diff options
Diffstat (limited to 'arch/arm64/mm/fault.c')
| -rw-r--r-- | arch/arm64/mm/fault.c | 397 |
1 files changed, 219 insertions, 178 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 596f46dabe4e..be9dab2c7d6a 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -23,6 +23,7 @@ #include <linux/sched/debug.h> #include <linux/highmem.h> #include <linux/perf_event.h> +#include <linux/pkeys.h> #include <linux/preempt.h> #include <linux/hugetlb.h> @@ -52,20 +53,16 @@ struct fault_info { }; static const struct fault_info fault_info[]; -static struct fault_info debug_fault_info[]; static inline const struct fault_info *esr_to_fault_info(unsigned long esr) { return fault_info + (esr & ESR_ELx_FSC); } -static inline const struct fault_info *esr_to_debug_fault_info(unsigned long esr) -{ - return debug_fault_info + DBG_ESR_EVT(esr); -} - static void data_abort_decode(unsigned long esr) { + unsigned long iss2 = ESR_ELx_ISS2(esr); + pr_alert("Data abort info:\n"); if (esr & ESR_ELx_ISV) { @@ -78,12 +75,21 @@ static void data_abort_decode(unsigned long esr) (esr & ESR_ELx_SF) >> ESR_ELx_SF_SHIFT, (esr & ESR_ELx_AR) >> ESR_ELx_AR_SHIFT); } else { - pr_alert(" ISV = 0, ISS = 0x%08lx\n", esr & ESR_ELx_ISS_MASK); + pr_alert(" ISV = 0, ISS = 0x%08lx, ISS2 = 0x%08lx\n", + esr & ESR_ELx_ISS_MASK, iss2); } - pr_alert(" CM = %lu, WnR = %lu\n", + pr_alert(" CM = %lu, WnR = %lu, TnD = %lu, TagAccess = %lu\n", (esr & ESR_ELx_CM) >> ESR_ELx_CM_SHIFT, - (esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT); + (esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT, + (iss2 & ESR_ELx_TnD) >> ESR_ELx_TnD_SHIFT, + (iss2 & ESR_ELx_TagAccess) >> ESR_ELx_TagAccess_SHIFT); + + pr_alert(" GCS = %ld, Overlay = %lu, DirtyBit = %lu, Xs = %llu\n", + (iss2 & ESR_ELx_GCS) >> ESR_ELx_GCS_SHIFT, + (iss2 & ESR_ELx_Overlay) >> ESR_ELx_Overlay_SHIFT, + (iss2 & ESR_ELx_DirtyBit) >> ESR_ELx_DirtyBit_SHIFT, + (iss2 & ESR_ELx_Xs_MASK) >> ESR_ELx_Xs_SHIFT); } static void mem_abort_decode(unsigned long esr) @@ -177,7 +183,10 @@ static void show_pte(unsigned long addr) break; ptep = pte_offset_map(pmdp, addr); - pte = READ_ONCE(*ptep); + if (!ptep) + break; + + pte = __ptep_get(ptep); pr_cont(", pte=%016llx", pte_val(pte)); pte_unmap(ptep); } while(0); @@ -191,16 +200,16 @@ static void show_pte(unsigned long addr) * * It needs to cope with hardware update of the accessed/dirty state by other * agents in the system and can safely skip the __sync_icache_dcache() call as, - * like set_pte_at(), the PTE is never changed from no-exec to exec here. + * like __set_ptes(), the PTE is never changed from no-exec to exec here. * * Returns whether or not the PTE actually changed. */ -int ptep_set_access_flags(struct vm_area_struct *vma, - unsigned long address, pte_t *ptep, - pte_t entry, int dirty) +int __ptep_set_access_flags(struct vm_area_struct *vma, + unsigned long address, pte_t *ptep, + pte_t entry, int dirty) { pteval_t old_pteval, pteval; - pte_t pte = READ_ONCE(*ptep); + pte_t pte = __ptep_get(ptep); if (pte_same(pte, entry)) return 0; @@ -224,9 +233,13 @@ int ptep_set_access_flags(struct vm_area_struct *vma, pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval); } while (pteval != old_pteval); - /* Invalidate a stale read-only entry */ + /* + * Invalidate the local stale read-only entry. Remote stale entries + * may still cause page faults and be invalidated via + * flush_tlb_fix_spurious_fault(). + */ if (dirty) - flush_tlb_page(vma, address); + local_flush_tlb_page(vma, address); return 1; } @@ -243,16 +256,14 @@ static bool is_el1_data_abort(unsigned long esr) static inline bool is_el1_permission_fault(unsigned long addr, unsigned long esr, struct pt_regs *regs) { - unsigned long fsc_type = esr & ESR_ELx_FSC_TYPE; - if (!is_el1_data_abort(esr) && !is_el1_instruction_abort(esr)) return false; - if (fsc_type == ESR_ELx_FSC_PERM) + if (esr_fsc_is_permission_fault(esr)) return true; if (is_ttbr0_addr(addr) && system_uses_ttbr0_pan()) - return fsc_type == ESR_ELx_FSC_FAULT && + return esr_fsc_is_translation_fault(esr) && (regs->pstate & PSR_PAN_BIT); return false; @@ -265,8 +276,7 @@ static bool __kprobes is_spurious_el1_translation_fault(unsigned long addr, unsigned long flags; u64 par, dfsc; - if (!is_el1_data_abort(esr) || - (esr & ESR_ELx_FSC_TYPE) != ESR_ELx_FSC_FAULT) + if (!is_el1_data_abort(esr) || !esr_fsc_is_translation_fault(esr)) return false; local_irq_save(flags); @@ -287,7 +297,7 @@ static bool __kprobes is_spurious_el1_translation_fault(unsigned long addr, * treat the translation fault as spurious. */ dfsc = FIELD_GET(SYS_PAR_EL1_FST, par); - return (dfsc & ESR_ELx_FSC_TYPE) != ESR_ELx_FSC_FAULT; + return !esr_fsc_is_translation_fault(dfsc); } static void die_kernel_fault(const char *msg, unsigned long addr, @@ -317,7 +327,7 @@ static void report_tag_fault(unsigned long addr, unsigned long esr, * find out access size. */ bool is_write = !!(esr & ESR_ELx_WNR); - kasan_report(addr, 0, is_write, regs->pc); + kasan_report((void *)addr, 0, is_write, regs->pc); } #else /* Tag faults aren't enabled without CONFIG_KASAN_HW_TAGS. */ @@ -354,11 +364,6 @@ static bool is_el1_mte_sync_tag_check_fault(unsigned long esr) return false; } -static bool is_translation_fault(unsigned long esr) -{ - return (esr & ESR_ELx_FSC_TYPE) == ESR_ELx_FSC_FAULT; -} - static void __do_kernel_fault(unsigned long addr, unsigned long esr, struct pt_regs *regs) { @@ -368,7 +373,7 @@ static void __do_kernel_fault(unsigned long addr, unsigned long esr, * Are we prepared to handle this kernel fault? * We are almost certainly not prepared to handle instruction faults. */ - if (!is_el1_instruction_abort(esr) && fixup_exception(regs)) + if (!is_el1_instruction_abort(esr) && fixup_exception(regs, esr)) return; if (WARN_RATELIMIT(is_spurious_el1_translation_fault(addr, esr, regs), @@ -391,7 +396,7 @@ static void __do_kernel_fault(unsigned long addr, unsigned long esr, } else if (addr < PAGE_SIZE) { msg = "NULL pointer dereference"; } else { - if (is_translation_fault(esr) && + if (esr_fsc_is_translation_fault(esr) && kfence_handle_page_fault(addr, esr & ESR_ELx_WNR, regs)) return; @@ -480,36 +485,41 @@ static void do_bad_area(unsigned long far, unsigned long esr, } } -#define VM_FAULT_BADMAP 0x010000 -#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 pt_regs *regs) +static bool fault_from_pkey(struct vm_area_struct *vma, unsigned int mm_flags) { - struct vm_area_struct *vma = find_vma(mm, addr); - - if (unlikely(!vma)) - return VM_FAULT_BADMAP; + if (!system_supports_poe()) + return false; /* - * Ok, we have a good vm_area for this memory access, so we can handle - * it. + * We do not check whether an Overlay fault has occurred because we + * cannot make a decision based solely on its value: + * + * - If Overlay is set, a fault did occur due to POE, but it may be + * spurious in those cases where we update POR_EL0 without ISB (e.g. + * on context-switch). We would then need to manually check POR_EL0 + * against vma_pkey(vma), which is exactly what + * arch_vma_access_permitted() does. + * + * - If Overlay is not set, we