diff options
Diffstat (limited to 'arch/arm/mm/fault.c')
| -rw-r--r-- | arch/arm/mm/fault.c | 169 |
1 files changed, 58 insertions, 111 deletions
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index aa33949fef60..bb7eac381a8e 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -27,19 +27,6 @@ #include "fault.h" -/* - * Fault status register encodings. We steal bit 31 for our own purposes. - */ -#define FSR_LNX_PF (1 << 31) -#define FSR_WRITE (1 << 11) -#define FSR_FS4 (1 << 10) -#define FSR_FS3_0 (15) - -static inline int fsr_fs(unsigned int fsr) -{ - return (fsr & FSR_FS3_0) | (fsr & FSR_FS4) >> 6; -} - #ifdef CONFIG_MMU #ifdef CONFIG_KPROBES @@ -123,8 +110,10 @@ void show_pte(struct mm_struct *mm, unsigned long addr) pte = pte_offset_map(pmd, addr); printk(", *pte=%08llx", (long long)pte_val(*pte)); +#ifndef CONFIG_ARM_LPAE printk(", *ppte=%08llx", (long long)pte_val(pte[PTE_HWTABLE_PTRS])); +#endif pte_unmap(pte); } while(0); @@ -231,7 +220,7 @@ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma) static int __kprobes __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, - struct task_struct *tsk) + unsigned int flags, struct task_struct *tsk) { struct vm_area_struct *vma; int fault; @@ -253,18 +242,7 @@ good_area: goto out; } - /* - * If for any reason at all we couldn't handle the fault, make - * sure we exit gracefully rather than endlessly redo the fault. - */ - fault = handle_mm_fault(mm, vma, addr & PAGE_MASK, (fsr & FSR_WRITE) ? FAULT_FLAG_WRITE : 0); - if (unlikely(fault & VM_FAULT_ERROR)) - return fault; - if (fault & VM_FAULT_MAJOR) - tsk->maj_flt++; - else - tsk->min_flt++; - return fault; + return handle_mm_fault(mm, vma, addr & PAGE_MASK, flags); check_stack: if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) @@ -279,6 +257,9 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) struct task_struct *tsk; struct mm_struct *mm; int fault, sig, code; + int write = fsr & FSR_WRITE; + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE | + (write ? FAULT_FLAG_WRITE : 0); if (notify_page_fault(regs, fsr)) return 0; @@ -305,6 +286,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (!down_read_trylock(&mm->mmap_sem)) { if (!user_mode(regs) && !search_exception_tables(regs->ARM_pc)) goto no_context; +retry: down_read(&mm->mmap_sem); } else { /* @@ -320,14 +302,41 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) #endif } - fault = __do_page_fault(mm, addr, fsr, tsk); - up_read(&mm->mmap_sem); + fault = __do_page_fault(mm, addr, fsr, flags, tsk); + + /* If we need to retry but a fatal signal is pending, handle the + * signal first. We do not need to release the mmap_sem because + * it would already be released in __lock_page_or_retry in + * mm/filemap.c. */ + if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) + return 0; + + /* + * Major/minor page fault accounting is only done on the + * initial attempt. If we go through a retry, it is extremely + * likely that the page will be found in page cache at that point. + */ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); - if (fault & VM_FAULT_MAJOR) - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, addr); - else if (fault & VM_FAULT_MINOR) - perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, addr); + if (flags & FAULT_FLAG_ALLOW_RETRY) { + if (fault & VM_FAULT_MAJOR) { + tsk->maj_flt++; + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, + regs, addr); + } else { + tsk->min_flt++; + perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, + regs, addr); + } + if (fault & VM_FAULT_RETRY) { + /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk + * of starvation. */ + flags &= ~FAULT_FLAG_ALLOW_RETRY; + goto retry; + } + } + + up_read(&mm->mmap_sem); /* * Handle the "normal" case first - VM_FAULT_MAJOR / VM_FAULT_MINOR @@ -441,6 +450,12 @@ do_translation_fault(unsigned long addr, unsigned int fsr, pmd = pmd_offset(pud, addr); pmd_k = pmd_offset(pud_k, addr); +#ifdef CONFIG_ARM_LPAE + /* + * Only one hardware entry per PMD with LPAE. + */ + index = 0; +#else /* * On ARM one Linux PGD entry contains two hardware entries (see page * tables layout in pgtable.h). We normally guarantee that we always @@ -450,6 +465,7 @@ do_translation_fault(unsigned long addr, unsigned int fsr, * for the first of pair. */ index = (addr >> SECTION_SHIFT) & 1; +#endif if (pmd_none(pmd_k[index])) goto bad_area; @@ -489,55 +505,20 @@ do_bad(unsigned long addr, unsigned int fsr, struct pt_regs *regs) return 1; } -static