Re: [Nouveau] [PATCH][next] nouveau/gsp: replace zero-length array with flex-array member and use __counted_by
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
Re: [Nouveau] [PATCH][next] nouveau/gsp: replace zero-length array with flex-array member and use __counted_by
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
Re: [Nouveau] [PATCH][next] nouveau/gsp: replace zero-length array with flex-array member and use __counted_by
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.
Re: [Nouveau] [PATCH][next] nouveau/gsp: replace zero-length array with flex-array member and use __counted_by
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.
Re: [Nouveau] [PATCH][next] nouveau/gsp: replace zero-length array with flex-array member and use __counted_by
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
> ---
> .../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;
> -NvU8type;
> -NvU32 data;
> -NvU32 length;
> + NvU32 nameOffset;
> + NvU8type;
> + 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-tt...@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
>
Re: [Nouveau] [PATCH][next] nouveau/gsp: replace zero-length array with flex-array member and use __counted_by
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-tt...@nvidia.com/T/
Re: [Nouveau] [PATCH][next] nouveau/gsp: replace zero-length array with flex-array member and use __counted_by
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 Looks nice to me. Reviewed-by: Kees Cook -- Kees Cook
[Nouveau] [PATCH][next] nouveau/gsp: replace zero-length array with flex-array member and use __counted_by
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
---
.../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;
-NvU8type;
-NvU32 data;
-NvU32 length;
+ NvU32 nameOffset;
+ NvU8type;
+ 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++)
--
2.34.1
