'struct nand_ecc_engine_ops' are not modified in these drivers.

Constifying this structure moves some data to a read-only section, so
increases overall security, especially when the structure holds some
function pointers.

Update the prototype of mxic_ecc_get_pipelined_ops() accordingly.

On a x86_64, with allmodconfig, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  16709	   1374	     16	  18099	   46b3	drivers/mtd/nand/ecc-mxic.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  16789	   1294	     16	  18099	   46b3	drivers/mtd/nand/ecc-mxic.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Compile tested only.
---
 drivers/mtd/nand/ecc-mxic.c       |  6 +++---
 drivers/mtd/nand/ecc-sw-bch.c     |  2 +-
 drivers/mtd/nand/ecc-sw-hamming.c |  2 +-
 drivers/mtd/nand/spi/core.c       |  2 +-
 drivers/spi/spi-mtk-snfi.c        |  2 +-
 drivers/spi/spi-mxic.c            | 10 +++++-----
 include/linux/mtd/nand-ecc-mxic.h |  4 ++--
 include/linux/mtd/nand.h          |  2 +-
 8 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/mtd/nand/ecc-mxic.c b/drivers/mtd/nand/ecc-mxic.c
index 47e10945b8d2..86895e09328f 100644
--- a/drivers/mtd/nand/ecc-mxic.c
+++ b/drivers/mtd/nand/ecc-mxic.c
@@ -723,21 +723,21 @@ static int mxic_ecc_finish_io_req_pipelined(struct nand_device *nand,
 	return ret;
 }
 
-static struct nand_ecc_engine_ops mxic_ecc_engine_external_ops = {
+static const struct nand_ecc_engine_ops mxic_ecc_engine_external_ops = {
 	.init_ctx = mxic_ecc_init_ctx_external,
 	.cleanup_ctx = mxic_ecc_cleanup_ctx,
 	.prepare_io_req = mxic_ecc_prepare_io_req_external,
 	.finish_io_req = mxic_ecc_finish_io_req_external,
 };
 
-static struct nand_ecc_engine_ops mxic_ecc_engine_pipelined_ops = {
+static const struct nand_ecc_engine_ops mxic_ecc_engine_pipelined_ops = {
 	.init_ctx = mxic_ecc_init_ctx_pipelined,
 	.cleanup_ctx = mxic_ecc_cleanup_ctx,
 	.prepare_io_req = mxic_ecc_prepare_io_req_pipelined,
 	.finish_io_req = mxic_ecc_finish_io_req_pipelined,
 };
 
-struct nand_ecc_engine_ops *mxic_ecc_get_pipelined_ops(void)
+const struct nand_ecc_engine_ops *mxic_ecc_get_pipelined_ops(void)
 {
 	return &mxic_ecc_engine_pipelined_ops;
 }
diff --git a/drivers/mtd/nand/ecc-sw-bch.c b/drivers/mtd/nand/ecc-sw-bch.c
index 405552d014a8..0d9310dd6f52 100644
--- a/drivers/mtd/nand/ecc-sw-bch.c
+++ b/drivers/mtd/nand/ecc-sw-bch.c
@@ -384,7 +384,7 @@ static int nand_ecc_sw_bch_finish_io_req(struct nand_device *nand,
 	return max_bitflips;
 }
 
-static struct nand_ecc_engine_ops nand_ecc_sw_bch_engine_ops = {
+static const struct nand_ecc_engine_ops nand_ecc_sw_bch_engine_ops = {
 	.init_ctx = nand_ecc_sw_bch_init_ctx,
 	.cleanup_ctx = nand_ecc_sw_bch_cleanup_ctx,
 	.prepare_io_req = nand_ecc_sw_bch_prepare_io_req,
diff --git a/drivers/mtd/nand/ecc-sw-hamming.c b/drivers/mtd/nand/ecc-sw-hamming.c
index 254db2e7f8bb..f2d0effad9d2 100644
--- a/drivers/mtd/nand/ecc-sw-hamming.c
+++ b/drivers/mtd/nand/ecc-sw-hamming.c
@@ -638,7 +638,7 @@ static int nand_ecc_sw_hamming_finish_io_req(struct nand_device *nand,
 	return max_bitflips;
 }
 
