Merge branch 'uprobes/core' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc into perf/core

Pull uprobes fixes from Oleg Nesterov.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 22 insertions, 23 deletions

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;
-
-        nbytes = PAGE_SIZE - (uprobe->offset & ~PAGE_MASK);
-        mapping = uprobe->inode->i_mapping;
+        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;
 
-        /* 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;
+        /* Copy only available bytes, -EIO if nothing was read */
+        do {
+                if (offs >= i_size_read(uprobe->inode))
+                        break;
 
-        /* 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);
 }