Merge branch 'perf/uprobes' into perf/core

These bits from Oleg are fully cooked, ship them to Linus.

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

1 files changed, 22 insertions, 13 deletions

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index d1edc5e6fd03..3b02c72938a8 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -127,7 +127,7 @@ struct xol_area {
  */
 static bool valid_vma(struct vm_area_struct *vma, bool is_register)
 {
-        vm_flags_t flags = VM_HUGETLB | VM_MAYEXEC | VM_SHARED;
+        vm_flags_t flags = VM_HUGETLB | VM_MAYEXEC | VM_MAYSHARE;
 
         if (is_register)
                 flags |= VM_WRITE;
@@ -279,18 +279,13 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t
  * supported by that architecture then we need to modify is_trap_at_addr and
  * uprobe_write_opcode accordingly. This would never be a problem for archs
  * that have fixed length instructions.
- */
-
-/*
+ *
  * uprobe_write_opcode - write the opcode at a given virtual address.
  * @mm: the probed process address space.
  * @vaddr: the virtual address to store the opcode.
  * @opcode: opcode to be written at @vaddr.
  *
- * Called with mm->mmap_sem held (for read and with a reference to
- * mm).
- *
- * For mm @mm, write the opcode at @vaddr.
+ * Called with mm->mmap_sem held for write.
  * Return 0 (success) or a negative errno.
  */
 int uprobe_write_opcode(struct mm_struct *mm, unsigned long vaddr,
@@ -310,21 +305,25 @@ retry:
         if (ret <= 0)
                 goto put_old;
 
+        ret = anon_vma_prepare(vma);
+        if (ret)
+                goto put_old;
+
         ret = -ENOMEM;
         new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr);
         if (!new_page)
                 goto put_old;
 
-        __SetPageUptodate(new_page);
+        if (mem_cgroup_charge_anon(new_page, mm, GFP_KERNEL))
+                goto put_new;
 
+        __SetPageUptodate(new_page);
         copy_highpage(new_page, old_page);
         copy_to_page(new_page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
 
-        ret = anon_vma_prepare(vma);
-        if (ret)
-                goto put_new;
-
         ret = __replace_page(vma, vaddr, old_page, new_page);
+        if (ret)
+                mem_cgroup_uncharge_page(new_page);
 
 put_new:
         page_cache_release(new_page);
@@ -1352,6 +1351,16 @@ unsigned long __weak uprobe_get_swbp_addr(struct pt_regs *regs)
         return instruction_pointer(regs) - UPROBE_SWBP_INSN_SIZE;
 }
 
+unsigned long uprobe_get_trap_addr(struct pt_regs *regs)
+{
+        struct uprobe_task *utask = current->utask;
+
+        if (unlikely(utask && utask->active_uprobe))
+                return utask->vaddr;
+
+        return instruction_pointer(regs);
+}
+
 /*
  * Called with no locks held.
  * Called in context of a exiting or a exec-ing thread.