From: kernel test robot <lkp@intel.com>
To: Yeoreum Yun <yeoreum.yun@arm.com>
Cc: llvm@lists.linux.dev, oe-kbuild-all@lists.linux.dev,
"David Hildenbrand (Arm)" <david@kernel.org>
Subject: [davidhildenbrand:get_dummy 14/21] include/linux/pgtable.h:2351:6: error: call to undeclared function 'mm_pmd_folded'; ISO C99 and later do not support implicit function declarations
Date: Thu, 27 Aug 2026 15:52:49 +0800 [thread overview]
Message-ID: <202608271502.qJGgVpP0-lkp@intel.com> (raw)
Hi Yeoreum,
FYI, the error/warning was bisected to this commit, please ignore it if it's irrelevant.
tree: https://github.com/davidhildenbrand/linux get_dummy
head: 112a153a97494becabd764fe6257578ba908801f
commit: db92928e80f5332bbfca9a70beaef62d46a0c9de [14/21] x86: mm: carve out the generic compile-time folded pgtable case in effective_prot()
config: arm-allnoconfig (https://download.01.org/0day-ci/archive/20260827/202608271502.qJGgVpP0-lkp@intel.com/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260827/202608271502.qJGgVpP0-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202608271502.qJGgVpP0-lkp@intel.com/
All errors (new ones prefixed by >>):
In file included from arch/arm/kernel/asm-offsets.c:14:
In file included from include/linux/mm.h:31:
>> include/linux/pgtable.h:2351:6: error: call to undeclared function 'mm_pmd_folded'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
2351 | if (mm_pmd_folded(mm))
| ^
>> include/linux/pgtable.h:2353:6: error: call to undeclared function 'mm_pud_folded'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
2353 | if (mm_pud_folded(mm))
| ^
>> include/linux/pgtable.h:2355:6: error: call to undeclared function 'mm_p4d_folded'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
2355 | if (mm_p4d_folded(mm))
| ^
In file included from arch/arm/kernel/asm-offsets.c:14:
In file included from include/linux/mm.h:36:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:6:
include/linux/signal.h:98:11: warning: array index 3 is past the end of the array (that has type 'unsigned long[2]') [-Warray-bounds]
98 | return (set->sig[3] | set->sig[2] |
| ^ ~
arch/arm/include/asm/signal.h:17:2: note: array 'sig' declared here
17 | unsigned long sig[_NSIG_WORDS];
| ^
In file included from arch/arm/kernel/asm-offsets.c:14:
In file included from include/linux/mm.h:36:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:6:
include/linux/signal.h:98:25: warning: array index 2 is past the end of the array (that has type 'unsigned long[2]') [-Warray-bounds]
98 | return (set->sig[3] | set->sig[2] |
| ^ ~
arch/arm/include/asm/signal.h:17:2: note: array 'sig' declared here
17 | unsigned long sig[_NSIG_WORDS];
| ^
In file included from arch/arm/kernel/asm-offsets.c:14:
In file included from include/linux/mm.h:36:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:6:
include/linux/signal.h:114:11: warning: array index 3 is past the end of the array (that has type 'const unsigned long[2]') [-Warray-bounds]
114 | return (set1->sig[3] == set2->sig[3]) &&
| ^ ~
arch/arm/include/asm/signal.h:17:2: note: array 'sig' declared here
17 | unsigned long sig[_NSIG_WORDS];
| ^
In file included from arch/arm/kernel/asm-offsets.c:14:
In file included from include/linux/mm.h:36:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:6:
include/linux/signal.h:114:27: warning: array index 3 is past the end of the array (that has type 'const unsigned long[2]') [-Warray-bounds]
114 | return (set1->sig[3] == set2->sig[3]) &&
| ^ ~
arch/arm/include/asm/signal.h:17:2: note: array 'sig' declared here
17 | unsigned long sig[_NSIG_WORDS];
| ^
In file included from arch/arm/kernel/asm-offsets.c:14:
In file included from include/linux/mm.h:36:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:6:
