dmaengine: ep93xx_dma: Annotate struct ep93xx_dma_engine with __counted_by

PATCH Applied Kees Cook 3 participants 3 messages Sep 28, 2023 – Oct 4, 2023 dmaengine

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Kees Cook

author

2023-09-28 23:43 UTC #0 lore raw

PATCH 1/1 dmaengine: ep93xx_dma: Annotate struct ep93xx_dma_engine with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).

As found with Coccinelle[1], add __counted_by for struct ep93xx_dma_engine.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc Vinod Koul <[email protected]>

Cc Nathan Chancellor <[email protected]>

Cc Nick Desaulniers <[email protected]>

Cc Tom Rix <[email protected]>

Cc [email protected]

Signed-off-by Kees Cook <[email protected]>

---
 drivers/dma/ep93xx_dma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

drivers/dma/ep93xx_dma.c +1 -1

index 5c4a448a1254..d6c60635e90d 100644
@@ -213,7 +213,7 @@ struct ep93xx_dma_engine {
 #define INTERRUPT_NEXT_BUFFER	2
 
 	size_t			num_channels;
-	struct ep93xx_dma_chan	channels[];
+	struct ep93xx_dma_chan	channels[] __counted_by(num_channels);
 };
 
 static inline struct device *chan2dev(struct ep93xx_dma_chan *edmac)

Signature · 1 line

2.34.1

Gustavo A. R. Silva

Reviewed-by on v1 1/1

2023-10-01 06:46 UTC #1 lore raw

Quoted 10 lines · Kees Cook

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).
As found with Coccinelle[1], add __counted_by for struct ep93xx_dma_engine.
[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Quoted 7 lines

Cc Vinod Koul <[email protected]>
Cc Nathan Chancellor <[email protected]>
Cc Nick Desaulniers <[email protected]>
Cc Tom Rix <[email protected]>
Cc [email protected]
Cc [email protected]
Signed-off-by Kees Cook <[email protected]>

Reviewed-by Gustavo A. R. Silva <[email protected]>

Thanks

Signature · 1 line

Gustavo

Quoted 17 lines

---
  drivers/dma/ep93xx_dma.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

drivers/dma/ep93xx_dma.c +1 -1

index 5c4a448a1254..d6c60635e90d 100644
@@ -213,7 +213,7 @@ struct ep93xx_dma_engine {
  #define INTERRUPT_NEXT_BUFFER	2
 
  	size_t			num_channels;
-	struct ep93xx_dma_chan	channels[];
+	struct ep93xx_dma_chan	channels[] __counted_by(num_channels);
  };
 
  static inline struct device *chan2dev(struct ep93xx_dma_chan *edmac)

Vinod Koul

maintainer Applied

2023-10-04 14:29 UTC #2 lore raw

In reply to Kees Cook

Quoted 9 lines · Kees Cook

Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).
As found with Coccinelle[1], add __counted_by for struct ep93xx_dma_engine.
[...]

Applied, thanks!

[1/1] dmaengine: ep93xx_dma: Annotate struct ep93xx_dma_engine with __counted_by

      commit: 74d885711c2f619e92f41ef308691948cc63f224

Best regards,

Signature · 1 line

~Vinod