[PATCH v2 01/37] powerpc/8xx: Fix pte_access_permitted() for PAGE_NONE
From: Christophe Leroy <hidden>
Date: 2023-09-25 18:31:39
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
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 <redacted>
---
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 21f681ee535a..e6fe1d5731f2 100644
--- a/arch/powerpc/include/asm/nohash/32/pte-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/pte-8xx.h@@ -94,6 +94,13 @@ 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 56ea48276356..c721478c5934 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h@@ -25,7 +25,9 @@ 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; }
--
2.41.0