2024-05-05 11:18:13

by Julia Lawall

[permalink] [raw]
Subject: drivers/gpu/drm/xe/xe_guc_ads.c:103:21-27: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays) (fwd)

Can a flexible array be used at the end of this structure?

julia

---------- Forwarded message ----------
Date: Sun, 5 May 2024 19:06:22 +0800
From: kernel test robot <[email protected]>
To: [email protected]
Cc: [email protected], Julia Lawall <[email protected]>
Subject: drivers/gpu/drm/xe/xe_guc_ads.c:103:21-27: WARNING use flexible-array
member instead
(https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-
and-one-element-arrays)

BCC: [email protected]
CC: [email protected]
CC: [email protected]
TO: Lucas De Marchi <[email protected]>
CC: Matt Roper <[email protected]>

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 7367539ad4b0f8f9b396baf02110962333719a48
commit: 237412e45390805e14a6936fb998d756c4eac9d8 drm/xe: Enable 32bits build
date: 3 months ago
:::::: branch date: 2 days ago
:::::: commit date: 3 months ago
config: i386-randconfig-054-20240505 (https://download.01.org/0day-ci/archive/20240505/[email protected]/config)
compiler: clang version 18.1.4 (https://github.com/llvm/llvm-project e6c3289804a67ea0bb6a86fadbe454dd93b8d855)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Reported-by: Julia Lawall <[email protected]>
| Closes: https://lore.kernel.org/r/[email protected]/

cocci warnings: (new ones prefixed by >>)
>> drivers/gpu/drm/xe/xe_guc_ads.c:103:21-27: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)

