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author Patrick J Volkerding <volkerdi@slackware.com>2012-09-26 01:10:42 +0000
committer Eric Hameleers <alien@slackware.com>2018-05-31 22:51:55 +0200
commit9664bee729d487bcc0a0bc35859f8e13d5421c75 (patch)
treeb428a16618e36ed864a8d76ea3435e19a452bf90 /source/l/glibc/glibc-2.15.nscd-race-fix.diff
parent75a4a592e5ccda30715f93563d741b83e0dcf39e (diff)
downloadcurrent-9664bee729d487bcc0a0bc35859f8e13d5421c75.tar.gz
current-9664bee729d487bcc0a0bc35859f8e13d5421c75.tar.xz
Slackware 14.0slackware-14.0
Wed Sep 26 01:10:42 UTC 2012 Slackware 14.0 x86_64 stable is released! We're perfectionists here at Slackware, so this release has been a long time a-brewing. But we think you'll agree that it was worth the wait. Slackware 14.0 combines modern components, ease of use, and flexible configuration... our "KISS" philosophy demands it. The ISOs are off to be replicated, a 6 CD-ROM 32-bit set and a dual-sided 32-bit/64-bit x86/x86_64 DVD. Please consider supporting the Slackware project by picking up a copy from store.slackware.com. We're taking pre-orders now, and offer a discount if you sign up for a subscription. Thanks to everyone who helped make this happen. The Slackware team, the upstream developers, and (of course) the awesome Slackware user community. Have fun! :-)
Diffstat (limited to 'source/l/glibc/glibc-2.15.nscd-race-fix.diff')
-rw-r--r--source/l/glibc/glibc-2.15.nscd-race-fix.diff47
1 files changed, 47 insertions, 0 deletions
diff --git a/source/l/glibc/glibc-2.15.nscd-race-fix.diff b/source/l/glibc/glibc-2.15.nscd-race-fix.diff
new file mode 100644
index 000000000..f1323570f
--- /dev/null
+++ b/source/l/glibc/glibc-2.15.nscd-race-fix.diff
@@ -0,0 +1,47 @@
+--- c/nscd/nscd_gethst_r.c 2012-01-01 05:16:32.000000000 -0700
++++ c/nscd/nscd_gethst_r.c 2012-03-28 10:45:51.546600822 -0600
+@@ -101,9 +101,27 @@ libc_freeres_fn (hst_map_free)
+ uint32_t
+ __nscd_get_nl_timestamp (void)
+ {
++ uint32_t retval;
+ if (__nss_not_use_nscd_hosts != 0)
+ return 0;
+
++ int cnt = 0;
++ /* __nscd_get_mapping can change hst_map_handle.mapped to NO_MAPPING.
++ However, __nscd_get_mapping assumes the prior value was not NO_MAPPING.
++ Thus we have to acquire the lock to prevent this thread from changing
++ hst_map_handle.mapped to NO_MAPPING while another thread is inside
++ __nscd_get_mapping. */
++ while (__builtin_expect
++ (atomic_compare_and_exchange_val_acq (&__hst_map_handle.lock,
++ 1, 0) != 0, 0))
++ {
++ // XXX Best number of rounds?
++ if (__builtin_expect (++cnt > 5, 0))
++ return 0;
++
++ atomic_delay ();
++ }
++
+ struct mapped_database *map = __hst_map_handle.mapped;
+
+ if (map == NULL
+@@ -113,9 +131,14 @@ __nscd_get_nl_timestamp (void)
+ map = __nscd_get_mapping (GETFDHST, "hosts", &__hst_map_handle.mapped);
+
+ if (map == NO_MAPPING)
+- return 0;
++ retval = 0;
++ else
++ retval = map->head->extra_data[NSCD_HST_IDX_CONF_TIMESTAMP];
++
++ /* Release the lock. */
++ __hst_map_handle.lock = 0;
+
+- return map->head->extra_data[NSCD_HST_IDX_CONF_TIMESTAMP];
++ return retval;
+ }
+
+