A new warning in clang [1] points out a few places in s5p_mfc_cmd_v6.c where an uninitialized variable is passed as a const pointer:
drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c:45:7: error: variable 'h2r_args' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] 45 | &h2r_args); | ^~~~~~~~ drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c:133:7: error: variable 'h2r_args' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] 133 | &h2r_args); | ^~~~~~~~ drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c:148:7: error: variable 'h2r_args' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] 148 | &h2r_args); | ^~~~~~~~
The args parameter in s5p_mfc_cmd_host2risc_v6() is never actually used, so just pass NULL to it in the places where h2r_args is currently passed, clearing up the warning and not changing the functionality of the code.
Cc: stable@vger.kernel.org Fixes: f96f3cfa0bb8 ("[media] s5p-mfc: Update MFC v4l2 driver to support MFC6.x") Link: https://github.com/llvm/llvm-project/commit/00dacf8c22f065cb52efb14cd091d441... [1] Closes: https://github.com/ClangBuiltLinux/linux/issues/2103 Signed-off-by: Nathan Chancellor nathan@kernel.org --- From what I can tell, it seems like ->cmd_host2risc() is only ever called from v6 code, which always passes NULL? It seems like it should be possible to just drop .cmd_host2risc on the v5 side, then update .cmd_host2risc to only take two parameters? If so, I can send a follow up as a clean up, so that this can go back relatively conflict free. --- .../platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c | 22 +++++----------------- 1 file changed, 5 insertions(+), 17 deletions(-)
diff --git a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c index 47bc3014b5d8..735471c50dbb 100644 --- a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c +++ b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c @@ -31,7 +31,6 @@ static int s5p_mfc_cmd_host2risc_v6(struct s5p_mfc_dev *dev, int cmd,
static int s5p_mfc_sys_init_cmd_v6(struct s5p_mfc_dev *dev) { - struct s5p_mfc_cmd_args h2r_args; const struct s5p_mfc_buf_size_v6 *buf_size = dev->variant->buf_size->priv; int ret;
@@ -41,33 +40,23 @@ static int s5p_mfc_sys_init_cmd_v6(struct s5p_mfc_dev *dev)
mfc_write(dev, dev->ctx_buf.dma, S5P_FIMV_CONTEXT_MEM_ADDR_V6); mfc_write(dev, buf_size->dev_ctx, S5P_FIMV_CONTEXT_MEM_SIZE_V6); - return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SYS_INIT_V6, - &h2r_args); + return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SYS_INIT_V6, NULL); }
static int s5p_mfc_sleep_cmd_v6(struct s5p_mfc_dev *dev) { - struct s5p_mfc_cmd_args h2r_args; - - memset(&h2r_args, 0, sizeof(struct s5p_mfc_cmd_args)); - return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SLEEP_V6, - &h2r_args); + return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SLEEP_V6, NULL); }
static int s5p_mfc_wakeup_cmd_v6(struct s5p_mfc_dev *dev) { - struct s5p_mfc_cmd_args h2r_args; - - memset(&h2r_args, 0, sizeof(struct s5p_mfc_cmd_args)); - return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_WAKEUP_V6, - &h2r_args); + return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_WAKEUP_V6, NULL); }
/* Open a new instance and get its number */ static int s5p_mfc_open_inst_cmd_v6(struct s5p_mfc_ctx *ctx) { struct s5p_mfc_dev *dev = ctx->dev; - struct s5p_mfc_cmd_args h2r_args; int codec_type;
mfc_debug(2, "Requested codec mode: %d\n", ctx->codec_mode); @@ -130,14 +119,13 @@ static int s5p_mfc_open_inst_cmd_v6(struct s5p_mfc_ctx *ctx) mfc_write(dev, 0, S5P_FIMV_D_CRC_CTRL_V6); /* no crc */
return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_OPEN_INSTANCE_V6, - &h2r_args); + NULL); }