vim +103 drivers/gpu/drm/xe/xe_guc_ads.c

dd08ebf6c3525a Matthew Brost 2023-03-30 53
dd08ebf6c3525a Matthew Brost 2023-03-30 54 /*
dd08ebf6c3525a Matthew Brost 2023-03-30 55 * The Additional Data Struct (ADS) has pointers for different buffers used by
dd08ebf6c3525a Matthew Brost 2023-03-30 56 * the GuC. One single gem object contains the ADS struct itself (guc_ads) and
dd08ebf6c3525a Matthew Brost 2023-03-30 57 * all the extra buffers indirectly linked via the ADS struct's entries.
dd08ebf6c3525a Matthew Brost 2023-03-30 58 *
dd08ebf6c3525a Matthew Brost 2023-03-30 59 * Layout of the ADS blob allocated for the GuC:
dd08ebf6c3525a Matthew Brost 2023-03-30 60 *
dd08ebf6c3525a Matthew Brost 2023-03-30 61 * +---------------------------------------+ <== base
dd08ebf6c3525a Matthew Brost 2023-03-30 62 * | guc_ads |
dd08ebf6c3525a Matthew Brost 2023-03-30 63 * +---------------------------------------+
dd08ebf6c3525a Matthew Brost 2023-03-30 64 * | guc_policies |
dd08ebf6c3525a Matthew Brost 2023-03-30 65 * +---------------------------------------+
dd08ebf6c3525a Matthew Brost 2023-03-30 66 * | guc_gt_system_info |
dd08ebf6c3525a Matthew Brost 2023-03-30 67 * +---------------------------------------+
dd08ebf6c3525a Matthew Brost 2023-03-30 68 * | guc_engine_usage |
dd08ebf6c3525a Matthew Brost 2023-03-30 69 * +---------------------------------------+
dd08ebf6c3525a Matthew Brost 2023-03-30 70 * | guc_um_init_params |
dd08ebf6c3525a Matthew Brost 2023-03-30 71 * +---------------------------------------+ <== static
dd08ebf6c3525a Matthew Brost 2023-03-30 72 * | guc_mmio_reg[countA] (engine 0.0) |
dd08ebf6c3525a Matthew Brost 2023-03-30 73 * | guc_mmio_reg[countB] (engine 0.1) |
dd08ebf6c3525a Matthew Brost 2023-03-30 74 * | guc_mmio_reg[countC] (engine 1.0) |
dd08ebf6c3525a Matthew Brost 2023-03-30 75 * | ... |
dd08ebf6c3525a Matthew Brost 2023-03-30 76 * +---------------------------------------+ <== dynamic
dd08ebf6c3525a Matthew Brost 2023-03-30 77 * | padding |
dd08ebf6c3525a Matthew Brost 2023-03-30 78 * +---------------------------------------+ <== 4K aligned
dd08ebf6c3525a Matthew Brost 2023-03-30 79 * | golden contexts |
dd08ebf6c3525a Matthew Brost 2023-03-30 80 * +---------------------------------------+
dd08ebf6c3525a Matthew Brost 2023-03-30 81 * | padding |
dd08ebf6c3525a Matthew Brost 2023-03-30 82 * +---------------------------------------+ <== 4K aligned
dd08ebf6c3525a Matthew Brost 2023-03-30 83 * | capture lists |
dd08ebf6c3525a Matthew Brost 2023-03-30 84 * +---------------------------------------+
dd08ebf6c3525a Matthew Brost 2023-03-30 85 * | padding |
dd08ebf6c3525a Matthew Brost 2023-03-30 86 * +---------------------------------------+ <== 4K aligned
dd08ebf6c3525a Matthew Brost 2023-03-30 87 * | UM queues |
dd08ebf6c3525a Matthew Brost 2023-03-30 88 * +---------------------------------------+
dd08ebf6c3525a Matthew Brost 2023-03-30 89 * | padding |
dd08ebf6c3525a Matthew Brost 2023-03-30 90 * +---------------------------------------+ <== 4K aligned
dd08ebf6c3525a Matthew Brost 2023-03-30 91 * | private data |
dd08ebf6c3525a Matthew Brost 2023-03-30 92 * +---------------------------------------+
dd08ebf6c3525a Matthew Brost 2023-03-30 93 * | padding |
dd08ebf6c3525a Matthew Brost 2023-03-30 94 * +---------------------------------------+ <== 4K aligned
dd08ebf6c3525a Matthew Brost 2023-03-30 95 */
dd08ebf6c3525a Matthew Brost 2023-03-30 96 struct __guc_ads_blob {
dd08ebf6c3525a Matthew Brost 2023-03-30 97 struct guc_ads ads;
dd08ebf6c3525a Matthew Brost 2023-03-30 98 struct guc_policies policies;
dd08ebf6c3525a Matthew Brost 2023-03-30 99 struct guc_gt_system_info system_info;
dd08ebf6c3525a Matthew Brost 2023-03-30 100 struct guc_engine_usage engine_usage;
dd08ebf6c3525a Matthew Brost 2023-03-30 101 struct guc_um_init_params um_init_params;
dd08ebf6c3525a Matthew Brost 2023-03-30 102 /* From here on, location is dynamic! Refer to above diagram. */
dd08ebf6c3525a Matthew Brost 2023-03-30 @103 struct guc_mmio_reg regset[0];
dd08ebf6c3525a Matthew Brost 2023-03-30 104 } __packed;
dd08ebf6c3525a Matthew Brost 2023-03-30 105

:::::: The code at line 103 was first introduced by commit
:::::: dd08ebf6c3525a7ea2186e636df064ea47281987 drm/xe: Introduce a new DRM driver for Intel GPUs

:::::: TO: Matthew Brost <[email protected]>
:::::: CC: Rodrigo Vivi <[email protected]>

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki


2024-05-06 14:29:20

by Lucas De Marchi

[permalink] [raw]
Subject: Re: drivers/gpu/drm/xe/xe_guc_ads.c:103:21-27: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays) (fwd)

On Sun, May 05, 2024 at 01:17:59PM GMT, Julia Lawall wrote:
>Can a flexible array be used at the end of this structure?

