[PATCH 0/4] drm: enable -Wformat-truncation

[PATCH 0/4] drm: enable -Wformat-truncation

[Jani Nikula]

Jani Nikula (4):
  drm/amdgpu: fix -Wformat-truncation warning in
    amdgpu_gfx_kiq_init_ring()
  drm/nouveau: fix -Wformat-truncation warning in
    nouveau_backlight_init()
  drm/imx: fix -Wformat-truncation warning in imx_ldb_probe()
  drm: enable -Wformat-truncation across the subsystem

 drivers/gpu/drm/Makefile                    | 3 +--
 drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c     | 6 ++++--
 drivers/gpu/drm/imx/ipuv3/imx-ldb.c         | 6 +++++-
 drivers/gpu/drm/nouveau/nouveau_backlight.c | 9 +++++++--
 4 files changed, 17 insertions(+), 7 deletions(-)

-- 
2.39.2

[PATCH 1/4] drm/amdgpu: fix -Wformat-truncation warning in amdgpu_gfx_kiq_init_ring()

[Jani Nikula]

Enabling -Wformat-truncation yields the following warning:

../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c: In function ‘amdgpu_gfx_kiq_init_ring’:
../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c:332:61: error: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size between 0 and 8 [-Werror=format-truncation=]
  332 |         snprintf(ring->name, sizeof(ring->name), "kiq_%d.%d.%d.%d",
      |                                                             ^~
../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c:332:50: note: directive argument in the range [0, 2147483647]
  332 |         snprintf(ring->name, sizeof(ring->name), "kiq_%d.%d.%d.%d",
      |                                                  ^~~~~~~~~~~~~~~~~
../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c:332:9: note: ‘snprintf’ output between 12 and 41 bytes into a destination of size 16
  332 |         snprintf(ring->name, sizeof(ring->name), "kiq_%d.%d.%d.%d",
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  333 |                  xcc_id, ring->me, ring->pipe, ring->queue);
      |                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Silence the warning by checking the snprintf() return value.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

---

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Pan Xinhui <Xinhui.Pan@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
index 1d955652f3ba..92744d0d2c10 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
@@ -329,8 +329,10 @@ int amdgpu_gfx_kiq_init_ring(struct amdgpu_device *adev, int xcc_id)
 
 	ring->eop_gpu_addr = kiq->eop_gpu_addr;
 	ring->no_scheduler = true;
-	snprintf(ring->name, sizeof(ring->name), "kiq_%d.%d.%d.%d",
-		 xcc_id, ring->me, ring->pipe, ring->queue);
+	r = snprintf(ring->name, sizeof(ring->name), "kiq_%d.%d.%d.%d",
+		     xcc_id, ring->me, ring->pipe, ring->queue);
+	if (r >= sizeof(ring->name))
+		dev_warn(adev->dev, "kiq ring name truncated\n");
 	r = amdgpu_ring_init(adev, ring, 1024, irq, AMDGPU_CP_KIQ_IRQ_DRIVER0,
 			     AMDGPU_RING_PRIO_DEFAULT, NULL);
 	if (r)
-- 
2.39.2

Re: [PATCH 1/4] drm/amdgpu: fix -Wformat-truncation warning in amdgpu_gfx_kiq_init_ring()

[Alex Deucher]

On Thu, May 23, 2024 at 11:51 AM Jani Nikula <jani.nikula@intel.com> wrote:
>
> Enabling -Wformat-truncation yields the following warning:
>
> ../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c: In function ‘amdgpu_gfx_kiq_init_ring’:
> ../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c:332:61: error: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size between 0 and 8 [-Werror=format-truncation=]
>   332 |         snprintf(ring->name, sizeof(ring->name), "kiq_%d.%d.%d.%d",
>       |                                                             ^~
> ../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c:332:50: note: directive argument in the range [0, 2147483647]
>   332 |         snprintf(ring->name, sizeof(ring->name), "kiq_%d.%d.%d.%d",
>       |                                                  ^~~~~~~~~~~~~~~~~
> ../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c:332:9: note: ‘snprintf’ output between 12 and 41 bytes into a destination of size 16
>   332 |         snprintf(ring->name, sizeof(ring->name), "kiq_%d.%d.%d.%d",
>       |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   333 |                  xcc_id, ring->me, ring->pipe, ring->queue);
>       |                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Silence the warning by checking the snprintf() return value.
>

