Messages in this thread Patch in this message | | | From | Sargun Dhillon <> | Subject | [PATCH v3] seccomp: Add find_notification helper | Date | Mon, 1 Jun 2020 04:25:32 -0700 |
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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 <sargun@sargun.me> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by: Tycho Andersen <tycho@tycho.ws> Cc: Matt Denton <mpdenton@google.com> Cc: Kees Cook <keescook@google.com>, Cc: Jann Horn <jannh@google.com>, Cc: Robert Sesek <rsesek@google.com>, Cc: Chris Palmer <palmer@google.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Tycho Andersen <tycho@tycho.ws> --- kernel/seccomp.c | 55 ++++++++++++++++++++++++------------------------ 1 file changed, 28 insertions(+), 27 deletions(-)
diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 55a6184f5990..cc6b47173a95 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -41,6 +41,7 @@ #include <linux/tracehook.h> #include <linux/uaccess.h> #include <linux/anon_inodes.h> +#include <linux/lockdep.h> enum notify_state { SECCOMP_NOTIFY_INIT, @@ -1021,10 +1022,27 @@ 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; + + lockdep_assert_held(&filter->notify_lock); + + 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; @@ -1078,15 +1096,8 @@ 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; up(&filter->notif->request); @@ -1101,7 +1112,7 @@ 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 +1129,7 @@ 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 +1155,7 @@ 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 +1166,12 @@ 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
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