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authorAmir Goldstein <amir73il@gmail.com>2018-10-04 00:25:38 +0300
committerJan Kara <jack@suse.cz>2018-10-08 13:48:45 +0200
commitd0a6a87e40da49cfc7954c491d3065a25a641b29 (patch)
tree49e34224bcda4f0a436beb3b4a4e0214606dfaa1
parentbdd5a46fe30653cb4d26c7c787a22159bf79eed9 (diff)
fanotify: support reporting thread id instead of process id
In order to identify which thread triggered the event in a multi-threaded program, add the FAN_REPORT_TID flag in fanotify_init to opt-in for reporting the event creator's thread id information. Signed-off-by: nixiaoming <nixiaoming@huawei.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
-rw-r--r--fs/notify/fanotify/fanotify.c9
-rw-r--r--fs/notify/fanotify/fanotify.h2
-rw-r--r--fs/notify/fanotify/fanotify_user.c4
-rw-r--r--include/linux/fanotify.h1
-rw-r--r--include/uapi/linux/fanotify.h3
5 files changed, 13 insertions, 6 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 361e3a0a445c..5769cf3ff035 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -25,7 +25,7 @@ static bool should_merge(struct fsnotify_event *old_fsn,
old = FANOTIFY_E(old_fsn);
new = FANOTIFY_E(new_fsn);
- if (old_fsn->inode == new_fsn->inode && old->tgid == new->tgid &&
+ if (old_fsn->inode == new_fsn->inode && old->pid == new->pid &&
old->path.mnt == new->path.mnt &&
old->path.dentry == new->path.dentry)
return true;
@@ -171,7 +171,10 @@ struct fanotify_event_info *fanotify_alloc_event(struct fsnotify_group *group,
goto out;
init: __maybe_unused
fsnotify_init_event(&event->fse, inode, mask);
- event->tgid = get_pid(task_tgid(current));
+ if (FAN_GROUP_FLAG(group, FAN_REPORT_TID))
+ event->pid = get_pid(task_pid(current));
+ else
+ event->pid = get_pid(task_tgid(current));
if (path) {
event->path = *path;
path_get(&event->path);
@@ -270,7 +273,7 @@ static void fanotify_free_event(struct fsnotify_event *fsn_event)
event = FANOTIFY_E(fsn_event);
path_put(&event->path);
- put_pid(event->tgid);
+ put_pid(event->pid);
if (fanotify_is_perm_event(fsn_event->mask)) {
kmem_cache_free(fanotify_perm_event_cachep,
FANOTIFY_PE(fsn_event));
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index 88a8290a61cb..ea05b8a401e7 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -19,7 +19,7 @@ struct fanotify_event_info {
* during this object's lifetime
*/
struct path path;
- struct pid *tgid;
+ struct pid *pid;
};
/*
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 14594e491d2b..e03be5071362 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -132,7 +132,7 @@ static int fill_event_metadata(struct fsnotify_group *group,
metadata->vers = FANOTIFY_METADATA_VERSION;
metadata->reserved = 0;
metadata->mask = fsn_event->mask & FANOTIFY_OUTGOING_EVENTS;
- metadata->pid = pid_vnr(event->tgid);
+ metadata->pid = pid_vnr(event->pid);
if (unlikely(fsn_event->mask & FAN_Q_OVERFLOW))
metadata->fd = FAN_NOFD;
else {
@@ -944,7 +944,7 @@ COMPAT_SYSCALL_DEFINE6(fanotify_mark,
*/
static int __init fanotify_user_setup(void)
{
- BUILD_BUG_ON(HWEIGHT32(FANOTIFY_INIT_FLAGS) != 6);
+ BUILD_BUG_ON(HWEIGHT32(FANOTIFY_INIT_FLAGS) != 7);
BUILD_BUG_ON(HWEIGHT32(FANOTIFY_MARK_FLAGS) != 9);
fanotify_mark_cache = KMEM_CACHE(fsnotify_mark,
diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
index caf55c67fc6c..a5a60691e48b 100644
--- a/include/linux/fanotify.h
+++ b/include/linux/fanotify.h
@@ -19,6 +19,7 @@
FAN_CLASS_PRE_CONTENT)
#define FANOTIFY_INIT_FLAGS (FANOTIFY_CLASS_BITS | \
+ FAN_REPORT_TID | \
FAN_CLOEXEC | FAN_NONBLOCK | \
FAN_UNLIMITED_QUEUE | FAN_UNLIMITED_MARKS)
diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h
index d0c05de670ef..b86740d1c50a 100644
--- a/include/uapi/linux/fanotify.h
+++ b/include/uapi/linux/fanotify.h
@@ -40,6 +40,9 @@
#define FAN_UNLIMITED_MARKS 0x00000020
#define FAN_ENABLE_AUDIT 0x00000040
+/* Flags to determine fanotify event format */
+#define FAN_REPORT_TID 0x00000100 /* event->pid is thread id */
+
/* Deprecated - do not use this in programs and do not add new flags here! */
#define FAN_ALL_INIT_FLAGS (FAN_CLOEXEC | FAN_NONBLOCK | \
FAN_ALL_CLASS_BITS | FAN_UNLIMITED_QUEUE |\