may still need to report a pkey fault. + * This is the case if an access was made within a mapping but with no + * page mapped, and POR_EL0 forbids the access (according to + * vma_pkey()). Such access will result in a SIGSEGV regardless + * because core code checks arch_vma_access_permitted(), but in order + * to report the correct error code - SEGV_PKUERR - we must handle + * that case here. */ - 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; - } + return !arch_vma_access_permitted(vma, + mm_flags & FAULT_FLAG_WRITE, + mm_flags & FAULT_FLAG_INSTRUCTION, + false); +} - /* - * Check that the permissions on the VMA allow for the fault which - * occurred. - */ - if (!(vma->vm_flags & vm_flags)) - return VM_FAULT_BADACCESS; - return handle_mm_fault(vma, addr, mm_flags, regs); +static bool is_gcs_fault(unsigned long esr) +{ + if (!esr_is_data_abort(esr)) + return false; + + return ESR_ELx_ISS2(esr) & ESR_ELx_GCS; } static bool is_el0_instruction_abort(unsigned long esr) @@ -526,15 +536,35 @@ static bool is_write_abort(unsigned long esr) return (esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM); } +static bool is_invalid_gcs_access(struct vm_area_struct *vma, u64 esr) +{ + if (!system_supports_gcs()) + return false; + + if (unlikely(is_gcs_fault(esr))) { + /* GCS accesses must be performed on a GCS page */ + if (!(vma->vm_flags & VM_SHADOW_STACK)) + return true; + } else if (unlikely(vma->vm_flags & VM_SHADOW_STACK)) { + /* Only GCS operations can write to a GCS page */ + return esr_is_data_abort(esr) && is_write_abort(esr); + } + + return false; +} + static int __kprobes do_page_fault(unsigned long far, unsigned long esr, struct pt_regs *regs) { const struct fault_info *inf; struct mm_struct *mm = current->mm; vm_fault_t fault; - unsigned long vm_flags; + vm_flags_t vm_flags; unsigned int mm_flags = FAULT_FLAG_DEFAULT; unsigned long addr = untagged_addr(far); + struct vm_area_struct *vma; + int si_code; + int pkey = -1; if (kprobe_page_fault(regs, esr)) return 0; @@ -559,6 +589,14 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr, /* It was exec fault */ vm_flags = VM_EXEC; mm_flags |= FAULT_FLAG_INSTRUCTION; + } else if (is_gcs_fault(esr)) { + /* + * The GCS permission on a page implies both read and + * write so always handle any GCS fault as a write fault, + * we need to trigger CoW even for GCS reads. + */ + vm_flags = VM_WRITE; + mm_flags |= FAULT_FLAG_WRITE; } else if (is_write_abort(esr)) { /* It was write fault */ vm_flags = VM_WRITE; @@ -569,7 +607,7 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr, /* Write implies read */ vm_flags |= VM_WRITE; /* If EPAN is absent then exec implies read */ - if (!cpus_have_const_cap(ARM64_HAS_EPAN)) + if (!alternative_has_cap_unlikely(ARM64_HAS_EPAN)) vm_flags |= VM_EXEC; } @@ -578,38 +616,88 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr, die_kernel_fault("execution of user memory", addr, esr, regs); - if (!search_exception_tables(regs->pc)) + if (!insn_may_access_user(regs->pc, esr)) die_kernel_fault("access to user memory outside uaccess routines", addr, esr, regs); } perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); - /* - * As per x86, we may deadlock here. However, since the kernel only - * validly references user space from well defined areas of the code, - * we can bug out early if this is from code which shouldn't. - */ - if (!mmap_read_trylock(mm)) { - if (!user_mode(regs) && !search_exception_tables(regs->pc)) + if (!