diff options
| author |   anton <anton@openbsd.org> | 2019-08-05 08:35:59 +0000 |
|---|---|---|
| committer | anton <anton@openbsd.org> | 2019-08-05 08:35:59 +0000 |
| commit | 836f297b392ea9a1d38b1ff0cf70716087e44f8a (patch) | |
| tree | 83dd65931d92ba9dd808f5209c217e697912c701 /sys/dev/pci/drm/drm_linux.c | |
| parent | sis(4) calls mii_phy_reset(); add explicit dependency on mii_phy in config (diff) | |
| download | wireguard-openbsd-836f297b392ea9a1d38b1ff0cf70716087e44f8a.tar.xz wireguard-openbsd-836f297b392ea9a1d38b1ff0cf70716087e44f8a.zip | |
Allow concurrent reads of the f_offset field of struct file by
serializing both read/write operations using the existing file mutex.
The vnode lock still grants exclusive write access to the offset; the
mutex is only used to make the actual write atomic and prevent any
concurrent reader from observing intermediate values.
ok mpi@ visa@
Diffstat (limited to 'sys/dev/pci/drm/drm_linux.c')
| -rw-r--r-- | sys/dev/pci/drm/drm_linux.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/sys/dev/pci/drm/drm_linux.c b/sys/dev/pci/drm/drm_linux.c index 641d21efd0d..4e77d829dbc 100644 --- a/sys/dev/pci/drm/drm_linux.c +++ b/sys/dev/pci/drm/drm_linux.c @@ -1,4 +1,4 @@ -/* $OpenBSD: drm_linux.c,v 1.46 2019/07/15 01:05:01 jsg Exp $ */ +/* $OpenBSD: drm_linux.c,v 1.47 2019/08/05 08:35:59 anton Exp $ */ /* * Copyright (c) 2013 Jonathan Gray <jsg@openbsd.org> * Copyright (c) 2015, 2016 Mark Kettenis <kettenis@openbsd.org> @@ -1378,7 +1378,10 @@ dmabuf_seek(struct file *fp, off_t *offset, int whence, struct proc *p) default: return (EINVAL); } - fp->f_offset = *offset = newoff; + mtx_enter(&fp->f_mtx); + fp->f_offset = newoff; + mtx_leave(&fp->f_mtx); + *offset = newoff; return (0); } |