5.4-stable review patch. If anyone has any objections, please let me know.
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From: Christophe Leroy christophe.leroy@csgroup.eu
[ Upstream commit 5d9cea8a552ee122e21fbd5a3c5d4eb85f648e06 ]
On 8xx, PAGE_NONE is handled by setting _PAGE_NA instead of clearing _PAGE_USER.
But then pte_user() returns 1 also for PAGE_NONE.
As _PAGE_NA prevent reads, add a specific version of pte_read() that returns 0 when _PAGE_NA is set instead of always returning 1.
Fixes: 351750331fc1 ("powerpc/mm: Introduce _PAGE_NA") Signed-off-by: Christophe Leroy christophe.leroy@csgroup.eu Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://msgid.link/57bcfbe578e43123f9ed73e040229b80f1ad56ec.1695659959.git.c... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/include/asm/nohash/32/pte-8xx.h | 7 +++++++ arch/powerpc/include/asm/nohash/pgtable.h | 2 ++ 2 files changed, 9 insertions(+)
diff --git a/arch/powerpc/include/asm/nohash/32/pte-8xx.h b/arch/powerpc/include/asm/nohash/32/pte-8xx.h index c9e4b2d90f65c..93ecf4e80ca70 100644 --- a/arch/powerpc/include/asm/nohash/32/pte-8xx.h +++ b/arch/powerpc/include/asm/nohash/32/pte-8xx.h @@ -91,6 +91,13 @@ static inline pte_t pte_wrprotect(pte_t pte)
#define pte_wrprotect pte_wrprotect
+static inline int pte_read(pte_t pte) +{ + return (pte_val(pte) & _PAGE_RO) != _PAGE_NA; +} + +#define pte_read pte_read + static inline int pte_write(pte_t pte) { return !(pte_val(pte) & _PAGE_RO); diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h index 3d2a78ab051a7..15dec9994c780 100644 --- a/arch/powerpc/include/asm/nohash/pgtable.h +++ b/arch/powerpc/include/asm/nohash/pgtable.h @@ -45,7 +45,9 @@ static inline int pte_write(pte_t pte) return pte_val(pte) & _PAGE_RW; } #endif +#ifndef pte_read static inline int pte_read(pte_t pte) { return 1; } +#endif static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; } static inline int pte_special(pte_t pte) { return pte_val(pte) & _PAGE_SPECIAL; } static inline int pte_none(pte_t pte) { return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }