __FILE__ and __LINE__ aren't particularly useful. And using ERR would add rather a lot of bloat as each codetag_error_code struct would be unique. +#define ERR(_err) \ +({ \ + static struct codetag_error_code \ + __used \ + __section("error_code_tags") \ + __aligned(8) e =3D { \ + .str =3D #_err " at " __FILE__ ":" __stringify(__LINE__),\ + .err =3D _err, \ + }; \ + \ + e.err; \ +})