diff options
| -rw-r--r-- | kernel/events/uprobes.c | 73 |
1 files changed, 24 insertions, 49 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 9248ee76b4bb..6136854da6c6 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -282,32 +282,6 @@ put_old: return ret; } -static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr) -{ - struct page *page; - uprobe_opcode_t opcode; - int result; - - if (current->mm == mm) { - pagefault_disable(); - result = __copy_from_user_inatomic(&opcode, (void __user*)vaddr, - sizeof(opcode)); - pagefault_enable(); - - if (likely(result == 0)) - goto out; - } - - result = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &page, NULL); - if (result < 0) - return result; - - copy_opcode(page, vaddr, &opcode); - put_page(page); - out: - return is_swbp_insn(&opcode); -} - /** * set_swbp - store breakpoint at a given address. * @auprobe: arch specific probepoint information. @@ -589,29 +563,6 @@ static int copy_insn(struct uprobe *uprobe, struct file *filp) return __copy_insn(mapping, filp, uprobe->arch.insn, bytes, uprobe->offset); } -/* - * How mm->uprobes_state.count gets updated - * uprobe_mmap() increments the count if - * - it successfully adds a breakpoint. - * - it cannot add a breakpoint, but sees that there is a underlying - * breakpoint (via a is_swbp_at_addr()). - * - * uprobe_munmap() decrements the count if - * - it sees a underlying breakpoint, (via is_swbp_at_addr) - * (Subsequent uprobe_unregister wouldnt find the breakpoint - * unless a uprobe_mmap kicks in, since the old vma would be - * dropped just after uprobe_munmap.) - * - * uprobe_register increments the count if: - * - it successfully adds a breakpoint. - * - * uprobe_unregister decrements the count if: - * - it sees a underlying breakpoint and removes successfully. - * (via is_swbp_at_addr) - * (Subsequent uprobe_munmap wouldnt find the breakpoint - * since there is no underlying breakpoint after the - * breakpoint removal.) - */ static int install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, struct vm_area_struct *vma, unsigned long vaddr) @@ -1389,6 +1340,30 @@ static void mmf_recalc_uprobes(struct mm_struct *mm) clear_bit(MMF_HAS_UPROBES, &mm->flags); } +static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr) +{ + struct page *page; + uprobe_opcode_t opcode; + int result; + + pagefault_disable(); + result = __copy_from_user_inatomic(&opcode, (void __user*)vaddr, + sizeof(opcode)); + pagefault_enable(); + + if (likely(result == 0)) + goto out; + + result = get_user_pages(NULL, mm, vaddr, 1, 0, 1, &page, NULL); + if (result < 0) + return result; + + copy_opcode(page, vaddr, &opcode); + put_page(page); + out: + return is_swbp_insn(&opcode); +} + static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp) { struct mm_struct *mm = current->mm; |