diff options
Diffstat (limited to 'arch/arm64/mm/fault.c')
| -rw-r--r-- | arch/arm64/mm/fault.c | 63 |
1 files changed, 42 insertions, 21 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index ce441d29e7f6..bff11553eb05 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -130,7 +130,8 @@ static void mem_abort_decode(unsigned int esr) void show_pte(unsigned long addr) { struct mm_struct *mm; - pgd_t *pgd; + pgd_t *pgdp; + pgd_t pgd; if (addr < TASK_SIZE) { /* TTBR0 */ @@ -149,33 +150,37 @@ void show_pte(unsigned long addr) return; } - pr_alert("%s pgtable: %luk pages, %u-bit VAs, pgd = %p\n", + pr_alert("%s pgtable: %luk pages, %u-bit VAs, pgdp = %p\n", mm == &init_mm ? "swapper" : "user", PAGE_SIZE / SZ_1K, VA_BITS, mm->pgd); - pgd = pgd_offset(mm, addr); - pr_alert("[%016lx] *pgd=%016llx", addr, pgd_val(*pgd)); + pgdp = pgd_offset(mm, addr); + pgd = READ_ONCE(*pgdp); + pr_alert("[%016lx] pgd=%016llx", addr, pgd_val(pgd)); do { - pud_t *pud; - pmd_t *pmd; - pte_t *pte; + pud_t *pudp, pud; + pmd_t *pmdp, pmd; + pte_t *ptep, pte; - if (pgd_none(*pgd) || pgd_bad(*pgd)) + if (pgd_none(pgd) || pgd_bad(pgd)) break; - pud = pud_offset(pgd, addr); - pr_cont(", *pud=%016llx", pud_val(*pud)); - if (pud_none(*pud) || pud_bad(*pud)) + pudp = pud_offset(pgdp, addr); + pud = READ_ONCE(*pudp); + pr_cont(", pud=%016llx", pud_val(pud)); + if (pud_none(pud) || pud_bad(pud)) break; - pmd = pmd_offset(pud, addr); - pr_cont(", *pmd=%016llx", pmd_val(*pmd)); - if (pmd_none(*pmd) || pmd_bad(*pmd)) + pmdp = pmd_offset(pudp, addr); + pmd = READ_ONCE(*pmdp); + pr_cont(", pmd=%016llx", pmd_val(pmd)); + if (pmd_none(pmd) || pmd_bad(pmd)) break; - pte = pte_offset_map(pmd, addr); - pr_cont(", *pte=%016llx", pte_val(*pte)); - pte_unmap(pte); + ptep = pte_offset_map(pmdp, addr); + pte = READ_ONCE(*ptep); + pr_cont(", pte=%016llx", pte_val(pte)); + pte_unmap(ptep); } while(0); pr_cont("\n"); @@ -196,8 +201,9 @@ int ptep_set_access_flags(struct vm_area_struct *vma, pte_t entry, int dirty) { pteval_t old_pteval, pteval; + pte_t pte = READ_ONCE(*ptep); - if (pte_same(*ptep, entry)) + if (pte_same(pte, entry)) return 0; /* only preserve the access flags and write permission */ @@ -210,7 +216,7 @@ int ptep_set_access_flags(struct vm_area_struct *vma, * (calculated as: a & b == ~(~a | ~b)). */ pte_val(entry) ^= PTE_RDONLY; - pteval = READ_ONCE(pte_val(*ptep)); + pteval = pte_val(pte); do { old_pteval = pteval; pteval ^= PTE_RDONLY; @@ -240,7 +246,7 @@ static inline bool is_permission_fault(unsigned int esr, struct pt_regs *regs, if (fsc_type == ESR_ELx_FSC_PERM) return true; - if (addr < USER_DS && system_uses_ttbr0_pan()) + if (addr < TASK_SIZE && system_uses_ttbr0_pan()) return fsc_type == ESR_ELx_FSC_FAULT && (regs->pstate & PSR_PAN_BIT); @@ -414,7 +420,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, mm_flags |= FAULT_FLAG_WRITE; } - if (addr < USER_DS && is_permission_fault(esr, regs, addr)) { + if (addr < TASK_SIZE && is_permission_fault(esr, regs, addr)) { /* regs->orig_addr_limit may be 0 if we entered from EL0 */ if (regs->orig_addr_limit == KERNEL_DS) die("Accessing user space memory with fs=KERNEL_DS", regs, esr); @@ -707,6 +713,12 @@ asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, arm64_notify_die("", regs, &info, esr); } +asmlinkage void __exception do_el0_irq_bp_hardening(void) +{ + /* PC has already been checked in entry.S */ + arm64_apply_bp_hardening(); +} + asmlinkage void __exception do_el0_ia_bp_hardening(unsigned long addr, unsigned int esr, struct pt_regs *regs) @@ -731,6 +743,12 @@ asmlinkage void __exception do_sp_pc_abort(unsigned long addr, struct siginfo info; struct task_struct *tsk = current; + if (user_mode(regs)) { + if (instruction_pointer(regs) > TASK_SIZE) + arm64_apply_bp_hardening(); + local_irq_enable(); + } + if (show_unhandled_signals && unhandled_signal(tsk, SIGBUS)) pr_info_ratelimited("%s[%d]: %s exception: pc=%p sp=%p\n", tsk->comm, task_pid_nr(tsk), @@ -790,6 +808,9 @@ asmlinkage int __exception do_debug_exception(unsigned long addr, if (interrupts_enabled(regs)) trace_hardirqs_off(); + if (user_mode(regs) && instruction_pointer(regs) > TASK_SIZE) + arm64_apply_bp_hardening(); + if (!inf->fn(addr, esr, regs)) { rv = 1; } else { |
