- dev - passt

[PATCH v13 0/6] State migration, kind of draft again
by Stefano Brivio 10 Feb '25

10 Feb '25

Some concerns came to my mind during the weekend and now I tried a bit quickly to fix them. A couple of functions became horrible as a result. More tests: IPv6 too, iperf3 inbound and outbound. From another read of: https://github.com/checkpoint-restore/criu/blob/criu-dev/soccr/soccr.c I noticed that the way I was dumping and restoring queues was almost entirely bogus. It should be fixed now. Handling of FIN might be needed, though: we might have an off-by-one when we restore queues, I guess. Riddle of this version: enabling the flow_migrate_source_early() callback (shrinking the window early on) breaks things if I run the source without strace: the source (I think? sends a reset when we close the sockets after we switch repair mode on the second time (we flip that twice). So it's commented out for the moment. By itself, it works, and effectively limits what the peer sends during migration. There must be some other race or issue in passt-repair or in the matching interface, but I couldn't figure it out. David Gibson (1): migrate: Migrate guest observed addresses Stefano Brivio (5): migrate: Skeleton of live migration logic Add interfaces and configuration bits for passt-repair vhost_user: Make source quit after reporting migration state migrate: Migrate TCP flows test: Add migration tests Makefile | 14 +- conf.c | 44 ++- epoll_type.h | 6 +- flow.c | 248 ++++++++++++ flow.h | 8 + migrate.c | 309 +++++++++++++++ migrate.h | 54 +++ passt.1 | 11 + passt.c | 21 +- passt.h | 15 + repair.c | 211 ++++++++++ repair.h | 16 + tap.c | 65 +-- tcp.c | 789 +++++++++++++++++++++++++++++++++++++ tcp_conn.h | 95 +++++ test/lib/layout | 55 ++- test/lib/setup | 134 +++++++ test/lib/test | 48 +++ test/migrate/basic | 59 +++ test/migrate/bidirectional | 64 +++ test/migrate/iperf3_in4 | 50 +++ test/migrate/iperf3_in6 | 58 +++ test/migrate/iperf3_out4 | 50 +++ test/migrate/iperf3_out6 | 58 +++ test/run | 10 + util.c | 62 +++ util.h | 30 ++ vhost_user.c | 68 +--- virtio.h | 4 - vu_common.c | 49 +-- vu_common.h | 2 +- 31 files changed, 2524 insertions(+), 183 deletions(-) create mode 100644 migrate.c create mode 100644 migrate.h create mode 100644 repair.c create mode 100644 repair.h create mode 100644 test/migrate/basic create mode 100644 test/migrate/bidirectional create mode 100644 test/migrate/iperf3_in4 create mode 100644 test/migrate/iperf3_in6 create mode 100644 test/migrate/iperf3_out4 create mode 100644 test/migrate/iperf3_out6 -- 2.43.0

2 13

[PATCH v14 00/14] State migration
by David Gibson 10 Feb '25

10 Feb '25

Changes from v13: * Split shrinking of windows before migration to a separate patch * Added assorted fixups for small issues David Gibson (7): fixup: Remove unused iov field in struct migrate_stage migrate: Migrate guest observed addresses fixup: Reorder conf options fixup: Correctly type repair_cmd global fixup: Sanity check passt-repair reply message fixup: Don't close repair socket after first migration attempt fixup: Adjust conditions under which we quite after completing migration Stefano Brivio (7): migrate: Skeleton of live migration logic Add interfaces and configuration bits for passt-repair vhost_user: Make source quit after reporting migration state migrate: Migrate TCP flows fixup: Check for errors on repair mode rollback test: Add migration tests WIP: migrate, tcp: Shrink windows before migration Makefile | 14 +- conf.c | 44 ++- epoll_type.h | 6 +- flow.c | 250 ++++++++++++ flow.h | 8 + migrate.c | 307 +++++++++++++++ migrate.h | 51 +++ passt.1 | 11 + passt.c | 21 +- passt.h | 15 + repair.c | 218 ++++++++++ repair.h | 16 + tap.c | 65 +-- tcp.c | 788 +++++++++++++++++++++++++++++++++++++ tcp_conn.h | 95 +++++ test/lib/layout | 55 ++- test/lib/setup | 134 +++++++ test/lib/test | 48 +++ test/migrate/basic | 59 +++ test/migrate/bidirectional | 64 +++ test/migrate/iperf3_in4 | 50 +++ test/migrate/iperf3_in6 | 58 +++ test/migrate/iperf3_out4 | 50 +++ test/migrate/iperf3_out6 | 58 +++ test/run | 10 + util.c | 62 +++ util.h | 30 ++ vhost_user.c | 67 +--- virtio.h | 4 - vu_common.c | 49 +-- vu_common.h | 2 +- 31 files changed, 2524 insertions(+), 185 deletions(-) create mode 100644 migrate.c create mode 100644 migrate.h create mode 100644 repair.c create mode 100644 repair.h create mode 100644 test/migrate/basic create mode 100644 test/migrate/bidirectional create mode 100644 test/migrate/iperf3_in4 create mode 100644 test/migrate/iperf3_in6 create mode 100644 test/migrate/iperf3_out4 create mode 100644 test/migrate/iperf3_out6 -- 2.48.1

