import glibc-2.28-236.el8_9.12

i8c changed/i8c/glibc-2.28-236.el8_9.12
MSVSphere Packaging Team 9 months ago
parent 3641efe605
commit 7316d96979

@ -0,0 +1,112 @@
commit 849274d48fc59bfa6db3c713c8ced8026b20f3b7
Author: Florian Weimer <fweimer@redhat.com>
Date: Thu Nov 16 19:55:35 2023 +0100
elf: Fix force_first handling in dlclose (bug 30981)
The force_first parameter was ineffective because the dlclose'd
object was not necessarily the first in the maps array. Also
enable force_first handling unconditionally, regardless of namespace.
The initial object in a namespace should be destructed first, too.
The _dl_sort_maps_dfs function had early returns for relocation
dependency processing which broke force_first handling, too, and
this is fixed in this change as well.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
diff --git a/elf/dl-close.c b/elf/dl-close.c
index 22225efb3226c3e1..16a39f5bf17b440f 100644
--- a/elf/dl-close.c
+++ b/elf/dl-close.c
@@ -182,6 +182,16 @@ _dl_close_worker (struct link_map *map, bool force)
}
assert (idx == nloaded);
+ /* Put the dlclose'd map first, so that its destructor runs first.
+ The map variable is NULL after a retry. */
+ if (map != NULL)
+ {
+ maps[map->l_idx] = maps[0];
+ maps[map->l_idx]->l_idx = map->l_idx;
+ maps[0] = map;
+ maps[0]->l_idx = 0;
+ }
+
/* Keep track of the lowest index link map we have covered already. */
int done_index = -1;
while (++done_index < nloaded)
@@ -255,9 +265,10 @@ _dl_close_worker (struct link_map *map, bool force)
}
}
- /* Sort the entries. We can skip looking for the binary itself which is
- at the front of the search list for the main namespace. */
- _dl_sort_maps (maps, nloaded, (nsid == LM_ID_BASE), true);
+ /* Sort the entries. Unless retrying, the maps[0] object (the
+ original argument to dlclose) needs to remain first, so that its
+ destructor runs first. */
+ _dl_sort_maps (maps, nloaded, /* force_first */ map != NULL, true);
/* Call all termination functions at once. */
bool unload_any = false;
@@ -768,7 +779,11 @@ _dl_close_worker (struct link_map *map, bool force)
/* Recheck if we need to retry, release the lock. */
out:
if (dl_close_state == rerun)
- goto retry;
+ {
+ /* The map may have been deallocated. */
+ map = NULL;
+ goto retry;
+ }
dl_close_state = not_pending;
}
diff --git a/elf/dl-sort-maps.c b/elf/dl-sort-maps.c
index aeb79b40b45054c0..c17ac325eca658ef 100644
--- a/elf/dl-sort-maps.c
+++ b/elf/dl-sort-maps.c
@@ -260,13 +260,12 @@ _dl_sort_maps_dfs (struct link_map **maps, unsigned int nmaps,
The below memcpy is not needed in the do_reldeps case here,
since we wrote back to maps[] during DFS traversal. */
if (maps_head == maps)
- return;
+ break;
}
assert (maps_head == maps);
- return;
}
-
- memcpy (maps, rpo, sizeof (struct link_map *) * nmaps);
+ else
+ memcpy (maps, rpo, sizeof (struct link_map *) * nmaps);
/* Skipping the first object at maps[0] is not valid in general,
since traversing along object dependency-links may "find" that
diff --git a/elf/dso-sort-tests-1.def b/elf/dso-sort-tests-1.def
index 4bf9052db16fb352..cf6453e9eb85ac65 100644
--- a/elf/dso-sort-tests-1.def
+++ b/elf/dso-sort-tests-1.def
@@ -56,14 +56,16 @@ output: b>a>{}<a<b
# relocation(dynamic) dependencies. While this is technically unspecified, the
# presumed reasonable practical behavior is for the destructor order to respect
# the static DT_NEEDED links (here this means the a->b->c->d order).
-# The older dynamic_sort=1 algorithm does not achieve this, while the DFS-based
-# dynamic_sort=2 algorithm does, although it is still arguable whether going
-# beyond spec to do this is the right thing to do.
+# The older dynamic_sort=1 algorithm originally did not achieve this,
+# but this was a bug in the way _dl_sort_maps was called from _dl_close_worker,
+# effectively disabling proper force_first handling.
