Messages in this thread | | | Subject | Re: cmpxchg.h:245:2: error: ‘asm’ operand has impossible constraints | From | Juergen Gross <> | Date | Thu, 6 Sep 2018 16:43:37 +0200 |
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On 06/09/18 15:54, Juergen Gross wrote: > Hey Meelis, > > On Mon, 27 Aug 2018, Meelis Roos wrote: > >> While trying to compile v4.18-13105-gaba16dc5cf93 with gcc 5.3.1 on a >> 32-bit x86 configured for AMD K6 >> CC mm/slub.o >> In file included from ./arch/x86/include/asm/atomic.h:8:0, >> from ./include/linux/atomic.h:7, >> from ./arch/x86/include/asm/thread_info.h:54, >> from ./include/linux/thread_info.h:38, >> from ./arch/x86/include/asm/preempt.h:7, >> from ./include/linux/preempt.h:81, >> from ./include/linux/spinlock.h:51, >> from ./include/linux/mmzone.h:8, >> from ./include/linux/gfp.h:6, >> from ./include/linux/mm.h:10, >> from mm/slub.c:13: >> mm/slub.c: In function ‘__slab_free’: >> ./arch/x86/include/asm/cmpxchg.h:245:2: error: ‘asm’ operand has > impossible constraints >> asm volatile(pfx "cmpxchg%c4b %2; sete %0" \ > > Could you give the attched patch a try? I've been hit by this issue > via kbuild robot complaining about one of my patches which didn't > touch the asm stuff above. > > I suspect the "=a" contraint of the outputs and "a" of the inputs > are the culprit. You could save me from having to search through > all the debian repos for a gcc showing that issue...
You don't to test. I've installed a debian VM and could reproduce the issue locally.
My patch changes the picture: instead of a build error gcc loops forever.
Juergen
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