2018-06-18 18:03:07

by Dan Williams

Subject: [PATCH] libnvdimm, pmem: Fix memcpy_mcsafe() return code handling in nsio_rw_bytes()

Commit 60622d68227d "x86/asm/memcpy_mcsafe: Return bytes remaining"
converted callers of memcpy_mcsafe() to expect a positive 'bytes
remaining' value rather than a negative error code. The nsio_rw_bytes()
conversion failed to return success. The failure is benign in that
nsio_rw_bytes() will end up writing back what it just read.

Fixes: 60622d68227d ("x86/asm/memcpy_mcsafe: Return bytes remaining")
Cc: Dan Williams <[email protected]>
Cc: Vishal Verma <[email protected]>
Signed-off-by: Dan Williams <[email protected]>
---
drivers/nvdimm/claim.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index 2e96b34bc936..fb667bf469c7 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -278,6 +278,7 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
return -EIO;
if (memcpy_mcsafe(buf, nsio->addr + offset, size) != 0)
return -EIO;
+ return 0;
}

if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {

2018-06-18 19:13:57

by Verma, Vishal L

Subject: Re: [PATCH] libnvdimm, pmem: Fix memcpy_mcsafe() return code handling in nsio_rw_bytes()

On 06/18, Dan Williams wrote:
> Commit 60622d68227d "x86/asm/memcpy_mcsafe: Return bytes remaining"
> converted callers of memcpy_mcsafe() to expect a positive 'bytes
> remaining' value rather than a negative error code. The nsio_rw_bytes()
> conversion failed to return success. The failure is benign in that
> nsio_rw_bytes() will end up writing back what it just read.
>
> Fixes: 60622d68227d ("x86/asm/memcpy_mcsafe: Return bytes remaining")
> Cc: Dan Williams <[email protected]>
> Cc: Vishal Verma <[email protected]>
> Signed-off-by: Dan Williams <[email protected]>
> ---
> drivers/nvdimm/claim.c | 1 +
> 1 file changed, 1 insertion(+)

Ah good catch. Looks good to me.
Reviewed-by: Vishal Verma <[email protected]>

>
> diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
> index 2e96b34bc936..fb667bf469c7 100644
> --- a/drivers/nvdimm/claim.c
> +++ b/drivers/nvdimm/claim.c
> @@ -278,6 +278,7 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
> return -EIO;
> if (memcpy_mcsafe(buf, nsio->addr + offset, size) != 0)
> return -EIO;
> + return 0;
> }
>
> if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
>

2018-06-18 22:07:56

by Jeff Moyer

Subject: Re: [PATCH] libnvdimm, pmem: Fix memcpy_mcsafe() return code handling in nsio_rw_bytes()

Dan Williams <[email protected]> writes:

> Commit 60622d68227d "x86/asm/memcpy_mcsafe: Return bytes remaining"
> converted callers of memcpy_mcsafe() to expect a positive 'bytes
> remaining' value rather than a negative error code. The nsio_rw_bytes()
> conversion failed to return success. The failure is benign in that
> nsio_rw_bytes() will end up writing back what it just read.
>
> Fixes: 60622d68227d ("x86/asm/memcpy_mcsafe: Return bytes remaining")
> Cc: Dan Williams <[email protected]>
> Cc: Vishal Verma <[email protected]>
> Signed-off-by: Dan Williams <[email protected]>
> ---
> drivers/nvdimm/claim.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
> index 2e96b34bc936..fb667bf469c7 100644
> --- a/drivers/nvdimm/claim.c
> +++ b/drivers/nvdimm/claim.c
> @@ -278,6 +278,7 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
> return -EIO;
> if (memcpy_mcsafe(buf, nsio->addr + offset, size) != 0)
> return -EIO;
> + return 0;
> }
>
> if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {

Reviewed-by: Jeff Moyer <[email protected]>