diff options
Diffstat (limited to 'arch/arm64/mm/fault.c')
| -rw-r--r-- | arch/arm64/mm/fault.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index f37d4e3830b7..871c82ab0a30 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -527,7 +527,7 @@ static int __kprobes do_page_fault(unsigned long far, unsigned int esr, const struct fault_info *inf; struct mm_struct *mm = current->mm; vm_fault_t fault; - unsigned long vm_flags = VM_ACCESS_FLAGS; + unsigned long vm_flags; unsigned int mm_flags = FAULT_FLAG_DEFAULT; unsigned long addr = untagged_addr(far); @@ -544,12 +544,28 @@ static int __kprobes do_page_fault(unsigned long far, unsigned int esr, if (user_mode(regs)) mm_flags |= FAULT_FLAG_USER; + /* + * vm_flags tells us what bits we must have in vma->vm_flags + * for the fault to be benign, __do_page_fault() would check + * vma->vm_flags & vm_flags and returns an error if the + * intersection is empty + */ if (is_el0_instruction_abort(esr)) { + /* It was exec fault */ vm_flags = VM_EXEC; mm_flags |= FAULT_FLAG_INSTRUCTION; } else if (is_write_abort(esr)) { + /* It was write fault */ vm_flags = VM_WRITE; mm_flags |= FAULT_FLAG_WRITE; + } else { + /* It was read fault */ + vm_flags = VM_READ; + /* Write implies read */ + vm_flags |= VM_WRITE; + /* If EPAN is absent then exec implies read */ + if (!cpus_have_const_cap(ARM64_HAS_EPAN)) + vm_flags |= VM_EXEC; } if (is_ttbr0_addr(addr) && is_el1_permission_fault(addr, esr, regs)) { |