io_uring: switch struct ext_arg from __kernel_timespec to timespec64

This avoids intermediate storage for turning a __kernel_timespec
user pointer into an on-stack struct timespec64, only then to turn it
into a ktime_t.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 140cd47fbdb31e499be369eb7fe2901b0c639cb0..8f0e0749a5812830e36864edb886b19eb53e770f 100644 (file)
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2495,9 +2495,10 @@ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx,
 
 struct ext_arg {
        size_t argsz;
-       struct __kernel_timespec __user *ts;
+       struct timespec64 ts;
        const sigset_t __user *sig;
        ktime_t min_time;
+       bool ts_set;
 };
 
 /*
@@ -2535,13 +2536,8 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, u32 flags,
        iowq.timeout = KTIME_MAX;
        start_time = io_get_time(ctx);
 
-       if (ext_arg->ts) {
-               struct timespec64 ts;
-
-               if (get_timespec64(&ts, ext_arg->ts))
-                       return -EFAULT;
-
-               iowq.timeout = timespec64_to_ktime(ts);
+       if (ext_arg->ts_set) {
+               iowq.timeout = timespec64_to_ktime(ext_arg->ts);
                if (!(flags & IORING_ENTER_ABS_TIMER))
                        iowq.timeout = ktime_add(iowq.timeout, start_time);
        }
@@ -3252,7 +3248,6 @@ static int io_get_ext_arg(unsigned flags, const void __user *argp,
         */
        if (!(flags & IORING_ENTER_EXT_ARG)) {
                ext_arg->sig = (const sigset_t __user *) argp;
-               ext_arg->ts = NULL;
                return 0;
        }
 
@@ -3267,7 +3262,11 @@ static int io_get_ext_arg(unsigned flags, const void __user *argp,
        ext_arg->min_time = arg.min_wait_usec * NSEC_PER_USEC;
        ext_arg->sig = u64_to_user_ptr(arg.sigmask);
        ext_arg->argsz = arg.sigmask_sz;
-       ext_arg->ts = u64_to_user_ptr(arg.ts);
+       if (arg.ts) {
+               if (get_timespec64(&ext_arg->ts, u64_to_user_ptr(arg.ts)))
+                       return -EFAULT;
+               ext_arg->ts_set = true;
+       }
        return 0;
 }