Hello Waldemar,
On Fri, 21 Jan 2022 11:04:57 +0100, Waldemar Brodkorb <[email protected]>
wrote:
> Hi Peter,
>
> sorry about coming so late up with a regression.
No problem...
>
> I get following failure when compiling the defconfig
> stm32f429_disco_xip_defconfig in buildroot with your patch:
>
> In file included from libc/inet/_res_state.c:8:
> libc/inet/resolv.c: In function '__res_state':
> libc/inet/resolv.c:3903:15: error: '__resp' undeclared (first use in this
> function); did you mean '_res'?
> 3903 | return __resp;
> | ^~~~~~
> | _res
> libc/inet/resolv.c:3903:15: note: each undeclared identifier is reported only
> once for each function it appears in
> libc/inet/resolv.c:3904:1: warning: control reaches end of non-void function
> [-Wreturn-type]
> 3904 | }
> | ^
> make[1]: *** [Makerules:368: libc/inet/_res_state.o] Error 1
> make[1]: Leaving directory '/home/wbx/buildroot/output/build/uclibc-1.0.39'
> make: *** [package/pkg-generic.mk:295:
> /home/wbx/buildroot/output/build/uclibc-1.0.39/.stamp_built] Error 2
>
> In this case Linuxthreads are used, because the target is noMMU and FLAT
> binary format.
>
> Any idea?
No...not yet, but will take a look at it ;-)
Regards,
Peter
>
> best regards
> Waldemar
>
> Peter Seiderer wrote,
>
> > - use the provided __res_state() method instead of direct access
> > to struct __res_state pointer &_res/*__resp
> >
> > - change the __UCLIBC_HAS_TLS__ protected __res_state() implementation
> > to the one where the comment 'When threaded, _res may be a per-thread
> > variable.' indicates this should be used with threads/TLS enabled
> >
> > Fixes the following segfaults with buildroot raspberrypi3_64_defconfig
> > (uclibc, -Os, Note: runs fine using the raspberrypi3_defconfig):
> >
> > $ /usr/sbin/ntpd -n -d
> > 1970-01-01T00:01:49 ntpd[249]: INIT: ntpd ntpsec-1.2.0
> > 2021-11-03T20:39:50Z: Starting
> > 1970-01-01T00:01:49 ntpd[249]: INIT: Command line: /usr/sbin/ntpd -n -d
> > 1970-01-01T00:01:49 ntpd[249]: INIT: precision = 7.240 usec (-17)
> > 1970-01-01T00:01:49 ntpd[249]: INIT: successfully locked into RAM
> > 1970-01-01T00:01:49 ntpd[249]: CONFIG: readconfig: parsing file:
> > /etc/ntp.conf
> > 1970-01-01T00:01:49 ntpd[249]: CONFIG: restrict nopeer ignored
> > 1970-01-01T00:01:49 ntpd[249]: INIT: Using SO_TIMESTAMPNS
> > 1970-01-01T00:01:49 ntpd[249]: IO: Listen and drop on 0 v6wildcard
> > [::]:123
> > 1970-01-01T00:01:49 ntpd[249]: IO: Listen and drop on 1 v4wildcard
> > 0.0.0.0:123
> > 1970-01-01T00:01:49 ntpd[249]: IO: Listen normally on 2 lo 127.0.0.1:123
> > 1970-01-01T00:01:49 ntpd[249]: IO: Listen normally on 3 eth0
> > 172.16.0.30:123
> > 1970-01-01T00:01:49 ntpd[249]: IO: Listen normally on 4 lo [::1]:123
> > 1970-01-01T00:01:49 ntpd[249]: IO: Listen normally on 5 eth0
> > [fe80::ba27:ebff:fea6:340%2]:123
> > 1970-01-01T00:01:49 ntpd[249]: IO: Listening on routing socket on fd #22
> > for interface updates
> > 1970-01-01T00:01:50 ntpd[249]: SYNC: Found 10 servers, suggest minsane at
> > least 3
> > 1970-01-01T00:01:50 ntpd[249]: INIT: MRU 10922 entries, 13 hash bits,
> > 65536 bytes
> > 1970-01-01T00:01:50 ntpd[249]: statistics directory /var/NTP/ does not
> > exist or is unwriteable, error No such file or directory
> > 1970-01-01T00:01:51 ntpd[249]: DNS: dns_probe: 0.pool.ntp.org,
> > cast_flags:8, flags:101
> > Segmentation fault (core dumped)
> >
> > $ ./host/bin/aarch64-buildroot-linux-uclibc-gdb
> > ./build/ntpsec-1_2_0/build/main/ntpd/ntpd core
> > Core was generated by `/usr/sbin/ntpd -n -d'.
> > Program terminated with signal SIGSEGV, Segmentation fault.