Already fixed with this patch:
https://patchwork.freedesktop.org/patch/594864/

Thanks,

Alex

> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>
> ---
>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: "Christian König" <christian.koenig@amd.com>
> Cc: Pan Xinhui <Xinhui.Pan@amd.com>
> Cc: amd-gfx@lists.freedesktop.org
> Cc: dri-devel@lists.freedesktop.org
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
> index 1d955652f3ba..92744d0d2c10 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
> @@ -329,8 +329,10 @@ int amdgpu_gfx_kiq_init_ring(struct amdgpu_device *adev, int xcc_id)
>
>         ring->eop_gpu_addr = kiq->eop_gpu_addr;
>         ring->no_scheduler = true;
> -       snprintf(ring->name, sizeof(ring->name), "kiq_%d.%d.%d.%d",
> -                xcc_id, ring->me, ring->pipe, ring->queue);
> +       r = snprintf(ring->name, sizeof(ring->name), "kiq_%d.%d.%d.%d",
> +                    xcc_id, ring->me, ring->pipe, ring->queue);
> +       if (r >= sizeof(ring->name))
> +               dev_warn(adev->dev, "kiq ring name truncated\n");
>         r = amdgpu_ring_init(adev, ring, 1024, irq, AMDGPU_CP_KIQ_IRQ_DRIVER0,
>                              AMDGPU_RING_PRIO_DEFAULT, NULL);
>         if (r)
> --
> 2.39.2
>

Re: [PATCH 1/4] drm/amdgpu: fix -Wformat-truncation warning in amdgpu_gfx_kiq_init_ring()

[Jani Nikula]

On Thu, 23 May 2024, Alex Deucher <alexdeucher@gmail.com> wrote:
> Already fixed with this patch:
> https://patchwork.freedesktop.org/patch/594864/

Great, thanks!

BR,
Jani.



-- 
Jani Nikula, Intel

[PATCH 2/4] drm/nouveau: fix -Wformat-truncation warning in nouveau_backlight_init()

[Jani Nikula]

Enabling -Wformat-truncation yields the following warning:

../drivers/gpu/drm/nouveau/nouveau_backlight.c: In function ‘nouveau_backlight_init’:
../drivers/gpu/drm/nouveau/nouveau_backlight.c:56:69: error: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size 3 [-Werror=format-truncation=]
   56 |                 snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
      |                                                                     ^~
In function ‘nouveau_get_backlight_name’,
    inlined from ‘nouveau_backlight_init’ at ../drivers/gpu/drm/nouveau/nouveau_backlight.c:351:7:
../drivers/gpu/drm/nouveau/nouveau_backlight.c:56:56: note: directive argument in the range [1, 2147483647]
   56 |                 snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
      |                                                        ^~~~~~~~~~~~~~~~
../drivers/gpu/drm/nouveau/nouveau_backlight.c:56:17: note: ‘snprintf’ output between 14 and 23 bytes into a destination of size 15
   56 |                 snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Silence the warning by checking the snprintf() return value.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

---

Cc: Karol Herbst <kherbst@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Danilo Krummrich <dakr@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Cc: nouveau@lists.freedesktop.org
---
 drivers/gpu/drm/nouveau/nouveau_backlight.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index d47442125fa1..1d77a5f280c5 100644
--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -49,13 +49,18 @@ nouveau_get_backlight_name(char backlight_name[BL_NAME_SIZE],
 			   struct nouveau_backlight *bl)
 {
 	const int nb = ida_alloc_max(&bl_ida, 99, GFP_KERNEL);
+	int ret;
 
 	if (nb < 0)
 		return false;
 	if (nb > 0)
-		snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
+		ret = snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
 	else
-		snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight");
+		ret = snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight");
+
+	if (ret >= BL_NAME_SIZE)
+		return false;
+
 	bl->id = nb;
 	return true;
 }
-- 
2.39.2

[PATCH 3/4] drm/imx: fix -Wformat-truncation warning in imx_ldb_probe()

[Jani Nikula]

Enabling -Wformat-truncation yields the following warning:

