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Diffstat (limited to 'kernel/kcmp.c')
-rw-r--r--kernel/kcmp.c57
1 files changed, 57 insertions, 0 deletions
diff --git a/kernel/kcmp.c b/kernel/kcmp.c
index 3a47fa998fe0..ea34ed8bb952 100644
--- a/kernel/kcmp.c
+++ b/kernel/kcmp.c
@@ -11,6 +11,10 @@
#include <linux/bug.h>
#include <linux/err.h>
#include <linux/kcmp.h>
+#include <linux/capability.h>
+#include <linux/list.h>
+#include <linux/eventpoll.h>
+#include <linux/file.h>
#include <asm/unistd.h>
@@ -94,6 +98,56 @@ static int kcmp_lock(struct mutex *m1, struct mutex *m2)
return err;
}
+#ifdef CONFIG_EPOLL
+static int kcmp_epoll_target(struct task_struct *task1,
+ struct task_struct *task2,
+ unsigned long idx1,
+ struct kcmp_epoll_slot __user *uslot)
+{
+ struct file *filp, *filp_epoll, *filp_tgt;
+ struct kcmp_epoll_slot slot;
+ struct files_struct *files;
+
+ if (copy_from_user(&slot, uslot, sizeof(slot)))
+ return -EFAULT;
+
+ filp = get_file_raw_ptr(task1, idx1);
+ if (!filp)
+ return -EBADF;
+
+ files = get_files_struct(task2);
+ if (!files)
+ return -EBADF;
+
+ spin_lock(&files->file_lock);
+ filp_epoll = fcheck_files(files, slot.efd);
+ if (filp_epoll)
+ get_file(filp_epoll);
+ else
+ filp_tgt = ERR_PTR(-EBADF);
+ spin_unlock(&files->file_lock);
+ put_files_struct(files);
+
+ if (filp_epoll) {
+ filp_tgt = get_epoll_tfile_raw_ptr(filp_epoll, slot.tfd, slot.toff);
+ fput(filp_epoll);
+ } else
+
+ if (IS_ERR(filp_tgt))
+ return PTR_ERR(filp_tgt);
+
+ return kcmp_ptr(filp, filp_tgt, KCMP_FILE);
+}
+#else
+static int kcmp_epoll_target(struct task_struct *task1,
+ struct task_struct *task2,
+ unsigned long idx1,
+ struct kcmp_epoll_slot __user *uslot)
+{
+ return -EOPNOTSUPP;
+}
+#endif
+
SYSCALL_DEFINE5(kcmp, pid_t, pid1, pid_t, pid2, int, type,
unsigned long, idx1, unsigned long, idx2)
{
@@ -165,6 +219,9 @@ SYSCALL_DEFINE5(kcmp, pid_t, pid1, pid_t, pid2, int, type,
ret = -EOPNOTSUPP;
#endif
break;
+ case KCMP_EPOLL_TFD:
+ ret = kcmp_epoll_target(task1, task2, idx1, (void *)idx2);
+ break;
default:
ret = -EINVAL;
break;