1 14

[PATCH] conf: Don't map DNS traffic to host, if host gateway is a resolver
by Stefano Brivio 09 Feb '25

09 Feb '25

This should be a relatively common case and I'm a bit surprised it's been broken since I added the "gateway mapping" functionality, but it doesn't happen with Podman, and not with systemd-resolved or similar local proxies, and also not with servers where typically the gateway is just a router and not a DNS resolver. That could be the reason why nobody noticed until now. By default, we'll map the address of the default gateway, in containers and guests, to represent "the host", so that we have a well-defined way to reach the host. Say: 0.0029: NAT to host 127.0.0.1: 192.168.100.1 But if the host gateway is also a DNS resolver: 0.0029: DNS: 0.0029: 192.168.100.1 then we'll send DNS queries directed to it to the host instead: 0.0372: Flow 0 (INI): TAP [192.168.100.157]:41892 -> [192.168.100.1]:53 => ? 0.0372: Flow 0 (TGT): INI -> TGT 0.0373: Flow 0 (TGT): TAP [192.168.100.157]:41892 -> [192.168.100.1]:53 => HOST [0.0.0.0]:41892 -> [127.0.0.1]:53 0.0373: Flow 0 (UDP flow): TGT -> TYPED 0.0373: Flow 0 (UDP flow): TAP [192.168.100.157]:41892 -> [192.168.100.1]:53 => HOST [0.0.0.0]:41892 -> [127.0.0.1]:53 0.0373: Flow 0 (UDP flow): Side 0 hash table insert: bucket: 31049 0.0374: Flow 0 (UDP flow): TYPED -> ACTIVE 0.0374: Flow 0 (UDP flow): TAP [192.168.100.157]:41892 -> [192.168.100.1]:53 => HOST [0.0.0.0]:41892 -> [127.0.0.1]:53 which doesn't quite work, of course: 0.0374: pasta: epoll event on UDP reply socket 95 (events: 0x00000008) 0.0374: ICMP error on UDP socket 95: Connection refused unless the host is a resolver itself... but then we wouldn't find the address of the gateway in its /etc/resolv.conf, presumably. Fix this by making an exception for DNS traffic: if the default gateway is a resolver, match on DNS traffic going to the default gateway, and explicitly forward it to the configured resolver. Reported-by: Prafulla Giri <prafulla.giri(a)protonmail.com> Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> --- conf.c | 16 ++++++++++------ passt.1 | 14 ++++++++++---- 2 files changed, 20 insertions(+), 10 deletions(-) diff --git a/conf.c b/conf.c index df2b016..360ce21 100644 --- a/conf.c +++ b/conf.c @@ -426,10 +426,12 @@ static void add_dns_resolv(struct ctx *c, const char *nameserver, if (IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns_host)) c->ip4.dns_host = ns4; - /* Guest or container can only access local addresses via - * redirect + /* Special handling if guest or container can only access local + * addresses via redirect, or if the host gateway is also a + * resolver and we shadow its address */ - if (IN4_IS_ADDR_LOOPBACK(&ns4)) { + if (IN4_IS_ADDR_LOOPBACK(&ns4) || + IN4_ARE_ADDR_EQUAL(&ns4, &c->ip4.map_host_loopback)) { if (IN4_IS_ADDR_UNSPECIFIED(&c->ip4.map_host_loopback)) return; @@ -445,10 +447,12 @@ static void add_dns_resolv(struct ctx *c, const char *nameserver, if (IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns_host)) c->ip6.dns_host = ns6; - /* Guest or container can only access local addresses via - * redirect + /* Special handling if guest or container can only access local + * addresses via redirect, or if the host gateway is also a + * resolver and we shadow its address */ - if (IN6_IS_ADDR_LOOPBACK(&ns6)) { + if (IN6_IS_ADDR_LOOPBACK(&ns6) || + IN6_ARE_ADDR_EQUAL(&ns6, &c->ip6.map_host_loopback)) { if (IN6_IS_ADDR_UNSPECIFIED(&c->ip6.map_host_loopback)) return; diff --git a/passt.1 b/passt.1 index d9cd33e..7b6eabd 100644 --- a/passt.1 +++ b/passt.1 @@ -941,10 +941,16 @@ with destination 127.0.0.10, and the default IPv4 gateway is 192.0.2.1, while the last observed source address from guest or namespace is 192.0.2.2, this will be translated to a connection from 192.0.2.1 to 192.0.2.2. -Similarly, for traffic coming from guest or namespace, packets with -destination address corresponding to the \fB\-\-map-host-loopback\fR -address will have their destination address translated to a loopback -address. +Similarly, for traffic coming from guest or namespace, packets with destination +address corresponding to the \fB\-\-map-host-loopback\fR address will have their +destination address translated to a loopback address. + +As an exception, traffic identified as DNS, originally directed to the +\fB\-\-map-host-loopback\fR address, if this address matches a resolver address +on the host, is \fBnot\fR translated to loopback, but rather handled in the same +way as if specified as \-\-dns-forward address, if no such option was given. +In the common case where the host gateway also acts a resolver, this avoids that +the host mapping shadows the gateway/resolver itself. .SS Handling of local traffic in pasta -- 2.43.0

