From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: linuxppc-dev@lists.ozlabs.org
Cc: aneesh.kumar@linux.vnet.ibm.com,
Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: [PATCH 21/24] powerpc/mm: Move page fault VMA access checks to a helper
Date: Wed, 19 Jul 2017 14:49:43 +1000 [thread overview]
Message-ID: <20170719044946.22030-21-benh@kernel.crashing.org> (raw)
In-Reply-To: <20170719044946.22030-1-benh@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
arch/powerpc/mm/fault.c | 57 ++++++++++++++++++++++++++++---------------------
1 file changed, 33 insertions(+), 24 deletions(-)
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 6a938fc8c5fb..2291686d24c6 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -222,6 +222,37 @@ static bool bad_kernel_fault(bool is_exec, unsigned long error_code,
return is_exec || (address >= TASK_SIZE);
}
+static bool access_error(bool is_write, bool is_exec,
+ struct vm_area_struct *vma)
+{
+ /*
+ * Allow execution from readable areas if the MMU does not
+ * provide separate controls over reading and executing.
+ *
+ * Note: That code used to not be enabled for 4xx/BookE.
+ * It is now as I/D cache coherency for these is done at
+ * set_pte_at() time and I see no reason why the test
+ * below wouldn't be valid on those processors. This -may-
+ * break programs compiled with a really old ABI though.
+ */
+ if (is_exec) {
+ return !(vma->vm_flags & VM_EXEC) &&
+ (cpu_has_feature(CPU_FTR_NOEXECUTE) ||
+ !(vma->vm_flags & (VM_READ | VM_WRITE)));
+ }
+
+ if (is_write) {
+ if (unlikely(!(vma->vm_flags & VM_WRITE)))
+ return true;
+ return false;
+ }
+
+ if (unlikely(!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))))
+ return true;
+
+ return false;
+}
+
#ifdef CONFIG_PPC_SMLPAR
static inline void cmo_account_page_fault(void)
{
@@ -461,30 +492,8 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
return bad_area(regs, address);
good_area:
- if (is_exec) {
- /*
- * Allow execution from readable areas if the MMU does not
- * provide separate controls over reading and executing.
- *
- * Note: That code used to not be enabled for 4xx/BookE.
- * It is now as I/D cache coherency for these is done at
- * set_pte_at() time and I see no reason why the test
- * below wouldn't be valid on those processors. This -may-
- * break programs compiled with a really old ABI though.
- */
- if (unlikely(!(vma->vm_flags & VM_EXEC) &&
- (cpu_has_feature(CPU_FTR_NOEXECUTE) ||
- !(vma->vm_flags & (VM_READ | VM_WRITE)))))
- return bad_area(regs, address);
- /* a write */
- } else if (is_write) {
- if (unlikely(!(vma->vm_flags & VM_WRITE)))
- return bad_area(regs, address);
- /* a read */
- } else {
- if (unlikely(!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))))
- return bad_area(regs, address);
- }
+ if (unlikely(access_error(is_write, is_exec, vma)))
+ return bad_area(regs, address);
/*
* If for any reason at all we couldn't handle the fault,
--
2.13.3
next prev parent reply other threads:[~2017-07-19 4:57 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-19 4:49 [PATCH 01/24] powerpc/mm: Move exception_enter/exit to a do_page_fault wrapper Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 02/24] powerpc/mm: Pre-filter SRR1 bits before do_page_fault() Benjamin Herrenschmidt
2017-07-22 16:43 ` LEROY Christophe
2017-07-23 1:10 ` Benjamin Herrenschmidt
2017-07-24 13:48 ` Michael Ellerman
2017-07-19 4:49 ` [PATCH 03/24] powerpc/6xx: Handle DABR match before calling do_page_fault Benjamin Herrenschmidt
2017-08-03 0:19 ` Michael Ellerman
2017-08-03 1:00 ` Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 04/24] powerpc/mm: Update definitions of DSISR bits Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 05/24] powerpc/mm: Update bits used to skip hash_page Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 06/24] powerpc/mm: Use symbolic constants for filtering SRR1 bits on ISIs Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 07/24] powerpc/mm: Move out definition of CPU specific is_write bits Benjamin Herrenschmidt
2017-07-22 16:40 ` LEROY Christophe
2017-07-23 1:06 ` Benjamin Herrenschmidt
2017-07-24 11:58 ` Michael Ellerman
2017-07-19 4:49 ` [PATCH 08/24] powerpc/mm: Move error_code checks for bad faults earlier Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 09/24] powerpc/mm: Overhaul handling of bad page faults Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 10/24] powerpc/mm: Move debugger check to notify_page_fault() Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 11/24] powerpc/mm: Simplify returns from __do_page_fault Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 12/24] powerpc/mm: Fix reporting of kernel execute faults Benjamin Herrenschmidt
2018-11-07 8:35 ` Christophe LEROY
2018-11-07 10:39 ` Benjamin Herrenschmidt
[not found] ` <87zhtr5d1v.fsf@linux.ibm.com>
2018-11-30 6:08 ` Christophe LEROY
2017-07-19 4:49 ` [PATCH 13/24] powerpc/mm: Make bad_area* helper functions Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 14/24] powerpc/mm: Rework mm_fault_error() Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 15/24] powerpc/mm: Move CMO accounting out of do_page_fault into a helper Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 16/24] powerpc/mm: Cosmetic fix to page fault accounting Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 17/24] powerpc/mm: Move the DSISR_PROTFAULT sanity check Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 18/24] powerpc/mm: Move/simplify faulthandler_disabled() and !mm check Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 19/24] powerpc/mm: Add a bunch of (un)likely annotations to do_page_fault Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 20/24] powerpc/mm: Set fault flags earlier Benjamin Herrenschmidt
2017-07-19 4:49 ` Benjamin Herrenschmidt [this message]
2017-07-19 4:49 ` [PATCH 22/24] powerpc/mm: Don't lose "major" fault indication on retry Benjamin Herrenschmidt
2017-07-19 4:49 ` [PATCH 23/24] powerpc/mm: Cleanup check for stack expansion Benjamin Herrenschmidt
2017-07-21 16:59 ` LEROY Christophe
2017-07-24 10:47 ` Michael Ellerman
2017-07-24 17:34 ` LEROY Christophe
2017-07-25 11:19 ` Michael Ellerman
2017-07-31 11:37 ` Christophe LEROY
2017-07-19 4:49 ` [PATCH 24/24] powerpc: Remove old unused icswx based coprocessor support Benjamin Herrenschmidt
2017-08-07 10:41 ` [01/24] powerpc/mm: Move exception_enter/exit to a do_page_fault wrapper Michael Ellerman
2017-08-07 16:37 ` Christophe LEROY
2017-08-08 2:16 ` Michael Ellerman
2017-08-08 6:45 ` Christophe LEROY
2017-08-08 10:00 ` Michael Ellerman
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