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authorAneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org>2023-12-04 15:06:37 +0530
committerMichael Ellerman <mpe@ellerman.id.au>2023-12-07 23:34:11 +1100
commit773b93f1d1c38c5c0d5308b8c9229c7a6ec5b2a0 (patch)
tree324ada961a6bcad350dc738ed3e8523ab6dd12ac /arch/powerpc/mm/book3s64/hash_utils.c
parent27951e1d8274e9f9a2925b069e4492939a3f2099 (diff)
powerpc/book3s/hash: Drop _PAGE_PRIVILEGED from PAGE_NONE
There used to be a dependency on _PAGE_PRIVILEGED with pte_savedwrite. But that got dropped by commit 6a56ccbcf6c6 ("mm/autonuma: use can_change_(pte|pmd)_writable() to replace savedwrite") With the change in this patch numa fault pte (pte_protnone()) gets mapped as regular user pte with RWX cleared (no-access) whereas earlier it used to be mapped _PAGE_PRIVILEGED. Hash fault handling code gets some WARN_ON added in this patch because those functions are not expected to get called with _PAGE_READ cleared. commit 18061c17c8ec ("powerpc/mm: Update PROTFAULT handling in the page fault path") explains the details. Signed-off-by: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231204093638.71503-1-aneesh.kumar@kernel.org
Diffstat (limited to 'arch/powerpc/mm/book3s64/hash_utils.c')
-rw-r--r--arch/powerpc/mm/book3s64/hash_utils.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index ad2afa08e62e..0626a25b0d72 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -310,9 +310,16 @@ unsigned long htab_convert_pte_flags(unsigned long pteflags, unsigned long flags
else
rflags |= 0x3;
}
+ VM_WARN_ONCE(!(pteflags & _PAGE_RWX), "no-access mapping request");
} else {
if (pteflags & _PAGE_RWX)
rflags |= 0x2;
+ /*
+ * We should never hit this in normal fault handling because
+ * a permission check (check_pte_access()) will bubble this
+ * to higher level linux handler even for PAGE_NONE.
+ */
+ VM_WARN_ONCE(!(pteflags & _PAGE_RWX), "no-access mapping request");
if (!((pteflags & _PAGE_WRITE) && (pteflags & _PAGE_DIRTY)))
rflags |= 0x1;
}