From: Geert Uytterhoeven <geert@linux-m68k.org> To: Marcel Holtmann <marcel@holtmann.org> Cc: "Gustavo F. Padovan" <gustavo@padovan.org>, Johan Hedberg <johan.hedberg@gmail.com>, BlueZ development <linux-bluetooth@vger.kernel.org>, netdev <netdev@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org> Subject: Re: [PATCH] Bluetooth: Pre-initialize variables in read_local_oob_ext_data_complete() Date: Mon, 20 Apr 2015 10:47:03 +0200 [thread overview] Message-ID: <CAMuHMdUXcAYe4KCqG9wV3O5QYzK9RGt+QZz7E_jk7v9yhtrkRQ@mail.gmail.com> (raw) In-Reply-To: <8684664B-22C2-45E8-B547-48F173B3CA7A@holtmann.org> Hi Marcel, On Fri, Apr 17, 2015 at 10:38 PM, Marcel Holtmann <marcel@holtmann.org> wrote: >>>> net/bluetooth/mgmt.c: In function ‘read_local_oob_ext_data_complete’: >>>> net/bluetooth/mgmt.c:6474: warning: ‘r256’ may be used uninitialized in this function >>>> net/bluetooth/mgmt.c:6474: warning: ‘h256’ may be used uninitialized in this function >>>> net/bluetooth/mgmt.c:6474: warning: ‘r192’ may be used uninitialized in this function >>>> net/bluetooth/mgmt.c:6474: warning: ‘h192’ may be used uninitialized in this function >>>> >>>> While these are false positives, the code can be shortened by >>>> pre-initializing the hash table pointers and eir_len. This has the side >>>> effect of killing the compiler warnings. >>> >>> can you be a bit specific on which compiler version is this. I fixed one occurrence that seemed valid. However in this case the compiler seems to be just plain stupid. On a gcc 4.9, I am not seeing these for example. >> >> gcc 4.1.2. As there were too many false positives, these warnings were >> disabled in later versions (throwing away the children with the bad water). >> >> If you don't like my patch, just drop it. I only look at newly >> introduced warnings >> of this kind anyway. > > I really do not know what is the best solution here. This is a false positive. And I have been looking at this particular code for a warning that was valid, but we missed initially. But these warnings that you are fixing are clearly false positive. I only sent patches to fix false positives if I think the patches improve the code. As this is a subjective matter, it's up to you as the maintainer to decide. > If this only happens with an old compiler version, I would tend to leave the code as is. Then again, what is the general preferred approach here? As this is a false positive, it's clearly up to the maintainer to decide if the patch improves the code or not. Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
WARNING: multiple messages have this Message-ID (diff)
From: Geert Uytterhoeven <geert@linux-m68k.org> To: Marcel Holtmann <marcel@holtmann.org> Cc: "Gustavo F. Padovan" <gustavo@padovan.org>, Johan Hedberg <johan.hedberg@gmail.com>, BlueZ development <linux-bluetooth@vger.kernel.org>, netdev <netdev@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org> Subject: Re: [PATCH] Bluetooth: Pre-initialize variables in read_local_oob_ext_data_complete() Date: Mon, 20 Apr 2015 10:47:03 +0200 [thread overview] Message-ID: <CAMuHMdUXcAYe4KCqG9wV3O5QYzK9RGt+QZz7E_jk7v9yhtrkRQ@mail.gmail.com> (raw) In-Reply-To: <8684664B-22C2-45E8-B547-48F173B3CA7A@holtmann.org> Hi Marcel, On Fri, Apr 17, 2015 at 10:38 PM, Marcel Holtmann <marcel@holtmann.org> wro= te: >>>> net/bluetooth/mgmt.c: In function =E2=80=98read_local_oob_ext_data_com= plete=E2=80=99: >>>> net/bluetooth/mgmt.c:6474: warning: =E2=80=98r256=E2=80=99 may be used= uninitialized in this function >>>> net/bluetooth/mgmt.c:6474: warning: =E2=80=98h256=E2=80=99 may be used= uninitialized in this function >>>> net/bluetooth/mgmt.c:6474: warning: =E2=80=98r192=E2=80=99 may be used= uninitialized in this function >>>> net/bluetooth/mgmt.c:6474: warning: =E2=80=98h192=E2=80=99 may be used= uninitialized in this function >>>> >>>> While these are false positives, the code can be shortened by >>>> pre-initializing the hash table pointers and eir_len. This has the sid= e >>>> effect of killing the compiler warnings. >>> >>> can you be a bit specific on which compiler version is this. I fixed on= e occurrence that seemed valid. However in this case the compiler seems to = be just plain stupid. On a gcc 4.9, I am not seeing these for example. >> >> gcc 4.1.2. As there were too many false positives, these warnings were >> disabled in later versions (throwing away the children with the bad wate= r). >> >> If you don't like my patch, just drop it. I only look at newly >> introduced warnings >> of this kind anyway. > > I really do not know what is the best solution here. This is a false posi= tive. And I have been looking at this particular code for a warning that wa= s valid, but we missed initially. But these warnings that you are fixing ar= e clearly false positive. I only sent patches to fix false positives if I think the patches improve t= he code. As this is a subjective matter, it's up to you as the maintainer to decide. > If this only happens with an old compiler version, I would tend to leave = the code as is. Then again, what is the general preferred approach here? As this is a false positive, it's clearly up to the maintainer to decide if the patch improves the code or not. Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k= .org In personal conversations with technical people, I call myself a hacker. Bu= t when I'm talking to journalists I just say "programmer" or something like t= hat. -- Linus Torvalds
next prev parent reply other threads:[~2015-04-20 8:47 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-04-16 19:24 [PATCH] Bluetooth: Pre-initialize variables in read_local_oob_ext_data_complete() Geert Uytterhoeven 2015-04-16 20:34 ` Marcel Holtmann 2015-04-17 20:03 ` Geert Uytterhoeven 2015-04-17 20:03 ` Geert Uytterhoeven 2015-04-17 20:03 ` Geert Uytterhoeven 2015-04-17 20:38 ` Marcel Holtmann 2015-04-17 20:38 ` Marcel Holtmann 2015-04-20 8:47 ` Geert Uytterhoeven [this message] 2015-04-20 8:47 ` Geert Uytterhoeven 2015-05-13 21:11 ` Marcel Holtmann
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