diff options
Diffstat (limited to 'arch/x86/mm/fault.c')
| -rw-r--r-- | arch/x86/mm/fault.c | 57 |
1 files changed, 7 insertions, 50 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 42394b353c6a..0a778e3c43ee 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c | |||
| @@ -10,6 +10,7 @@ | |||
| 10 | #include <linux/string.h> | 10 | #include <linux/string.h> |
| 11 | #include <linux/types.h> | 11 | #include <linux/types.h> |
| 12 | #include <linux/ptrace.h> | 12 | #include <linux/ptrace.h> |
| 13 | #include <linux/mmiotrace.h> | ||
| 13 | #include <linux/mman.h> | 14 | #include <linux/mman.h> |
| 14 | #include <linux/mm.h> | 15 | #include <linux/mm.h> |
| 15 | #include <linux/smp.h> | 16 | #include <linux/smp.h> |
| @@ -49,58 +50,14 @@ | |||
| 49 | #define PF_RSVD (1<<3) | 50 | #define PF_RSVD (1<<3) |
| 50 | #define PF_INSTR (1<<4) | 51 | #define PF_INSTR (1<<4) |
| 51 | 52 | ||
| 52 | #ifdef CONFIG_PAGE_FAULT_HANDLERS | 53 | static inline int kmmio_fault(struct pt_regs *regs, unsigned long addr) |
| 53 | static HLIST_HEAD(pf_handlers); /* protected by RCU */ | ||
| 54 | static DEFINE_SPINLOCK(pf_handlers_writer); | ||
| 55 | |||
| 56 | void register_page_fault_handler(struct pf_handler *new_pfh) | ||
| 57 | { | ||
| 58 | unsigned long flags; | ||
| 59 | spin_lock_irqsave(&pf_handlers_writer, flags); | ||
| 60 | hlist_add_head_rcu(&new_pfh->hlist, &pf_handlers); | ||
| 61 | spin_unlock_irqrestore(&pf_handlers_writer, flags); | ||
| 62 | } | ||
| 63 | EXPORT_SYMBOL_GPL(register_page_fault_handler); | ||
| 64 | |||
| 65 | /** | ||
| 66 | * unregister_page_fault_handler: | ||
| 67 | * The caller must ensure @old_pfh is not in use anymore before freeing it. | ||
| 68 | * This function does not guarantee it. The list of handlers is protected by | ||
| 69 | * RCU, so you can do this by e.g. calling synchronize_rcu(). | ||
| 70 | */ | ||
| 71 | void unregister_page_fault_handler(struct pf_handler *old_pfh) | ||
| 72 | { | 54 | { |
| 73 | unsigned long flags; | 55 | #ifdef CONFIG_MMIOTRACE_HOOKS |
| 74 | spin_lock_irqsave(&pf_handlers_writer, flags); | 56 | if (unlikely(is_kmmio_active())) |
| 75 | hlist_del_rcu(&old_pfh->hlist); | 57 | if (kmmio_handler(regs, addr) == 1) |
| 76 | spin_unlock_irqrestore(&pf_handlers_writer, flags); | 58 | return -1; |
| 77 | } | ||
| 78 | EXPORT_SYMBOL_GPL(unregister_page_fault_handler); | ||
| 79 | #endif | 59 | #endif |
| 80 | |||
| 81 | /* returns non-zero if do_page_fault() should return */ | ||
| 82 | static int handle_custom_pf(struct pt_regs *regs, unsigned long error_code, | ||
| 83 | unsigned long address) | ||
| 84 | { | ||
| 85 | #ifdef CONFIG_PAGE_FAULT_HANDLERS | ||
| 86 | int ret = 0; | ||
| 87 | struct pf_handler *cur; | ||
| 88 | struct hlist_node *ncur; | ||
| 89 | |||
| 90 | if (hlist_empty(&pf_handlers)) | ||
| 91 | return 0; | ||
| 92 | |||
| 93 | rcu_read_lock(); | ||
| 94 | hlist_for_each_entry_rcu(cur, ncur, &pf_handlers, hlist) { | ||
| 95 | ret = cur->handler(regs, error_code, address); | ||
| 96 | if (ret) | ||
| 97 | break; | ||
| 98 | } | ||
| 99 | rcu_read_unlock(); | ||
| 100 | return ret; | ||
| 101 | #else | ||
| 102 | return 0; | 60 | return 0; |
| 103 | #endif | ||
| 104 | } | 61 | } |
| 105 | 62 | ||
| 106 | static inline int notify_page_fault(struct pt_regs *regs) | 63 | static inline int notify_page_fault(struct pt_regs *regs) |
| @@ -660,7 +617,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) | |||
| 660 | 617 | ||
| 661 | if (notify_page_fault(regs)) | 618 | if (notify_page_fault(regs)) |
| 662 | return; | 619 | return; |
| 663 | if (handle_custom_pf(regs, error_code, address)) | 620 | if (unlikely(kmmio_fault(regs, address))) |
| 664 | return; | 621 | return; |
| 665 | 622 | ||
| 666 | /* | 623 | /* |
