[PATCH v2 1/3] seccomp: Add find_notification helper
From: Sargun Dhillon <hidden>
Date: 2020-05-28 11:09:34
Also in:
lkml
Subsystem:
secure computing, the rest · Maintainers:
Kees Cook, Linus Torvalds
This adds a helper which can iterate through a seccomp_filter to find a notification matching an ID. It removes several replicated chunks of code. Signed-off-by: Sargun Dhillon <redacted> Cc: Matt Denton <redacted> Cc: Kees Cook <redacted>, Cc: Jann Horn <jannh@google.com>, Cc: Robert Sesek <redacted>, Cc: Chris Palmer <redacted> Cc: Christian Brauner <redacted> Cc: Tycho Andersen <redacted> --- kernel/seccomp.c | 51 ++++++++++++++++++++++++------------------------ 1 file changed, 25 insertions(+), 26 deletions(-)
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 55a6184f5990..94ae4c7502cc 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c@@ -1021,10 +1021,25 @@ static int seccomp_notify_release(struct inode *inode, struct file *file) return 0; } +/* must be called with notif_lock held */ +static inline struct seccomp_knotif * +find_notification(struct seccomp_filter *filter, u64 id) +{ + struct seccomp_knotif *cur; + + list_for_each_entry(cur, &filter->notif->notifications, list) { + if (cur->id == id) + return cur; + } + + return NULL; +} + + static long seccomp_notify_recv(struct seccomp_filter *filter, void __user *buf) { - struct seccomp_knotif *knotif = NULL, *cur; + struct seccomp_knotif *knotif, *cur; struct seccomp_notif unotif; ssize_t ret;
@@ -1078,14 +1093,8 @@ static long seccomp_notify_recv(struct seccomp_filter *filter, * may have died when we released the lock, so we need to make * sure it's still around. */ - knotif = NULL; mutex_lock(&filter->notify_lock); - list_for_each_entry(cur, &filter->notif->notifications, list) { - if (cur->id == unotif.id) { - knotif = cur; - break; - } - } + knotif = find_notification(filter, unotif.id); if (knotif) { knotif->state = SECCOMP_NOTIFY_INIT;
@@ -1101,7 +1110,7 @@ static long seccomp_notify_send(struct seccomp_filter *filter, void __user *buf) { struct seccomp_notif_resp resp = {}; - struct seccomp_knotif *knotif = NULL, *cur; + struct seccomp_knotif *knotif; long ret; if (copy_from_user(&resp, buf, sizeof(resp)))
@@ -1118,13 +1127,7 @@ static long seccomp_notify_send(struct seccomp_filter *filter, if (ret < 0) return ret; - list_for_each_entry(cur, &filter->notif->notifications, list) { - if (cur->id == resp.id) { - knotif = cur; - break; - } - } - + knotif = find_notification(filter, resp.id); if (!knotif) { ret = -ENOENT; goto out;
@@ -1150,7 +1153,7 @@ static long seccomp_notify_send(struct seccomp_filter *filter, static long seccomp_notify_id_valid(struct seccomp_filter *filter, void __user *buf) { - struct seccomp_knotif *knotif = NULL; + struct seccomp_knotif *knotif; u64 id; long ret;
@@ -1161,16 +1164,12 @@ static long seccomp_notify_id_valid(struct seccomp_filter *filter, if (ret < 0) return ret; - ret = -ENOENT; - list_for_each_entry(knotif, &filter->notif->notifications, list) { - if (knotif->id == id) { - if (knotif->state == SECCOMP_NOTIFY_SENT) - ret = 0; - goto out; - } - } + knotif = find_notification(filter, id); + if (knotif && knotif->state == SECCOMP_NOTIFY_SENT) + ret = 0; + else + ret = -ENOENT; -out: mutex_unlock(&filter->notify_lock); return ret; }
--
2.25.1