drm: make drm_get_format_name thread-safe

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
[danvet: Clarify that the returned pointer must be freed with
kfree().]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

11 files changed, 88 insertions, 47 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
index c1b04e9aab57..0bf895920fbc 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
@@ -2071,6 +2071,7 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
         u32 tmp, viewport_w, viewport_h;
         int r;
         bool bypass_lut = false;
+        const char *format_name;
 
         /* no fb bound */
         if (!atomic && !crtc->primary->fb) {
@@ -2182,8 +2183,9 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
                 bypass_lut = true;
                 break;
         default:
-                DRM_ERROR("Unsupported screen format %s\n",
-                        drm_get_format_name(target_fb->pixel_format));
+                format_name = drm_get_format_name(target_fb->pixel_format);
+                DRM_ERROR("Unsupported screen format %s\n", format_name);
+                kfree(format_name);
                 return -EINVAL;
         }
 
diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
index d4bf133908b1..1558a974ad00 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
@@ -2046,6 +2046,7 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
         u32 tmp, viewport_w, viewport_h;
         int r;
         bool bypass_lut = false;
+        const char *format_name;
 
         /* no fb bound */
         if (!atomic && !crtc->primary->fb) {
@@ -2157,8 +2158,9 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
                 bypass_lut = true;
                 break;
         default:
-                DRM_ERROR("Unsupported screen format %s\n",
-                        drm_get_format_name(target_fb->pixel_format));
+                format_name = drm_get_format_name(target_fb->pixel_format);
+                DRM_ERROR("Unsupported screen format %s\n", format_name);
+                kfree(format_name);
                 return -EINVAL;
         }
 
diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
index 4fdfab1e9200..71a037546dae 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
@@ -1952,6 +1952,7 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
         u32 viewport_w, viewport_h;
         int r;
         bool bypass_lut = false;
+        const char *format_name;
 
         /* no fb bound */
         if (!atomic && !crtc->primary->fb) {
@@ -2056,8 +2057,9 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
                 bypass_lut = true;
                 break;
         default:
-                DRM_ERROR("Unsupported screen format %s\n",
-                          drm_get_format_name(target_fb->pixel_format));
+                format_name = drm_get_format_name(target_fb->pixel_format);
+                DRM_ERROR("Unsupported screen format %s\n", format_name);
+                kfree(format_name);
                 return -EINVAL;
         }
 
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index fa3930757972..087391f08a69 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -837,8 +837,9 @@ static int drm_atomic_plane_check(struct drm_plane *plane,
         /* Check whether this plane supports the fb pixel format. */
         ret = drm_plane_check_pixel_format(plane, state->fb->pixel_format);
         if (ret) {
-                DRM_DEBUG_ATOMIC("Invalid pixel format %s\n",
-                                 drm_get_format_name(state->fb->pixel_format));
+                const char *format_name = drm_get_format_name(state->fb->pixel_format);
+                DRM_DEBUG_ATOMIC("Invalid pixel format %s\n", format_name);
+                kfree(format_name);
                 return ret;
         }
 
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index e92bb9d3f90f..f4e3ebebe79a 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -2592,8 +2592,9 @@ static int __setplane_internal(struct drm_plane *plane,
         /* Check whether this plane supports the fb pixel format. */
         ret = drm_plane_check_pixel_format(plane, fb->pixel_format);
         if (ret) {
-                DRM_DEBUG_KMS("Invalid pixel format %s\n",
-                              drm_get_format_name(fb->pixel_format));
+                const char *format_name = drm_get_format_name(fb->pixel_format);
+                DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
+                kfree(format_name);
                 goto out;
         }
 
