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authorOleg Nesterov <oleg@redhat.com>2012-08-06 14:13:23 +0200
committerAnton Arapov <anton@redhat.com>2012-10-29 11:42:34 +0100
commit1b3001711bcdfdd1ef83b264334dddf17f2b9055 (patch)
treee2f5a53db564106c08c4b8f1b10d76d81e8a44a8
parented518a63c9a8f99e4ef0791b8db2ceaf9b86cc60 (diff)
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uprobes: Kill dup_mmap()->uprobe_mmap(), simplify uprobe_mmap/munmap
1. Kill dup_mmap()->uprobe_mmap(), it was only needed to calculate new_mm->uprobes_state.count removed by the previous patch. If the forking process has a pending uprobe (int3) in vma, it will be copied by copy_page_range(), note that it checks vma->anon_vma so "Don't copy ptes" is not possible after install_breakpoint() which does anon_vma_prepare(). 2. Remove is_swbp_at_addr() and "int count" in uprobe_mmap(). Again, this was needed for uprobes_state.count. As a side effect this fixes the bug pointed out by Srikar, this code lacked the necessary put_uprobe(). 3. uprobe_munmap() becomes a nop after the previous patch. Remove the meaningless code but do not remove the helper, we will need it. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
-rw-r--r--kernel/events/uprobes.c30
-rw-r--r--kernel/fork.c3
2 files changed, 3 insertions, 30 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 6f1664d..ce59c10 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1010,7 +1010,7 @@ int uprobe_mmap(struct vm_area_struct *vma)
struct list_head tmp_list;
struct uprobe *uprobe, *u;
struct inode *inode;
- int ret, count;
+ int ret;
if (!atomic_read(&uprobe_events) || !valid_vma(vma, true))
return 0;
@@ -1023,8 +1023,6 @@ int uprobe_mmap(struct vm_area_struct *vma)
build_probe_list(inode, vma, vma->vm_start, vma->vm_end, &tmp_list);
ret = 0;
- count = 0;
-
list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
if (!ret) {
unsigned long vaddr = offset_to_vaddr(vma, uprobe->offset);
@@ -1034,19 +1032,11 @@ int uprobe_mmap(struct vm_area_struct *vma)
* We can race against uprobe_register(), see the
* comment near uprobe_hash().
*/
- if (ret == -EEXIST) {
+ if (ret == -EEXIST)
ret = 0;
-
- if (!is_swbp_at_addr(vma->vm_mm, vaddr))
- continue;
- }
-
- if (!ret)
- count++;
}
put_uprobe(uprobe);
}
-
mutex_unlock(uprobes_mmap_hash(inode));
return ret;
@@ -1057,27 +1047,13 @@ int uprobe_mmap(struct vm_area_struct *vma)
*/
void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
- struct list_head tmp_list;
- struct uprobe *uprobe, *u;
- struct inode *inode;
-
if (!atomic_read(&uprobe_events) || !valid_vma(vma, false))
return;
if (!atomic_read(&vma->vm_mm->mm_users)) /* called by mmput() ? */
return;
- inode = vma->vm_file->f_mapping->host;
- if (!inode)
- return;
-
- mutex_lock(uprobes_mmap_hash(inode));
- build_probe_list(inode, vma, start, end, &tmp_list);
-
- list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
- put_uprobe(uprobe);
- }
- mutex_unlock(uprobes_mmap_hash(inode));
+ /* TODO: unmapping uprobe(s) will need more work */
}
/* Slot allocation for XOL */
diff --git a/kernel/fork.c b/kernel/fork.c
index 2c8857e..912b6f6 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -454,9 +454,6 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
if (retval)
goto out;
-
- if (file)
- uprobe_mmap(tmp);
}
/* a new mm has just been created */
arch_dup_mmap(oldmm, mm);