../drivers/gpu/drm/imx/ipuv3/imx-ldb.c: In function ‘imx_ldb_probe’:
../drivers/gpu/drm/imx/ipuv3/imx-ldb.c:658:57: error: ‘_sel’ directive output may be truncated writing 4 bytes into a region of size between 3 and 13 [-Werror=format-truncation=]
  658 |                 snprintf(clkname, sizeof(clkname), "di%d_sel", i);
      |                                                         ^~~~
../drivers/gpu/drm/imx/ipuv3/imx-ldb.c:658:17: note: ‘snprintf’ output between 8 and 18 bytes into a destination of size 16
  658 |                 snprintf(clkname, sizeof(clkname), "di%d_sel", i);
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Silence the warning by checking the snprintf() return value.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

---

Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Cc: imx@lists.linux.dev
---
 drivers/gpu/drm/imx/ipuv3/imx-ldb.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/imx/ipuv3/imx-ldb.c b/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
index 71d70194fcbd..46f779fe60ee 100644
--- a/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
+++ b/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
@@ -654,8 +654,12 @@ static int imx_ldb_probe(struct platform_device *pdev)
 	 */
 	for (i = 0; i < 4; i++) {
 		char clkname[16];
+		int len;
+
+		len = snprintf(clkname, sizeof(clkname), "di%d_sel", i);
+		if (len >= sizeof(clkname))
+			dev_err(dev, "clkname truncated\n");
 
-		snprintf(clkname, sizeof(clkname), "di%d_sel", i);
 		imx_ldb->clk_sel[i] = devm_clk_get(imx_ldb->dev, clkname);
 		if (IS_ERR(imx_ldb->clk_sel[i])) {
 			ret = PTR_ERR(imx_ldb->clk_sel[i]);
-- 
2.39.2

Re: [PATCH 3/4] drm/imx: fix -Wformat-truncation warning in imx_ldb_probe()

[Ville Syrjälä]

On Thu, May 23, 2024 at 06:51:08PM +0300, Jani Nikula wrote:
> Enabling -Wformat-truncation yields the following warning:
> 
> ../drivers/gpu/drm/imx/ipuv3/imx-ldb.c: In function ‘imx_ldb_probe’:
> ../drivers/gpu/drm/imx/ipuv3/imx-ldb.c:658:57: error: ‘_sel’ directive output may be truncated writing 4 bytes into a region of size between 3 and 13 [-Werror=format-truncation=]
>   658 |                 snprintf(clkname, sizeof(clkname), "di%d_sel", i);
>       |                                                         ^~~~
> ../drivers/gpu/drm/imx/ipuv3/imx-ldb.c:658:17: note: ‘snprintf’ output between 8 and 18 bytes into a destination of size 16
>   658 |                 snprintf(clkname, sizeof(clkname), "di%d_sel", i);
>       |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

If only the compiler could count to three...

> 
> Silence the warning by checking the snprintf() return value.
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> 
> ---
> 
> Cc: Philipp Zabel <p.zabel@pengutronix.de>
> Cc: Shawn Guo <shawnguo@kernel.org>
> Cc: Sascha Hauer <s.hauer@pengutronix.de>
> Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
> Cc: Fabio Estevam <festevam@gmail.com>
> Cc: dri-devel@lists.freedesktop.org
> Cc: imx@lists.linux.dev
> ---
>  drivers/gpu/drm/imx/ipuv3/imx-ldb.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/imx/ipuv3/imx-ldb.c b/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
> index 71d70194fcbd..46f779fe60ee 100644
> --- a/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
> +++ b/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
> @@ -654,8 +654,12 @@ static int imx_ldb_probe(struct platform_device *pdev)
>  	 */
>  	for (i = 0; i < 4; i++) {
>  		char clkname[16];
> +		int len;
> +
> +		len = snprintf(clkname, sizeof(clkname), "di%d_sel", i);
> +		if (len >= sizeof(clkname))
> +			dev_err(dev, "clkname truncated\n");
>  
> -		snprintf(clkname, sizeof(clkname), "di%d_sel", i);
>  		imx_ldb->clk_sel[i] = devm_clk_get(imx_ldb->dev, clkname);
>  		if (IS_ERR(imx_ldb->clk_sel[i])) {
>  			ret = PTR_ERR(imx_ldb->clk_sel[i]);
> -- 
> 2.39.2

-- 
Ville Syrjälä
Intel

Re: [PATCH 3/4] drm/imx: fix -Wformat-truncation warning in imx_ldb_probe()

[Jani Nikula]

