From: Mel Gorman <mgorman@suse.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>,
LinuxPPC-dev <linuxppc-dev@lists.ozlabs.org>,
Hugh Dickins <hughd@google.com>,
Linux Kernel <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>, Ingo Molnar <mingo@redhat.com>,
Paul Mackerras <paulus@samba.org>,
Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>,
Sasha Levin <sasha.levin@oracle.com>,
Dave Jones <davej@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Kirill Shutemov <kirill.shutemov@linux.intel.com>,
Mel Gorman <mgorman@suse.de>
Subject: [PATCH 04/10] ppc64: Add paranoid warnings for unexpected DSISR_PROTFAULT
Date: Thu, 4 Dec 2014 11:24:27 +0000 [thread overview]
Message-ID: <1417692273-27170-5-git-send-email-mgorman@suse.de> (raw)
In-Reply-To: <1417692273-27170-1-git-send-email-mgorman@suse.de>
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@suse.de>
Acked-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
---
arch/powerpc/mm/copro_fault.c | 8 ++++++--
arch/powerpc/mm/fault.c | 20 +++++++++-----------
2 files changed, 15 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/mm/copro_fault.c b/arch/powerpc/mm/copro_fault.c
index 5a236f0..0450d68 100644
--- a/arch/powerpc/mm/copro_fault.c
+++ b/arch/powerpc/mm/copro_fault.c
@@ -64,10 +64,14 @@ int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
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 --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index b434153..1bcd378 100644
--- a/arch/powerpc/mm/fault.c
+++ b/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);
}
/*
--
2.1.2
next prev parent reply other threads:[~2014-12-04 11:24 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-04 11:24 [PATCH 0/10] Replace _PAGE_NUMA with PAGE_NONE protections v4 Mel Gorman
2014-12-04 11:24 ` [PATCH 01/10] mm: numa: Do not dereference pmd outside of the lock during NUMA hinting fault Mel Gorman
2014-12-04 11:24 ` [PATCH 02/10] mm: Add p[te|md] protnone helpers for use by NUMA balancing Mel Gorman
2014-12-04 11:24 ` [PATCH 03/10] mm: Convert p[te|md]_numa users to p[te|md]_protnone_numa Mel Gorman
2014-12-04 11:24 ` Mel Gorman [this message]
2014-12-04 11:24 ` [PATCH 05/10] mm: Convert p[te|md]_mknonnuma and remaining page table manipulations Mel Gorman
2014-12-04 11:24 ` [PATCH 06/10] mm: Remove remaining references to NUMA hinting bits and helpers Mel Gorman
2014-12-04 11:24 ` [PATCH 07/10] mm: numa: Do not trap faults on the huge zero page Mel Gorman
2014-12-04 11:24 ` [PATCH 08/10] x86: mm: Restore original pte_special check Mel Gorman
2014-12-04 11:24 ` [PATCH 09/10] mm: numa: Add paranoid check around pte_protnone_numa Mel Gorman
2014-12-04 11:24 ` [PATCH 10/10] mm: numa: Avoid unnecessary TLB flushes when setting NUMA hinting entries Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2015-01-05 10:54 [PATCH 0/10] Replace _PAGE_NUMA with PAGE_NONE protections v5 Mel Gorman
2015-01-05 10:54 ` [PATCH 04/10] ppc64: Add paranoid warnings for unexpected DSISR_PROTFAULT Mel Gorman
2014-11-21 13:57 [PATCH 0/10] Replace _PAGE_NUMA with PAGE_NONE protections v3 Mel Gorman
2014-11-21 13:57 ` [PATCH 04/10] ppc64: Add paranoid warnings for unexpected DSISR_PROTFAULT Mel Gorman
2014-11-20 10:19 [PATCH 0/10] Replace _PAGE_NUMA with PAGE_NONE protections v2 Mel Gorman
2014-11-20 10:19 ` [PATCH 04/10] ppc64: Add paranoid warnings for unexpected DSISR_PROTFAULT Mel Gorman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1417692273-27170-5-git-send-email-mgorman@suse.de \
--to=mgorman@suse.de \
--cc=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.vnet.ibm.com \
--cc=davej@redhat.com \
--cc=hughd@google.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mingo@redhat.com \
--cc=paulus@samba.org \
--cc=riel@redhat.com \
--cc=sasha.levin@oracle.com \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).