| Message ID | ZVZbX7C5suLMiBf+@work (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [next] nouveau/gsp: replace zero-length array with flex-array member and use __counted_by | expand |
On Thu, Nov 16, 2023 at 12:11:43PM -0600, Gustavo A. R. Silva wrote: > Fake flexible arrays (zero-length and one-element arrays) are deprecated, > and should be replaced by flexible-array members. So, replace > zero-length array with a flexible-array member in `struct > PACKED_REGISTRY_TABLE`. > > Also annotate array `entries` with `__counted_by()` to prepare for the > coming implementation by GCC and Clang of the `__counted_by` attribute. > Flexible array members annotated with `__counted_by` can have their > accesses bounds-checked at run-time via `CONFIG_UBSAN_BOUNDS` (for array > indexing) and `CONFIG_FORTIFY_SOURCE` (for strcpy/memcpy-family functions). > > This fixes multiple -Warray-bounds warnings: > drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c:1069:29: warning: array subscript 0 is outside array bounds of 'PACKED_REGISTRY_ENTRY[0]' [-Warray-bounds=] > drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c:1070:29: warning: array subscript 0 is outside array bounds of 'PACKED_REGISTRY_ENTRY[0]' [-Warray-bounds=] > drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c:1071:29: warning: array subscript 0 is outside array bounds of 'PACKED_REGISTRY_ENTRY[0]' [-Warray-bounds=] > drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c:1072:29: warning: array subscript 0 is outside array bounds of 'PACKED_REGISTRY_ENTRY[0]' [-Warray-bounds=] > > While there, also make use of the struct_size() helper, and address > checkpatch.pl warning: > WARNING: please, no spaces at the start of a line > > This results in no differences in binary output. > > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Looks nice to me. Reviewed-by: Kees Cook <keescook@chromium.org>
On Thu, 2023-11-16 at 12:11 -0600, Gustavo A. R. Silva wrote:
typedef struct PACKED_REGISTRY_TABLE
{
- NvU32 size;
- NvU32 numEntries;
- PACKED_REGISTRY_ENTRY entries[0];
+ NvU32 size;
+ NvU32 numEntries;
+ PACKED_REGISTRY_ENTRY entries[] __counted_by(numEntries);
} PACKED_REGISTRY_TABLE;
Well, it's better than mine: https://lore.kernel.org/all/20231107234726.854248-1-ttabi@nvidia.com/T/
Hi Gustavo, On Thu, Nov 16, 2023 at 12:11:43PM -0600, Gustavo A. R. Silva wrote: > Fake flexible arrays (zero-length and one-element arrays) are deprecated, > and should be replaced by flexible-array members. So, replace > zero-length array with a flexible-array member in `struct > PACKED_REGISTRY_TABLE`. > > Also annotate array `entries` with `__counted_by()` to prepare for the > coming implementation by GCC and Clang of the `__counted_by` attribute. > Flexible array members annotated with `__counted_by` can have their > accesses bounds-checked at run-time via `CONFIG_UBSAN_BOUNDS` (for array > indexing) and `CONFIG_FORTIFY_SOURCE` (for strcpy/memcpy-family functions). > > This fixes multiple -Warray-bounds warnings: > drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c:1069:29: warning: array subscript 0 is outside array bounds of 'PACKED_REGISTRY_ENTRY[0]' [-Warray-bounds=] > drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c:1070:29: warning: array subscript 0 is outside array bounds of 'PACKED_REGISTRY_ENTRY[0]' [-Warray-bounds=] > drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c:1071:29: warning: array subscript 0 is outside array bounds of 'PACKED_REGISTRY_ENTRY[0]' [-Warray-bounds=] > drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c:1072:29: warning: array subscript 0 is outside array bounds of 'PACKED_REGISTRY_ENTRY[0]' [-Warray-bounds=] > > While there, also make use of the struct_size() helper, and address > checkpatch.pl warning: > WARNING: please, no spaces at the start of a line > > This results in no differences in binary output. > > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> > --- > .../nvrm/535.113.01/nvidia/generated/g_os_nvoc.h | 14 +++++++------- > drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c | 2 +- > 2 files changed, 8 insertions(+), 8 deletions(-) > > diff --git a/drivers/gpu/drm/nouveau/include/nvrm/535.113.01/nvidia/generated/g_os_nvoc.h b/drivers/gpu/drm/nouveau/include/nvrm/535.113.01/nvidia/generated/g_os_nvoc.h > index 754c6af42f30..259b25c2ac6b 100644 > --- a/drivers/gpu/drm/nouveau/include/nvrm/535.113.01/nvidia/generated/g_os_nvoc.h > +++ b/drivers/gpu/drm/nouveau/include/nvrm/535.113.01/nvidia/generated/g_os_nvoc.h > @@ -28,17 +28,17 @@ > > typedef struct PACKED_REGISTRY_ENTRY > { > - NvU32 nameOffset; > - NvU8 type; > - NvU32 data; > - NvU32 length; > + NvU32 nameOffset; > + NvU8 type; > + NvU32 data; > + NvU32 length; > } PACKED_REGISTRY_ENTRY; > > typedef struct PACKED_REGISTRY_TABLE > { > - NvU32 size; > - NvU32 numEntries; > - PACKED_REGISTRY_ENTRY entries[0]; > + NvU32 size; > + NvU32 numEntries; > + PACKED_REGISTRY_ENTRY entries[] __counted_by(numEntries); > } PACKED_REGISTRY_TABLE; Thanks for the fix! However, I have some concerns about changing those header files, since they're just copied over from Nvidia's driver [1]. Once we add the header files for a new firmware revision, we'd potentially run into the same issue, applying the same fix again. As I already mentioned for Timur's patch [2], I'd prefer to get a fix upstream (meaning [1] in this case). Of course, that's probably more up to Timur to tell if this will work out. If we can't get a fix upstream, I'd probably prefer to silence warning elsewhere. [1] https://github.com/NVIDIA/open-gpu-kernel-modules [2] https://lore.kernel.org/all/20231107234726.854248-1-ttabi@nvidia.com/T/ > > #endif > diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c > index dc44f5c7833f..228335487af5 100644 > --- a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c > +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c > @@ -1048,7 +1048,7 @@ r535_gsp_rpc_set_registry(struct nvkm_gsp *gsp) > char *strings; > int str_offset; > int i; > - size_t rpc_size = sizeof(*rpc) + sizeof(rpc->entries[0]) * NV_GSP_REG_NUM_ENTRIES; > + size_t rpc_size = struct_size(rpc, entries, NV_GSP_REG_NUM_ENTRIES); > > /* add strings + null terminator */ > for (i = 0; i < NV_GSP_REG_NUM_ENTRIES; i++) > -- > 2.34.1 >
On Thu, 2023-11-16 at 20:45 +0100, Danilo Krummrich wrote: > As I already mentioned for Timur's patch [2], I'd prefer to get a fix > upstream > (meaning [1] in this case). Of course, that's probably more up to Timur to > tell > if this will work out. Don't count on it. Even if I did change [0] to [], I'm not going to be able to add the "__counted_by(numEntries);" because that's just not something that our build system uses. And even then, I would need to change all [0] to []. You're not going to be able to use RM's header files as-is anyway in the long term. If we changed the layout of PACKED_REGISTRY_TABLE, we're not going to create a PACKED_REGISTRY_TABLE2 and keep both around. We're just going to change PACKED_REGISTRY_TABLE and pretend the previous version never existed. You will then have to manually copy the new struct to your header files and and maintain two versions yourself.
On 11/16/23 20:55, Timur Tabi wrote: > On Thu, 2023-11-16 at 20:45 +0100, Danilo Krummrich wrote: >> As I already mentioned for Timur's patch [2], I'd prefer to get a fix >> upstream >> (meaning [1] in this case). Of course, that's probably more up to Timur to >> tell >> if this will work out. > > Don't count on it. I see. Well, I think it's fine. Once we implement a decent abstraction we likely don't need those header files in the kernel anymore. @Gustavo, if you agree I will discard the indentation change when applying the patch to keep the diff as small as possible. - Danilo > > Even if I did change [0] to [], I'm not going to be able to add the > "__counted_by(numEntries);" because that's just not something that our build > system uses. > > And even then, I would need to change all [0] to []. > > You're not going to be able to use RM's header files as-is anyway in the > long term. If we changed the layout of PACKED_REGISTRY_TABLE, we're not > going to create a PACKED_REGISTRY_TABLE2 and keep both around. We're just > going to change PACKED_REGISTRY_TABLE and pretend the previous version never > existed. You will then have to manually copy the new struct to your header > files and and maintain two versions yourself. > > >