On Thu, 23 May 2024, Ville Syrjälä <ville.syrjala@linux.intel.com> wrote:
> On Thu, May 23, 2024 at 06:51:08PM +0300, Jani Nikula wrote:
>> Enabling -Wformat-truncation yields the following warning:
>> 
>> ../drivers/gpu/drm/imx/ipuv3/imx-ldb.c: In function ‘imx_ldb_probe’:
>> ../drivers/gpu/drm/imx/ipuv3/imx-ldb.c:658:57: error: ‘_sel’ directive output may be truncated writing 4 bytes into a region of size between 3 and 13 [-Werror=format-truncation=]
>>   658 |                 snprintf(clkname, sizeof(clkname), "di%d_sel", i);
>>       |                                                         ^~~~
>> ../drivers/gpu/drm/imx/ipuv3/imx-ldb.c:658:17: note: ‘snprintf’ output between 8 and 18 bytes into a destination of size 16
>>   658 |                 snprintf(clkname, sizeof(clkname), "di%d_sel", i);
>>       |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> If only the compiler could count to three...

I did not try, but apparently using %hhd would hide the issue too:

	snprintf(clkname, sizeof(clkname), "di%hhd_sel", i);

BR,
Jani.


>
>> 
>> Silence the warning by checking the snprintf() return value.
>> 
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>> 
>> ---
>> 
>> Cc: Philipp Zabel <p.zabel@pengutronix.de>
>> Cc: Shawn Guo <shawnguo@kernel.org>
>> Cc: Sascha Hauer <s.hauer@pengutronix.de>
>> Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
>> Cc: Fabio Estevam <festevam@gmail.com>
>> Cc: dri-devel@lists.freedesktop.org
>> Cc: imx@lists.linux.dev
>> ---
>>  drivers/gpu/drm/imx/ipuv3/imx-ldb.c | 6 +++++-
>>  1 file changed, 5 insertions(+), 1 deletion(-)
>> 
>> diff --git a/drivers/gpu/drm/imx/ipuv3/imx-ldb.c b/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
>> index 71d70194fcbd..46f779fe60ee 100644
>> --- a/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
>> +++ b/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
>> @@ -654,8 +654,12 @@ static int imx_ldb_probe(struct platform_device *pdev)
>>  	 */
>>  	for (i = 0; i < 4; i++) {
>>  		char clkname[16];
>> +		int len;
>> +
>> +		len = snprintf(clkname, sizeof(clkname), "di%d_sel", i);
>> +		if (len >= sizeof(clkname))
>> +			dev_err(dev, "clkname truncated\n");
>>  
>> -		snprintf(clkname, sizeof(clkname), "di%d_sel", i);
>>  		imx_ldb->clk_sel[i] = devm_clk_get(imx_ldb->dev, clkname);
>>  		if (IS_ERR(imx_ldb->clk_sel[i])) {
>>  			ret = PTR_ERR(imx_ldb->clk_sel[i]);
>> -- 
>> 2.39.2

-- 
Jani Nikula, Intel

[PATCH 4/4] drm: enable -Wformat-truncation across the subsystem

[Jani Nikula]

With the -Wformat-truncation warnings fixed, finish the job started in
commit a61ddb4393ad ("drm: enable (most) W=1 warnings by default across
the subsystem"), and enable that warning too.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

---

Gut feeling says there are more issues, and my configs just don't catch
them all, but let's see what the build bots have to say. ;)
---
 drivers/gpu/drm/Makefile | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 68cc9258ffc4..644613dbedda 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -16,8 +16,7 @@ subdir-ccflags-y += $(call cc-option, -Wunused-but-set-variable)
 subdir-ccflags-y += $(call cc-option, -Wunused-const-variable)
 subdir-ccflags-y += $(call cc-option, -Wpacked-not-aligned)
 subdir-ccflags-y += $(call cc-option, -Wformat-overflow)
-# FIXME: fix -Wformat-truncation warnings and uncomment
-#subdir-ccflags-y += $(call cc-option, -Wformat-truncation)
+subdir-ccflags-y += $(call cc-option, -Wformat-truncation)
 subdir-ccflags-y += $(call cc-option, -Wstringop-truncation)
 # The following turn off the warnings enabled by -Wextra
 ifeq ($(findstring 2, $(KBUILD_EXTRA_WARN)),)
-- 
2.39.2

Re: [PATCH 4/4] drm: enable -Wformat-truncation across the subsystem

[Sam Ravnborg]