(mm_flags & FAULT_FLAG_USER)) + goto lock_mmap; + + vma = lock_vma_under_rcu(mm, addr); + if (!vma) + goto lock_mmap; + + if (is_invalid_gcs_access(vma, esr)) { + vma_end_read(vma); + fault = 0; + si_code = SEGV_ACCERR; + goto bad_area; + } + + if (!(vma->vm_flags & vm_flags)) { + vma_end_read(vma); + fault = 0; + si_code = SEGV_ACCERR; + count_vm_vma_lock_event(VMA_LOCK_SUCCESS); + goto bad_area; + } + + if (fault_from_pkey(vma, mm_flags)) { + pkey = vma_pkey(vma); + vma_end_read(vma); + fault = 0; + si_code = SEGV_PKUERR; + count_vm_vma_lock_event(VMA_LOCK_SUCCESS); + goto bad_area; + } + + fault = handle_mm_fault(vma, addr, mm_flags | FAULT_FLAG_VMA_LOCK, regs); + if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED))) + vma_end_read(vma); + + if (!(fault & VM_FAULT_RETRY)) { + count_vm_vma_lock_event(VMA_LOCK_SUCCESS); + goto done; + } + count_vm_vma_lock_event(VMA_LOCK_RETRY); + if (fault & VM_FAULT_MAJOR) + mm_flags |= FAULT_FLAG_TRIED; + + /* Quick path to respond to signals */ + if (fault_signal_pending(fault, regs)) { + if (!user_mode(regs)) goto no_context; + return 0; + } +lock_mmap: + retry: - mmap_read_lock(mm); - } else { - /* - * The above mmap_read_trylock() might have succeeded in which - * case, we'll have missed the might_sleep() from down_read(). - */ - might_sleep(); -#ifdef CONFIG_DEBUG_VM - if (!user_mode(regs) && !search_exception_tables(regs->pc)) { - mmap_read_unlock(mm); - goto no_context; - } -#endif + vma = lock_mm_and_find_vma(mm, addr, regs); + if (unlikely(!vma)) { + fault = 0; + si_code = SEGV_MAPERR; + goto bad_area; } - fault = __do_page_fault(mm, addr, mm_flags, vm_flags, regs); + if (!(vma->vm_flags & vm_flags)) { + mmap_read_unlock(mm); + fault = 0; + si_code = SEGV_ACCERR; + goto bad_area; + } + + if (fault_from_pkey(vma, mm_flags)) { + pkey = vma_pkey(vma); + mmap_read_unlock(mm); + fault = 0; + si_code = SEGV_PKUERR; + goto bad_area; + } + + fault = handle_mm_fault(vma, addr, mm_flags, regs); /* Quick path to respond to signals */ if (fault_signal_pending(fault, regs)) { @@ -628,13 +716,13 @@ retry: } mmap_read_unlock(mm); - /* - * Handle the "normal" (no error) case first. - */ - if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | - VM_FAULT_BADACCESS)))) +done: + /* Handle the "normal" (no error) case first. */ + if (likely(!(fault & VM_FAULT_ERROR))) return 0; + si_code = SEGV_MAPERR; +bad_area: /* * If we are in kernel mode at this point, we have no context to * handle this fault with. @@ -670,12 +758,22 @@ retry: arm64_force_sig_mceerr(BUS_MCEERR_AR, far, lsb, inf->name); } else { /* - * Something tried to access memory that isn't in our memory - * map. + * The pkey value that we return to userspace can be different + * from the pkey that caused the fault. + * + * 1. T1 : mprotect_key(foo, PAGE_SIZE, pkey=4); + * 2. T1 : set POR_EL0 to deny access to pkey=4, touches, page + * 3. T1 : faults... + * 4. T2: mprotect_key(foo, PAGE_SIZE, pkey=5); + * 5. T1 : enters fault handler, takes mmap_lock, etc... + * 6. T1 : reaches here, sees vma_pkey(vma)=5, when we really + * faulted on a pte with its pkey=4. */ - arm64_force_sig_fault(SIGSEGV, - fault == VM_FAULT_BADACCESS ? SEGV_ACCERR : SEGV_MAPERR, - far, inf->name); + /* Something tried to access memory that out of memory map */ + if (si_code == SEGV_PKUERR) + arm64_force_sig_fault_pkey(far, inf->name, pkey); + else + arm64_force_sig_fault(SIGSEGV, si_code, far, inf->name); } return 0; @@ -738,6 +836,7 @@ static int do_sea(unsigned long far, unsigned long esr, struct pt_regs *regs) */ siaddr = untagged_addr(far); } + add_taint(TAINT_MACHINE_CHECK, LOCKDEP_STILL_OK); arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr); return 