yes, we should. Just submitted a fix. Thanks

Lucas De Marchi

>
>julia
>
>---------- Forwarded message ----------
>Date: Sun, 5 May 2024 19:06:22 +0800
>From: kernel test robot <[email protected]>
>To: [email protected]
>Cc: [email protected], Julia Lawall <[email protected]>
>Subject: drivers/gpu/drm/xe/xe_guc_ads.c:103:21-27: WARNING use flexible-array
> member instead
> (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-
> and-one-element-arrays)
>
>BCC: [email protected]
>CC: [email protected]
>CC: [email protected]
>TO: Lucas De Marchi <[email protected]>
>CC: Matt Roper <[email protected]>
>
>tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
>head: 7367539ad4b0f8f9b396baf02110962333719a48
>commit: 237412e45390805e14a6936fb998d756c4eac9d8 drm/xe: Enable 32bits build
>date: 3 months ago
>:::::: branch date: 2 days ago
>:::::: commit date: 3 months ago
>config: i386-randconfig-054-20240505 (https://download.01.org/0day-ci/archive/20240505/[email protected]/config)
>compiler: clang version 18.1.4 (https://github.com/llvm/llvm-project e6c3289804a67ea0bb6a86fadbe454dd93b8d855)
>
>If you fix the issue in a separate patch/commit (i.e. not just a new version of
>the same patch/commit), kindly add following tags
>| Reported-by: kernel test robot <[email protected]>
>| Reported-by: Julia Lawall <[email protected]>
>| Closes: https://lore.kernel.org/r/[email protected]/
>
>cocci warnings: (new ones prefixed by >>)
>>> drivers/gpu/drm/xe/xe_guc_ads.c:103:21-27: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
>
>vim +103 drivers/gpu/drm/xe/xe_guc_ads.c
>
>dd08ebf6c3525a Matthew Brost 2023-03-30 53
>dd08ebf6c3525a Matthew Brost 2023-03-30 54 /*
>dd08ebf6c3525a Matthew Brost 2023-03-30 55 * The Additional Data Struct (ADS) has pointers for different buffers used by
>dd08ebf6c3525a Matthew Brost 2023-03-30 56 * the GuC. One single gem object contains the ADS struct itself (guc_ads) and
>dd08ebf6c3525a Matthew Brost 2023-03-30 57 * all the extra buffers indirectly linked via the ADS struct's entries.
>dd08ebf6c3525a Matthew Brost 2023-03-30 58 *
>dd08ebf6c3525a Matthew Brost 2023-03-30 59 * Layout of the ADS blob allocated for the GuC:
>dd08ebf6c3525a Matthew Brost 2023-03-30 60 *
>dd08ebf6c3525a Matthew Brost 2023-03-30 61 * +---------------------------------------+ <== base
>dd08ebf6c3525a Matthew Brost 2023-03-30 62 * | guc_ads |
>dd08ebf6c3525a Matthew Brost 2023-03-30 63 * +---------------------------------------+
>dd08ebf6c3525a Matthew Brost 2023-03-30 64 * | guc_policies |
>dd08ebf6c3525a Matthew Brost 2023-03-30 65 * +---------------------------------------+
>dd08ebf6c3525a Matthew Brost 2023-03-30 66 * | guc_gt_system_info |
>dd08ebf6c3525a Matthew Brost 2023-03-30 67 * +---------------------------------------+
>dd08ebf6c3525a Matthew Brost 2023-03-30 68 * | guc_engine_usage |
>dd08ebf6c3525a Matthew Brost 2023-03-30 69 * +---------------------------------------+
>dd08ebf6c3525a Matthew Brost 2023-03-30 70 * | guc_um_init_params |
