Commit d4726d77 authored by Rob Clark's avatar Rob Clark
Browse files

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: default avatarRob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220317165144.222101-4-robdclark@gmail.com


Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
parent 39ba0c0d

drivers/gpu/drm/msm/adreno/adreno_gpu.c

+40 −3
Original line number Diff line number Diff line
@@ -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 */

	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;

drivers/gpu/drm/msm/msm_gpu.c

+10 −2
Original line number Diff line number Diff line
@@ -353,13 +353,21 @@ 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;



	if (!*comm)

		*comm = kstrdup(task->comm, GFP_KERNEL);



	if (!*cmd)

		*cmd = kstrdup_quotable_cmdline(task, GFP_KERNEL);



	put_task_struct(task);

drivers/gpu/drm/msm/msm_gpu.h

+6 −0
Original line number Diff line number Diff line
@@ -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:

	 *

drivers/gpu/drm/msm/msm_submitqueue.c

+2 −0
Original line number Diff line number Diff line
@@ -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);

}

include/uapi/drm/msm_drm.h

+2 −0
Original line number Diff line number Diff line
@@ -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 #