powerpc/8xx: Fix pte_access_permitted() for PAGE_NONE

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.christophe.leroy@csgroup.eu

diff --git a/arch/powerpc/include/asm/nohash/32/pte-8xx.h b/arch/powerpc/include/asm/nohash/32/pte-8xx.h
index 21f681ee535a23906bc021a9357d3b41e8b17e2c..e6fe1d5731f2c5bb1813c34959c46c740ec6428a 100644 (file)
--- 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 56ea48276356c67dcc5e36bf1a054a8c34e00af6..c721478c5934726b1cb8eaadd4dfb046974044e0 100644 (file)
--- 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; }