2 2

[PATCH v12 0/6] Non-draft state migration
by Stefano Brivio 08 Feb '25

08 Feb '25

v12: - clean up, add comments, complete error handling - add iperf3 test with 6 concurrent flows and migration under flood This looks reasonably stable and polished to me, probably enough to be merged. The behaviour now looks solid under flood, too. Still to do, I guess: 1. more iperf3 tests, with IPv6, in the other direction, and with mixed flows 2. support for other types of flow (assuming that we care at all... things already work) 3. find a way to close the window socket-side early on, and reopen it in the target, to entirely avoid retransmissions. I can set the socket in repair mode in the source, fetch TCP_REPAIR_WINDOW parameters, just change rcv_wnd to 0, set them back, then disable repair mode. Nothing bad happens and the window probe from TCP_REPAIR_OFF is visible, but the window isn't updated, because it's not actually recalculated using rcv_wnd meanwhile. Dummy send/recv() calls don't really change things, either. But there must be some other way. I haven't tried doing this guest-side but that part should be trivial. David Gibson (1): migrate: Migrate guest observed addresses Stefano Brivio (5): migrate: Skeleton of live migration logic Add interfaces and configuration bits for passt-repair vhost_user: Make source quit after reporting migration state migrate: Migrate TCP flows test: Add migration tests Makefile | 14 +- conf.c | 44 ++- epoll_type.h | 6 +- flow.c | 202 +++++++++++++ flow.h | 6 + migrate.c | 300 +++++++++++++++++++ migrate.h | 54 ++++ passt.1 | 11 + passt.c | 15 +- passt.h | 15 + repair.c | 211 ++++++++++++++ repair.h | 16 + tap.c | 65 +---- tcp.c | 583 +++++++++++++++++++++++++++++++++++++ tcp_conn.h | 87 ++++++ test/lib/layout | 55 +++- test/lib/setup | 128 ++++++++ test/lib/test | 48 +++ test/migrate/basic | 54 ++++ test/migrate/bidirectional | 59 ++++ test/migrate/iperf3_out4 | 42 +++ test/run | 10 + util.c | 62 ++++ util.h | 30 ++ vhost_user.c | 68 ++--- virtio.h | 4 - vu_common.c | 49 +--- vu_common.h | 2 +- 28 files changed, 2060 insertions(+), 180 deletions(-) create mode 100644 migrate.c create mode 100644 migrate.h create mode 100644 repair.c create mode 100644 repair.h create mode 100644 test/migrate/basic create mode 100644 test/migrate/bidirectional create mode 100644 test/migrate/iperf3_out4 -- 2.43.0

