[PATCH] drm: make drm_get_format_name thread-safe

From: Eric Engestrom
Date: Sun Aug 14 2016 - 20:04:05 EST

Signed-off-by: Eric Engestrom <eric@xxxxxxxxxxxx>
---

I moved the main bits to be the first diffs, shouldn't affect anything
when applying the patch, but I wanted to ask:
I don't like the hard-coded `32` the appears in both kmalloc() and
snprintf(), what do you think? If you don't like it either, what would
you suggest? Should I #define it?

Second question is about the patch mail itself: should I send this kind
of patch separated by module, with a note requesting them to be squashed
when applying? It has to land as a single patch, but for review it might
be easier if people only see the bits they each care about, as well as
to collect ack's/r-b's.

Cheers,
Eric

---
drivers/gpu/drm/amd/amdgpu/dce_v10_0.c | 6 ++--
drivers/gpu/drm/amd/amdgpu/dce_v11_0.c | 6 ++--
drivers/gpu/drm/amd/amdgpu/dce_v8_0.c | 6 ++--
drivers/gpu/drm/drm_atomic.c | 5 ++--
drivers/gpu/drm/drm_crtc.c | 21 ++++++++-----
drivers/gpu/drm/drm_fourcc.c | 17 ++++++-----
drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c | 6 ++--
drivers/gpu/drm/i915/i915_debugfs.c | 11 ++++++-
drivers/gpu/drm/i915/intel_atomic_plane.c | 6 ++--
drivers/gpu/drm/i915/intel_display.c | 39 ++++++++++++++++---------
drivers/gpu/drm/radeon/atombios_crtc.c | 12 +++++---
include/drm/drm_fourcc.h | 2 +-
12 files changed, 89 insertions(+), 48 deletions(-)

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index 0645c85..38216a1 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.
*/
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/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
index 7f90a39..030d22d 100644
--- a/include/drm/drm_fourcc.h
+++ b/include/drm/drm_fourcc.h
@@ -32,6 +32,6 @@ int drm_format_horz_chroma_subsampling(uint32_t format);
int drm_format_vert_chroma_subsampling(uint32_t format);
int drm_format_plane_width(int width, uint32_t format, int plane);
int drm_format_plane_height(int height, uint32_t format, int plane);
-const char *drm_get_format_name(uint32_t format);
+const char *drm_get_format_name(uint32_t format) __malloc;

#endif /* __DRM_FOURCC_H__ */
diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
index c1b04e9..0bf8959 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 d4bf133..1558a97 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 4fdfab1..71a0375 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 fa39307..087391f 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 b1dbb60..7da5d33 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/hisilicon/kirin/kirin_drm_ade.c b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
index c3707d4..ac7fa02 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 844fea7..904720b 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -3109,6 +3109,7 @@ 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");
@@ -3117,6 +3118,12 @@ 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),
@@ -3130,8 +3137,10 @@ 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 7de7721..e06131a 100644
--- a/drivers/gpu/drm/i915/intel_atomic_plane.c
+++ b/drivers/gpu/drm/i915/intel_atomic_plane.c
@@ -157,6 +157,7 @@ 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");
@@ -171,8 +172,9 @@ 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 c457eed..071399b 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12282,6 +12282,7 @@ 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;
@@ -12294,11 +12295,12 @@ 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->src.x1 >> 16, state->src.y1 >> 16,
@@ -12307,6 +12309,8 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
state->dst.x1, state->dst.y1,
drm_rect_width(&state->dst),
drm_rect_height(&state->dst));
+
+ kfree(format_name);
}
}

@@ -14936,6 +14940,7 @@ 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));

@@ -15009,16 +15014,18 @@ 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;
@@ -15026,15 +15033,17 @@ 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;
@@ -15043,14 +15052,16 @@ 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 a97abc8..981ca3f 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;
}

--
2.9.3