Hi Jani,

On Thu, May 23, 2024 at 06:51:09PM +0300, Jani Nikula wrote:
> With the -Wformat-truncation warnings fixed, finish the job started in
> commit a61ddb4393ad ("drm: enable (most) W=1 warnings by default across
> the subsystem"), and enable that warning too.
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

When it is enabled for all of drm then the explicit assignments here
could be dropped I think:

drivers/gpu/drm/i915/Makefile:subdir-ccflags-y += $(call cc-option, -Wformat-truncation)
drivers/gpu/drm/xe/Makefile:subdir-ccflags-y += $(call cc-option, -Wformat-truncation)

Just a drive-by comment, I know this patch was mostly for the bots.

	Sam

> 
> ---
> 
> Gut feeling says there are more issues, and my configs just don't catch
> them all, but let's see what the build bots have to say. ;)
> ---
>  drivers/gpu/drm/Makefile | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 68cc9258ffc4..644613dbedda 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -16,8 +16,7 @@ subdir-ccflags-y += $(call cc-option, -Wunused-but-set-variable)
>  subdir-ccflags-y += $(call cc-option, -Wunused-const-variable)
>  subdir-ccflags-y += $(call cc-option, -Wpacked-not-aligned)
>  subdir-ccflags-y += $(call cc-option, -Wformat-overflow)
> -# FIXME: fix -Wformat-truncation warnings and uncomment
> -#subdir-ccflags-y += $(call cc-option, -Wformat-truncation)
> +subdir-ccflags-y += $(call cc-option, -Wformat-truncation)
>  subdir-ccflags-y += $(call cc-option, -Wstringop-truncation)
>  # The following turn off the warnings enabled by -Wextra
>  ifeq ($(findstring 2, $(KBUILD_EXTRA_WARN)),)
> -- 
> 2.39.2

Re: [PATCH 4/4] drm: enable -Wformat-truncation across the subsystem

[Jani Nikula]

On Thu, 23 May 2024, Sam Ravnborg <sam@ravnborg.org> wrote:
> Hi Jani,
>
> On Thu, May 23, 2024 at 06:51:09PM +0300, Jani Nikula wrote:
>> With the -Wformat-truncation warnings fixed, finish the job started in
>> commit a61ddb4393ad ("drm: enable (most) W=1 warnings by default across
>> the subsystem"), and enable that warning too.
>> 
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>
> When it is enabled for all of drm then the explicit assignments here
> could be dropped I think:
>
> drivers/gpu/drm/i915/Makefile:subdir-ccflags-y += $(call cc-option, -Wformat-truncation)
> drivers/gpu/drm/xe/Makefile:subdir-ccflags-y += $(call cc-option, -Wformat-truncation)
>
> Just a drive-by comment, I know this patch was mostly for the bots.

Additionally, I didn't want to create any conflicts with [1]. There's no
harm in having the duplication.

BR,
Jani.

[1] https://lore.kernel.org/r/cover.1716471145.git.jani.nikula@intel.com


>
> 	Sam
>
>> 
>> ---
>> 
>> Gut feeling says there are more issues, and my configs just don't catch
>> them all, but let's see what the build bots have to say. ;)
>> ---
>>  drivers/gpu/drm/Makefile | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
>> index 68cc9258ffc4..644613dbedda 100644
>> --- a/drivers/gpu/drm/Makefile
>> +++ b/drivers/gpu/drm/Makefile
>> @@ -16,8 +16,7 @@ subdir-ccflags-y += $(call cc-option, -Wunused-but-set-variable)
>>  subdir-ccflags-y += $(call cc-option, -Wunused-const-variable)
>>  subdir-ccflags-y += $(call cc-option, -Wpacked-not-aligned)
>>  subdir-ccflags-y += $(call cc-option, -Wformat-overflow)
>> -# FIXME: fix -Wformat-truncation warnings and uncomment
>> -#subdir-ccflags-y += $(call cc-option, -Wformat-truncation)
>> +subdir-ccflags-y += $(call cc-option, -Wformat-truncation)
>>  subdir-ccflags-y += $(call cc-option, -Wstringop-truncation)
>>  # The following turn off the warnings enabled by -Wextra
>>  ifeq ($(findstring 2, $(KBUILD_EXTRA_WARN)),)
>> -- 
>> 2.39.2

-- 
Jani Nikula, Intel