1 7

migrate/bidirectional debugging
by David Gibson 08 Feb '25

08 Feb '25

I've spent today trying to debug this failure. I've gathered a bunch of information, but no breakthroughs, alas. At this point I suspect a kernel bug, though I hope I'm wrong. # Background. I think these are as you described it on your system: * Most (but not every) time I run migrate/bidirectional it fails, with the "outbound" stream only getting the before migration piece * I can't reproduce if I put strace on the guest 2 passt. Possibly unlike you: * I'm able to use TRACE=1, and the problem still reproduces * I can put strace on the outer pasta and the problem still reproduces The specific anomolies I was focused on were: * The passt_2 pcap shows "and from guest 2" coming _inbound_ a bit after it (correctly) went outbound * The pasta_1 pcap doesn't seem to show "and from guest 2" in either direction # Observations * I added a hack (see other series) that let me log comments to the pcap file as ethertype 0xffff, this was so I could have debugging messages in order with the the captured packets. * I used that to bin down exactly where the bogus output "and from guest 2" was being recorded, and it's in tcp_vu_data_from_sock() * I traced back from there, and passt_2 really does seem to be getting "and from guest 2" from a recvmsg() on the socket. I see from my pcap comments that we're getting 17 bytes from recvmsg() right before capturing the inbound packet, at any rate. * As noted, I couldn't reproduce with an strace on passt_2, so I couldn't confirm that piece that way It kind of seemed like we were sendmsg()ing "and from guest 2" and it was bouncing straight back to our socket, instead of being delivered to the outer pasta. * I tried putting a dumpcap on 'lo' in the pasta namespace, thinking I might see this weird passt->passt packet. But, nothing. There are thousands of packets of the qemu migration stream, and absolutely nothing else. * I also tried dumpcap on the external interface in the pasta namspace, and I didn't see anything different from what pasta captured (although I didn't check super carefully). In particular I didn't seem to see "and from guest 2" in either direction there either * Since I couldn't strace() passt_2, I instead tried logging TCP sendmsg() and recvmsg() calls of length 17 using systemtap (script attached). At this point it gets even weirder: On a working run (achieved by adding the strace), I get this: BEGIN tcp sendmsg(-129530279294592) len=17 - ./passt -s /tmp/passt-tests-niICXS/migrate/passt_2.socket -P /tmp/passt-tests-niICXS/migrate/passt_2.pid -f --vhost-user -p /home/dwg/src/passt/test/test_logs/passt_2.pcap --trace -t 10004 -u 10004 tcp sendmsg(-129489810388608) len=17 - ./pasta -p /home/dwg/src/passt/test/test_logs/pasta_1.pcap --trace --trace -l /tmp/pasta1.log -P /tmp/passt-tests-niICXS/migrate/pasta_1.pid -t 10001,10002,10004 -T 10003 -u 10001,10002,10004 -U 10003 --map-guest-addr 169.254.1.1 --config-net /home/dwg/src/passt/test/nstool hold /tmp/passt-tests-niICXS/migrate/ns1.hold END This mostly makes sense. passt_2 sends the expected outbound packet to the namespace, then pasta_1 forwards it on to the host. I don't know why I'm not seeing the recvmsg() from the socat server, though. In the failing case, though, I get this: BEGIN tcp sendmsg(-129471392995840) len=17 - ./passt -s /tmp/passt-tests-CV71zo/migrate/passt_2.socket -P /tmp/passt-tests-CV71zo/migrate/passt_2.pid -f --vhost-user -p /home/dwg/src/passt/test/test_logs/passt_2.pcap --trace -t 10004 -u 10004 tcp recvmsg(-129476447043584) len=17 - ./pasta -p /home/dwg/src/passt/test/test_logs/pasta_1.pcap --trace --trace -l /tmp/pasta1.log -P /tmp/passt-tests-CV71zo/migrate/pasta_1.pid -t 10001,10002,10004 -T 10003 -u 10001,10002,10004 -U 10003 --map-guest-addr 169.254.1.1 --config-net /home/dwg/src/passt/test/nstool hold /tmp/passt-tests-CV71zo/migrate/ns1.hold END First event seems the same: passt_2 sending the outbound packet, as expected. The second, though, is weird: the outer pasta seems to receive the data from a socket, not from tap as we'd expect. That might explain the other symptoms, if pasta received it on its socket, it would send inwards. But... I don't see pasta sending that "and from guest 2" inbound in its packet capture. And, weirder still, although I see that recvmsg() with systemtap, I don't see it in an strace of pasta. ...and.. that's where I'm at. Attaching my systemtap script and a ball of logs. Hoping they're helpful :/. -- David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson

2 3

[PATCH] passt-repair: Send one confirmation *per command*, not *per socket*
by Stefano Brivio 08 Feb '25

08 Feb '25

It looks like me, myself and I couldn't agree on the "simple" protocol between passt and passt-repair. The man page and passt say it's one confirmation per command, but the passt-repair implementation had one confirmation per socket instead. This caused all sort of mysterious issues with repair mode pseudo-randomly enabled, and leading to hours of fun (mostly not mine). Oops. Switch to one confirmation per command (of course). Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> --- passt-repair.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/passt-repair.c b/passt-repair.c index 322066a..614cee0 100644 --- a/passt-repair.c +++ b/passt-repair.c @@ -63,6 +63,7 @@ int main(int argc, char **argv) struct cmsghdr *cmsg; struct msghdr msg; struct iovec iov; + int op; prctl(PR_SET_DUMPABLE, 0); @@ -150,25 +151,24 @@ loop: _exit(1); } - for (i = 0; i < n; i++) { - int o = cmd; + op = cmd; - if (setsockopt(fds[i], SOL_TCP, TCP_REPAIR, &o, sizeof(o))) { + for (i = 0; i < n; i++) { + if (setsockopt(fds[i], SOL_TCP, TCP_REPAIR, &op, sizeof(op))) { fprintf(stderr, - "Setting TCP_REPAIR to %i on socket %i: %s", o, + "Setting TCP_REPAIR to %i on socket %i: %s", op, fds[i], strerror(errno)); _exit(1); } /* Close _our_ copy */ close(fds[i]); + } - /* Confirm setting by echoing the command back */ - if (send(s, &cmd, sizeof(cmd), 0) < 0) { - fprintf(stderr, "Reply to command %i: %s\n", - o, strerror(errno)); - _exit(1); - } + /* Confirm setting by echoing the command back */ + if (send(s, &cmd, sizeof(cmd), 0) < 0) { + fprintf(stderr, "Reply to %i: %s\n", op, strerror(errno)); + _exit(1); } goto loop; -- 2.43.0

2 1

[PATCH v2] dhcp: Don't re-use request message for reply
by Enrique Llorente 07 Feb '25