include/linux/signal.h:115:5: warning: array index 2 is past the end of the array (that has type 'const unsigned long[2]') [-Warray-bounds]
115 | (set1->sig[2] == set2->sig[2]) &&
| ^ ~
arch/arm/include/asm/signal.h:17:2: note: array 'sig' declared here
17 | unsigned long sig[_NSIG_WORDS];
| ^
In file included from arch/arm/kernel/asm-offsets.c:14:
In file included from include/linux/mm.h:36:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:6:
include/linux/signal.h:115:21: warning: array index 2 is past the end of the array (that has type 'const unsigned long[2]') [-Warray-bounds]
115 | (set1->sig[2] == set2->sig[2]) &&
| ^ ~
arch/arm/include/asm/signal.h:17:2: note: array 'sig' declared here
17 | unsigned long sig[_NSIG_WORDS];
| ^
In file included from arch/arm/kernel/asm-offsets.c:14:
In file included from include/linux/mm.h:36:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:6:
include/linux/signal.h:157:1: warning: array index 3 is past the end of the array (that has type 'const unsigned long[2]') [-Warray-bounds]
157 | _SIG_SET_BINOP(sigorsets, _sig_or)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/signal.h:138:8: note: expanded from macro '_SIG_SET_BINOP'
138 | a3 = a->sig[3]; a2 = a->sig[2]; \
| ^ ~
arch/arm/include/asm/signal.h:17:2: note: array 'sig' declared here
17 | unsigned long sig[_NSIG_WORDS];
| ^
In file included from arch/arm/kernel/asm-offsets.c:14:
In file included from include/linux/mm.h:36:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:6:
include/linux/signal.h:157:1: warning: array index 2 is past the end of the array (that has type 'const unsigned long[2]') [-Warray-bounds]
157 | _SIG_SET_BINOP(sigorsets, _sig_or)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/signal.h:138:24: note: expanded from macro '_SIG_SET_BINOP'
138 | a3 = a->sig[3]; a2 = a->sig[2]; \
| ^ ~
arch/arm/include/asm/signal.h:17:2: note: array 'sig' declared here
17 | unsigned long sig[_NSIG_WORDS];
| ^
In file included from arch/arm/kernel/asm-offsets.c:14:
In file included from include/linux/mm.h:36:
In file included from include/linux/rcuwait.h:6:
In file included from include/linux/sched/signal.h:6:
include/linux/signal.h:157:1: warning: array index 3 is past the end of the array (that has type 'const unsigned long[2]') [-Warray-bounds]
157 | _SIG_SET_BINOP(sigorsets, _sig_or)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/signal.h:139:8: note: expanded from macro '_SIG_SET_BINOP'
139 | b3 = b->sig[3]; b2 = b->sig[2]; \
| ^ ~
arch/arm/include/asm/signal.h:17:2: note: array 'sig' declared here
17 | unsigned long sig[_NSIG_WORDS];
vim +/mm_pmd_folded +2351 include/linux/pgtable.h
2331
2332 /**
2333 * mm_first_pgtable_level - return the first non-folded page-table level
2334 * @mm: The mm structure.
2335 *
2336 * With runtime- or compile-time folded page tables, page-table walkers
2337 * effectively skip the folded top-level page tables, treating them as
2338 * always-present entries pointing to the next lower-level page table.
2339 *
2340 * Return the first page-table level in @mm that is not folded.
2341 *
2342 * Return: the first non-folded page-table level.
2343 */
2344 static inline enum pgtable_level mm_first_pgtable_level(struct mm_struct *mm)
2345 {
2346 /*
2347 * "PMD folded" actually means "PMD is folded into PUD", and
2348 * pud_present() etc. are hard-coded to look like present page table
2349 * levels, whereby pmd_present() etc. contain real logic.
2350 */
> 2351 if (mm_pmd_folded(mm))
2352 return PGTABLE_LEVEL_PMD;
> 2353 if (mm_pud_folded(mm))
2354 return PGTABLE_LEVEL_PUD;
> 2355 if (mm_p4d_folded(mm))
2356 return PGTABLE_LEVEL_P4D;
2357 return PGTABLE_LEVEL_PGD;
2358 }
2359
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
reply other threads:[~2026-08-27 7:53 UTC|newest]
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