@@ -2902,8 +2903,9 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
                         ret = drm_plane_check_pixel_format(crtc->primary,
                                                            fb->pixel_format);
                         if (ret) {
-                                DRM_DEBUG_KMS("Invalid pixel format %s\n",
-                                        drm_get_format_name(fb->pixel_format));
+                                const char *format_name = drm_get_format_name(fb->pixel_format);
+                                DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
+                                kfree(format_name);
                                 goto out;
                         }
                 }
@@ -3279,6 +3281,7 @@ int drm_mode_addfb(struct drm_device *dev,
 static int format_check(const struct drm_mode_fb_cmd2 *r)
 {
         uint32_t format = r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN;
+        const char *format_name;
 
         switch (format) {
         case DRM_FORMAT_C8:
@@ -3343,8 +3346,9 @@ static int format_check(const struct drm_mode_fb_cmd2 *r)
         case DRM_FORMAT_YVU444:
                 return 0;
         default:
-                DRM_DEBUG_KMS("invalid pixel format %s\n",
-                              drm_get_format_name(r->pixel_format));
+                format_name = drm_get_format_name(r->pixel_format);
+                DRM_DEBUG_KMS("invalid pixel format %s\n", format_name);
+                kfree(format_name);
                 return -EINVAL;
         }
 }
@@ -3355,8 +3359,9 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
 
         ret = format_check(r);
         if (ret) {
-                DRM_DEBUG_KMS("bad framebuffer format %s\n",
-                              drm_get_format_name(r->pixel_format));
+                const char *format_name = drm_get_format_name(r->pixel_format);
+                DRM_DEBUG_KMS("bad framebuffer format %s\n", format_name);
+                kfree(format_name);
                 return ret;
         }
 
diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index 0645c85d5f95..d8f65c4fadf7 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -39,16 +39,14 @@ static char printable_char(int c)
  * drm_get_format_name - return a string for drm fourcc format
  * @format: format to compute name of
  *
- * Note that the buffer used by this function is globally shared and owned by
- * the function itself.
- *
- * FIXME: This isn't really multithreading safe.
+ * Note that the buffer returned by this function is owned by the caller
+ * and will need to be freed using kfree().
  */
 const char *drm_get_format_name(uint32_t format)
 {
-        static char buf[32];
+        char *buf = kmalloc(32, GFP_KERNEL);
 
-        snprintf(buf, sizeof(buf),
+        snprintf(buf, 32,
                  "%c%c%c%c %s-endian (0x%08x)",
                  printable_char(format & 0xff),
                  printable_char((format >> 8) & 0xff),
@@ -73,6 +71,8 @@ EXPORT_SYMBOL(drm_get_format_name);
 void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
                           int *bpp)
 {
+        const char *format_name;
+
         switch (format) {
         case DRM_FORMAT_C8:
         case DRM_FORMAT_RGB332:
@@ -127,8 +127,9 @@ void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
                 *bpp = 32;
                 break;
         default:
-                DRM_DEBUG_KMS("unsupported pixel format %s\n",
-                              drm_get_format_name(format));
+                format_name = drm_get_format_name(format);
+                DRM_DEBUG_KMS("unsupported pixel format %s\n", format_name);
+                kfree(format_name);
                 *depth = 0;
                 *bpp = 0;
                 break;
diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
index c3707d47cd89..ac7fa02b341f 100644
--- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
+++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
@@ -608,15 +608,17 @@ static void ade_rdma_set(void __iomem *base, struct drm_framebuffer *fb,
                          u32 ch, u32 y, u32 in_h, u32 fmt)
 {
         struct drm_gem_cma_object *obj = drm_fb_cma_get_gem_obj(fb, 0);
+        const char *format_name;
         u32 reg_ctrl, reg_addr, reg_size, reg_stride, reg_space, reg_en;
         u32 stride = fb->pitches[0];
         u32 addr = (u32)obj->paddr + y * stride;
 
         DRM_DEBUG_DRIVER("rdma%d: (y=%d, height=%d), stride=%d, paddr=0x%x\n",
                          ch + 1, y, in_h, stride, (u32)obj->paddr);
+        format_name = drm_get_format_name(fb->pixel_format);
         DRM_DEBUG_DRIVER("addr=0x%x, fb:%dx%d, pixel_format=%d(%s)\n",
-                         addr, fb->width, fb->height, fmt,
-                         drm_get_format_name(fb->pixel_format));
+                         addr, fb->width, fb->height, fmt, format_name);
+        kfree(format_name);
 
         /* get reg offset */
         reg_ctrl = RD_CH_CTRL(ch);
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index f62285c1ed7f..120869e7622d 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -3113,6 +3113,7 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
         for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
                 struct drm_plane_state *state;
                 struct drm_plane *plane = &intel_plane->base;
+                const char *format_name;
 
                 if (!plane->state) {
                         seq_puts(m, "plane->state is NULL!\n");
@@ -3121,6 +3122,12 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
 
                 state = plane->state;
 