0; @@ -749,9 +848,12 @@ static int do_tag_check_fault(unsigned long far, unsigned long esr, /* * The architecture specifies that bits 63:60 of FAR_EL1 are UNKNOWN * for tag check faults. Set them to corresponding bits in the untagged - * address. + * address if ARM64_MTE_FAR isn't supported. + * Otherwise, bits 63:60 of FAR_EL1 are not UNKNOWN. */ - far = (__untagged_addr(far) & ~MTE_TAG_MASK) | (far & MTE_TAG_MASK); + if (!cpus_have_cap(ARM64_MTE_FAR)) + far = (__untagged_addr(far) & ~MTE_TAG_MASK) | (far & MTE_TAG_MASK); + do_bad_area(far, esr, regs); return 0; } @@ -765,18 +867,18 @@ static const struct fault_info fault_info[] = { { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" }, { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" }, { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 8" }, + { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 0 access flag fault" }, { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" }, { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" }, { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 12" }, + { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 0 permission fault" }, { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" }, { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" }, { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" }, { do_sea, SIGBUS, BUS_OBJERR, "synchronous external abort" }, { do_tag_check_fault, SIGSEGV, SEGV_MTESERR, "synchronous tag check fault" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 18" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 19" }, + { do_sea, SIGKILL, SI_KERNEL, "level -1 (translation table walk)" }, { do_sea, SIGKILL, SI_KERNEL, "level 0 (translation table walk)" }, { do_sea, SIGKILL, SI_KERNEL, "level 1 (translation table walk)" }, { do_sea, SIGKILL, SI_KERNEL, "level 2 (translation table walk)" }, @@ -784,7 +886,7 @@ static const struct fault_info fault_info[] = { { do_sea, SIGBUS, BUS_OBJERR, "synchronous parity or ECC error" }, // Reserved when RAS is implemented { do_bad, SIGKILL, SI_KERNEL, "unknown 25" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 26" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 27" }, + { do_sea, SIGKILL, SI_KERNEL, "level -1 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented { do_sea, SIGKILL, SI_KERNEL, "level 0 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented { do_sea, SIGKILL, SI_KERNEL, "level 1 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented { do_sea, SIGKILL, SI_KERNEL, "level 2 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented @@ -798,9 +900,9 @@ static const struct fault_info fault_info[] = { { do_bad, SIGKILL, SI_KERNEL, "unknown 38" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 39" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 40" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 41" }, + { do_bad, SIGKILL, SI_KERNEL, "level -1 address size fault" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 42" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 43" }, + { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level -1 translation fault" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 44" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 45" }, { do_bad, SIGKILL, SI_KERNEL, "unknown 46" }, @@ -850,82 +952,10 @@ void do_sp_pc_abort(unsigned long addr, unsigned long esr, struct pt_regs *regs) } NOKPROBE_SYMBOL(do_sp_pc_abort); -int __init early_brk64(unsigned long