If the get_user(x, ptr) has x as a pointer, then the setting
of (x) = 0 is going to produce the following sparse warning,
so fix this by forcing the type of 'x' when access_ok() fails.
fs/aio.c:2073:21: warning: Using plain integer as NULL pointer
Signed-off-by: Ben Dooks <[email protected]>
---
arch/riscv/include/asm/uaccess.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h
index 855450bed9f5..ec0cab9fbddd 100644
--- a/arch/riscv/include/asm/uaccess.h
+++ b/arch/riscv/include/asm/uaccess.h
@@ -165,7 +165,7 @@ do { \
might_fault(); \
access_ok(__p, sizeof(*__p)) ? \
__get_user((x), __p) : \
- ((x) = 0, -EFAULT); \
+ ((x) = (__force __typeof__(x))0, -EFAULT); \
})
#define __put_user_asm(insn, x, ptr, err) \
--
2.39.0
On Thu, 29 Dec 2022 09:05:45 PST (-0800), [email protected] wrote:
> If the get_user(x, ptr) has x as a pointer, then the setting
> of (x) = 0 is going to produce the following sparse warning,
> so fix this by forcing the type of 'x' when access_ok() fails.
>
> fs/aio.c:2073:21: warning: Using plain integer as NULL pointer
>
> Signed-off-by: Ben Dooks <[email protected]>
> ---
> arch/riscv/include/asm/uaccess.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h
> index 855450bed9f5..ec0cab9fbddd 100644
> --- a/arch/riscv/include/asm/uaccess.h
> +++ b/arch/riscv/include/asm/uaccess.h
> @@ -165,7 +165,7 @@ do { \
> might_fault(); \
> access_ok(__p, sizeof(*__p)) ? \
> __get_user((x), __p) : \
> - ((x) = 0, -EFAULT); \
> + ((x) = (__force __typeof__(x))0, -EFAULT); \
> })
>
> #define __put_user_asm(insn, x, ptr, err) \
Looks like arm64 has a pretty similar pattern. They've got the __force
__typeof__ already, but given the similarity it might be worth
refactoring these to share the error checking code.
Reviewed-by: Palmer Dabbelt <[email protected]>
I'll give this a bit of time like usual, unless anyone's opposed I'll
put it on fixes. I wasn't planning on sending a PR this week anyway due
to the holidays.
Thanks!
On Thu, Dec 29, 2022 at 09:31:27AM -0800, Palmer Dabbelt wrote:
> On Thu, 29 Dec 2022 09:05:45 PST (-0800), [email protected] wrote:
> > If the get_user(x, ptr) has x as a pointer, then the setting
> > of (x) = 0 is going to produce the following sparse warning,
> > so fix this by forcing the type of 'x' when access_ok() fails.
> >
> > fs/aio.c:2073:21: warning: Using plain integer as NULL pointer
> >
> > Signed-off-by: Ben Dooks <[email protected]>
> > ---
> > arch/riscv/include/asm/uaccess.h | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h
> > index 855450bed9f5..ec0cab9fbddd 100644
> > --- a/arch/riscv/include/asm/uaccess.h
> > +++ b/arch/riscv/include/asm/uaccess.h
> > @@ -165,7 +165,7 @@ do { \
> > might_fault(); \
> > access_ok(__p, sizeof(*__p)) ? \
> > __get_user((x), __p) : \
> > - ((x) = 0, -EFAULT); \
> > + ((x) = (__force __typeof__(x))0, -EFAULT); \
> > })
> >
> > #define __put_user_asm(insn, x, ptr, err) \
>
> Looks like arm64 has a pretty similar pattern. They've got the __force
> __typeof__ already, but given the similarity it might be worth refactoring
> these to share the error checking code.
I looked there for an idea on how to fix.
> Reviewed-by: Palmer Dabbelt <[email protected]>
>
> I'll give this a bit of time like usual, unless anyone's opposed I'll put it
> on fixes. I wasn't planning on sending a PR this week anyway due to the
> holidays.
Ok, it's a warning which would be nice to be fixed.
--
Ben Dooks, [email protected], http://www.fluff.org/ben/
Large Hadron Colada: A large Pina Colada that makes the universe disappear.
On Thu, 29 Dec 2022 17:05:45 +0000, Ben Dooks wrote:
> If the get_user(x, ptr) has x as a pointer, then the setting
> of (x) = 0 is going to produce the following sparse warning,
> so fix this by forcing the type of 'x' when access_ok() fails.
>
> fs/aio.c:2073:21: warning: Using plain integer as NULL pointer
>
>
> [...]
Applied, thanks!
[1/1] riscv: uaccess: fix type of 0 variable on error in get_user()
https://git.kernel.org/palmer/c/b9b916aee671
Best regards,
--
Palmer Dabbelt <[email protected]>
Hello:
This patch was applied to riscv/linux.git (fixes)
by Palmer Dabbelt <[email protected]>:
On Thu, 29 Dec 2022 17:05:45 +0000 you wrote:
> If the get_user(x, ptr) has x as a pointer, then the setting
> of (x) = 0 is going to produce the following sparse warning,
> so fix this by forcing the type of 'x' when access_ok() fails.
>
> fs/aio.c:2073:21: warning: Using plain integer as NULL pointer
>
> Signed-off-by: Ben Dooks <[email protected]>
>
> [...]
Here is the summary with links:
- riscv: uaccess: fix type of 0 variable on error in get_user()
https://git.kernel.org/riscv/c/b9b916aee671
You are awesome, thank you!
--
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