| Message ID | 20200507192228.GA16355@embeddedor (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 2d6201ee1123325c089008570bd5ddea3c5b131a |
| Headers | show |
| Series | ASoC: soc-core: Replace zero-length array with flexible-array | expand |
On Thu, 7 May 2020 14:22:28 -0500, Gustavo A. R. Silva wrote: > The current codebase makes use of the zero-length array language > extension to the C90 standard, but the preferred mechanism to declare > variable-length types such as these ones is a flexible array member[1][2], > introduced in C99: > > struct foo { > int stuff; > struct boo array[]; > }; > > [...] Applied to https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-5.8 Thanks! [1/1] ASoC: soc-core: Replace zero-length array with flexible-array commit: 2d6201ee1123325c089008570bd5ddea3c5b131a All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark
diff --git a/include/sound/soc-dapm.h b/include/sound/soc-dapm.h index 08495f8d86dc..cc3dcb815282 100644 --- a/include/sound/soc-dapm.h +++ b/include/sound/soc-dapm.h @@ -689,7 +689,7 @@ struct snd_soc_dapm_context { /* A list of widgets associated with an object, typically a snd_kcontrol */ struct snd_soc_dapm_widget_list { int num_widgets; - struct snd_soc_dapm_widget *widgets[0]; + struct snd_soc_dapm_widget *widgets[]; }; #define for_each_dapm_widgets(list, i, widget) \ diff --git a/include/sound/soc.h b/include/sound/soc.h index 13458e4fbb13..3e14442de2ec 100644 --- a/include/sound/soc.h +++ b/include/sound/soc.h @@ -1167,7 +1167,7 @@ struct snd_soc_pcm_runtime { unsigned int fe_compr:1; /* for Dynamic PCM */ int num_components; - struct snd_soc_component *components[0]; /* CPU/Codec/Platform */ + struct snd_soc_component *components[]; /* CPU/Codec/Platform */ }; /* see soc_new_pcm_runtime() */ #define asoc_rtd_to_cpu(rtd, n) (rtd)->dais[n]
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- include/sound/soc-dapm.h | 2 +- include/sound/soc.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)