Messages in this thread | | | Subject | Re: [PATCH 1/2] powerpc/irq: don't use current_stack_pointer() in check_stack_overflow() | From | Christophe Leroy <> | Date | Fri, 24 Jan 2020 07:03:36 +0000 |
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On 01/24/2020 06:19 AM, Christophe Leroy wrote: > > > Le 24/01/2020 à 06:46, Michael Ellerman a écrit : >> >> If I do this it seems to work, but feels a little dicey: >> >> asm ("" : "=r" (r1)); >> sp = r1 & (THREAD_SIZE - 1); > > > Or we could do add in asm/reg.h what we have in boot/reg.h: > > register void *__stack_pointer asm("r1"); > #define get_sp() (__stack_pointer) > > And use get_sp() >
It works, and I guess doing it this way is acceptable as it's exactly what's done for current in asm/current.h with register r2.
Now I (still) get:
sp = get_sp() & (THREAD_SIZE - 1); b9c: 54 24 04 fe clrlwi r4,r1,19 if (unlikely(sp < 2048)) { ba4: 2f 84 07 ff cmpwi cr7,r4,2047
Allthough GCC 8.1 what doing exactly the same with the form CLANG don't like:
register unsigned long r1 asm("r1"); long sp = r1 & (THREAD_SIZE - 1); b84: 54 24 04 fe clrlwi r4,r1,19 if (unlikely(sp < 2048)) { b8c: 2f 84 07 ff cmpwi cr7,r4,2047
Christophe
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