The kernel test bot reported[1] that using set_mask_bits on a u8 causes
the following issue on SuperH:
>> ERROR: modpost: "__cmpxchg_called_with_bad_pointer" [drivers/phy/ti/phy-tusb1210.ko] undefined!
Add support for cmpxchg on u8 and u16 pointers.
[1] https://lore.kernel.org/patchwork/patch/1288894/#1485536
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Liam Beguin <[email protected]>
---
Hi,
This was reported by the kernel test bot on an architecture I can't
really test on. I was only able to make sure the build succeeds, but
nothing more.
This patch is based on the __cmpxchg_u32 impletmentation and seems
incomplete based on the different cmpxchg headers I can find.
Do these function need to be impletmented in each header
simulataneously?
Thanks,
Liam
arch/sh/include/asm/cmpxchg-irq.h | 27 +++++++++++++++++++++++++++
arch/sh/include/asm/cmpxchg.h | 5 +++--
2 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/arch/sh/include/asm/cmpxchg-irq.h b/arch/sh/include/asm/cmpxchg-irq.h
index 07d3e7f08389..918c4153a930 100644
--- a/arch/sh/include/asm/cmpxchg-irq.h
+++ b/arch/sh/include/asm/cmpxchg-irq.h
@@ -51,4 +51,31 @@ static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
return retval;
}
+static inline unsigned long __cmpxchg_u16(volatile u16 *m, unsigned long old,
+ unsigned long new)
+{
+ u16 retval;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ retval = *m;
+ if (retval == old)
+ *m = new;
+ local_irq_restore(flags);
+ return (unsigned long)retval;
+}
+
+static inline unsigned long __cmpxchg_u8(volatile u8 *m, unsigned long old,
+ unsigned long new)
+{
+ u8 retval;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ retval = *m;
+ if (retval == old)
+ *m = new;
+ local_irq_restore(flags);
+ return (unsigned long)retval;
+}
#endif /* __ASM_SH_CMPXCHG_IRQ_H */
diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
index e9501d85c278..7d65d0fd1665 100644
--- a/arch/sh/include/asm/cmpxchg.h
+++ b/arch/sh/include/asm/cmpxchg.h
@@ -56,8 +56,9 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
unsigned long new, int size)
{
switch (size) {
- case 4:
- return __cmpxchg_u32(ptr, old, new);
+ case 4: return __cmpxchg_u32((int *)ptr, old, new);
+ case 2: return __cmpxchg_u16((u16 *)ptr, old, new);
+ case 1: return __cmpxchg_u8((u8 *)ptr, old, new);
}
__cmpxchg_called_with_bad_pointer();
return old;
--
2.27.0
Hi Liam,
On Wed, Aug 19, 2020 at 5:07 AM Liam Beguin <[email protected]> wrote:
> The kernel test bot reported[1] that using set_mask_bits on a u8 causes
> the following issue on SuperH:
>
> >> ERROR: modpost: "__cmpxchg_called_with_bad_pointer" [drivers/phy/ti/phy-tusb1210.ko] undefined!
>
> Add support for cmpxchg on u8 and u16 pointers.
>
> [1] https://lore.kernel.org/patchwork/patch/1288894/#1485536
>
> Reported-by: kernel test robot <[email protected]>
> Signed-off-by: Liam Beguin <[email protected]>
> ---
>
> Hi,
>
> This was reported by the kernel test bot on an architecture I can't
> really test on. I was only able to make sure the build succeeds, but
> nothing more.
> This patch is based on the __cmpxchg_u32 impletmentation and seems
> incomplete based on the different cmpxchg headers I can find.
Indeed. This version is suitable for non-SMP machines only.
BTW, it looks like this version can be replaced by the one in asm-generic?
>
> Do these function need to be impletmented in each header
> simulataneously?
Yes, we need them for all variants.