On 11/28/23 19:01, Danilo Krummrich wrote: > On 11/16/23 20:55, Timur Tabi wrote: >> On Thu, 2023-11-16 at 20:45 +0100, Danilo Krummrich wrote: >>> As I already mentioned for Timur's patch [2], I'd prefer to get a fix >>> upstream >>> (meaning [1] in this case). Of course, that's probably more up to Timur to >>> tell >>> if this will work out. >> >> Don't count on it. > > I see. Well, I think it's fine. Once we implement a decent abstraction we likely > don't need those header files in the kernel anymore. > > @Gustavo, if you agree I will discard the indentation change when applying the > patch to keep the diff as small as possible. No problem. Thanks -- Gustavo
On 11/29/23 02:06, Gustavo A. R. Silva wrote: > > > On 11/28/23 19:01, Danilo Krummrich wrote: >> On 11/16/23 20:55, Timur Tabi wrote: >>> On Thu, 2023-11-16 at 20:45 +0100, Danilo Krummrich wrote: >>>> As I already mentioned for Timur's patch [2], I'd prefer to get a fix >>>> upstream >>>> (meaning [1] in this case). Of course, that's probably more up to Timur to >>>> tell >>>> if this will work out. >>> >>> Don't count on it. >> >> I see. Well, I think it's fine. Once we implement a decent abstraction we likely >> don't need those header files in the kernel anymore. >> >> @Gustavo, if you agree I will discard the indentation change when applying the >> patch to keep the diff as small as possible. > > No problem. Applied to drm-misc-fixes. > > Thanks > -- > Gustavo > >
diff --git a/drivers/gpu/drm/nouveau/include/nvrm/535.113.01/nvidia/generated/g_os_nvoc.h b/drivers/gpu/drm/nouveau/include/nvrm/535.113.01/nvidia/generated/g_os_nvoc.h index 754c6af42f30..259b25c2ac6b 100644 --- a/drivers/gpu/drm/nouveau/include/nvrm/535.113.01/nvidia/generated/g_os_nvoc.h +++ b/drivers/gpu/drm/nouveau/include/nvrm/535.113.01/nvidia/generated/g_os_nvoc.h @@ -28,17 +28,17 @@ typedef struct PACKED_REGISTRY_ENTRY { - NvU32 nameOffset; - NvU8 type; - NvU32 data; - NvU32 length; + NvU32 nameOffset; + NvU8 type; + NvU32 data; + NvU32 length; } PACKED_REGISTRY_ENTRY; typedef struct PACKED_REGISTRY_TABLE { - NvU32 size; - NvU32 numEntries; - PACKED_REGISTRY_ENTRY entries[0]; + NvU32 size; + NvU32 numEntries; + PACKED_REGISTRY_ENTRY entries[] __counted_by(numEntries); } PACKED_REGISTRY_TABLE; #endif diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c index dc44f5c7833f..228335487af5 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c @@ -1048,7 +1048,7 @@ r535_gsp_rpc_set_registry(struct nvkm_gsp *gsp) char *strings; int str_offset; int i; - size_t rpc_size = sizeof(*rpc) + sizeof(rpc->entries[0]) * NV_GSP_REG_NUM_ENTRIES; + size_t rpc_size = struct_size(rpc, entries, NV_GSP_REG_NUM_ENTRIES); /* add strings + null terminator */ for (i = 0; i < NV_GSP_REG_NUM_ENTRIES; i++)
Fake flexible arrays (zero-length and one-element arrays) are deprecated, and should be replaced by flexible-array members. So, replace zero-length array with a flexible-array member in `struct PACKED_REGISTRY_TABLE`. Also annotate array `entries` with `__counted_by()` to prepare for the coming implementation by GCC and Clang of the `__counted_by` attribute. Flexible array members annotated with `__counted_by` can have their accesses bounds-checked at run-time via `CONFIG_UBSAN_BOUNDS` (for array indexing) and `CONFIG_FORTIFY_SOURCE` (for strcpy/memcpy-family functions). This fixes multiple -Warray-bounds warnings: drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c:1069:29: warning: array subscript 0 is outside array bounds of 'PACKED_REGISTRY_ENTRY[0]' [-Warray-bounds=] drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c:1070:29: warning: array subscript 0 is outside array bounds of 'PACKED_REGISTRY_ENTRY[0]' [-Warray-bounds=] drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c:1071:29: warning: array subscript 0 is outside array bounds of 'PACKED_REGISTRY_ENTRY[0]' [-Warray-bounds=] drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c:1072:29: warning: array subscript 0 is outside array bounds of 'PACKED_REGISTRY_ENTRY[0]' [-Warray-bounds=] While there, also make use of the struct_size() helper, and address checkpatch.pl warning: WARNING: please, no spaces at the start of a line This results in no differences in binary output. Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- .../nvrm/535.113.01/nvidia/generated/g_os_nvoc.h | 14 +++++++------- drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c | 2 +- 2 files changed, 8 insertions(+), 8 deletions(-)