diff options
Diffstat (limited to 'kdbus-use-rcu-to-access-exe-file-in-metadata.patch')
| -rw-r--r-- | kdbus-use-rcu-to-access-exe-file-in-metadata.patch | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/kdbus-use-rcu-to-access-exe-file-in-metadata.patch b/kdbus-use-rcu-to-access-exe-file-in-metadata.patch new file mode 100644 index 000000000..19678786a --- /dev/null +++ b/kdbus-use-rcu-to-access-exe-file-in-metadata.patch @@ -0,0 +1,44 @@ +From: Daniel Mack <daniel@zonque.org> +Date: Sat, 18 Apr 2015 12:04:36 +0200 +Subject: [PATCH] kdbus: use rcu to access exe file in metadata + +Commit 90f31d0ea888 ("mm: rcu-protected get_mm_exe_file()") removed +mm->mmap_sem from mm->exe_file read side. Follow that change in the +kdbus metadata code. + +Signed-off-by: Daniel Mack <daniel@zonque.org> +Signed-off-by: David Herrmann <dh.herrmann@gmail.com> +--- + ipc/kdbus/metadata.c | 10 ++++++---- + 1 file changed, 6 insertions(+), 4 deletions(-) + +diff --git a/ipc/kdbus/metadata.c b/ipc/kdbus/metadata.c +index 7949c8d3ed64..a85eac34a5c4 100644 +--- a/ipc/kdbus/metadata.c ++++ b/ipc/kdbus/metadata.c +@@ -283,19 +283,21 @@ static void kdbus_meta_proc_collect_pid_comm(struct kdbus_meta_proc *mp) + static void kdbus_meta_proc_collect_exe(struct kdbus_meta_proc *mp) + { + struct mm_struct *mm; ++ struct file *exe_file; + + mm = get_task_mm(current); + if (!mm) + return; + +- down_read(&mm->mmap_sem); +- if (mm->exe_file) { +- mp->exe_path = mm->exe_file->f_path; ++ rcu_read_lock(); ++ exe_file = rcu_dereference(mm->exe_file); ++ if (exe_file) { ++ mp->exe_path = exe_file->f_path; + path_get(&mp->exe_path); + get_fs_root(current->fs, &mp->root_path); + mp->valid |= KDBUS_ATTACH_EXE; + } +- up_read(&mm->mmap_sem); ++ rcu_read_unlock(); + + mmput(mm); + } |