07 Feb '25

The logic composing the DHCP reply message is reusing the request message to compose it, future long options like FQDN may exceed the request message limit making it go beyond the lower bound. This change creates a new reply message with a fixed options size of 308 and fills it in with proper fields from requests adding on top the generated options, this way the reply lower bound does not depend on the request. Signed-off-by: Enrique Llorente <ellorent(a)redhat.com> --- dhcp.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/dhcp.c b/dhcp.c index d8515aa..2a23ed4 100644 --- a/dhcp.c +++ b/dhcp.c @@ -151,9 +151,6 @@ static int fill(struct msg *m) { int i, o, offset = 0; - m->op = BOOTREPLY; - m->secs = 0; - for (o = 0; o < 255; o++) opts[o].sent = 0; @@ -291,8 +288,9 @@ int dhcp(const struct ctx *c, const struct pool *p) const struct ethhdr *eh; const struct iphdr *iph; const struct udphdr *uh; + struct msg const *m; + struct msg reply; unsigned int i; - struct msg *m; eh = packet_get(p, 0, offset, sizeof(*eh), NULL); offset += sizeof(*eh); @@ -321,6 +319,22 @@ int dhcp(const struct ctx *c, const struct pool *p) m->op != BOOTREQUEST) return -1; + reply.op = BOOTREPLY; + reply.htype = m->htype; + reply.hlen = m->hlen; + reply.hops = 0; + reply.xid = m->xid; + reply.secs = 0; + reply.flags = m->flags; + reply.ciaddr = m->ciaddr; + reply.yiaddr = c->ip4.addr; + reply.siaddr = 0; + reply.giaddr = m->giaddr; + memcpy(&reply.chaddr, m->chaddr, sizeof(reply.chaddr)); + memset(&reply.sname, 0, sizeof(reply.sname)); + memset(&reply.file, 0, sizeof(reply.file)); + reply.magic = m->magic; + offset += offsetof(struct msg, o); for (i = 0; i < ARRAY_SIZE(opts); i++) @@ -364,7 +378,6 @@ int dhcp(const struct ctx *c, const struct pool *p) info(" from %s", eth_ntop(m->chaddr, macstr, sizeof(macstr))); - m->yiaddr = c->ip4.addr; mask.s_addr = htonl(0xffffffff << (32 - c->ip4.prefix_len)); memcpy(opts[1].s, &mask, sizeof(mask)); memcpy(opts[3].s, &c->ip4.guest_gw, sizeof(c->ip4.guest_gw)); @@ -401,14 +414,14 @@ int dhcp(const struct ctx *c, const struct pool *p) if (!c->no_dhcp_dns_search) opt_set_dns_search(c, sizeof(m->o)); - dlen = offsetof(struct msg, o) + fill(m); + dlen = offsetof(struct msg, o) + fill(&reply); if (m->flags & FLAG_BROADCAST) dst = in4addr_broadcast; else dst = c->ip4.addr; - tap_udp4_send(c, c->ip4.our_tap_addr, 67, dst, 68, m, dlen); + tap_udp4_send(c, c->ip4.our_tap_addr, 67, dst, 68, &reply, dlen); return 1; } -- 2.47.0

2 1

[PATCH] passt-repair: Don't use perror(), accept ECONNRESET as termination
by Stefano Brivio 07 Feb '25

07 Feb '25

If we use glibc's perror(), we need to allow dup() and fcntl() in our seccomp profiles, which are a bit too much for this simple helper. On top of that, we would probably need a wrapper to avoid allocation for translated messages. While at it: ECONNRESET is just a close() from passt, treat it like EOF. Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> --- passt-repair.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/passt-repair.c b/passt-repair.c index 3c3247b..d137a18 100644 --- a/passt-repair.c +++ b/passt-repair.c @@ -95,7 +95,7 @@ int main(int argc, char **argv) } if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) { - perror("Failed to create AF_UNIX socket"); + fprintf(stderr, "Failed to create AF_UNIX socket: %i\n", errno); _exit(1); } @@ -108,8 +108,12 @@ int main(int argc, char **argv) loop: ret = recvmsg(s, &msg, 0); if (ret < 0) { - perror("Failed to receive message"); - _exit(1); + if (errno == ECONNRESET) { + ret = 0; + } else { + fprintf(stderr, "Failed to read message: %i\n", errno); + _exit(1); + } } if (!ret) /* Done */ -- 2.43.0

2 4

[PATCH 0/2] Migration debugging hacks
by David Gibson 07 Feb '25

07 Feb '25

Here are a couple of hacky patches I was using for debugging the failures in the migrate/bidirectional test. Further details on where I'm at coming in another email. David Gibson (2): pcap comment hacks debug pcap.c | 20 ++++++++++++++++++++ pcap.h | 2 ++ tap.c | 1 + tcp_vu.c | 6 ++++++ test/lib/setup | 8 +++++--- test/migrate/bidirectional | 15 ++++++++++++++- vu_common.c | 1 + 7 files changed, 49 insertions(+), 4 deletions(-) -- 2.48.1

1 2

[PATCH] passt-repair: Dodge "structurally unreachable code" warning from Coverity
by Stefano Brivio 07 Feb '25

07 Feb '25

While main() conventionally returns int, and we need a return at the end of the function to avoid compiler warnings, turning that return into _exit() to avoid exit handlers triggers a Coverity warning. It's unreachable code anyway, so switch that single occurence back to a plain return. Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> --- passt-repair.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/passt-repair.c b/passt-repair.c index 5ad5c9c..322066a 100644 --- a/passt-repair.c +++ b/passt-repair.c @@ -173,5 +173,5 @@ loop: goto loop; - _exit(0); + return 0; } -- 2.43.0

2 1