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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2020-06-25 20:30:04 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-26 00:27:37 -0700 |
| commit | 9449c9cb420b249eb6d7dad3953e4686443d7bd9 (patch) | |
| tree | 633505118f090e396ec7c9224bef5f553b027b7a | |
| parent | 7f70c2a68a51496289df163f6969d4db7c383f30 (diff) | |
| download | linux-9449c9cb420b249eb6d7dad3953e4686443d7bd9.tar.bz2 | |
mm/debug_vm_pgtable: fix build failure with powerpc 8xx
Since commit 9e343b467c70 ("READ_ONCE: Enforce atomicity for
{READ,WRITE}_ONCE() memory accesses"), READ_ONCE() cannot be used
anymore to read complex page table entries.
This leads to:
CC mm/debug_vm_pgtable.o
In file included from ./include/asm-generic/bug.h:5,
from ./arch/powerpc/include/asm/bug.h:109,
from ./include/linux/bug.h:5,
from ./include/linux/mmdebug.h:5,
from ./include/linux/gfp.h:5,
from mm/debug_vm_pgtable.c:13:
In function 'pte_clear_tests',
inlined from 'debug_vm_pgtable' at mm/debug_vm_pgtable.c:363:2:
./include/linux/compiler.h:392:38: error: Unsupported access size for {READ,WRITE}_ONCE().
mm/debug_vm_pgtable.c:249:14: note: in expansion of macro 'READ_ONCE'
249 | pte_t pte = READ_ONCE(*ptep);
| ^~~~~~~~~
make[2]: *** [mm/debug_vm_pgtable.o] Error 1
Fix it by using the recently added ptep_get() helper.
Link: http://lkml.kernel.org/r/6ca8c972e6c920dc4ae0d4affbed9703afa4d010.1592490570.git.christophe.leroy@csgroup.eu
Fixes: 9e343b467c70 ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/debug_vm_pgtable.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index e45623016aea..61ab16fb2e36 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -246,13 +246,13 @@ static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp, static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep, unsigned long vaddr) { - pte_t pte = READ_ONCE(*ptep); + pte_t pte = ptep_get(ptep); pte = __pte(pte_val(pte) | RANDOM_ORVALUE); set_pte_at(mm, vaddr, ptep, pte); barrier(); pte_clear(mm, vaddr, ptep); - pte = READ_ONCE(*ptep); + pte = ptep_get(ptep); WARN_ON(!pte_none(pte)); } |