>dd08ebf6c3525a Matthew Brost 2023-03-30 71 * +---------------------------------------+ <== static
>dd08ebf6c3525a Matthew Brost 2023-03-30 72 * | guc_mmio_reg[countA] (engine 0.0) |
>dd08ebf6c3525a Matthew Brost 2023-03-30 73 * | guc_mmio_reg[countB] (engine 0.1) |
>dd08ebf6c3525a Matthew Brost 2023-03-30 74 * | guc_mmio_reg[countC] (engine 1.0) |
>dd08ebf6c3525a Matthew Brost 2023-03-30 75 * | ... |
>dd08ebf6c3525a Matthew Brost 2023-03-30 76 * +---------------------------------------+ <== dynamic
>dd08ebf6c3525a Matthew Brost 2023-03-30 77 * | padding |
>dd08ebf6c3525a Matthew Brost 2023-03-30 78 * +---------------------------------------+ <== 4K aligned
>dd08ebf6c3525a Matthew Brost 2023-03-30 79 * | golden contexts |
>dd08ebf6c3525a Matthew Brost 2023-03-30 80 * +---------------------------------------+
>dd08ebf6c3525a Matthew Brost 2023-03-30 81 * | padding |
>dd08ebf6c3525a Matthew Brost 2023-03-30 82 * +---------------------------------------+ <== 4K aligned
>dd08ebf6c3525a Matthew Brost 2023-03-30 83 * | capture lists |
>dd08ebf6c3525a Matthew Brost 2023-03-30 84 * +---------------------------------------+
>dd08ebf6c3525a Matthew Brost 2023-03-30 85 * | padding |
>dd08ebf6c3525a Matthew Brost 2023-03-30 86 * +---------------------------------------+ <== 4K aligned
>dd08ebf6c3525a Matthew Brost 2023-03-30 87 * | UM queues |
>dd08ebf6c3525a Matthew Brost 2023-03-30 88 * +---------------------------------------+
>dd08ebf6c3525a Matthew Brost 2023-03-30 89 * | padding |
>dd08ebf6c3525a Matthew Brost 2023-03-30 90 * +---------------------------------------+ <== 4K aligned
>dd08ebf6c3525a Matthew Brost 2023-03-30 91 * | private data |
>dd08ebf6c3525a Matthew Brost 2023-03-30 92 * +---------------------------------------+
>dd08ebf6c3525a Matthew Brost 2023-03-30 93 * | padding |
>dd08ebf6c3525a Matthew Brost 2023-03-30 94 * +---------------------------------------+ <== 4K aligned
>dd08ebf6c3525a Matthew Brost 2023-03-30 95 */
>dd08ebf6c3525a Matthew Brost 2023-03-30 96 struct __guc_ads_blob {
>dd08ebf6c3525a Matthew Brost 2023-03-30 97 struct guc_ads ads;
>dd08ebf6c3525a Matthew Brost 2023-03-30 98 struct guc_policies policies;
>dd08ebf6c3525a Matthew Brost 2023-03-30 99 struct guc_gt_system_info system_info;
>dd08ebf6c3525a Matthew Brost 2023-03-30 100 struct guc_engine_usage engine_usage;
>dd08ebf6c3525a Matthew Brost 2023-03-30 101 struct guc_um_init_params um_init_params;
>dd08ebf6c3525a Matthew Brost 2023-03-30 102 /* From here on, location is dynamic! Refer to above diagram. */
>dd08ebf6c3525a Matthew Brost 2023-03-30 @103 struct guc_mmio_reg regset[0];
>dd08ebf6c3525a Matthew Brost 2023-03-30 104 } __packed;
>dd08ebf6c3525a Matthew Brost 2023-03-30 105
>
>:::::: The code at line 103 was first introduced by commit
>:::::: dd08ebf6c3525a7ea2186e636df064ea47281987 drm/xe: Introduce a new DRM driver for Intel GPUs
>
>:::::: TO: Matthew Brost <[email protected]>
>:::::: CC: Rodrigo Vivi <[email protected]>
>
>--
>0-DAY CI Kernel Test Service
>https://github.com/intel/lkp-tests/wiki