+                if (state->fb) {
+                        format_name = drm_get_format_name(state->fb->pixel_format);
+                } else {
+                        format_name = kstrdup("N/A", GFP_KERNEL);
+                }
+
                 seq_printf(m, "\t--Plane id %d: type=%s, crtc_pos=%4dx%4d, crtc_size=%4dx%4d, src_pos=%d.%04ux%d.%04u, src_size=%d.%04ux%d.%04u, format=%s, rotation=%s\n",
                            plane->base.id,
                            plane_type(intel_plane->base.type),
@@ -3134,8 +3141,10 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
                            ((state->src_w & 0xffff) * 15625) >> 10,
                            (state->src_h >> 16),
                            ((state->src_h & 0xffff) * 15625) >> 10,
-                           state->fb ? drm_get_format_name(state->fb->pixel_format) : "N/A",
+                           format_name,
                            plane_rotation(state->rotation));
+
+                kfree(format_name);
         }
 }
 
diff --git a/drivers/gpu/drm/i915/intel_atomic_plane.c b/drivers/gpu/drm/i915/intel_atomic_plane.c
index e06d1f5334cf..98288d87c2ce 100644
--- a/drivers/gpu/drm/i915/intel_atomic_plane.c
+++ b/drivers/gpu/drm/i915/intel_atomic_plane.c
@@ -143,6 +143,7 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
                 crtc_state->base.enable ? crtc_state->pipe_src_h : 0;
 
         if (state->fb && intel_rotation_90_or_270(state->rotation)) {
+                const char *format_name;
                 if (!(state->fb->modifier[0] == I915_FORMAT_MOD_Y_TILED ||
                         state->fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED)) {
                         DRM_DEBUG_KMS("Y/Yf tiling required for 90/270!\n");
@@ -157,8 +158,9 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
                 switch (state->fb->pixel_format) {
                 case DRM_FORMAT_C8:
                 case DRM_FORMAT_RGB565:
-                        DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n",
-                                        drm_get_format_name(state->fb->pixel_format));
+                        format_name = drm_get_format_name(state->fb->pixel_format);
+                        DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n", format_name);
+                        kfree(format_name);
                         return -EINVAL;
 
                 default:
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index c6f27ab99e8f..acc1ba36c5fa 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12258,6 +12258,7 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
 
         DRM_DEBUG_KMS("planes on this crtc\n");
         list_for_each_entry(plane, &dev->mode_config.plane_list, head) {
+                const char *format_name;
                 intel_plane = to_intel_plane(plane);
                 if (intel_plane->pipe != crtc->pipe)
                         continue;
@@ -12270,11 +12271,12 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
                         continue;
                 }
 
+                format_name = drm_get_format_name(fb->pixel_format);
+
                 DRM_DEBUG_KMS("[PLANE:%d:%s] enabled",
                               plane->base.id, plane->name);
                 DRM_DEBUG_KMS("\tFB:%d, fb = %ux%u format = %s",
-                              fb->base.id, fb->width, fb->height,
-                              drm_get_format_name(fb->pixel_format));
+                              fb->base.id, fb->width, fb->height, format_name);
                 DRM_DEBUG_KMS("\tscaler:%d src %dx%d+%d+%d dst %dx%d+%d+%d\n",
                               state->scaler_id,
                               state->base.src.x1 >> 16,
@@ -12284,6 +12286,8 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
                               state->base.dst.x1, state->base.dst.y1,
                               drm_rect_width(&state->base.dst),
                               drm_rect_height(&state->base.dst));
+
+                kfree(format_name);
         }
 }
 
@@ -14911,6 +14915,7 @@ static int intel_framebuffer_init(struct drm_device *dev,
         unsigned int aligned_height;
         int ret;
         u32 pitch_limit, stride_alignment;
+        const char *format_name;
 
