diff options
Diffstat (limited to 'kernel/events/uprobes.c')
| -rw-r--r-- | kernel/events/uprobes.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index c74fc9826250..f08ba79ee5d1 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -612,10 +612,6 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file, if (ret) goto out; - /* uprobe_write_opcode() assumes we don't cross page boundary */ - BUG_ON((uprobe->offset & ~PAGE_MASK) + - UPROBE_SWBP_INSN_SIZE > PAGE_SIZE); - smp_wmb(); /* pairs with the smp_rmb() in handle_swbp() */ set_bit(UPROBE_COPY_INSN, &uprobe->flags); @@ -894,6 +890,13 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer * if (offset > i_size_read(inode)) return -EINVAL; + /* + * This ensures that copy_from_page() and copy_to_page() + * can't cross page boundary. + */ + if (!IS_ALIGNED(offset, UPROBE_SWBP_INSN_SIZE)) + return -EINVAL; + retry: uprobe = alloc_uprobe(inode, offset); if (!uprobe) @@ -1704,6 +1707,9 @@ static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr) uprobe_opcode_t opcode; int result; + if (WARN_ON_ONCE(!IS_ALIGNED(vaddr, UPROBE_SWBP_INSN_SIZE))) + return -EINVAL; + pagefault_disable(); result = __get_user(opcode, (uprobe_opcode_t __user *)vaddr); pagefault_enable(); @@ -1887,7 +1893,7 @@ static void handle_swbp(struct pt_regs *regs) if (!uprobe) { if (is_swbp > 0) { /* No matching uprobe; signal SIGTRAP. */ - send_sig(SIGTRAP, current, 0); + force_sig(SIGTRAP, current); } else { /* * Either we raced with uprobe_unregister() or we can't |