| Message ID | 20230628094938.2318171-1-arnd@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | sparc: mark __arch_xchg() as __always_inline | expand |
On Wed, Jun 28, 2023 at 11:49:18AM +0200, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > An otherwise correct change to the atomic operations uncovered an > existing bug in the sparc __arch_xchg() function, which is calls > __xchg_called_with_bad_pointer() when its arguments are unknown at > compile time: > > ERROR: modpost: "__xchg_called_with_bad_pointer" [lib/atomic64_test.ko] undefined! > > This now happens because gcc determines that it's better to not inline the > function. Avoid this by just marking the function as __always_inline > to force the compiler to do the right thing here. > > Reported-by: Guenter Roeck <linux@roeck-us.net> > Link: https://lore.kernel.org/all/c525adc9-6623-4660-8718-e0c9311563b8@roeck-us.net/ > Fixes: d12157efc8e08 ("locking/atomic: make atomic*_{cmp,}xchg optional") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Aha; you saved me writing a patch! :) We should probably do likewise for all the other bits like __cmpxchg(), but either way: Acked-by: Mark Rutland <mark.rutland@arm.com> Mark. > --- > arch/sparc/include/asm/cmpxchg_32.h | 2 +- > arch/sparc/include/asm/cmpxchg_64.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/sparc/include/asm/cmpxchg_32.h b/arch/sparc/include/asm/cmpxchg_32.h > index 7a1339533d1d7..d0af82c240b73 100644 > --- a/arch/sparc/include/asm/cmpxchg_32.h > +++ b/arch/sparc/include/asm/cmpxchg_32.h > @@ -15,7 +15,7 @@ > unsigned long __xchg_u32(volatile u32 *m, u32 new); > void __xchg_called_with_bad_pointer(void); > > -static inline unsigned long __arch_xchg(unsigned long x, __volatile__ void * ptr, int size) > +static __always_inline unsigned long __arch_xchg(unsigned long x, __volatile__ void * ptr, int size) > { > switch (size) { > case 4: > diff --git a/arch/sparc/include/asm/cmpxchg_64.h b/arch/sparc/include/asm/cmpxchg_64.h > index 66cd61dde9ec1..3de25262c4118 100644 > --- a/arch/sparc/include/asm/cmpxchg_64.h > +++ b/arch/sparc/include/asm/cmpxchg_64.h > @@ -87,7 +87,7 @@ xchg16(__volatile__ unsigned short *m, unsigned short val) > return (load32 & mask) >> bit_shift; > } > > -static inline unsigned long > +static __always_inline unsigned long > __arch_xchg(unsigned long x, __volatile__ void * ptr, int size) > { > switch (size) { > -- > 2.39.2 >
On 6/28/23 02:49, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > An otherwise correct change to the atomic operations uncovered an > existing bug in the sparc __arch_xchg() function, which is calls > __xchg_called_with_bad_pointer() when its arguments are unknown at > compile time: > > ERROR: modpost: "__xchg_called_with_bad_pointer" [lib/atomic64_test.ko] undefined! > > This now happens because gcc determines that it's better to not inline the > function. Avoid this by just marking the function as __always_inline > to force the compiler to do the right thing here. > > Reported-by: Guenter Roeck <linux@roeck-us.net> > Link: https://lore.kernel.org/all/c525adc9-6623-4660-8718-e0c9311563b8@roeck-us.net/ > Fixes: d12157efc8e08 ("locking/atomic: make atomic*_{cmp,}xchg optional") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Nice catch. Acked-by: Guenter Roeck <linux@roeck-us.net> > --- > arch/sparc/include/asm/cmpxchg_32.h | 2 +- > arch/sparc/include/asm/cmpxchg_64.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/sparc/include/asm/cmpxchg_32.h b/arch/sparc/include/asm/cmpxchg_32.h > index 7a1339533d1d7..d0af82c240b73 100644 > --- a/arch/sparc/include/asm/cmpxchg_32.h > +++ b/arch/sparc/include/asm/cmpxchg_32.h > @@ -15,7 +15,7 @@ > unsigned long __xchg_u32(volatile u32 *m, u32 new); > void __xchg_called_with_bad_pointer(void); > > -static inline unsigned long __arch_xchg(unsigned long x, __volatile__ void * ptr, int size) > +static __always_inline unsigned long __arch_xchg(unsigned long x, __volatile__ void * ptr, int size) > { > switch (size) { > case 4: > diff --git a/arch/sparc/include/asm/cmpxchg_64.h b/arch/sparc/include/asm/cmpxchg_64.h > index 66cd61dde9ec1..3de25262c4118 100644 > --- a/arch/sparc/include/asm/cmpxchg_64.h > +++ b/arch/sparc/include/asm/cmpxchg_64.h > @@ -87,7 +87,7 @@ xchg16(__volatile__ unsigned short *m, unsigned short val) > return (load32 & mask) >> bit_shift; > } > > -static inline unsigned long > +static __always_inline unsigned long > __arch_xchg(unsigned long x, __volatile__ void * ptr, int size) > { > switch (size) {
On Wed, Jun 28, 2023 at 11:49:18AM +0200, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > An otherwise correct change to the atomic operations uncovered an > existing bug in the sparc __arch_xchg() function, which is calls > __xchg_called_with_bad_pointer() when its arguments are unknown at > compile time: > > ERROR: modpost: "__xchg_called_with_bad_pointer" [lib/atomic64_test.ko] undefined! > > This now happens because gcc determines that it's better to not inline the > function. Avoid this by just marking the function as __always_inline > to force the compiler to do the right thing here. > > Reported-by: Guenter Roeck <linux@roeck-us.net> > Link: https://lore.kernel.org/all/c525adc9-6623-4660-8718-e0c9311563b8@roeck-us.net/ > Fixes: d12157efc8e08 ("locking/atomic: make atomic*_{cmp,}xchg optional") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Sam Ravnborg <sam@ravnborg.org> I assume you will find a way to apply the patch. Sam
Hi Arnd, > An otherwise correct change to the atomic operations uncovered an > existing bug in the sparc __arch_xchg() function, which is calls > __xchg_called_with_bad_pointer() when its arguments are unknown at > compile time: > > ERROR: modpost: "__xchg_called_with_bad_pointer" [lib/atomic64_test.ko] undefined! > > This now happens because gcc determines that it's better to not inline the > function. Avoid this by just marking the function as __always_inline > to force the compiler to do the right thing here. > > Reported-by: Guenter Roeck <linux@roeck-us.net> > Link: https://lore.kernel.org/all/c525adc9-6623-4660-8718-e0c9311563b8@roeck-us.net/ > Fixes: d12157efc8e08 ("locking/atomic: make atomic*_{cmp,}xchg optional") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Andi Shyti <andi.shyti@linux.intel.com> Thanks, Andi
On 28.06.23 17:51, Sam Ravnborg wrote: > On Wed, Jun 28, 2023 at 11:49:18AM +0200, Arnd Bergmann wrote: >> From: Arnd Bergmann <arnd@arndb.de> >> >> An otherwise correct change to the atomic operations uncovered an >> existing bug in the sparc __arch_xchg() function, which is calls >> __xchg_called_with_bad_pointer() when its arguments are unknown at >> compile time: >> >> ERROR: modpost: "__xchg_called_with_bad_pointer" [lib/atomic64_test.ko] undefined! >> >> This now happens because gcc determines that it's better to not inline the >> function. Avoid this by just marking the function as __always_inline >> to force the compiler to do the right thing here. >> >> Reported-by: Guenter Roeck <linux@roeck-us.net> >> Link: https://lore.kernel.org/all/c525adc9-6623-4660-8718-e0c9311563b8@roeck-us.net/ >> Fixes: d12157efc8e08 ("locking/atomic: make atomic*_{cmp,}xchg optional") >> Signed-off-by: Arnd Bergmann <arnd@arndb.de> > Reviewed-by: Sam Ravnborg <sam@ravnborg.org> > > I assume you will find a way to apply the patch. Hmmm, looks to me like this patch is sitting here for two weeks now without having made any progress. From a quick search on lore it also looks like Dave is not very active currently. Hence: Arnd, is that maybe something that is worth sending straight to Linus? Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) -- Everything you wanna know about Linux kernel regression tracking: https://linux-regtracking.leemhuis.info/about/#tldr If I did something stupid, please tell me, as explained on that page.
On Wed, 28 Jun 2023 04:45:43 PDT (-0700), Mark Rutland wrote: > On Wed, Jun 28, 2023 at 11:49:18AM +0200, Arnd Bergmann wrote: >> From: Arnd Bergmann <arnd@arndb.de> >> >> An otherwise correct change to the atomic operations uncovered an >> existing bug in the sparc __arch_xchg() function, which is calls >> __xchg_called_with_bad_pointer() when its arguments are unknown at >> compile time: >> >> ERROR: modpost: "__xchg_called_with_bad_pointer" [lib/atomic64_test.ko] undefined! >> >> This now happens because gcc determines that it's better to not inline the >> function. Avoid this by just marking the function as __always_inline >> to force the compiler to do the right thing here. >> >> Reported-by: Guenter Roeck <linux@roeck-us.net> >> Link: https://lore.kernel.org/all/c525adc9-6623-4660-8718-e0c9311563b8@roeck-us.net/ >> Fixes: d12157efc8e08 ("locking/atomic: make atomic*_{cmp,}xchg optional") >> Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > Aha; you saved me writing a patch! :) > > We should probably do likewise for all the other bits like __cmpxchg(), but > either way: > > Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Though I'm not sure that means a whole lot over here ;) > Mark. > >> --- >> arch/sparc/include/asm/cmpxchg_32.h | 2 +- >> arch/sparc/include/asm/cmpxchg_64.h | 2 +- >> 2 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/sparc/include/asm/cmpxchg_32.h b/arch/sparc/include/asm/cmpxchg_32.h >> index 7a1339533d1d7..d0af82c240b73 100644 >> --- a/arch/sparc/include/asm/cmpxchg_32.h >> +++ b/arch/sparc/include/asm/cmpxchg_32.h >> @@ -15,7 +15,7 @@ >> unsigned long __xchg_u32(volatile u32 *m, u32 new); >> void __xchg_called_with_bad_pointer(void); >> >> -static inline unsigned long __arch_xchg(unsigned long x, __volatile__ void * ptr, int size) >> +static __always_inline unsigned long __arch_xchg(unsigned long x, __volatile__ void * ptr, int size) >> { >> switch (size) { >> case 4: >> diff --git a/arch/sparc/include/asm/cmpxchg_64.h b/arch/sparc/include/asm/cmpxchg_64.h >> index 66cd61dde9ec1..3de25262c4118 100644 >> --- a/arch/sparc/include/asm/cmpxchg_64.h >> +++ b/arch/sparc/include/asm/cmpxchg_64.h >> @@ -87,7 +87,7 @@ xchg16(__volatile__ unsigned short *m, unsigned short val) >> return (load32 & mask) >> bit_shift; >> } >> >> -static inline unsigned long >> +static __always_inline unsigned long >> __arch_xchg(unsigned long x, __volatile__ void * ptr, int size) >> { >> switch (size) { >> -- >> 2.39.2 >>
On Thu, Jul 13, 2023 at 07:00:37AM -0700, Palmer Dabbelt wrote: > On Wed, 28 Jun 2023 04:45:43 PDT (-0700), Mark Rutland wrote: > > On Wed, Jun 28, 2023 at 11:49:18AM +0200, Arnd Bergmann wrote: > > > From: Arnd Bergmann <arnd@arndb.de> > > > > > > An otherwise correct change to the atomic operations uncovered an > > > existing bug in the sparc __arch_xchg() function, which is calls > > > __xchg_called_with_bad_pointer() when its arguments are unknown at > > > compile time: > > > > > > ERROR: modpost: "__xchg_called_with_bad_pointer" [lib/atomic64_test.ko] undefined! > > > > > > This now happens because gcc determines that it's better to not inline the > > > function. Avoid this by just marking the function as __always_inline > > > to force the compiler to do the right thing here. > > > > > > Reported-by: Guenter Roeck <linux@roeck-us.net> > > > Link: https://lore.kernel.org/all/c525adc9-6623-4660-8718-e0c9311563b8@roeck-us.net/ > > > Fixes: d12157efc8e08 ("locking/atomic: make atomic*_{cmp,}xchg optional") > > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > > > Aha; you saved me writing a patch! :) > > > > We should probably do likewise for all the other bits like __cmpxchg(), but > > either way: > > > > Acked-by: Mark Rutland <mark.rutland@arm.com> > > Acked-by: Palmer Dabbelt <palmer@rivosinc.com> > > Though I'm not sure that means a whole lot over here ;) I've carried some other sparc stuff before. I can send this to Linus with other fixes.
On Wed, 28 Jun 2023 11:49:18 +0200, Arnd Bergmann wrote: > An otherwise correct change to the atomic operations uncovered an > existing bug in the sparc __arch_xchg() function, which is calls > __xchg_called_with_bad_pointer() when its arguments are unknown at > compile time: > > ERROR: modpost: "__xchg_called_with_bad_pointer" [lib/atomic64_test.ko] undefined! > > [...] Applied, thanks! [1/1] sparc: mark __arch_xchg() as __always_inline https://git.kernel.org/kees/c/ec7633de404e Best regards,
diff --git a/arch/sparc/include/asm/cmpxchg_32.h b/arch/sparc/include/asm/cmpxchg_32.h index 7a1339533d1d7..d0af82c240b73 100644 --- a/arch/sparc/include/asm/cmpxchg_32.h +++ b/arch/sparc/include/asm/cmpxchg_32.h @@ -15,7 +15,7 @@ unsigned long __xchg_u32(volatile u32 *m, u32 new); void __xchg_called_with_bad_pointer(void); -static inline unsigned long __arch_xchg(unsigned long x, __volatile__ void * ptr, int size) +static __always_inline unsigned long __arch_xchg(unsigned long x, __volatile__ void * ptr, int size) { switch (size) { case 4: diff --git a/arch/sparc/include/asm/cmpxchg_64.h b/arch/sparc/include/asm/cmpxchg_64.h index 66cd61dde9ec1..3de25262c4118 100644 --- a/arch/sparc/include/asm/cmpxchg_64.h +++ b/arch/sparc/include/asm/cmpxchg_64.h @@ -87,7 +87,7 @@ xchg16(__volatile__ unsigned short *m, unsigned short val) return (load32 & mask) >> bit_shift; } -static inline unsigned long +static __always_inline unsigned long __arch_xchg(unsigned long x, __volatile__ void * ptr, int size) { switch (size) {