         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 
@@ -14985,16 +14990,18 @@ static int intel_framebuffer_init(struct drm_device *dev,
                 break;
         case DRM_FORMAT_XRGB1555:
                 if (INTEL_INFO(dev)->gen > 3) {
-                        DRM_DEBUG("unsupported pixel format: %s\n",
-                                  drm_get_format_name(mode_cmd->pixel_format));
+                        format_name = drm_get_format_name(mode_cmd->pixel_format);
+                        DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+                        kfree(format_name);
                         return -EINVAL;
                 }
                 break;
         case DRM_FORMAT_ABGR8888:
                 if (!IS_VALLEYVIEW(dev) && !IS_CHERRYVIEW(dev) &&
                     INTEL_INFO(dev)->gen < 9) {
-                        DRM_DEBUG("unsupported pixel format: %s\n",
-                                  drm_get_format_name(mode_cmd->pixel_format));
+                        format_name = drm_get_format_name(mode_cmd->pixel_format);
+                        DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+                        kfree(format_name);
                         return -EINVAL;
                 }
                 break;
@@ -15002,15 +15009,17 @@ static int intel_framebuffer_init(struct drm_device *dev,
         case DRM_FORMAT_XRGB2101010:
         case DRM_FORMAT_XBGR2101010:
                 if (INTEL_INFO(dev)->gen < 4) {
-                        DRM_DEBUG("unsupported pixel format: %s\n",
-                                  drm_get_format_name(mode_cmd->pixel_format));
+                        format_name = drm_get_format_name(mode_cmd->pixel_format);
+                        DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+                        kfree(format_name);
                         return -EINVAL;
                 }
                 break;
         case DRM_FORMAT_ABGR2101010:
                 if (!IS_VALLEYVIEW(dev) && !IS_CHERRYVIEW(dev)) {
-                        DRM_DEBUG("unsupported pixel format: %s\n",
-                                  drm_get_format_name(mode_cmd->pixel_format));
+                        format_name = drm_get_format_name(mode_cmd->pixel_format);
+                        DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+                        kfree(format_name);
                         return -EINVAL;
                 }
                 break;
@@ -15019,14 +15028,16 @@ static int intel_framebuffer_init(struct drm_device *dev,
         case DRM_FORMAT_YVYU:
         case DRM_FORMAT_VYUY:
                 if (INTEL_INFO(dev)->gen < 5) {
-                        DRM_DEBUG("unsupported pixel format: %s\n",
-                                  drm_get_format_name(mode_cmd->pixel_format));
+                        format_name = drm_get_format_name(mode_cmd->pixel_format);
+                        DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+                        kfree(format_name);
                         return -EINVAL;
                 }
                 break;
         default:
-                DRM_DEBUG("unsupported pixel format: %s\n",
-                          drm_get_format_name(mode_cmd->pixel_format));
+                format_name = drm_get_format_name(mode_cmd->pixel_format);
+                DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+                kfree(format_name);
                 return -EINVAL;
         }
 
diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
index a97abc8af657..981ca3f5842e 100644
--- a/drivers/gpu/drm/radeon/atombios_crtc.c
+++ b/drivers/gpu/drm/radeon/atombios_crtc.c
@@ -1154,6 +1154,7 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
         u32 tmp, viewport_w, viewport_h;
         int r;
         bool bypass_lut = false;
+        const char *format_name;
 
         /* no fb bound */
         if (!atomic && !crtc->primary->fb) {
@@ -1257,8 +1258,9 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
                 bypass_lut = true;
                 break;
         default:
-                DRM_ERROR("Unsupported screen format %s\n",
-                          drm_get_format_name(target_fb->pixel_format));
+                format_name = drm_get_format_name(target_fb->pixel_format);
+                DRM_ERROR("Unsupported screen format %s\n", format_name);
+                kfree(format_name);
                 return -EINVAL;
         }
 
@@ -1469,6 +1471,7 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
         u32 viewport_w, viewport_h;
         int r;
         bool bypass_lut = false;
+        const char *format_name;
 
         /* no fb bound */
         if (!atomic && !crtc->primary->fb) {
@@ -1558,8 +1561,9 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
                 bypass_lut = true;
                 break;
         default:
-                DRM_ERROR("Unsupported screen format %s\n",
-                          drm_get_format_name(target_fb->pixel_format));
+                format_name = drm_get_format_name(target_fb->pixel_format);
+                DRM_ERROR("Unsupported screen format %s\n", format_name);
+                kfree(format_name);
                 return -EINVAL;
         }