From d4726d7700688835f4784d3b94de6fff2cbe16c2 Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Thu, 17 Mar 2022 09:51:40 -0700 Subject: [PATCH] drm/msm: Add a way to override processes comm/cmdline In the cause of using the GPU via virtgpu, the host side process is really a sort of proxy, and not terribly interesting from the PoV of crash/fault logging. Add a way to override these per process so that we can see the guest process's name. v2: Handle kmalloc failure, add comment to explain kstrdup returns NULL if passed NULL [Dan Carpenter] Signed-off-by: Rob Clark Link: https://lore.kernel.org/r/20220317165144.222101-4-robdclark@gmail.com Signed-off-by: Rob Clark --- drivers/gpu/drm/msm/adreno/adreno_gpu.c | 43 ++++++++++++++++++++++++++++++--- drivers/gpu/drm/msm/msm_gpu.c | 12 +++++++-- drivers/gpu/drm/msm/msm_gpu.h | 6 +++++ drivers/gpu/drm/msm/msm_submitqueue.c | 2 ++ include/uapi/drm/msm_drm.h | 2 ++ 5 files changed, 60 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c index 3d307b3..45f2c60 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c @@ -290,11 +290,48 @@ int adreno_get_param(struct msm_gpu *gpu, struct msm_file_private *ctx, int adreno_set_param(struct msm_gpu *gpu, struct msm_file_private *ctx, uint32_t param, uint64_t value, uint32_t len) { - /* No pointer params yet */ - if (len != 0) - return -EINVAL; + switch (param) { + case MSM_PARAM_COMM: + case MSM_PARAM_CMDLINE: + /* kstrdup_quotable_cmdline() limits to PAGE_SIZE, so + * that should be a reasonable upper bound + */ + if (len > PAGE_SIZE) + return -EINVAL; + break; + default: + if (len != 0) + return -EINVAL; + } switch (param) { + case MSM_PARAM_COMM: + case MSM_PARAM_CMDLINE: { + char *str, **paramp; + + str = kmalloc(len + 1, GFP_KERNEL); + if (!str) + return -ENOMEM; + + if (copy_from_user(str, u64_to_user_ptr(value), len)) { + kfree(str); + return -EFAULT; + } + + /* Ensure string is null terminated: */ + str[len] = '\0'; + + if (param == MSM_PARAM_COMM) { + paramp = &ctx->comm; + } else { + paramp = &ctx->cmdline; + } + + kfree(*paramp); + *paramp = str; + + return 0; + } case MSM_PARAM_SYSPROF: if (!capable(CAP_SYS_ADMIN)) return -EPERM; diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c index 7a88dd6..f292b70 100644 --- a/drivers/gpu/drm/msm/msm_gpu.c +++ b/drivers/gpu/drm/msm/msm_gpu.c @@ -353,14 +353,22 @@ static void retire_submits(struct msm_gpu *gpu); static void get_comm_cmdline(struct msm_gem_submit *submit, char **comm, char **cmd) { + struct msm_file_private *ctx = submit->queue->ctx; struct task_struct *task; + /* Note that kstrdup will return NULL if argument is NULL: */ + *comm = kstrdup(ctx->comm, GFP_KERNEL); + *cmd = kstrdup(ctx->cmdline, GFP_KERNEL); + task = get_pid_task(submit->pid, PIDTYPE_PID); if (!task) return; - *comm = kstrdup(task->comm, GFP_KERNEL); - *cmd = kstrdup_quotable_cmdline(task, GFP_KERNEL); + if (!*comm) + *comm = kstrdup(task->comm, GFP_KERNEL); + + if (!*cmd) + *cmd = kstrdup_quotable_cmdline(task, GFP_KERNEL); put_task_struct(task); } diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h index ab5d31f..321e41d 100644 --- a/drivers/gpu/drm/msm/msm_gpu.h +++ b/drivers/gpu/drm/msm/msm_gpu.h @@ -355,6 +355,12 @@ struct msm_file_private { */ int sysprof; + /** comm: Overridden task comm, see MSM_PARAM_COMM */ + char *comm; + + /** cmdline: Overridden task cmdline, see MSM_PARAM_CMDLINE */ + char *cmdline; + /** * entities: * diff --git a/drivers/gpu/drm/msm/msm_submitqueue.c b/drivers/gpu/drm/msm/msm_submitqueue.c index 79b6ccd..f486a3c 100644 --- a/drivers/gpu/drm/msm/msm_submitqueue.c +++ b/drivers/gpu/drm/msm/msm_submitqueue.c @@ -61,6 +61,8 @@ void __msm_file_private_destroy(struct kref *kref) } msm_gem_address_space_put(ctx->aspace); + kfree(ctx->comm); + kfree(ctx->cmdline); kfree(ctx); } diff --git a/include/uapi/drm/msm_drm.h b/include/uapi/drm/msm_drm.h index 0aa1a8c..794ad19 100644 --- a/include/uapi/drm/msm_drm.h +++ b/include/uapi/drm/msm_drm.h @@ -82,6 +82,8 @@ struct drm_msm_timespec { #define MSM_PARAM_FAULTS 0x09 /* RO */ #define MSM_PARAM_SUSPENDS 0x0a /* RO */ #define MSM_PARAM_SYSPROF 0x0b /* WO: 1 preserves perfcntrs, 2 also disables suspend */ +#define MSM_PARAM_COMM 0x0c /* WO: override for task->comm */ +#define MSM_PARAM_CMDLINE 0x0d /* WO: override for task cmdline */ /* For backwards compat. The original support for preemption was based on * a single ring per priority level so # of priority levels equals the # -- 2.7.4