arch/x86/include/asm/cmpxchg.h:245:2: error: 'asm' operand has impossible constraints

From: kbuild test robot
Date: Tue Jan 01 2019 - 09:02:41 EST


Hi Ingo,

FYI, the error/warning still remains.

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: e1ef035d272ef4dbfdda98e58699698305138856
commit: ffb61c6346d0f02b2a03377a3edac838c1f09b45 Revert "x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs"
date: 13 days ago
config: i386-randconfig-sb0-01012038 (attached as .config)
compiler: gcc-4.9 (Debian 4.9.4-2) 4.9.4
reproduce:
git checkout ffb61c6346d0f02b2a03377a3edac838c1f09b45
# save the attached .config to linux build tree
make ARCH=i386

All errors (new ones prefixed by >>):

In file included from arch/x86/include/asm/atomic.h:8:0,
from include/linux/atomic.h:7,
from include/linux/jump_label.h:250,
from include/linux/static_key.h:1,
from arch/x86/include/asm/nospec-branch.h:6,
from arch/x86/include/asm/paravirt_types.h:46,
from arch/x86/include/asm/ptrace.h:94,
from arch/x86/include/asm/math_emu.h:5,
from arch/x86/include/asm/processor.h:12,
from arch/x86/include/asm/cpufeature.h:5,
from arch/x86/include/asm/thread_info.h:53,
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%c5b %1" \
^
arch/x86/include/asm/cmpxchg.h:256:2: note: in expansion of macro '__cmpxchg_double'
__cmpxchg_double(LOCK_PREFIX, p1, p2, o1, o2, n1, n2)
^
include/asm-generic/atomic-instrumented.h:457:2: note: in expansion of macro 'arch_cmpxchg_double'
arch_cmpxchg_double(__ai_p1, (p2), (o1), (o2), (n1), (n2)); \
^
mm/slub.c:403:7: note: in expansion of macro 'cmpxchg_double'
if (cmpxchg_double(&page->freelist, &page->counters,
^

vim +/asm +245 arch/x86/include/asm/cmpxchg.h

3d94ae0c Jeremy Fitzhardinge 2011-09-28 235
cdcd6298 Jan Beulich 2012-01-02 236 #define __cmpxchg_double(pfx, p1, p2, o1, o2, n1, n2) \
cdcd6298 Jan Beulich 2012-01-02 237 ({ \
cdcd6298 Jan Beulich 2012-01-02 238 bool __ret; \
cdcd6298 Jan Beulich 2012-01-02 239 __typeof__(*(p1)) __old1 = (o1), __new1 = (n1); \
cdcd6298 Jan Beulich 2012-01-02 240 __typeof__(*(p2)) __old2 = (o2), __new2 = (n2); \
cdcd6298 Jan Beulich 2012-01-02 241 BUILD_BUG_ON(sizeof(*(p1)) != sizeof(long)); \
cdcd6298 Jan Beulich 2012-01-02 242 BUILD_BUG_ON(sizeof(*(p2)) != sizeof(long)); \
cdcd6298 Jan Beulich 2012-01-02 243 VM_BUG_ON((unsigned long)(p1) % (2 * sizeof(long))); \
cdcd6298 Jan Beulich 2012-01-02 244 VM_BUG_ON((unsigned long)((p1) + 1) != (unsigned long)(p2)); \
c808c09b Uros Bizjak 2018-09-28 @245 asm volatile(pfx "cmpxchg%c5b %1" \
c808c09b Uros Bizjak 2018-09-28 246 CC_SET(e) \
c808c09b Uros Bizjak 2018-09-28 247 : CC_OUT(e) (__ret), \
c808c09b Uros Bizjak 2018-09-28 248 "+m" (*(p1)), "+m" (*(p2)), \
c808c09b Uros Bizjak 2018-09-28 249 "+a" (__old1), "+d" (__old2) \
c808c09b Uros Bizjak 2018-09-28 250 : "i" (2 * sizeof(long)), \
cdcd6298 Jan Beulich 2012-01-02 251 "b" (__new1), "c" (__new2)); \
cdcd6298 Jan Beulich 2012-01-02 252 __ret; \
cdcd6298 Jan Beulich 2012-01-02 253 })
cdcd6298 Jan Beulich 2012-01-02 254

:::::: The code at line 245 was first introduced by commit
:::::: c808c09b527cd60d9a0d53799935f75e2452174d x86/asm: Use CC_SET()/CC_OUT() in __cmpxchg_double()

:::::: TO: Uros Bizjak <ubizjak@xxxxxxxxx>
:::::: CC: Borislav Petkov <bp@xxxxxxx>

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