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authorDave Airlie <airlied@redhat.com>2021-01-25 14:35:44 +1000
committerDave Airlie <airlied@redhat.com>2021-01-25 14:35:44 +1000
commitbc96ad6722f86a377ed2872c9a4854c90caf78ca (patch)
treeece8859165a1faa10e4e2203d231fc7e87925139 /drivers/net/ppp/ppp_generic.c
parentMerge tag 'drm-intel-gt-next-2021-01-21-1' of git://anongit.freedesktop.org/drm/drm-intel into drm-next (diff)
parentLinux 5.11-rc5 (diff)
downloadlinux-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.c12
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;
}