/* Close instance */ static int s5p_mfc_close_inst_cmd_v6(struct s5p_mfc_ctx *ctx) { struct s5p_mfc_dev *dev = ctx->dev; - struct s5p_mfc_cmd_args h2r_args; int ret = 0;
dev->curr_ctx = ctx->num; @@ -145,7 +133,7 @@ static int s5p_mfc_close_inst_cmd_v6(struct s5p_mfc_ctx *ctx) mfc_write(dev, ctx->inst_no, S5P_FIMV_INSTANCE_ID_V6); ret = s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_CLOSE_INSTANCE_V6, - &h2r_args); + NULL); } else { ret = -EINVAL; }
--- base-commit: 347e9f5043c89695b01e66b3ed111755afcf1911 change-id: 20250715-media-s5p-mfc-fix-uninit-const-pointer-cbf944ae4b4b
Best regards, -- Nathan Chancellor nathan@kernel.org
Hi Nathan,
Le mardi 15 juillet 2025 à 15:13 -0700, Nathan Chancellor a écrit :
A new warning in clang [1] points out a few places in s5p_mfc_cmd_v6.c where an uninitialized variable is passed as a const pointer:
drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c:45:7: error: variable 'h2r_args' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] 45 | &h2r_args); | ^~~~~~~~ drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c:133:7: error: variable 'h2r_args' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] 133 | &h2r_args); | ^~~~~~~~ drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c:148:7: error: variable 'h2r_args' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] 148 | &h2r_args); | ^~~~~~~~
The args parameter in s5p_mfc_cmd_host2risc_v6() is never actually used, so just pass NULL to it in the places where h2r_args is currently passed, clearing up the warning and not changing the functionality of the code.
Cc: stable@vger.kernel.org Fixes: f96f3cfa0bb8 ("[media] s5p-mfc: Update MFC v4l2 driver to support MFC6.x") Link: https://github.com/llvm/llvm-project/commit/00dacf8c22f065cb52efb14cd091d441...] Closes: https://github.com/ClangBuiltLinux/linux/issues/2103 Signed-off-by: Nathan Chancellor nathan@kernel.org
From what I can tell, it seems like ->cmd_host2risc() is only ever called from v6 code, which always passes NULL? It seems like it should be possible to just drop .cmd_host2risc on the v5 side, then update .cmd_host2risc to only take two parameters? If so, I can send a follow up as a clean up, so that this can go back relatively conflict free.
It seems so yes. For this specific patch, I would probably rename "args" to "__unused" to make the reading faster. But does not matter so much if you later remove it.
Reviewed-by: Nicolas Dufresne nicolas.dufresne@collabora.com
.../platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c | 22 +++++----------------- 1 file changed, 5 insertions(+), 17 deletions(-)
diff --git a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c index 47bc3014b5d8..735471c50dbb 100644 --- a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c +++ b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c @@ -31,7 +31,6 @@ static int s5p_mfc_cmd_host2risc_v6(struct s5p_mfc_dev *dev, int cmd, static int s5p_mfc_sys_init_cmd_v6(struct s5p_mfc_dev *dev) {
- struct s5p_mfc_cmd_args h2r_args;
const struct s5p_mfc_buf_size_v6 *buf_size = dev->variant->buf_size->priv; int ret; @@ -41,33 +40,23 @@ static int s5p_mfc_sys_init_cmd_v6(struct s5p_mfc_dev *dev) mfc_write(dev, dev->ctx_buf.dma, S5P_FIMV_CONTEXT_MEM_ADDR_V6); mfc_write(dev, buf_size->dev_ctx, S5P_FIMV_CONTEXT_MEM_SIZE_V6);
- return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SYS_INIT_V6,
&h2r_args);
- return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SYS_INIT_V6, NULL);
} static int s5p_mfc_sleep_cmd_v6(struct s5p_mfc_dev *dev) {
- struct s5p_mfc_cmd_args h2r_args;