-static struct nand_ecc_engine_ops nand_ecc_sw_hamming_engine_ops = {
+static const struct nand_ecc_engine_ops nand_ecc_sw_hamming_engine_ops = {
 	.init_ctx = nand_ecc_sw_hamming_init_ctx,
 	.cleanup_ctx = nand_ecc_sw_hamming_cleanup_ctx,
 	.prepare_io_req = nand_ecc_sw_hamming_prepare_io_req,
diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 4d76f9f71a0e..b1df7f627161 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -337,7 +337,7 @@ static int spinand_ondie_ecc_finish_io_req(struct nand_device *nand,
 	return ret;
 }
 
-static struct nand_ecc_engine_ops spinand_ondie_ecc_engine_ops = {
+static const struct nand_ecc_engine_ops spinand_ondie_ecc_engine_ops = {
 	.init_ctx = spinand_ondie_ecc_init_ctx,
 	.cleanup_ctx = spinand_ondie_ecc_cleanup_ctx,
 	.prepare_io_req = spinand_ondie_ecc_prepare_io_req,
diff --git a/drivers/spi/spi-mtk-snfi.c b/drivers/spi/spi-mtk-snfi.c
index debe0e3c1c8b..4169d622f28c 100644
--- a/drivers/spi/spi-mtk-snfi.c
+++ b/drivers/spi/spi-mtk-snfi.c
@@ -776,7 +776,7 @@ static int mtk_snand_ecc_finish_io_req(struct nand_device *nand,
 	return snf->ecc_stats.failed ? -EBADMSG : snf->ecc_stats.bitflips;
 }
 
-static struct nand_ecc_engine_ops mtk_snfi_ecc_engine_ops = {
+static const struct nand_ecc_engine_ops mtk_snfi_ecc_engine_ops = {
 	.init_ctx = mtk_snand_ecc_init_ctx,
 	.cleanup_ctx = mtk_snand_ecc_cleanup_ctx,
 	.prepare_io_req = mtk_snand_ecc_prepare_io_req,
diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
index 9699e0bb6a5e..809767d3145c 100644
--- a/drivers/spi/spi-mxic.c
+++ b/drivers/spi/spi-mxic.c
@@ -649,7 +649,7 @@ static int mxic_spi_transfer_one(struct spi_controller *host,
 /* ECC wrapper */
 static int mxic_spi_mem_ecc_init_ctx(struct nand_device *nand)
 {
-	struct nand_ecc_engine_ops *ops = mxic_ecc_get_pipelined_ops();
+	const struct nand_ecc_engine_ops *ops = mxic_ecc_get_pipelined_ops();
 	struct mxic_spi *mxic = nand->ecc.engine->priv;
 
 	mxic->ecc.use_pipelined_conf = true;
@@ -659,7 +659,7 @@ static int mxic_spi_mem_ecc_init_ctx(struct nand_device *nand)
 
 static void mxic_spi_mem_ecc_cleanup_ctx(struct nand_device *nand)
 {
-	struct nand_ecc_engine_ops *ops = mxic_ecc_get_pipelined_ops();
+	const struct nand_ecc_engine_ops *ops = mxic_ecc_get_pipelined_ops();
 	struct mxic_spi *mxic = nand->ecc.engine->priv;
 
 	mxic->ecc.use_pipelined_conf = false;
@@ -670,7 +670,7 @@ static void mxic_spi_mem_ecc_cleanup_ctx(struct nand_device *nand)
 static int mxic_spi_mem_ecc_prepare_io_req(struct nand_device *nand,
 					   struct nand_page_io_req *req)
 {
-	struct nand_ecc_engine_ops *ops = mxic_ecc_get_pipelined_ops();
+	const struct nand_ecc_engine_ops *ops = mxic_ecc_get_pipelined_ops();
 