addr, unsigned long esr, - struct pt_regs *regs); - -/* - * __refdata because early_brk64 is __init, but the reference to it is - * clobbered at arch_initcall time. - * See traps.c and debug-monitors.c:debug_traps_init(). - */ -static struct fault_info __refdata debug_fault_info[] = { - { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" }, - { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" }, - { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 3" }, - { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" }, - { do_bad, SIGKILL, SI_KERNEL, "aarch32 vector catch" }, - { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" }, - { do_bad, SIGKILL, SI_KERNEL, "unknown 7" }, -}; - -void __init hook_debug_fault_code(int nr, - int (*fn)(unsigned long, unsigned long, struct pt_regs *), - int sig, int code, const char *name) -{ - BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info)); - - debug_fault_info[nr].fn = fn; - debug_fault_info[nr].sig = sig; - debug_fault_info[nr].code = code; - debug_fault_info[nr].name = name; -} - -/* - * In debug exception context, we explicitly disable preemption despite - * having interrupts disabled. - * This serves two purposes: it makes it much less likely that we would - * accidentally schedule in exception context and it will force a warning - * if we somehow manage to schedule by accident. - */ -static void debug_exception_enter(struct pt_regs *regs) -{ - preempt_disable(); - - /* This code is a bit fragile. Test it. */ - RCU_LOCKDEP_WARN(!rcu_is_watching(), "exception_enter didn't work"); -} -NOKPROBE_SYMBOL(debug_exception_enter); - -static void debug_exception_exit(struct pt_regs *regs) -{ - preempt_enable_no_resched(); -} -NOKPROBE_SYMBOL(debug_exception_exit); - -void do_debug_exception(unsigned long addr_if_watchpoint, unsigned long esr, - struct pt_regs *regs) -{ - const struct fault_info *inf = esr_to_debug_fault_info(esr); - unsigned long pc = instruction_pointer(regs); - - debug_exception_enter(regs); - - if (user_mode(regs) && !is_ttbr0_addr(pc)) - arm64_apply_bp_hardening(); - - if (inf->fn(addr_if_watchpoint, esr, regs)) { - arm64_notify_die(inf->name, regs, inf->sig, inf->code, pc, esr); - } - - debug_exception_exit(regs); -} -NOKPROBE_SYMBOL(do_debug_exception); - /* * Used during anonymous page fault handling. */ -struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma, +struct folio *vma_alloc_zeroed_movable_folio(struct vm_area_struct *vma, unsigned long vaddr) { gfp_t flags = GFP_HIGHUSER_MOVABLE | __GFP_ZERO; @@ -938,13 +968,24 @@ struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma, if (vma->vm_flags & VM_MTE) flags |= __GFP_ZEROTAGS; - return alloc_page_vma(flags, vma, vaddr); + return vma_alloc_folio(flags, 0, vma, vaddr); } -void tag_clear_highpage(struct page *page) +bool tag_clear_highpages(struct page *page, int numpages) { - /* Newly allocated page, shouldn't have been tagged yet */ - WARN_ON_ONCE(!try_page_mte_tagging(page)); - mte_zero_clear_page_tags(page_address(page)); - set_page_mte_tagged(page); + /* + * Check if MTE is supported and fall back to clear_highpage(). + * get_huge_zero_folio() unconditionally passes __GFP_ZEROTAGS and + * post_alloc_hook() will invoke tag_clear_highpages(). + */ + if (!system_supports_mte()) + return false; + + /* Newly allocated pages, shouldn't have been tagged yet */ + for (int i = 0; i < numpages; i++, page++) { + WARN_ON_ONCE(!try_page_mte_tagging(page)); + mte_zero_clear_page_tags(page_address(page)); + set_page_mte_tagged(page); + } + return true; } |