- memset(&h2r_args, 0, sizeof(struct s5p_mfc_cmd_args));
- return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SLEEP_V6,
&h2r_args);
- return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SLEEP_V6, NULL);
} static int s5p_mfc_wakeup_cmd_v6(struct s5p_mfc_dev *dev) {
- struct s5p_mfc_cmd_args h2r_args;
- memset(&h2r_args, 0, sizeof(struct s5p_mfc_cmd_args));
- return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_WAKEUP_V6,
&h2r_args);
- return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_WAKEUP_V6, NULL);
} /* Open a new instance and get its number */ static int s5p_mfc_open_inst_cmd_v6(struct s5p_mfc_ctx *ctx) { struct s5p_mfc_dev *dev = ctx->dev;
- struct s5p_mfc_cmd_args h2r_args;
int codec_type; mfc_debug(2, "Requested codec mode: %d\n", ctx->codec_mode); @@ -130,14 +119,13 @@ static int s5p_mfc_open_inst_cmd_v6(struct s5p_mfc_ctx *ctx) mfc_write(dev, 0, S5P_FIMV_D_CRC_CTRL_V6); /* no crc */ return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_OPEN_INSTANCE_V6,
&h2r_args);
NULL);} /* Close instance */ static int s5p_mfc_close_inst_cmd_v6(struct s5p_mfc_ctx *ctx) { struct s5p_mfc_dev *dev = ctx->dev;
- struct s5p_mfc_cmd_args h2r_args;
int ret = 0; dev->curr_ctx = ctx->num; @@ -145,7 +133,7 @@ static int s5p_mfc_close_inst_cmd_v6(struct s5p_mfc_ctx *ctx) mfc_write(dev, ctx->inst_no, S5P_FIMV_INSTANCE_ID_V6); ret = s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_CLOSE_INSTANCE_V6,
&h2r_args);
NULL);} else { ret = -EINVAL; }
base-commit: 347e9f5043c89695b01e66b3ed111755afcf1911 change-id: 20250715-media-s5p-mfc-fix-uninit-const-pointer-cbf944ae4b4b
Best regards, -- Nathan Chancellor nathan@kernel.org
Hi Nicolas,
On Tue, Jul 29, 2025 at 10:24:22AM -0400, Nicolas Dufresne wrote:
Le mardi 15 juillet 2025 à 15:13 -0700, Nathan Chancellor a écrit :
From what I can tell, it seems like ->cmd_host2risc() is only ever called from v6 code, which always passes NULL? It seems like it should be possible to just drop .cmd_host2risc on the v5 side, then update .cmd_host2risc to only take two parameters? If so, I can send a follow up as a clean up, so that this can go back relatively conflict free.
It seems so yes. For this specific patch, I would probably rename "args" to "__unused" to make the reading faster. But does not matter so much if you later remove it.
Yes, after this change is picked up in a maintainer's tree, I do plan to send a patch to remove the "args" parameter altogether. If you really care, I can certainly rename the parameter in this change to "__unused" as suggested but if you don't, I will just leave it as is to make backporting this a little easier.
Reviewed-by: Nicolas Dufresne nicolas.dufresne@collabora.com
Thanks a lot for taking a look!
Cheers, Nathan
On 16.07.2025 00:13, Nathan Chancellor wrote:
A new warning in clang [1] points out a few places in s5p_mfc_cmd_v6.c where an uninitialized variable is passed as a const pointer:
drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c:45:7: error: variable 'h2r_args' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] 45 | &h2r_args); | ^~~~~~~~ drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c:133:7: error: variable 'h2r_args' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] 133 | &h2r_args); | ^~~~~~~~ drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c:148:7: error: variable 'h2r_args' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] 148 | &h2r_args); | ^~~~~~~~
The args parameter in s5p_mfc_cmd_host2risc_v6() is never actually used, so just pass NULL to it in the places where h2r_args is currently passed, clearing up the warning and not changing the functionality of the code.
