[v1] powerpc: floppy: Add missing checks after DMA map

[PATCH] powerpc: floppy: Add missing checks after DMA map

Posted by Thomas Fourier 7 months, 3 weeks ago

The DMA map functions can fail and should be tested for errors.

Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
---
 arch/powerpc/include/asm/floppy.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/floppy.h b/arch/powerpc/include/asm/floppy.h
index f8ce178b43b7..df8ce2ae636d 100644
--- a/arch/powerpc/include/asm/floppy.h
+++ b/arch/powerpc/include/asm/floppy.h
@@ -144,9 +144,14 @@ static int hard_dma_setup(char *addr, unsigned long size, int mode, int io)
 		bus_addr = 0;
 	}
 
-	if (!bus_addr)	/* need to map it */
+	if (!bus_addr) {	/* need to map it */
 		bus_addr = dma_map_single(&isa_bridge_pcidev->dev, addr, size,
 					  dir);
+		if (dma_mapping_error(&isa_bridge_pcidev->dev, bus_addr)) {
+			bus_addr = 0;
+			return -ENOMEM;
+		}
+	}
 
 	/* remember this one as prev */
 	prev_addr = addr;
-- 
2.43.0

Re: [PATCH] powerpc: floppy: Add missing checks after DMA map

Posted by Christophe Leroy 7 months, 3 weeks ago

Hi Thomas,

Le 19/06/2025 à 13:07, Thomas Fourier a écrit :
> [Vous ne recevez pas souvent de courriers de fourier.thomas@gmail.com. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ]
> 
> The DMA map functions can fail and should be tested for errors.
> 
> Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
> ---
>   arch/powerpc/include/asm/floppy.h | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/include/asm/floppy.h b/arch/powerpc/include/asm/floppy.h
> index f8ce178b43b7..df8ce2ae636d 100644
> --- a/arch/powerpc/include/asm/floppy.h
> +++ b/arch/powerpc/include/asm/floppy.h
> @@ -144,9 +144,14 @@ static int hard_dma_setup(char *addr, unsigned long size, int mode, int io)
>                  bus_addr = 0;
>          }
> 
> -       if (!bus_addr)  /* need to map it */
> +       if (!bus_addr) {        /* need to map it */
>                  bus_addr = dma_map_single(&isa_bridge_pcidev->dev, addr, size,
>                                            dir);
> +               if (dma_mapping_error(&isa_bridge_pcidev->dev, bus_addr)) {
> +                       bus_addr = 0;

bus_addr is a local variable, there is no point in setting it to zero 
here. Just return -ENOMEM.

> +                       return -ENOMEM;
> +               }
> +       }
> 
>          /* remember this one as prev */
>          prev_addr = addr;
> --
> 2.43.0
>