+# The new dynamic_sort=2 algorithm shows the effect of the simpler force_first
+# handling: the a object is simply moved to the front.
# The below expected outputs are what the two algorithms currently produce
# respectively, for regression testing purposes.
tst-bz15311: {+a;+e;+f;+g;+d;%d;-d;-g;-f;-e;-a};a->b->c->d;d=>[ba];c=>a;b=>e=>a;c=>f=>b;d=>g=>c
-output(glibc.rtld.dynamic_sort=1): {+a[d>c>b>a>];+e[e>];+f[f>];+g[g>];+d[];%d(b(e(a()))a()g(c(a()f(b(e(a()))))));-d[];-g[];-f[];-e[];-a[<a<c<d<g<f<b<e];}
-output(glibc.rtld.dynamic_sort=2): {+a[d>c>b>a>];+e[e>];+f[f>];+g[g>];+d[];%d(b(e(a()))a()g(c(a()f(b(e(a()))))));-d[];-g[];-f[];-e[];-a[<g<f<a<b<c<d<e];}
+output(glibc.rtld.dynamic_sort=1): {+a[d>c>b>a>];+e[e>];+f[f>];+g[g>];+d[];%d(b(e(a()))a()g(c(a()f(b(e(a()))))));-d[];-g[];-f[];-e[];-a[<a<b<c<d<g<f<e];}
+output(glibc.rtld.dynamic_sort=2): {+a[d>c>b>a>];+e[e>];+f[f>];+g[g>];+d[];%d(b(e(a()))a()g(c(a()f(b(e(a()))))));-d[];-g[];-f[];-e[];-a[<a<g<f<b<c<d<e];}
# Test that even in the presence of dependency loops involving dlopen'ed
# object, that object is initialized last (and not unloaded prematurely).

@ -0,0 +1,35 @@
commit b893410be304ddcea0bd43f537a13e8b18d37cf2
Author: Florian Weimer <fweimer@redhat.com>
Date: Mon Nov 27 11:28:07 2023 +0100
elf: In _dl_relocate_object, skip processing if object is relocated
This is just a minor optimization. It also makes it more obvious that
_dl_relocate_object can be called multiple times.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
diff --git a/elf/dl-reloc.c b/elf/dl-reloc.c
index 7a84b1fa8c3a7fdd..a80a54fb013adab5 100644
--- a/elf/dl-reloc.c
+++ b/elf/dl-reloc.c
@@ -165,6 +165,9 @@ void
_dl_relocate_object (struct link_map *l, struct r_scope_elem *scope[],
int reloc_mode, int consider_profiling)
{
+ if (l->l_relocated)
+ return;
+
struct textrels
{
caddr_t start;
@@ -202,9 +205,6 @@ _dl_relocate_object (struct link_map *l, struct r_scope_elem *scope[],
# define consider_symbind 0
#endif
- if (l->l_relocated)
- return;
-
/* If DT_BIND_NOW is set relocate all references in this object. We
do not do this if we are profiling, of course. */
// XXX Correct for auditing?

@ -0,0 +1,121 @@
commit a74c2e1cbc8673dd7e97aae2f2705392e2ccc3f6
Author: Florian Weimer <fweimer@redhat.com>
Date: Mon Nov 27 11:28:10 2023 +0100
elf: Introduce the _dl_open_relocate_one_object function
It is extracted from dl_open_worker_begin.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
diff --git a/elf/dl-open.c b/elf/dl-open.c
index e82e53ff8b38fa11..1505fdb73088dcdb 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -466,6 +466,50 @@ activate_nodelete (struct link_map *new)
}
}
+/* Relocate the object L. *RELOCATION_IN_PROGRESS controls whether
+ the debugger is notified of the start of relocation processing. */
+static void
+_dl_open_relocate_one_object (struct dl_open_args *args, struct r_debug *r,
+ struct link_map *l, int reloc_mode,
+ bool *relocation_in_progress)
+{
+ if (l->l_real->l_relocated)
+ return;
+
+ if (!*relocation_in_progress)
+ {
+ /* Notify the debugger that relocations are about to happen. */
+ LIBC_PROBE (reloc_start, 2, args->nsid, r);
+ *relocation_in_progress = true;
+ }
+
+#ifdef SHARED
+ if (__glibc_unlikely (GLRO(dl_profile) != NULL))
+ {
+ /* If this here is the shared object which we want to profile
+ make sure the profile is started. We can find out whether
+ this is necessary or not by observing the `_dl_profile_map'
+ variable. If it was NULL but is not NULL afterwards we must
+ start the profiling. */
+ struct link_map *old_profile_map = GL(dl_profile_map);
+
+ _dl_relocate_object (l, l->l_scope, reloc_mode | RTLD_LAZY, 1);
+
+ if (old_profile_map == NULL && GL(dl_profile_map) != NULL)
