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authorTony Lindgren <tony@atomide.com>2013-07-31 01:12:49 -0700
committerTony Lindgren <tony@atomide.com>2013-07-31 01:12:49 -0700
commitdc46c79043a85624c78993919615abf743565ff5 (patch)
tree085846e275c2d0a069a6a0589307a482351f2829 /arch/arm64/mm/fault.c
parentad81f0545ef01ea651886dddac4bef6cec930092 (diff)
parent11dab344053f726fe17ede95aa52c1eea1258a66 (diff)
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Merge tag 'for-v3.11-rc/omap-fixes-a' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into omap-for-v3.12/cleanup
This series removes the currently-unused PRCM macros from arch/arm/mach-omap2. Basic test logs are available at: http://www.pwsan.com/omap/testlogs/drop_unused_prcm_macros_v3.11-rc/20130721211401/ Once, years ago, we thought that it would be good to document the PRCM register bits in the Linux codebase. Most folks in the broader community did not have access to the same documentation, so we thought that they might be able to use these bits to fix bugs and improve the code. We were also able to autogenerate most of these macros, so it was thought that defining them in advance would reduce the risk of error, inconsistencies, and merge conflicts caused when patch sets incrementally defined them by hand. Well, nice thoughts. But the first rationale was rendered partially obsolete when TI started to release public TRM documentation PDFs at some point in the OMAP3 timeframe. (Despite their weaknesses, TI's public OMAP TRMs remain the most useful public documentation available for any ARM Linux SoC -- at least to the extent of my knowledge.) And then the current Linux development tropism towards development-by-negative-diffstat obliterated the remainder of the above two philosophies. So, for the few, the masochistic, out there who wish to continue developing TI PRCM code, I would ask that you resurrect any additionally-needed macros from these commits, rather than writing them manually. Purely for the sake of a pleasant atavism, perhaps; the way one appreciates a used bookstore, or a video rental store... And thanks to the upstream maintainers for being patient while we adjust.
Diffstat (limited to 'arch/arm64/mm/fault.c')
-rw-r--r--arch/arm64/mm/fault.c46
1 files changed, 20 insertions, 26 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 0ecac8980aae..6c8ba25bf6bb 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -152,25 +152,8 @@ void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
#define ESR_CM (1 << 8)
#define ESR_LNX_EXEC (1 << 24)
-/*
- * Check that the permissions on the VMA allow for the fault which occurred.
- * If we encountered a write fault, we must have write permission, otherwise
- * we allow any permission.
- */
-static inline bool access_error(unsigned int esr, struct vm_area_struct *vma)
-{
- unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
-
- if (esr & ESR_WRITE)
- mask = VM_WRITE;
- if (esr & ESR_LNX_EXEC)
- mask = VM_EXEC;
-
- return vma->vm_flags & mask ? false : true;
-}
-
static int __do_page_fault(struct mm_struct *mm, unsigned long addr,
- unsigned int esr, unsigned int flags,
+ unsigned int mm_flags, unsigned long vm_flags,
struct task_struct *tsk)
{
struct vm_area_struct *vma;
@@ -188,12 +171,17 @@ static int __do_page_fault(struct mm_struct *mm, unsigned long addr,
* it.
*/
good_area:
- if (access_error(esr, vma)) {
+ /*
+ * Check that the permissions on the VMA allow for the fault which
+ * occurred. If we encountered a write or exec fault, we must have
+ * appropriate permissions, otherwise we allow any permission.
+ */
+ if (!(vma->vm_flags & vm_flags)) {
fault = VM_FAULT_BADACCESS;
goto out;
}
- return handle_mm_fault(mm, vma, addr & PAGE_MASK, flags);
+ return handle_mm_fault(mm, vma, addr & PAGE_MASK, mm_flags);
check_stack:
if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
@@ -208,9 +196,15 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
struct task_struct *tsk;
struct mm_struct *mm;
int fault, sig, code;
- bool write = (esr & ESR_WRITE) && !(esr & ESR_CM);
- unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
- (write ? FAULT_FLAG_WRITE : 0);
+ unsigned long vm_flags = VM_READ | VM_WRITE | VM_EXEC;
+ unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+
+ if (esr & ESR_LNX_EXEC) {
+ vm_flags = VM_EXEC;
+ } else if ((esr & ESR_WRITE) && !(esr & ESR_CM)) {
+ vm_flags = VM_WRITE;
+ mm_flags |= FAULT_FLAG_WRITE;
+ }
tsk = current;
mm = tsk->mm;
@@ -248,7 +242,7 @@ retry:
#endif
}
- fault = __do_page_fault(mm, addr, esr, flags, tsk);
+ fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk);
/*
* If we need to retry but a fatal signal is pending, handle the
@@ -265,7 +259,7 @@ retry:
*/
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
- if (flags & FAULT_FLAG_ALLOW_RETRY) {
+ if (mm_flags & FAULT_FLAG_ALLOW_RETRY) {
if (fault & VM_FAULT_MAJOR) {
tsk->maj_flt++;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs,
@@ -280,7 +274,7 @@ retry:
* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of
* starvation.
*/
- flags &= ~FAULT_FLAG_ALLOW_RETRY;
+ mm_flags &= ~FAULT_FLAG_ALLOW_RETRY;
goto retry;
}
}