> > (gdb) where
> > #0 0x0000007f8ff1f150 in res_sync_func () at libc/inet/resolv.c:3356
> > #1 0x0000007f8ff1c468 in __open_nameservers () at libc/inet/resolv.c:949
> > #2 0x0000007f8ff1b498 in __dns_lookup (name=0x55943c67f0
> > "0.pool.ntp.org",
> > type=1, outpacket=0x7f8fe91c48, a=0x7f8fe91c08) at
> > libc/inet/resolv.c:1134
> > #3 0x0000007f8ff1d744 in __GI_gethostbyname_r (
> > name=0x55943c67f0 "0.pool.ntp.org", result_buf=0x7f8fe92628,
> > buf=0x7f8fe91d90 "", buflen=992, result=0x7f8fe92670,
> > h_errnop=0x7f8fe92668) at libc/inet/resolv.c:1966
> > #4 0x0000007f8ff1d9a0 in __GI_gethostbyname2_r (
> > name=0x55943c67f0 "0.pool.ntp.org", family=2, result_buf=0x7f8fe92628,
> > buf=0x7f8fe91d70 "0.pool.ntp.org", buflen=1024, result=0x7f8fe92670,
> > h_errnop=0x7f8fe92668) at libc/inet/resolv.c:2065
> > #5 0x0000007f8ff16924 in gaih_inet (name=0x55943c67f0 "0.pool.ntp.org",
> > service=0x7f8fe92828, req=0x7f8fe92890, pai=0x7f8fe92838)
> > at libc/inet/getaddrinfo.c:596
> > #6 0x0000007f8ff17624 in __GI_getaddrinfo (
> > name=0x55943c67f0 "0.pool.ntp.org",
> > service=0x5582eb8acd "\377H\213D$\bL\211\367H\213\260\270",
> > hints=0x7f8fe92890, pai=0x5582ee1bf8) at libc/inet/getaddrinfo.c:957
> > #7 0x0000005582ea60f4 in _start ()
> > (gdb) p _res
> > $1 = {options = 0, nsaddr_list = {{sin_family = 0, sin_port = 0, sin_addr
> > = {
> > s_addr = 0}, sin_zero = "\000\000\000\000\000\000\000"}, {
> > sin_family = 0, sin_port = 0, sin_addr = {s_addr = 0},
> > sin_zero = "\000\000\000\000\000\000\000"}, {sin_family = 0,
> > sin_port = 0, sin_addr = {s_addr = 0},
> > sin_zero = "\000\000\000\000\000\000\000"}}, dnsrch = {0x0, 0x0,
> > 0x0,
> > 0x0, 0x0, 0x0, 0x0}, nscount = 0 '\000', ndots = 0 '\000',
> > retrans = 0 '\000', retry = 0 '\000', defdname = '\000' <repeats 255
> > times>,
> > nsort = 0 '\000', pfcode = 0, id = 0, res_h_errno = 0, sort_list =
> > {{addr = {
> > s_addr = 0}, mask = 0}, {addr = {s_addr = 0}, mask = 0}, {addr = {
> > s_addr = 0}, mask = 0}, {addr = {s_addr = 0}, mask = 0}, {addr = {
> > s_addr = 0}, mask = 0}, {addr = {s_addr = 0}, mask = 0}, {addr = {
> > s_addr = 0}, mask = 0}, {addr = {s_addr = 0}, mask = 0}, {addr = {
> > s_addr = 0}, mask = 0}, {addr = {s_addr = 0}, mask = 0}}, _u = {
> > _ext = {nsaddrs = {0x0, 0x0, 0x0}, nscount = 0 '\000', nstimes = {0,
> > 0,
> > 0}, nssocks = {0, 0, 0}, nscount6 = 0, nsinit = 0}}}
> > (gdb) p &_res
> > $2 = (struct __res_state *) 0x7f8ff8fd98 <_res>
> > (gdb) p rp
> > $3 = (struct __res_state *) 0x7fffffffff
> >
> > And the following uclibc code at libc/inet/resolv.c:3356:
> >
> > 3345 static void res_sync_func(void)
> > 3346 {
> > 3347 struct __res_state *rp = &(_res);
> > 3348 int n;
> > 3349
> > 3350 /* If we didn't get malloc failure earlier... */
> > 3351 if (__nameserver != (void*) &__local_nameserver) {
> > 3352 /* TODO:
> > 3353 * if (__nameservers < rp->nscount) - try to grow
> > __nameserver[]?