+ {
+ /* We must prepare the profiling. */
+ _dl_start_profile ();
+
+ /* Prevent unloading the object. */
+ GL(dl_profile_map)->l_nodelete_active = true;
+ }
+ }
+ else
+#endif
+ _dl_relocate_object (l, l->l_scope, reloc_mode, 0);
+}
+
+
/* struct dl_init_args and call_dl_init are used to call _dl_init with
exception handling disabled. */
struct dl_init_args
@@ -638,7 +682,7 @@ dl_open_worker_begin (void *a)
}
while (l != NULL);
- int relocation_in_progress = 0;
+ bool relocation_in_progress = false;
/* Perform relocation. This can trigger lazy binding in IFUNC
resolvers. For NODELETE mappings, these dependencies are not
@@ -649,44 +693,8 @@ dl_open_worker_begin (void *a)
are undefined anyway, so this is not a problem. */
for (unsigned int i = last; i-- > first; )
- {
- l = new->l_initfini[i];
-
- if (l->l_real->l_relocated)
- continue;
-
- if (! relocation_in_progress)
- {
- /* Notify the debugger that relocations are about to happen. */
- LIBC_PROBE (reloc_start, 2, args->nsid, r);
- relocation_in_progress = 1;
- }
-
-#ifdef SHARED
- if (__glibc_unlikely (GLRO(dl_profile) != NULL))
- {
- /* If this here is the shared object which we want to profile
- make sure the profile is started. We can find out whether
- this is necessary or not by observing the `_dl_profile_map'
- variable. If it was NULL but is not NULL afterwards we must
- start the profiling. */
- struct link_map *old_profile_map = GL(dl_profile_map);
-
- _dl_relocate_object (l, l->l_scope, reloc_mode | RTLD_LAZY, 1);
-
- if (old_profile_map == NULL && GL(dl_profile_map) != NULL)
- {
- /* We must prepare the profiling. */
- _dl_start_profile ();
-
- /* Prevent unloading the object. */
- GL(dl_profile_map)->l_nodelete_active = true;
- }
- }
- else
-#endif
- _dl_relocate_object (l, l->l_scope, reloc_mode, 0);
- }
+ _dl_open_relocate_one_object (args, r, new->l_initfini[i], reloc_mode,
+ &relocation_in_progress);
/* This only performs the memory allocations. The actual update of
the scopes happens below, after failure is impossible. */

@ -0,0 +1,223 @@
commit 78ca44da0160a0b442f0ca1f253e3360f044b2ec
Author: Florian Weimer <fweimer@redhat.com>
Date: Mon Nov 27 11:28:13 2023 +0100
elf: Relocate libc.so early during startup and dlmopen (bug 31083)
This makes it more likely that objects without dependencies can
use IFUNC resolvers in libc.so.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Conflicts:
elf/Makefile
(differences in test backports)
elf/rtld.c
(removal of prelink support upstream)
diff --git a/elf/Makefile b/elf/Makefile
index 634c3113227d64a6..6f0f36cdfe3961e8 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -386,6 +386,8 @@ tests += \
tst-nodelete2 \
tst-nodelete-dlclose \
tst-nodelete-opened \
+ tst-nodeps1 \
+ tst-nodeps2 \
tst-noload \
tst-null-argv \
tst-relsort1 \
@@ -740,6 +742,8 @@ modules-names = \
tst-nodelete-dlclose-dso \
tst-nodelete-dlclose-plugin \
tst-nodelete-opened-lib \
+ tst-nodeps1-mod \
+ tst-nodeps2-mod \
tst-null-argv-lib \
tst-relsort1mod1 \
tst-relsort1mod2 \
@@ -886,8 +890,13 @@ modules-execstack-yes = tst-execstack-mod
extra-test-objs += $(addsuffix .os,$(strip $(modules-names)))
# filtmod1.so has a special rule
-modules-names-nobuild := filtmod1 \
- tst-audit24bmod1 tst-audit24bmod2
+modules-names-nobuild += \
+ filtmod1 \
+ tst-audit24bmod1 \
+ tst-audit24bmod2 \
+ tst-nodeps1-mod \
+ tst-nodeps2-mod \
+ # modules-names-nobuild
tests += $(tests-static)
@@ -2697,3 +2706,19 @@ $(objpfx)tst-dlmopen-twice: $(libdl)
$(objpfx)tst-dlmopen-twice.out: \
$(objpfx)tst-dlmopen-twice-mod1.so \
$(objpfx)tst-dlmopen-twice-mod2.so
+
+# The object tst-nodeps1-mod.so has no explicit dependencies on libc.so.
