tu: Add TU_DEBUG=comm

The debug flag overrides the process's comm/cmdline values with the
process's comm/cmdline.  This can be useful for debugging faults that
happen after the process exits (when normally the comm/cmdline would no
longer be available to capture in a GPU devcoredump).

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34846>

src/freedreno/vulkan/tu_knl_drm_msm.cc

@@ -16,6 +16,7 @@
 
 #include "drm-uapi/msm_drm.h"
 #include "util/u_debug.h"
+#include "util/u_process.h"
 #include "util/hash_table.h"
 
 #include "tu_cmd_buffer.h"
@@ -126,6 +127,36 @@ tu_drm_has_preemption(const struct tu_physical_device *dev)
    return true;
 }
 
+static int
+tu_drm_set_param(int fd, uint32_t param, uint64_t value, uint32_t len)
+{
+   struct drm_msm_param param_req = {
+      .pipe = MSM_PIPE_3D0,
+      .param = param,
+      .value = value,
+      .len = len,
+   };
+
+   int ret = drmCommandWriteRead(fd, DRM_MSM_SET_PARAM, &param_req,
+                                 sizeof(param_req));
+   return ret;
+}
+
+static void
+tu_drm_set_debuginfo(int fd)
+{
+   if (!TU_DEBUG(COMM))
+      return;
+
+   const char *comm = util_get_process_name();
+   if (comm)
+      tu_drm_set_param(fd, MSM_PARAM_COMM, (uintptr_t)comm, strlen(comm));
+
+   static char cmdline[0x1000];
+   if (util_get_command_line(cmdline, sizeof(cmdline)))
+      tu_drm_set_param(fd, MSM_PARAM_CMDLINE, (uintptr_t)cmdline, strlen(cmdline));
+}
+
 static uint32_t
 tu_drm_get_priorities(const struct tu_physical_device *dev)
 {
@@ -209,6 +240,8 @@ msm_device_init(struct tu_device *dev)
             "failed to open device %s", dev->physical_device->fd_path);
    }
 
+   tu_drm_set_debuginfo(fd);
+
    int ret = tu_drm_get_param(fd, MSM_PARAM_FAULTS, &dev->fault_count);
    if (ret != 0) {
       close(fd);
@@ -1070,6 +1103,8 @@ tu_knl_drm_msm_load(struct tu_instance *instance,
       (device->msm_minor_version >= 8) &&
       tu_drm_is_memory_type_supported(fd, MSM_BO_CACHED_COHERENT);
 
+   tu_drm_set_debuginfo(fd);
+
    device->submitqueue_priority_count = tu_drm_get_priorities(device);
 
    device->ubwc_config.highest_bank_bit = tu_drm_get_highest_bank_bit(device);

src/freedreno/vulkan/tu_util.cc

@@ -51,6 +51,7 @@ static const struct debug_control tu_debug_options[] = {
    { "perfcraw", TU_DEBUG_PERFCRAW },
    { "fdmoffset", TU_DEBUG_FDM_OFFSET },
    { "check_cmd_buffer_status", TU_DEBUG_CHECK_CMD_BUFFER_STATUS },
+   { "comm", TU_DEBUG_COMM },
    { NULL, 0 }
 };
 

src/freedreno/vulkan/tu_util.h

@@ -71,6 +71,7 @@ enum tu_debug_flags : uint64_t
    TU_DEBUG_PERFCRAW                 = BITFIELD64_BIT(30),
    TU_DEBUG_FDM_OFFSET               = BITFIELD64_BIT(31),
    TU_DEBUG_CHECK_CMD_BUFFER_STATUS  = BITFIELD64_BIT(32),
+   TU_DEBUG_COMM                     = BITFIELD64_BIT(33),
 };
 
 struct tu_env {