> > 3354 */
> > 3355 #ifdef __UCLIBC_HAS_IPV6__
> > 3356 if (__nameservers > rp->_u._ext.nscount)
> > 3357 __nameservers = rp->_u._ext.nscount;
> > 3358 n = __nameservers;
> >
> > The special thing about ntpsec is the DNS lookup in an extra thread
> > and/or the call to res_init(), see ntpsec-1_2_0/ntpd/ntp_dns.c:
> >
> > 69 msyslog(LOG_INFO, "DNS: dns_probe: %s, cast_flags:%x,
> > flags:%x%s",
> > 70 hostname, pp->cast_flags, pp->cfg.flags, busy);
> > 71 if (NULL != active) /* normally redundant */
> > 72 return false;
> > 73
> > 74 active = pp;
> > 75
> > 76 sigfillset(&block_mask);
> > 77 pthread_sigmask(SIG_BLOCK, &block_mask, &saved_sig_mask);
> > 78 rc = pthread_create(&worker, NULL, dns_lookup, pp);
> >
> > and
> >
> > 165 static void* dns_lookup(void* arg)
> > 166 {
> > 167 struct peer *pp = (struct peer *) arg;
> > 168 struct addrinfo hints;
> > 169
> > 170 #ifdef HAVE_SECCOMP_H
> > 171 setup_SIGSYS_trap(); /* enable trap for this thread */
> > 172 #endif
> > 173
> > 174 #ifdef HAVE_RES_INIT
> > 175 /* Reload DNS servers from /etc/resolv.conf in case DHCP has
> > updated it.
> > 176 * We only need to do this occasionally, but it's not
> > expensive
> > 177 * and simpler to do it every time than it is to figure out
> > when
> > 178 * to do it.
> > 179 * This res_init() covers NTS too.
> > 180 */
> > 181 res_init();
> > 182 #endif
> > 183
> > 184 if (pp->cfg.flags & FLAG_NTS) {
> > 185 #ifndef DISABLE_NTS
> > 186 nts_probe(pp);
> > 187 #endif
> > 188 } else {
> > 189 ZERO(hints);
> > 190 hints.ai_protocol = IPPROTO_UDP;
> > 191 hints.ai_socktype = SOCK_DGRAM;
> > 192 hints.ai_family = AF(&pp->srcadr);
> > 193 gai_rc = getaddrinfo(pp->hostname, NTP_PORTA, &hints,
> > &answer);
> > 194 }
> >
> > $ /usr/lib/uclibc-ng-test/test/inet/tst-res
> > Segmentation fault (core dumped)
> >
> > $ ./host/bin/aarch64-buildroot-linux-uclibc-gdb
> > ./build/uclibc-ng-test-0844445e7358eb10e716155b55b0fb23e88d644a/test/inet/tst-res
> > core
> > Core was generated by `/usr/lib/uclibc-ng-test/test/inet/tst-res'.
> > Program terminated with signal SIGSEGV, Segmentation fault.
> > (gdb) where
> > #0 __GI___res_init () at libc/inet/resolv.c:3514
> > #1 0x0000005591e507e4 in main (argc=<optimized out>, argv=<optimized
> > out>)
> > at tst-res.c:20
> >
> > Signed-off-by: Peter Seiderer <[email protected]>
> > ---
> > include/resolv.h | 2 +-
> > libc/inet/resolv.c | 4 ++--
> > 2 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/include/resolv.h b/include/resolv.h
> > index 485b8db98..2a82641a4 100644
> > --- a/include/resolv.h
> > +++ b/include/resolv.h
> > @@ -457,7 +457,7 @@ __END_DECLS
> > # ifndef NOT_IN_libc
> > # define __resp __libc_resp
> > # endif
> > -# define _res (*__resp)
> > +# define _res (*__res_state())
> > extern __thread struct __res_state *__resp attribute_tls_model_ie;
> > # endif
> > # else
> > diff --git a/libc/inet/resolv.c b/libc/inet/resolv.c
> > index 8bbd7c7cd..cf170fba6 100644
> > --- a/libc/inet/resolv.c
> > +++ b/libc/inet/resolv.c
> > @@ -3344,7 +3344,7 @@ libc_hidden_def(dn_skipname)
> > /* Will be called under __resolv_lock. */
> > static void res_sync_func(void)
> > {
> > - struct __res_state *rp = &(_res);
> > + struct __res_state *rp = __res_state();
> > int n;
> >
> > /* If we didn't get malloc failure earlier... */
> > @@ -3896,7 +3896,7 @@ res_ninit(res_state statp)
> > #endif /* L_res_init */
> >
> > #ifdef L_res_state
> > -# if defined __UCLIBC_HAS_TLS__
> > +# if !defined __UCLIBC_HAS_TLS__
> > struct __res_state *
> > __res_state (void)
> > {
> > --
> > 2.33.1
> >
> > _______________________________________________
> > devel mailing list -- [email protected]
> > To unsubscribe send an email to [email protected]
> >
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