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| author | Jens Axboe <axboe@kernel.dk> | 2024-10-22 21:41:42 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-10-29 20:43:27 +0100 |
| commit | 371b47da25e1f7a1a6323f84c776bd9fa079a490 (patch) | |
| tree | 6ae5cba18cd6563a9b52b26fdcdc31a6a5416fea /io_uring/io_uring.c | |
| parent | io_uring: switch struct ext_arg from __kernel_timespec to timespec64 (diff) | |
| download | linux-371b47da25e1f7a1a6323f84c776bd9fa079a490.tar.xz linux-371b47da25e1f7a1a6323f84c776bd9fa079a490.zip | |
io_uring: change io_get_ext_arg() to use uaccess begin + end
In scenarios where a high frequency of wait events are seen, the copy
of the struct io_uring_getevents_arg is quite noticeable in the
profiles in terms of time spent. It can be seen as up to 3.5-4.5%.
Rewrite the copy-in logic, saving about 0.5% of the time.
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring/io_uring.c')
| -rw-r--r-- | io_uring/io_uring.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 8f0e0749a581..4cd0ee52710d 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -3240,6 +3240,7 @@ static int io_validate_ext_arg(unsigned flags, const void __user *argp, size_t a static int io_get_ext_arg(unsigned flags, const void __user *argp, struct ext_arg *ext_arg) { + const struct io_uring_getevents_arg __user *uarg = argp; struct io_uring_getevents_arg arg; /* @@ -3257,8 +3258,18 @@ static int io_get_ext_arg(unsigned flags, const void __user *argp, */ if (ext_arg->argsz != sizeof(arg)) return -EINVAL; - if (copy_from_user(&arg, argp, sizeof(arg))) +#ifdef CONFIG_64BIT + if (!user_access_begin(uarg, sizeof(*uarg))) return -EFAULT; + unsafe_get_user(arg.sigmask, &uarg->sigmask, uaccess_end); + unsafe_get_user(arg.sigmask_sz, &uarg->sigmask_sz, uaccess_end); + unsafe_get_user(arg.min_wait_usec, &uarg->min_wait_usec, uaccess_end); + unsafe_get_user(arg.ts, &uarg->ts, uaccess_end); + user_access_end(); +#else + if (copy_from_user(&arg, uarg, sizeof(arg))) + return -EFAULT; +#endif 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; @@ -3268,6 +3279,11 @@ static int io_get_ext_arg(unsigned flags, const void __user *argp, ext_arg->ts_set = true; } return 0; +#ifdef CONFIG_64BIT +uaccess_end: + user_access_end(); + return -EFAULT; +#endif } SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, |