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Diffstat (limited to 'arch/arm64/mm/fault.c')
-rw-r--r--arch/arm64/mm/fault.c61
1 files changed, 30 insertions, 31 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 2d115016feb4..c8c61b1eb479 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -384,40 +384,31 @@ static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *re
#define VM_FAULT_BADACCESS 0x020000
static vm_fault_t __do_page_fault(struct mm_struct *mm, unsigned long addr,
- unsigned int mm_flags, unsigned long vm_flags,
- struct task_struct *tsk)
+ unsigned int mm_flags, unsigned long vm_flags)
{
- struct vm_area_struct *vma;
- vm_fault_t fault;
+ struct vm_area_struct *vma = find_vma(mm, addr);
- vma = find_vma(mm, addr);
- fault = VM_FAULT_BADMAP;
if (unlikely(!vma))
- goto out;
- if (unlikely(vma->vm_start > addr))
- goto check_stack;
+ return VM_FAULT_BADMAP;
/*
* Ok, we have a good vm_area for this memory access, so we can handle
* it.
*/
-good_area:
+ if (unlikely(vma->vm_start > addr)) {
+ if (!(vma->vm_flags & VM_GROWSDOWN))
+ return VM_FAULT_BADMAP;
+ if (expand_stack(vma, addr))
+ return VM_FAULT_BADMAP;
+ }
+
/*
* Check that the permissions on the VMA allow for the fault which
* occurred.
*/
- if (!(vma->vm_flags & vm_flags)) {
- fault = VM_FAULT_BADACCESS;
- goto out;
- }
-
+ if (!(vma->vm_flags & vm_flags))
+ return VM_FAULT_BADACCESS;
return handle_mm_fault(vma, addr & PAGE_MASK, mm_flags);
-
-check_stack:
- if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
- goto good_area;
-out:
- return fault;
}
static bool is_el0_instruction_abort(unsigned int esr)
@@ -425,12 +416,20 @@ static bool is_el0_instruction_abort(unsigned int esr)
return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW;
}
+/*
+ * Note: not valid for EL1 DC IVAC, but we never use that such that it
+ * should fault. EL0 cannot issue DC IVAC (undef).
+ */
+static bool is_write_abort(unsigned int esr)
+{
+ return (esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM);
+}
+
static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
{
const struct fault_info *inf;
- struct task_struct *tsk;
- struct mm_struct *mm;
+ struct mm_struct *mm = current->mm;
vm_fault_t fault, major = 0;
unsigned long vm_flags = VM_READ | VM_WRITE;
unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
@@ -438,9 +437,6 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
if (notify_page_fault(regs, esr))
return 0;
- tsk = current;
- mm = tsk->mm;
-
/*
* If we're in an interrupt or have no user context, we must not take
* the fault.
@@ -453,7 +449,8 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
if (is_el0_instruction_abort(esr)) {
vm_flags = VM_EXEC;
- } else if ((esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM)) {
+ mm_flags |= FAULT_FLAG_INSTRUCTION;
+ } else if (is_write_abort(esr)) {
vm_flags = VM_WRITE;
mm_flags |= FAULT_FLAG_WRITE;
}
@@ -492,12 +489,14 @@ retry:
*/
might_sleep();
#ifdef CONFIG_DEBUG_VM
- if (!user_mode(regs) && !search_exception_tables(regs->pc))
+ if (!user_mode(regs) && !search_exception_tables(regs->pc)) {
+ up_read(&mm->mmap_sem);
goto no_context;
+ }
#endif
}
- fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk);
+ fault = __do_page_fault(mm, addr, mm_flags, vm_flags);
major |= fault & VM_FAULT_MAJOR;
if (fault & VM_FAULT_RETRY) {
@@ -537,11 +536,11 @@ retry:
* that point.
*/
if (major) {
- tsk->maj_flt++;
+ current->maj_flt++;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs,
addr);
} else {
- tsk->min_flt++;
+ current->min_flt++;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs,
addr);
}