 	return ops->prepare_io_req(nand, req);
 }
@@ -678,12 +678,12 @@ static int mxic_spi_mem_ecc_prepare_io_req(struct nand_device *nand,
 static int mxic_spi_mem_ecc_finish_io_req(struct nand_device *nand,
 					  struct nand_page_io_req *req)
 {
-	struct nand_ecc_engine_ops *ops = mxic_ecc_get_pipelined_ops();
+	const struct nand_ecc_engine_ops *ops = mxic_ecc_get_pipelined_ops();
 
 	return ops->finish_io_req(nand, req);
 }
 
-static struct nand_ecc_engine_ops mxic_spi_mem_ecc_engine_pipelined_ops = {
+static const struct nand_ecc_engine_ops mxic_spi_mem_ecc_engine_pipelined_ops = {
 	.init_ctx = mxic_spi_mem_ecc_init_ctx,
 	.cleanup_ctx = mxic_spi_mem_ecc_cleanup_ctx,
 	.prepare_io_req = mxic_spi_mem_ecc_prepare_io_req,
diff --git a/include/linux/mtd/nand-ecc-mxic.h b/include/linux/mtd/nand-ecc-mxic.h
index b125926e458c..0da4b2999576 100644
--- a/include/linux/mtd/nand-ecc-mxic.h
+++ b/include/linux/mtd/nand-ecc-mxic.h
@@ -16,7 +16,7 @@ struct mxic_ecc_engine;
 
 #if IS_ENABLED(CONFIG_MTD_NAND_ECC_MXIC) && IS_REACHABLE(CONFIG_MTD_NAND_CORE)
 
-struct nand_ecc_engine_ops *mxic_ecc_get_pipelined_ops(void);
+const struct nand_ecc_engine_ops *mxic_ecc_get_pipelined_ops(void);
 struct nand_ecc_engine *mxic_ecc_get_pipelined_engine(struct platform_device *spi_pdev);
 void mxic_ecc_put_pipelined_engine(struct nand_ecc_engine *eng);
 int mxic_ecc_process_data_pipelined(struct nand_ecc_engine *eng,
@@ -24,7 +24,7 @@ int mxic_ecc_process_data_pipelined(struct nand_ecc_engine *eng,
 
 #else /* !CONFIG_MTD_NAND_ECC_MXIC */
 
-static inline struct nand_ecc_engine_ops *mxic_ecc_get_pipelined_ops(void)
+static inline const struct nand_ecc_engine_ops *mxic_ecc_get_pipelined_ops(void)
 {
 	return NULL;
 }
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 1e4208040956..0e2f228e8b4a 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -293,7 +293,7 @@ enum nand_ecc_engine_integration {
 struct nand_ecc_engine {
 	struct device *dev;
 	struct list_head node;
-	struct nand_ecc_engine_ops *ops;
+	const struct nand_ecc_engine_ops *ops;
 	enum nand_ecc_engine_integration integration;
 	void *priv;
 };
-- 
2.47.0

On Fri, 2024-10-18 at 17:05:57 UTC, Christophe JAILLET wrote:
> 'struct nand_ecc_engine_ops' are not modified in these drivers.
> 
> Constifying this structure moves some data to a read-only section, so
> increases overall security, especially when the structure holds some
> function pointers.
> 
> Update the prototype of mxic_ecc_get_pipelined_ops() accordingly.
> 
> On a x86_64, with allmodconfig, as an example:
> Before:
> ======
>    text	   data	    bss	    dec	    hex	filename
>   16709	   1374	     16	  18099	   46b3	drivers/mtd/nand/ecc-mxic.o
> 
> After:
> =====
>    text	   data	    bss	    dec	    hex	filename
>   16789	   1294	     16	  18099	   46b3	drivers/mtd/nand/ecc-mxic.o
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git nand/next, thanks.

Miquel