2024-06-07 16:13:37

by Joy Chakraborty

[permalink] [raw]
Subject: [PATCH v3] nvmem: rmem: Fix return value of rmem_read()

reg_read() callback registered with nvmem core expects 0 on success and
a negative value on error but rmem_read() returns the number of bytes
read which is treated as an error at the nvmem core.

This does not break when rmem is accessed using sysfs via
bin_attr_nvmem_read()/write() but causes an error when accessed from
places like nvmem_access_with_keepouts(), etc.

Change to return 0 on success and error in case
memory_read_from_buffer() returns an error or -EIO if bytes read do not
match what was requested.

Fixes: 5a3fa75a4d9c ("nvmem: Add driver to expose reserved memory as nvmem")
Cc: [email protected]
Signed-off-by: Joy Chakraborty <[email protected]>
---
drivers/nvmem/rmem.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/nvmem/rmem.c b/drivers/nvmem/rmem.c
index 752d0bf4445e..7f907c5a445e 100644
--- a/drivers/nvmem/rmem.c
+++ b/drivers/nvmem/rmem.c
@@ -46,7 +46,10 @@ static int rmem_read(void *context, unsigned int offset,

memunmap(addr);

- return count;
+ if (count < 0)
+ return count;
+
+ return count == bytes ? 0 : -EIO;
}

static int rmem_probe(struct platform_device *pdev)
--
2.45.2.505.gda0bf45e8d-goog



2024-06-07 16:47:41

by Dan Carpenter

[permalink] [raw]
Subject: Re: [PATCH v3] nvmem: rmem: Fix return value of rmem_read()

On Fri, Jun 07, 2024 at 04:05:10PM +0000, Joy Chakraborty wrote:
> reg_read() callback registered with nvmem core expects 0 on success and
> a negative value on error but rmem_read() returns the number of bytes
> read which is treated as an error at the nvmem core.
>
> This does not break when rmem is accessed using sysfs via
> bin_attr_nvmem_read()/write() but causes an error when accessed from
> places like nvmem_access_with_keepouts(), etc.
>
> Change to return 0 on success and error in case
> memory_read_from_buffer() returns an error or -EIO if bytes read do not
> match what was requested.
>
> Fixes: 5a3fa75a4d9c ("nvmem: Add driver to expose reserved memory as nvmem")
> Cc: [email protected]
> Signed-off-by: Joy Chakraborty <[email protected]>
> ---

Thanks!

Reviewed-by: Dan Carpenter <[email protected]>

You mentioned some other functions that had similar bugs. Could you
fix those as well.

regards,
dan carpenter


2024-06-11 09:31:25

by Srinivas Kandagatla

[permalink] [raw]
Subject: Re: [PATCH v3] nvmem: rmem: Fix return value of rmem_read()


On Fri, 07 Jun 2024 16:05:10 +0000, Joy Chakraborty wrote:
> reg_read() callback registered with nvmem core expects 0 on success and
> a negative value on error but rmem_read() returns the number of bytes
> read which is treated as an error at the nvmem core.
>
> This does not break when rmem is accessed using sysfs via
> bin_attr_nvmem_read()/write() but causes an error when accessed from
> places like nvmem_access_with_keepouts(), etc.
>
> [...]

Applied, thanks!

[1/1] nvmem: rmem: Fix return value of rmem_read()
commit: 139eb4bb33a2857fe439c02a201a85af52ce6186

Best regards,
--
Srinivas Kandagatla <[email protected]>