Cc: stable@vger.kernel.org Fixes: f96f3cfa0bb8 ("[media] s5p-mfc: Update MFC v4l2 driver to support MFC6.x") Link: https://github.com/llvm/llvm-project/commit/00dacf8c22f065cb52efb14cd091d441... [1] Closes: https://github.com/ClangBuiltLinux/linux/issues/2103 Signed-off-by: Nathan Chancellor nathan@kernel.org
Acked-by: Marek Szyprowski m.szyprowski@samsung.com
From what I can tell, it seems like ->cmd_host2risc() is only ever called from v6 code, which always passes NULL? It seems like it should be possible to just drop .cmd_host2risc on the v5 side, then update .cmd_host2risc to only take two parameters? If so, I can send a follow up as a clean up, so that this can go back relatively conflict free.
.../platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c | 22 +++++----------------- 1 file changed, 5 insertions(+), 17 deletions(-)
diff --git a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c index 47bc3014b5d8..735471c50dbb 100644 --- a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c +++ b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c @@ -31,7 +31,6 @@ static int s5p_mfc_cmd_host2risc_v6(struct s5p_mfc_dev *dev, int cmd, static int s5p_mfc_sys_init_cmd_v6(struct s5p_mfc_dev *dev) {
- struct s5p_mfc_cmd_args h2r_args; const struct s5p_mfc_buf_size_v6 *buf_size = dev->variant->buf_size->priv; int ret;
@@ -41,33 +40,23 @@ static int s5p_mfc_sys_init_cmd_v6(struct s5p_mfc_dev *dev) mfc_write(dev, dev->ctx_buf.dma, S5P_FIMV_CONTEXT_MEM_ADDR_V6); mfc_write(dev, buf_size->dev_ctx, S5P_FIMV_CONTEXT_MEM_SIZE_V6);
- return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SYS_INIT_V6,
&h2r_args);
- return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SYS_INIT_V6, NULL); }
static int s5p_mfc_sleep_cmd_v6(struct s5p_mfc_dev *dev) {
- struct s5p_mfc_cmd_args h2r_args;
- memset(&h2r_args, 0, sizeof(struct s5p_mfc_cmd_args));
- return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SLEEP_V6,
&h2r_args);
- return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SLEEP_V6, NULL); }
static int s5p_mfc_wakeup_cmd_v6(struct s5p_mfc_dev *dev) {
- struct s5p_mfc_cmd_args h2r_args;
- memset(&h2r_args, 0, sizeof(struct s5p_mfc_cmd_args));
- return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_WAKEUP_V6,
&h2r_args);
- return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_WAKEUP_V6, NULL); }
/* Open a new instance and get its number */ static int s5p_mfc_open_inst_cmd_v6(struct s5p_mfc_ctx *ctx) { struct s5p_mfc_dev *dev = ctx->dev;
- struct s5p_mfc_cmd_args h2r_args; int codec_type;
mfc_debug(2, "Requested codec mode: %d\n", ctx->codec_mode); @@ -130,14 +119,13 @@ static int s5p_mfc_open_inst_cmd_v6(struct s5p_mfc_ctx *ctx) mfc_write(dev, 0, S5P_FIMV_D_CRC_CTRL_V6); /* no crc */ return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_OPEN_INSTANCE_V6,
&h2r_args);
NULL);/* Close instance */ static int s5p_mfc_close_inst_cmd_v6(struct s5p_mfc_ctx *ctx) { struct s5p_mfc_dev *dev = ctx->dev;
- struct s5p_mfc_cmd_args h2r_args; int ret = 0;
dev->curr_ctx = ctx->num; @@ -145,7 +133,7 @@ static int s5p_mfc_close_inst_cmd_v6(struct s5p_mfc_ctx *ctx) mfc_write(dev, ctx->inst_no, S5P_FIMV_INSTANCE_ID_V6); ret = s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_CLOSE_INSTANCE_V6,
&h2r_args);
NULL);
base-commit: 347e9f5043c89695b01e66b3ed111755afcf1911 change-id: 20250715-media-s5p-mfc-fix-uninit-const-pointer-cbf944ae4b4b
Best regards,
Nathan Chancellor nathan@kernel.org
Best regards
linux-stable-mirror@lists.linaro.org
-
Marek Szyprowski -
Nathan Chancellor -
Nicolas Dufresne