struct fsr_info { +struct fsr_info { int (*fn)(unsigned long addr, unsigned int fsr, struct pt_regs *regs); int sig; int code; const char *name; -} fsr_info[] = { - /* - * The following are the standard ARMv3 and ARMv4 aborts. ARMv5 - * defines these to be "precise" aborts. - */ - { do_bad, SIGSEGV, 0, "vector exception" }, - { do_bad, SIGBUS, BUS_ADRALN, "alignment exception" }, - { do_bad, SIGKILL, 0, "terminal exception" }, - { do_bad, SIGBUS, BUS_ADRALN, "alignment exception" }, - { do_bad, SIGBUS, 0, "external abort on linefetch" }, - { do_translation_fault, SIGSEGV, SEGV_MAPERR, "section translation fault" }, - { do_bad, SIGBUS, 0, "external abort on linefetch" }, - { do_page_fault, SIGSEGV, SEGV_MAPERR, "page translation fault" }, - { do_bad, SIGBUS, 0, "external abort on non-linefetch" }, - { do_bad, SIGSEGV, SEGV_ACCERR, "section domain fault" }, - { do_bad, SIGBUS, 0, "external abort on non-linefetch" }, - { do_bad, SIGSEGV, SEGV_ACCERR, "page domain fault" }, - { do_bad, SIGBUS, 0, "external abort on translation" }, - { do_sect_fault, SIGSEGV, SEGV_ACCERR, "section permission fault" }, - { do_bad, SIGBUS, 0, "external abort on translation" }, - { do_page_fault, SIGSEGV, SEGV_ACCERR, "page permission fault" }, - /* - * The following are "imprecise" aborts, which are signalled by bit - * 10 of the FSR, and may not be recoverable. These are only - * supported if the CPU abort handler supports bit 10. - */ - { do_bad, SIGBUS, 0, "unknown 16" }, - { do_bad, SIGBUS, 0, "unknown 17" }, - { do_bad, SIGBUS, 0, "unknown 18" }, - { do_bad, SIGBUS, 0, "unknown 19" }, - { do_bad, SIGBUS, 0, "lock abort" }, /* xscale */ - { do_bad, SIGBUS, 0, "unknown 21" }, - { do_bad, SIGBUS, BUS_OBJERR, "imprecise external abort" }, /* xscale */ - { do_bad, SIGBUS, 0, "unknown 23" }, - { do_bad, SIGBUS, 0, "dcache parity error" }, /* xscale */ - { do_bad, SIGBUS, 0, "unknown 25" }, - { do_bad, SIGBUS, 0, "unknown 26" }, - { do_bad, SIGBUS, 0, "unknown 27" }, - { do_bad, SIGBUS, 0, "unknown 28" }, - { do_bad, SIGBUS, 0, "unknown 29" }, - { do_bad, SIGBUS, 0, "unknown 30" }, - { do_bad, SIGBUS, 0, "unknown 31" } }; +/* FSR definition */ +#ifdef CONFIG_ARM_LPAE +#include "fsr-3level.c" +#else +#include "fsr-2level.c" +#endif + void __init hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *), int sig, int code, const char *name) @@ -573,42 +554,6 @@ do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs) arm_notify_die("", regs, &info, fsr, 0); } - -static struct fsr_info ifsr_info[] = { - { do_bad, SIGBUS, 0, "unknown 0" }, - { do_bad, SIGBUS, 0, "unknown 1" }, - { do_bad, SIGBUS, 0, "debug event" }, - { do_bad, SIGSEGV, SEGV_ACCERR, "section access flag fault" }, - { do_bad, SIGBUS, 0, "unknown 4" }, - { do_translation_fault, SIGSEGV, SEGV_MAPERR, "section translation fault" }, - { do_bad, SIGSEGV, SEGV_ACCERR, "page access flag fault" }, - { do_page_fault, SIGSEGV, SEGV_MAPERR, "page translation fault" }, - { do_bad, SIGBUS, 0, "external abort on non-linefetch" }, - { do_bad, SIGSEGV, SEGV_ACCERR, "section domain fault" }, - { do_bad, SIGBUS, 0, "unknown 10" }, - { do_bad, SIGSEGV, SEGV_ACCERR, "page domain fault" }, - { do_bad, SIGBUS, 0, "external abort on translation" }, - { do_sect_fault, SIGSEGV, SEGV_ACCERR, "section permission fault" }, - { do_bad, SIGBUS, 0, "external abort on translation" }, - { do_page_fault, SIGSEGV, SEGV_ACCERR, "page permission fault" }, - { do_bad, SIGBUS, 0, "unknown 16" }, - { do_bad, SIGBUS, 0, "unknown 17" }, - { do_bad, SIGBUS, 0, "unknown 18" }, - { do_bad, SIGBUS, 0, "unknown 19" }, - { do_bad, SIGBUS, 0, "unknown 20" }, - { do_bad, SIGBUS, 0, "unknown 21" }, - { do_bad, SIGBUS, 0, "unknown 22" }, - { do_bad, SIGBUS, 0, "unknown 23" }, - { do_bad, SIGBUS, 0, "unknown 24" }, - { do_bad, SIGBUS, 0, "unknown 25" }, - { do_bad, SIGBUS, 0, "unknown 26" }, - { do_bad, SIGBUS, 0, "unknown 27" }, - { do_bad, SIGBUS, 0, "unknown 28" }, - { do_bad, SIGBUS, 0, "unknown 29" }, - { do_bad, SIGBUS, 0, "unknown 30" }, - { do_bad, SIGBUS, 0, "unknown 31" }, -}; - void __init hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *), int sig, int code, const char *name) @@ -641,6 +586,7 @@ do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs) arm_notify_die("", regs, &info, ifsr, 0); } +#ifndef CONFIG_ARM_LPAE static int __init exceptions_init(void) { if (cpu_architecture() >= CPU_ARCH_ARMv6) { @@ -663,3 +609,4 @@ static int __init exceptions_init(void) } arch_initcall(exceptions_init); +#endif |