In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memcpy(), memmove(), and memset(), avoid intentionally writing across neighboring fields.
The "Board Parameters" members of the structs: struct atom_smc_dpm_info_v4_5 struct atom_smc_dpm_info_v4_6 struct atom_smc_dpm_info_v4_7 struct atom_smc_dpm_info_v4_10 are written to the corresponding members of the corresponding PPTable_t variables, but they lack destination size bounds checking, which means the compiler cannot verify at compile time that this is an intended and safe memcpy().
Since the header files are effectively immutable[1] and a struct_group() cannot be used, nor a common struct referenced by both sides of the memcpy() arguments, add a new helper, amdgpu_memcpy_trailing(), to perform the bounds checking at compile time. Replace the open-coded memcpy()s with amdgpu_memcpy_trailing() which includes enough context for the bounds checking.
"objdump -d" shows no object code changes.
[1] https://lore.kernel.org/lkml/e56aad3c-a06f-da07-f491-a894a570d78f@amd.com
Cc: "Christian König" christian.koenig@amd.com Cc: "Pan, Xinhui" Xinhui.Pan@amd.com Cc: David Airlie airlied@linux.ie Cc: Daniel Vetter daniel@ffwll.ch Cc: Hawking Zhang Hawking.Zhang@amd.com Cc: Feifei Xu Feifei.Xu@amd.com Cc: Likun Gao Likun.Gao@amd.com Cc: Jiawei Gu Jiawei.Gu@amd.com Cc: Evan Quan evan.quan@amd.com Cc: amd-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org Reviewed-by: Lijo Lazar lijo.lazar@amd.com Acked-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Kees Cook keescook@chromium.org --- v3: rename amdgpu_memcpy_trailing() to smu_memcpy_trailing() v2: https://lore.kernel.org/lkml/20210825161957.3904130-1-keescook@chromium.org v1: https://lore.kernel.org/lkml/20210819201441.3545027-1-keescook@chromium.org --- drivers/gpu/drm/amd/pm/inc/amdgpu_smu.h | 24 +++++++++++++++++++ .../gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c | 6 ++--- .../gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c | 8 +++---- .../drm/amd/pm/swsmu/smu13/aldebaran_ppt.c | 5 ++-- 4 files changed, 32 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/amd/pm/inc/amdgpu_smu.h b/drivers/gpu/drm/amd/pm/inc/amdgpu_smu.h index 715b4225f5ee..8156729c370b 100644 --- a/drivers/gpu/drm/amd/pm/inc/amdgpu_smu.h +++ b/drivers/gpu/drm/amd/pm/inc/amdgpu_smu.h @@ -1335,6 +1335,30 @@ enum smu_cmn2asic_mapping_type { #define WORKLOAD_MAP(profile, workload) \ [profile] = {1, (workload)}
+/** + * smu_memcpy_trailing - Copy the end of one structure into the middle of another + * + * @dst: Pointer to destination struct + * @first_dst_member: The member name in @dst where the overwrite begins + * @last_dst_member: The member name in @dst where the overwrite ends after + * @src: Pointer to the source struct + * @first_src_member: The member name in @src where the copy begins + * + */ +#define smu_memcpy_trailing(dst, first_dst_member, last_dst_member, \ + src, first_src_member) \ +({ \ + size_t __src_offset = offsetof(typeof(*(src)), first_src_member); \ + size_t __src_size = sizeof(*(src)) - __src_offset; \ + size_t __dst_offset = offsetof(typeof(*(dst)), first_dst_member); \ + size_t __dst_size = offsetofend(typeof(*(dst)), last_dst_member) - \ + __dst_offset; \ + BUILD_BUG_ON(__src_size != __dst_size); \ + __builtin_memcpy((u8 *)(dst) + __dst_offset, \ + (u8 *)(src) + __src_offset, \ + __dst_size); \ +}) + #if !defined(SWSMU_CODE_LAYER_L2) && !defined(SWSMU_CODE_LAYER_L3) && !defined(SWSMU_CODE_LAYER_L4) int smu_get_power_limit(void *handle, uint32_t *limit, diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c index 273df66cac14..e343cc218990 100644 --- a/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c +++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c @@ -483,10 +483,8 @@ static int arcturus_append_powerplay_table(struct smu_context *smu)
if ((smc_dpm_table->table_header.format_revision == 4) && (smc_dpm_table->table_header.content_revision == 6)) - memcpy(&smc_pptable->MaxVoltageStepGfx, - &smc_dpm_table->maxvoltagestepgfx, - sizeof(*smc_dpm_table) - offsetof(struct atom_smc_dpm_info_v4_6, maxvoltagestepgfx)); - + smu_memcpy_trailing(smc_pptable, MaxVoltageStepGfx, BoardReserved, + smc_dpm_table, maxvoltagestepgfx); return 0; }
diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c index f96681700c41..a5fc5d7cb6c7 100644 --- a/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c +++ b/drivers/gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c @@ -431,16 +431,16 @@ static int navi10_append_powerplay_table(struct smu_context *smu)
switch (smc_dpm_table->table_header.content_revision) { case 5: /* nv10 and nv14 */ - memcpy(smc_pptable->I2cControllers, smc_dpm_table->I2cControllers, - sizeof(*smc_dpm_table) - sizeof(smc_dpm_table->table_header)); + smu_memcpy_trailing(smc_pptable, I2cControllers, BoardReserved, + smc_dpm_table, I2cControllers); break; case 7: /* nv12 */ ret = amdgpu_atombios_get_data_table(adev, index, NULL, NULL, NULL, (uint8_t **)&smc_dpm_table_v4_7); if (ret) return ret; - memcpy(smc_pptable->I2cControllers, smc_dpm_table_v4_7->I2cControllers, - sizeof(*smc_dpm_table_v4_7) - sizeof(smc_dpm_table_v4_7->table_header)); + smu_memcpy_trailing(smc_pptable, I2cControllers, BoardReserved, + smc_dpm_table_v4_7, I2cControllers); break; default: dev_err(smu->adev->dev, "smc_dpm_info with unsupported content revision %d!\n", diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c index ec8c30daf31c..ab652028e003 100644 --- a/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c +++ b/drivers/gpu/drm/amd/pm/swsmu/smu13/aldebaran_ppt.c @@ -409,9 +409,8 @@ static int aldebaran_append_powerplay_table(struct smu_context *smu)
if ((smc_dpm_table->table_header.format_revision == 4) && (smc_dpm_table->table_header.content_revision == 10)) - memcpy(&smc_pptable->GfxMaxCurrent, - &smc_dpm_table->GfxMaxCurrent, - sizeof(*smc_dpm_table) - offsetof(struct atom_smc_dpm_info_v4_10, GfxMaxCurrent)); + smu_memcpy_trailing(smc_pptable, GfxMaxCurrent, reserved, + smc_dpm_table, GfxMaxCurrent); return 0; }