Hold a write lock across udp_notify()
With the new route cache feature udp_notify() will modify the inp when it needs to invalidate the route cache. Ensure that we hold a write lock on the inp before calling the function to ensure that multiple threads don't race while trying to invalidate the cache (which previously lead to a page fault). Differential Revision: https://reviews.freebsd.org/D17246 Reviewed by: sbruno, bz, karels Sponsored by: Dell EMC Isilon Approved by: re (gjb)
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083a010c62
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=339185
@ -756,13 +756,7 @@ struct inpcb *
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udp_notify(struct inpcb *inp, int errno)
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{
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/*
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* While udp_ctlinput() always calls udp_notify() with a read lock
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* when invoking it directly, in_pcbnotifyall() currently uses write
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* locks due to sharing code with TCP. For now, accept either a read
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* or a write lock, but a read lock is sufficient.
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*/
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INP_LOCK_ASSERT(inp);
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INP_WLOCK_ASSERT(inp);
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if ((errno == EHOSTUNREACH || errno == ENETUNREACH ||
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errno == EHOSTDOWN) && inp->inp_route.ro_rt) {
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RTFREE(inp->inp_route.ro_rt);
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@ -808,13 +802,13 @@ udp_common_ctlinput(int cmd, struct sockaddr *sa, void *vip,
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if (ip != NULL) {
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uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
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inp = in_pcblookup(pcbinfo, faddr, uh->uh_dport,
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ip->ip_src, uh->uh_sport, INPLOOKUP_RLOCKPCB, NULL);
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ip->ip_src, uh->uh_sport, INPLOOKUP_WLOCKPCB, NULL);
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if (inp != NULL) {
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INP_RLOCK_ASSERT(inp);
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INP_WLOCK_ASSERT(inp);
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if (inp->inp_socket != NULL) {
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udp_notify(inp, inetctlerrmap[cmd]);
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}
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INP_RUNLOCK(inp);
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INP_WUNLOCK(inp);
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} else {
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inp = in_pcblookup(pcbinfo, faddr, uh->uh_dport,
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ip->ip_src, uh->uh_sport,
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