diff options
Diffstat (limited to 'arch/arm/mm')
| -rw-r--r-- | arch/arm/mm/Kconfig | 5 | ||||
| -rw-r--r-- | arch/arm/mm/fault.c | 110 | ||||
| -rw-r--r-- | arch/arm/mm/proc-xscale.S | 2 |
3 files changed, 68 insertions, 49 deletions
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index 5fe595a..8d43e58 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -771,3 +771,8 @@ config CACHE_XSC3L2 select OUTER_CACHE help This option enables the L2 cache on XScale3. + +config ARM_L1_CACHE_SHIFT + int + default 6 if ARCH_OMAP3 + default 5 diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index cc8829d..379f785 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -25,6 +25,19 @@ #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 @@ -182,18 +195,35 @@ void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs) #define VM_FAULT_BADMAP 0x010000 #define VM_FAULT_BADACCESS 0x020000 -static int +/* + * Check that the permissions on the VMA allow for the fault which occurred. + * If we encountered a write fault, we must have write permission, otherwise + * we allow any permission. + */ +static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma) +{ + unsigned int mask = VM_READ | VM_WRITE | VM_EXEC; + + if (fsr & FSR_WRITE) + mask = VM_WRITE; + if (fsr & FSR_LNX_PF) + mask = VM_EXEC; + + return vma->vm_flags & mask ? false : true; +} + +static int __kprobes __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, struct task_struct *tsk) { struct vm_area_struct *vma; - int fault, mask; + int fault; vma = find_vma(mm, addr); fault = VM_FAULT_BADMAP; - if (!vma) + if (unlikely(!vma)) goto out; - if (vma->vm_start > addr) + if (unlikely(vma->vm_start > addr)) goto check_stack; /* @@ -201,47 +231,24 @@ __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, * memory access, so we can handle it. */ good_area: - if (fsr & (1 << 11)) /* write? */ - mask = VM_WRITE; - else - mask = VM_READ|VM_EXEC|VM_WRITE; - - fault = VM_FAULT_BADACCESS; - if (!(vma->vm_flags & mask)) + if (access_error(fsr, vma)) { + fault = VM_FAULT_BADACCESS; 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. + * If for any reason at all we couldn't handle the fault, make + * sure we exit gracefully rather than endlessly redo the fault. */ -survive: - fault = handle_mm_fault(mm, vma, addr & PAGE_MASK, (fsr & (1 << 11)) ? FAULT_FLAG_WRITE : 0); - if (unlikely(fault & VM_FAULT_ERROR)) { - if (fault & VM_FAULT_OOM) - goto out_of_memory; - else if (fault & VM_FAULT_SIGBUS) - return fault; - BUG(); - } + 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; -out_of_memory: - if (!is_global_init(tsk)) - goto out; - - /* - * If we are out of memory for pid1, sleep for a while and retry - */ - up_read(&mm->mmap_sem); - yield(); - down_read(&mm->mmap_sem); - goto survive; - check_stack: if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) goto good_area; @@ -278,6 +285,13 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (!user_mode(regs) && !search_exception_tables(regs->ARM_pc)) goto no_context; down_read(&mm->mmap_sem); + } else { + /* + * The above down_read_trylock() might have succeeded in + * which case, we'll have missed the might_sleep() from + * down_read() + */ + might_sleep(); } fault = __do_page_fault(mm, addr, fsr, tsk); @@ -289,6 +303,16 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | VM_FAULT_BADACCESS)))) return 0; + if (fault & VM_FAULT_OOM) { + /* + * We ran out of memory, call the OOM killer, and return to + * userspace (which will retry the fault, or kill us if we + * got oom-killed) + */ + pagefault_out_of_memory(); + return 0; + } + /* * If we are in kernel mode at this point, we * have no context to handle this fault with. @@ -296,16 +320,6 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (!user_mode(regs)) goto no_context; - if (fault & VM_FAULT_OOM) { - /* - * We ran out of memory, or some other thing - * happened to us that made us unable to handle - * the page fault gracefully. - */ - printk("VM: killing process %s\n", tsk->comm); - do_group_exit(SIGKILL); - return 0; - } if (fault & VM_FAULT_SIGBUS) { /* * We had some memory, but were unable to @@ -489,10 +503,10 @@ hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *) asmlinkage void __exception do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs) { - const struct fsr_info *inf = fsr_info + (fsr & 15) + ((fsr & (1 << 10)) >> 6); + const struct fsr_info *inf = fsr_info + fsr_fs(fsr); struct siginfo info; - if (!inf->fn(addr, fsr, regs)) + if (!inf->fn(addr, fsr & ~FSR_LNX_PF, regs)) return; printk(KERN_ALERT "Unhandled fault: %s (0x%03x) at 0x%08lx\n", @@ -508,6 +522,6 @@ do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs) asmlinkage void __exception do_PrefetchAbort(unsigned long addr, struct pt_regs *regs) { - do_translation_fault(addr, 0, regs); + do_translation_fault(addr, FSR_LNX_PF, regs); } diff --git a/arch/arm/mm/proc-xscale.S b/arch/arm/mm/proc-xscale.S index 0cce37b..4233942 100644 --- a/arch/arm/mm/proc-xscale.S +++ b/arch/arm/mm/proc-xscale.S @@ -17,7 +17,7 @@ * * 2001 Sep 08: * Completely revisited, many important fixes - * Nicolas Pitre <nico@cam.org> + * Nicolas Pitre <nico@fluxnic.net> */ #include <linux/linkage.h> |
