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author | Dave Airlie <airlied@redhat.com> | 2021-01-25 14:35:44 +1000 |
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committer | Dave Airlie <airlied@redhat.com> | 2021-01-25 14:35:44 +1000 |
commit | bc96ad6722f86a377ed2872c9a4854c90caf78ca (patch) | |
tree | ece8859165a1faa10e4e2203d231fc7e87925139 /drivers/net/ppp/ppp_generic.c | |
parent | Merge tag 'drm-intel-gt-next-2021-01-21-1' of git://anongit.freedesktop.org/drm/drm-intel into drm-next (diff) | |
parent | Linux 5.11-rc5 (diff) | |
download | linux-dev-bc96ad6722f86a377ed2872c9a4854c90caf78ca.tar.xz linux-dev-bc96ad6722f86a377ed2872c9a4854c90caf78ca.zip |
Merge tag 'v5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into drm-next
Backmerge v5.11-rc5 into drm-next to clean up a bunch of conflicts we are dragging around.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/net/ppp/ppp_generic.c')
-rw-r--r-- | drivers/net/ppp/ppp_generic.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c index 09c27f7773f9..d445ecb1d0c7 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -623,6 +623,7 @@ static int ppp_bridge_channels(struct channel *pch, struct channel *pchb) write_unlock_bh(&pch->upl); return -EALREADY; } + refcount_inc(&pchb->file.refcnt); rcu_assign_pointer(pch->bridge, pchb); write_unlock_bh(&pch->upl); @@ -632,19 +633,24 @@ static int ppp_bridge_channels(struct channel *pch, struct channel *pchb) write_unlock_bh(&pchb->upl); goto err_unset; } + refcount_inc(&pch->file.refcnt); rcu_assign_pointer(pchb->bridge, pch); write_unlock_bh(&pchb->upl); - refcount_inc(&pch->file.refcnt); - refcount_inc(&pchb->file.refcnt); - return 0; err_unset: write_lock_bh(&pch->upl); + /* Re-read pch->bridge with upl held in case it was modified concurrently */ + pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)); RCU_INIT_POINTER(pch->bridge, NULL); write_unlock_bh(&pch->upl); synchronize_rcu(); + + if (pchb) + if (refcount_dec_and_test(&pchb->file.refcnt)) + ppp_destroy_channel(pchb); + return -EALREADY; } |