diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 0ac346ae5edb..24b7d6ca871b 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -504,9 +504,8 @@ static bool consumer_del(struct uprobe *uprobe, struct uprobe_consumer *uc) return ret; } -static int -__copy_insn(struct address_space *mapping, struct file *filp, char *insn, - unsigned long nbytes, loff_t offset) +static int __copy_insn(struct address_space *mapping, struct file *filp, + void *insn, int nbytes, loff_t offset) { struct page *page; @@ -528,28 +527,28 @@ __copy_insn(struct address_space *mapping, struct file *filp, char *insn, static int copy_insn(struct uprobe *uprobe, struct file *filp) { - struct address_space *mapping; - unsigned long nbytes; - int bytes; + struct address_space *mapping = uprobe->inode->i_mapping; + loff_t offs = uprobe->offset; + void *insn = uprobe->arch.insn; + int size = MAX_UINSN_BYTES; + int len, err = -EIO; - nbytes = PAGE_SIZE - (uprobe->offset & ~PAGE_MASK); - mapping = uprobe->inode->i_mapping; + /* Copy only available bytes, -EIO if nothing was read */ + do { + if (offs >= i_size_read(uprobe->inode)) + break; - /* Instruction at end of binary; copy only available bytes */ - if (uprobe->offset + MAX_UINSN_BYTES > uprobe->inode->i_size) - bytes = uprobe->inode->i_size - uprobe->offset; - else - bytes = MAX_UINSN_BYTES; - - /* Instruction at the page-boundary; copy bytes in second page */ - if (nbytes < bytes) { - int err = __copy_insn(mapping, filp, uprobe->arch.insn + nbytes, - bytes - nbytes, uprobe->offset + nbytes); + len = min_t(int, size, PAGE_SIZE - (offs & ~PAGE_MASK)); + err = __copy_insn(mapping, filp, insn, len, offs); if (err) - return err; - bytes = nbytes; - } - return __copy_insn(mapping, filp, uprobe->arch.insn, bytes, uprobe->offset); + break; + + insn += len; + offs += len; + size -= len; + } while (size); + + return err; } static int prepare_uprobe(struct uprobe *uprobe, struct file *file, @@ -1447,7 +1446,7 @@ void uprobe_copy_process(struct task_struct *t, unsigned long flags) if (!work) return uprobe_warn(t, "dup xol area"); - utask->vaddr = area->vaddr; + t->utask->vaddr = area->vaddr; init_task_work(work, dup_xol_work); task_work_add(t, work, true); }