The patch titled
Subject: ppc64: add paranoid warnings for unexpected DSISR_PROTFAULT
has been added to the -mm tree. Its filename is
ppc64-add-paranoid-warnings-for-unexpected-dsisr_protfault.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/ppc64-add-paranoid-warnings-for-unexpected-dsisr_protfault.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/ppc64-add-paranoid-warnings-for-unexpected-dsisr_protfault.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Mel Gorman <mgorman@xxxxxxx>
Subject: ppc64: add paranoid warnings for unexpected DSISR_PROTFAULT
ppc64 should not be depending on DSISR_PROTFAULT and it's unexpected if
they are triggered. This patch adds warnings just in case they are being
accidentally depended upon.
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
Acked-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Tested-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Dave Jones <davej@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Kirill Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/mm/copro_fault.c | 8 ++++++--
arch/powerpc/mm/fault.c | 20 +++++++++-----------
2 files changed, 15 insertions(+), 13 deletions(-)
diff -puN arch/powerpc/mm/copro_fault.c~ppc64-add-paranoid-warnings-for-unexpected-dsisr_protfault arch/powerpc/mm/copro_fault.c
--- a/arch/powerpc/mm/copro_fault.c~ppc64-add-paranoid-warnings-for-unexpected-dsisr_protfault
+++ a/arch/powerpc/mm/copro_fault.c
@@ -64,10 +64,14 @@ int copro_handle_mm_fault(struct mm_stru
if (!(vma->vm_flags & VM_WRITE))
goto out_unlock;
} else {
- if (dsisr & DSISR_PROTFAULT)
- goto out_unlock;
if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
goto out_unlock;
+ /*
+ * protfault should only happen due to us
+ * mapping a region readonly temporarily. PROT_NONE
+ * is also covered by the VMA check above.
+ */
+ WARN_ON_ONCE(dsisr & DSISR_PROTFAULT);
}
ret = 0;
diff -puN arch/powerpc/mm/fault.c~ppc64-add-paranoid-warnings-for-unexpected-dsisr_protfault arch/powerpc/mm/fault.c
--- a/arch/powerpc/mm/fault.c~ppc64-add-paranoid-warnings-for-unexpected-dsisr_protfault
+++ a/arch/powerpc/mm/fault.c
@@ -389,17 +389,6 @@ good_area:
#endif /* CONFIG_8xx */
if (is_exec) {
-#ifdef CONFIG_PPC_STD_MMU
- /* Protection fault on exec go straight to failure on
- * Hash based MMUs as they either don't support per-page
- * execute permission, or if they do, it's handled already
- * at the hash level. This test would probably have to
- * be removed if we change the way this works to make hash
- * processors use the same I/D cache coherency mechanism
- * as embedded.
- */
-#endif /* CONFIG_PPC_STD_MMU */
-
/*
* Allow execution from readable areas if the MMU does not
* provide separate controls over reading and executing.
@@ -414,6 +403,14 @@ good_area:
(cpu_has_feature(CPU_FTR_NOEXECUTE) ||
!(vma->vm_flags & (VM_READ | VM_WRITE))))
goto bad_area;
+#ifdef CONFIG_PPC_STD_MMU
+ /*
+ * protfault should only happen due to us
+ * mapping a region readonly temporarily. PROT_NONE
+ * is also covered by the VMA check above.
+ */
+ WARN_ON_ONCE(error_code & DSISR_PROTFAULT);
+#endif /* CONFIG_PPC_STD_MMU */
/* a write */
} else if (is_write) {
if (!(vma->vm_flags & VM_WRITE))
@@ -423,6 +420,7 @@ good_area:
} else {
if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
goto bad_area;
+ WARN_ON_ONCE(error_code & DSISR_PROTFAULT);
}
/*
_
Patches currently in -mm which might be from mgorman@xxxxxxx are
mm-debug-pagealloc-prepare-boottime-configurable-on-off.patch
mm-vmscan-prevent-kswapd-livelock-due-to-pfmemalloc-throttled-process-being-killed.patch
mm-page_alloc-place-zone_id-check-before-vm_bug_on_page-check.patch
mm-vmscan-wake-up-all-pfmemalloc-throttled-processes-at-once.patch
mm-numa-do-not-dereference-pmd-outside-of-the-lock-during-numa-hinting-fault.patch
mm-add-p-protnone-helpers-for-use-by-numa-balancing.patch
mm-convert-p_numa-users-to-p_protnone_numa.patch
ppc64-add-paranoid-warnings-for-unexpected-dsisr_protfault.patch
mm-convert-p_mknonnuma-and-remaining-page-table-manipulations.patch
mm-remove-remaining-references-to-numa-hinting-bits-and-helpers.patch
mm-numa-do-not-trap-faults-on-the-huge-zero-page.patch
x86-mm-restore-original-pte_special-check.patch
mm-numa-add-paranoid-check-around-pte_protnone_numa.patch
mm-numa-avoid-unnecessary-tlb-flushes-when-setting-numa-hinting-entries.patch
do_shared_fault-check-that-mmap_sem-is-held.patch
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