> arch/sh/include/asm/cmpxchg-irq.h | 27 +++++++++++++++++++++++++++
> arch/sh/include/asm/cmpxchg.h | 5 +++--
> 2 files changed, 30 insertions(+), 2 deletions(-)
>
> diff --git a/arch/sh/include/asm/cmpxchg-irq.h b/arch/sh/include/asm/cmpxchg-irq.h
> index 07d3e7f08389..918c4153a930 100644
> --- a/arch/sh/include/asm/cmpxchg-irq.h
> +++ b/arch/sh/include/asm/cmpxchg-irq.h
> @@ -51,4 +51,31 @@ static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
> return retval;
> }
>
> +static inline unsigned long __cmpxchg_u16(volatile u16 *m, unsigned long old,
> + unsigned long new)
> +{
> + u16 retval;
> + unsigned long flags;
> +
> + local_irq_save(flags);
> + retval = *m;
> + if (retval == old)
> + *m = new;
> + local_irq_restore(flags);
> + return (unsigned long)retval;
> +}
> +
> +static inline unsigned long __cmpxchg_u8(volatile u8 *m, unsigned long old,
> + unsigned long new)
> +{
> + u8 retval;
> + unsigned long flags;
> +
> + local_irq_save(flags);
> + retval = *m;
> + if (retval == old)
> + *m = new;
> + local_irq_restore(flags);
> + return (unsigned long)retval;
> +}
> #endif /* __ASM_SH_CMPXCHG_IRQ_H */
> diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
> index e9501d85c278..7d65d0fd1665 100644
> --- a/arch/sh/include/asm/cmpxchg.h
> +++ b/arch/sh/include/asm/cmpxchg.h
> @@ -56,8 +56,9 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
> unsigned long new, int size)
> {
> switch (size) {
> - case 4:
> - return __cmpxchg_u32(ptr, old, new);
> + case 4: return __cmpxchg_u32((int *)ptr, old, new);
> + case 2: return __cmpxchg_u16((u16 *)ptr, old, new);
> + case 1: return __cmpxchg_u8((u8 *)ptr, old, new);
> }
> __cmpxchg_called_with_bad_pointer();
> return old;
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
Hi Geert,
On Wed Aug 19, 2020 at 5:09 AM EDT, Geert Uytterhoeven wrote:
> Hi Liam,
>
> On Wed, Aug 19, 2020 at 5:07 AM Liam Beguin <[email protected]>
> wrote:
> > The kernel test bot reported[1] that using set_mask_bits on a u8 causes
> > the following issue on SuperH:
> >
> > >> ERROR: modpost: "__cmpxchg_called_with_bad_pointer" [drivers/phy/ti/phy-tusb1210.ko] undefined!
> >
> > Add support for cmpxchg on u8 and u16 pointers.
> >
> > [1] https://lore.kernel.org/patchwork/patch/1288894/#1485536
> >
> > Reported-by: kernel test robot <[email protected]>
> > Signed-off-by: Liam Beguin <[email protected]>
> > ---
> >
> > Hi,
> >
> > This was reported by the kernel test bot on an architecture I can't
> > really test on. I was only able to make sure the build succeeds, but
> > nothing more.
> > This patch is based on the __cmpxchg_u32 impletmentation and seems
> > incomplete based on the different cmpxchg headers I can find.
>
> Indeed. This version is suitable for non-SMP machines only.
> BTW, it looks like this version can be replaced by the one in
> asm-generic?
>
Thanks for your feedback I'll have a look at the asm-generic functions
and try to use those instead.
> >
> > Do these function need to be impletmented in each header
> > simulataneously?
>
> Yes, we need them for all variants.
>
Okay, I'll look into that. Would you recommend a good way to test these
changes?
> > arch/sh/include/asm/cmpxchg-irq.h | 27 +++++++++++++++++++++++++++
> > arch/sh/include/asm/cmpxchg.h | 5 +++--
> > 2 files changed, 30 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/sh/include/asm/cmpxchg-irq.h b/arch/sh/include/asm/cmpxchg-irq.h
> > index 07d3e7f08389..918c4153a930 100644
> > --- a/arch/sh/include/asm/cmpxchg-irq.h
> > +++ b/arch/sh/include/asm/cmpxchg-irq.h
> > @@ -51,4 +51,31 @@ static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
> > return retval;
> > }
> >
> > +static inline unsigned long __cmpxchg_u16(volatile u16 *m, unsigned long old,
> > + unsigned long new)
> > +{
> > + u16 retval;
> > + unsigned long flags;
> > +
> > + local_irq_save(flags);
> > + retval = *m;
> > + if (retval == old)
> > + *m = new;
> > + local_irq_restore(flags);
> > + return (unsigned long)retval;
> > +}
> > +
> > +static inline unsigned long __cmpxchg_u8(volatile u8 *m, unsigned long old,
> > + unsigned long new)
> > +{
> > + u8 retval;
> > + unsigned long flags;
> > +
> > + local_irq_save(flags);
> > + retval = *m;
> > + if (retval == old)
> > + *m = new;
> > + local_irq_restore(flags);
> > + return (unsigned long)retval;
> > +}
> > #endif /* __ASM_SH_CMPXCHG_IRQ_H */
> > diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
> > index e9501d85c278..7d65d0fd1665 100644
> > --- a/arch/sh/include/asm/cmpxchg.h
> > +++ b/arch/sh/include/asm/cmpxchg.h
> > @@ -56,8 +56,9 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
> > unsigned long new, int size)
> > {
> > switch (size) {
> > - case 4:
> > - return __cmpxchg_u32(ptr, old, new);
> > + case 4: return __cmpxchg_u32((int *)ptr, old, new);
> > + case 2: return __cmpxchg_u16((u16 *)ptr, old, new);
> > + case 1: return __cmpxchg_u8((u8 *)ptr, old, new);
> > }
> > __cmpxchg_called_with_bad_pointer();
> > return old;
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 --
> [email protected]
>
> In personal conversations with technical people, I call myself a hacker.
> But
> when I'm talking to journalists I just say "programmer" or something
> like that.
> -- Linus Torvalds
Thanks for your time,
Liam
Hi Liam,
On Wed, Aug 19, 2020 at 3:34 PM Liam Beguin <[email protected]> wrote:
> On Wed Aug 19, 2020 at 5:09 AM EDT, Geert Uytterhoeven wrote:
> > On Wed, Aug 19, 2020 at 5:07 AM Liam Beguin <[email protected]>
> > wrote:
> > > The kernel test bot reported[1] that using set_mask_bits on a u8 causes
> > > the following issue on SuperH:
> > >
> > > >> ERROR: modpost: "__cmpxchg_called_with_bad_pointer" [drivers/phy/ti/phy-tusb1210.ko] undefined!
> > >
> > > Add support for cmpxchg on u8 and u16 pointers.
> > >
> > > [1] https://lore.kernel.org/patchwork/patch/1288894/#1485536
> > >
> > > Reported-by: kernel test robot <[email protected]>
> > > Signed-off-by: Liam Beguin <[email protected]>
> > > ---
> > >
> > > Hi,
> > >
> > > This was reported by the kernel test bot on an architecture I can't
> > > really test on. I was only able to make sure the build succeeds, but
> > > nothing more.
> > > This patch is based on the __cmpxchg_u32 impletmentation and seems
> > > incomplete based on the different cmpxchg headers I can find.
> >
> > Indeed. This version is suitable for non-SMP machines only.
> > BTW, it looks like this version can be replaced by the one in
> > asm-generic?
> >
>
> Thanks for your feedback I'll have a look at the asm-generic functions
> and try to use those instead.
>
> > >
> > > Do these function need to be impletmented in each header
> > > simulataneously?
> >
> > Yes, we need them for all variants.
> >
>
> Okay, I'll look into that. Would you recommend a good way to test these
> changes?
That's gonna be harder, I'm afraid.
Who has suitable hardware?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds