| Message ID | 20150720072043.GA7696@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/20/2015 12:20 AM, Ingo Molnar wrote: > > * Guenter <linux@roeck-us.net> wrote: > >> On Sat, Jul 18, 2015 at 04:27:17PM -0700, Guenter wrote: >>> Hi, >>> >>> Commit 0c8c0f03e3a2 ("x86/fpu, sched: Dynamically allocate 'struct fpu'") >>> causes s390 builds in mainline to fail as follows. >>> >>> arch/s390/kernel/traps.c: Assembler messages: >>> arch/s390/kernel/traps.c:262: Error: operand out of range >>> (0x00000000000023e8 is not between 0x0000000000000000 and 0x0000000000000fff) >>> arch/s390/kernel/traps.c:300: Error: operand out of range >>> (0x00000000000023e8 is not between 0x0000000000000000 and 0x0000000000000fff) >>> >> >> Also: >> >> arm64:allmodconfig: >> >> arch/arm64/kernel/entry.S: Assembler messages: >> arch/arm64/kernel/entry.S:588: Error: immediate out of range >> arch/arm64/kernel/entry.S:597: Error: immediate out of range >> make[1]: *** [arch/arm64/kernel/entry.o] Error 1 >> >> I didn't bisect that one, but it looks like the cause is the same. > > Hm, it looks like the new, increased offset of 'thread_struct' within > 'task_struct' goes over a limit that these instructions are able to support on > arm64: > > arch/arm64/kernel/asm-offsets.c: DEFINE(THREAD_CPU_CONTEXT, offsetof(struct task_struct, thread.cpu_context)); > arch/arm64/kernel/entry.S: add x8, x0, #THREAD_CPU_CONTEXT > arch/arm64/kernel/entry.S: add x8, x1, #THREAD_CPU_CONTEXT > > If there's no instruction that can support such offset sizes then I suspect the > straightforward fix would be to pass in thread_struct instead - like the patch > below. That's a tiny bit cleaner for type encapsulation anyway. > Olof submitted a different patch to solve the problem: http://www.spinics.net/lists/kernel/msg2036825.html His patch is passing cpu_context instead of thread_context. > Warning: it's not even build tested, but in case it works: > > Signed-off-by: Ingo Molnar <mingo@kernel.org> > > Thanks, > > Ingo > > ================ > > arch/arm64/include/asm/processor.h | 4 ++-- > arch/arm64/kernel/asm-offsets.c | 2 +- > arch/arm64/kernel/process.c | 2 +- > 3 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h > index e4c893e54f01..890f84bb3b8c 100644 > --- a/arch/arm64/include/asm/processor.h > +++ b/arch/arm64/include/asm/processor.h > @@ -152,8 +152,8 @@ static inline void cpu_relax(void) > #define cpu_relax_lowlatency() cpu_relax() > > /* Thread switching */ > -extern struct task_struct *cpu_switch_to(struct task_struct *prev, > - struct task_struct *next); > +extern struct task_struct *cpu_switch_to(struct thread_struct *prev, > + struct thread_struct *next); > > #define task_pt_regs(p) \ > ((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1) > diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c > index c99701a34d7b..3785373c2369 100644 > --- a/arch/arm64/kernel/asm-offsets.c > +++ b/arch/arm64/kernel/asm-offsets.c > @@ -39,7 +39,7 @@ int main(void) > DEFINE(TI_TASK, offsetof(struct thread_info, task)); > DEFINE(TI_CPU, offsetof(struct thread_info, cpu)); > BLANK(); > - DEFINE(THREAD_CPU_CONTEXT, offsetof(struct task_struct, thread.cpu_context)); > + DEFINE(THREAD_CPU_CONTEXT, offsetof(struct thread_struct, cpu_context)); > BLANK(); > DEFINE(S_X0, offsetof(struct pt_regs, regs[0])); > DEFINE(S_X1, offsetof(struct pt_regs, regs[1])); > diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c > index 223b093c9440..436e95bda1b2 100644 > --- a/arch/arm64/kernel/process.c > +++ b/arch/arm64/kernel/process.c > @@ -325,7 +325,7 @@ struct task_struct *__switch_to(struct task_struct *prev, > dsb(ish); > > /* the actual thread switch */ > - last = cpu_switch_to(prev, next); > + last = cpu_switch_to(&prev.thread, &next.thread); Doesn't compile. arch/arm64/kernel/process.c: In function ‘__switch_to’: arch/arm64/kernel/process.c:328:28: error: request for member ‘thread’ in something not a structure or union last = cpu_switch_to(&prev.thread, &next.thread); ^ arch/arm64/kernel/process.c:328:42: error: request for member ‘thread’ in something not a structure or union last = cpu_switch_to(&prev.thread, &next.thread); It would have to be last = cpu_switch_to(&prev->thread, &next->thread); which does compile, but fails to run in qemu. Guenter
On Mon, Jul 20, 2015 at 06:52:28AM -0700, Guenter Roeck wrote: > On 07/20/2015 12:20 AM, Ingo Molnar wrote: > >* Guenter <linux@roeck-us.net> wrote: > >>On Sat, Jul 18, 2015 at 04:27:17PM -0700, Guenter wrote: > >>>Commit 0c8c0f03e3a2 ("x86/fpu, sched: Dynamically allocate 'struct fpu'") > >>>causes s390 builds in mainline to fail as follows. > >>> > >>>arch/s390/kernel/traps.c: Assembler messages: > >>>arch/s390/kernel/traps.c:262: Error: operand out of range > >>> (0x00000000000023e8 is not between 0x0000000000000000 and 0x0000000000000fff) > >>>arch/s390/kernel/traps.c:300: Error: operand out of range > >>> (0x00000000000023e8 is not between 0x0000000000000000 and 0x0000000000000fff) > >>> > >> > >>Also: > >> > >>arm64:allmodconfig: > >> > >>arch/arm64/kernel/entry.S: Assembler messages: > >>arch/arm64/kernel/entry.S:588: Error: immediate out of range > >>arch/arm64/kernel/entry.S:597: Error: immediate out of range > >>make[1]: *** [arch/arm64/kernel/entry.o] Error 1 > >> > >>I didn't bisect that one, but it looks like the cause is the same. > > > >Hm, it looks like the new, increased offset of 'thread_struct' within > >'task_struct' goes over a limit that these instructions are able to support on > >arm64: > > > > arch/arm64/kernel/asm-offsets.c: DEFINE(THREAD_CPU_CONTEXT, offsetof(struct task_struct, thread.cpu_context)); > > arch/arm64/kernel/entry.S: add x8, x0, #THREAD_CPU_CONTEXT > > arch/arm64/kernel/entry.S: add x8, x1, #THREAD_CPU_CONTEXT > > > >If there's no instruction that can support such offset sizes then I suspect the > >straightforward fix would be to pass in thread_struct instead - like the patch > >below. That's a tiny bit cleaner for type encapsulation anyway. > > Olof submitted a different patch to solve the problem: > http://www.spinics.net/lists/kernel/msg2036825.html > > His patch is passing cpu_context instead of thread_context. It's likely that we'll use this patch instead: http://lkml.kernel.org/g/20150720105345.GC9908@arm.com
================ arch/arm64/include/asm/processor.h | 4 ++-- arch/arm64/kernel/asm-offsets.c | 2 +- arch/arm64/kernel/process.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index e4c893e54f01..890f84bb3b8c 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -152,8 +152,8 @@ static inline void cpu_relax(void) #define cpu_relax_lowlatency() cpu_relax() /* Thread switching */ -extern struct task_struct *cpu_switch_to(struct task_struct *prev, - struct task_struct *next); +extern struct task_struct *cpu_switch_to(struct thread_struct *prev, + struct thread_struct *next); #define task_pt_regs(p) \ ((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1) diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index c99701a34d7b..3785373c2369 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -39,7 +39,7 @@ int main(void) DEFINE(TI_TASK, offsetof(struct thread_info, task)); DEFINE(TI_CPU, offsetof(struct thread_info, cpu)); BLANK(); - DEFINE(THREAD_CPU_CONTEXT, offsetof(struct task_struct, thread.cpu_context)); + DEFINE(THREAD_CPU_CONTEXT, offsetof(struct thread_struct, cpu_context)); BLANK(); DEFINE(S_X0, offsetof(struct pt_regs, regs[0])); DEFINE(S_X1, offsetof(struct pt_regs, regs[1])); diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 223b093c9440..436e95bda1b2 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -325,7 +325,7 @@ struct task_struct *__switch_to(struct task_struct *prev, dsb(ish); /* the actual thread switch */ - last = cpu_switch_to(prev, next); + last = cpu_switch_to(&prev.thread, &next.thread); return last; }