+$(objpfx)tst-nodeps1-mod.so: $(objpfx)tst-nodeps1-mod.os
+ $(LINK.o) -nostartfiles -nostdlib -shared -o $@ $^
+tst-nodeps1.so-no-z-defs = yes
+# Link libc.so before the test module with the IFUNC resolver reference.
+LDFLAGS-tst-nodeps1 = $(common-objpfx)libc.so $(objpfx)tst-nodeps1-mod.so
+$(objpfx)tst-nodeps1: $(objpfx)tst-nodeps1-mod.so
+# Reuse the tst-nodeps1 module. Link libc.so before the test module
+# with the IFUNC resolver reference.
+$(objpfx)tst-nodeps2-mod.so: $(common-objpfx)libc.so \
+ $(objpfx)tst-nodeps1-mod.so $(objpfx)tst-nodeps2-mod.os
+ $(LINK.o) -Wl,--no-as-needed -nostartfiles -nostdlib -shared -o $@ $^
+$(objpfx)tst-nodeps2: $(libdl)
+$(objpfx)tst-nodeps2.out: \
+ $(objpfx)tst-nodeps1-mod.so $(objpfx)tst-nodeps2-mod.so
diff --git a/elf/dl-open.c b/elf/dl-open.c
index 1505fdb73088dcdb..6508b0ea545440b8 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -692,6 +692,17 @@ dl_open_worker_begin (void *a)
them. However, such relocation dependencies in IFUNC resolvers
are undefined anyway, so this is not a problem. */
+ /* Ensure that libc is relocated first. This helps with the
+ execution of IFUNC resolvers in libc, and matters only to newly
+ created dlmopen namespaces. Do not do this for static dlopen
+ because libc has relocations against ld.so, which may not have
+ been relocated at this point. */
+#ifdef SHARED
+ if (GL(dl_ns)[args->nsid].libc_map != NULL)
+ _dl_open_relocate_one_object (args, r, GL(dl_ns)[args->nsid].libc_map,
+ reloc_mode, &relocation_in_progress);
+#endif
+
for (unsigned int i = last; i-- > first; )
_dl_open_relocate_one_object (args, r, new->l_initfini[i], reloc_mode,
&relocation_in_progress);
diff --git a/elf/rtld.c b/elf/rtld.c
index cd2cc4024a3581c2..502d2a1c58505d88 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -2414,11 +2414,17 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]);
objects. We do not re-relocate the dynamic linker itself in this
loop because that could result in the GOT entries for functions we
call being changed, and that would break us. It is safe to relocate
- the dynamic linker out of order because it has no copy relocs (we
- know that because it is self-contained). */
+ the dynamic linker out of order because it has no copy relocations.
+ Likewise for libc, which is relocated early to ensure that IFUNC
+ resolvers in libc work. */
int consider_profiling = GLRO(dl_profile) != NULL;
+ if (GL(dl_ns)[LM_ID_BASE].libc_map != NULL)
+ _dl_relocate_object (GL(dl_ns)[LM_ID_BASE].libc_map,
+ GL(dl_ns)[LM_ID_BASE].libc_map->l_scope,
+ GLRO(dl_lazy) ? RTLD_LAZY : 0, consider_profiling);
+
/* If we are profiling we also must do lazy reloaction. */
GLRO(dl_lazy) |= consider_profiling;
diff --git a/elf/tst-nodeps1-mod.c b/elf/tst-nodeps1-mod.c
new file mode 100644
index 0000000000000000..45c8e3c631251a89
--- /dev/null
+++ b/elf/tst-nodeps1-mod.c
@@ -0,0 +1,25 @@
+/* Test module with no libc.so dependency and string function references.
+ Copyright (C) 2023 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <string.h>
+
+/* Some references to libc symbols which are likely to have IFUNC
+ resolvers. If they do not, this module does not exercise bug 31083. */
+void *memcpy_pointer = memcpy;
+void *memmove_pointer = memmove;
+void *memset_pointer = memset;
diff --git a/elf/tst-nodeps1.c b/elf/tst-nodeps1.c
new file mode 100644
index 0000000000000000..1a8bde36cdb71446
--- /dev/null
+++ b/elf/tst-nodeps1.c
@@ -0,0 +1,23 @@
+/* Test initially loaded module with implicit libc.so dependency (bug 31083).
+ Copyright (C) 2023 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+/* Testing happens before main. */
+int
+main (void)
+{
+}
diff --git a/elf/tst-nodeps2-mod.c b/elf/tst-nodeps2-mod.c
new file mode 100644
index 0000000000000000..4913feee9b56e0e1
--- /dev/null
+++ b/elf/tst-nodeps2-mod.c
@@ -0,0 +1 @@
+/* Empty test module which depends on tst-nodeps1-mod.so. */
diff --git a/elf/tst-nodeps2.c b/elf/tst-nodeps2.c
new file mode 100644
index 0000000000000000..0bdc8eeb8cba3a99
--- /dev/null
+++ b/elf/tst-nodeps2.c
@@ -0,0 +1,29 @@
+/* Test dlmopen with implicit libc.so dependency (bug 31083).
+ Copyright (C) 2023 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <support/xdlfcn.h>
+
+static int
+do_test (void)
+{
+ void *handle = xdlmopen (LM_ID_NEWLM, "tst-nodeps2-mod.so", RTLD_NOW);
+ xdlclose (handle);
+ return 0;
+}
+
+#include <support/test-driver.c>

@ -0,0 +1,41 @@
commit b3bee76c5f59498b9c189608f0a3132e2013fa1a
Author: Florian Weimer <fweimer@redhat.com>
Date: Fri Dec 8 09:51:34 2023 +0100
elf: Initialize GLRO(dl_lazy) before relocating libc in dynamic startup
GLRO(dl_lazy) is used to set the parameters for the early
_dl_relocate_object call, so the consider_profiling setting has to
be applied before the call.
Fixes commit 78ca44da0160a0b442f0ca1f253e3360f044b2ec ("elf: Relocate
libc.so early during startup and dlmopen (bug 31083)").
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Conflicts:
elf/rtld.c
(removal of prelink support upstream)
diff --git a/elf/rtld.c b/elf/rtld.c
index 502d2a1c58505d88..4f317a2a874e6af7 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -2420,14 +2420,14 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]);
int consider_profiling = GLRO(dl_profile) != NULL;
+ /* If we are profiling we also must do lazy reloaction. */
+ GLRO(dl_lazy) |= consider_profiling;
+
if (GL(dl_ns)[LM_ID_BASE].libc_map != NULL)
_dl_relocate_object (GL(dl_ns)[LM_ID_BASE].libc_map,
GL(dl_ns)[LM_ID_BASE].libc_map->l_scope,
GLRO(dl_lazy) ? RTLD_LAZY : 0, consider_profiling);
- /* If we are profiling we also must do lazy reloaction. */
- GLRO(dl_lazy) |= consider_profiling;
-
RTLD_TIMING_VAR (start);
rtld_timer_start (&start);
unsigned i = main_map->l_searchlist.r_nlist;

@ -0,0 +1,83 @@
commit c00b984fcd53f679ca2dafcd1aee2c89836e6e73
Author: Florian Weimer <fweimer@redhat.com>
Date: Tue Aug 29 08:28:31 2023 +0200
nscd: Skip unusable entries in first pass in prune_cache (bug 30800)
Previously, if an entry was marked unusable for any reason, but had
not timed out yet, the assert would trigger.
One way to get into such state is if a data change is detected during
re-validation of an entry. This causes the entry to be marked as not
usable. If exits nscd soon after that, then the clock jumps
backwards, and nscd restarted, the cache re-validation run after
startup triggers the removed assert.
The change is more complicated than just the removal of the assert
because entries marked as not usable should be garbage-collected in
the second pass. To make this happen, it is necessary to update some
book-keeping data.
Reviewed-by: DJ Delorie <dj@redhat.com>
diff --git a/nscd/cache.c b/nscd/cache.c
index efe4214d953edb30..2fd3f78ebb567bbe 100644
--- a/nscd/cache.c
+++ b/nscd/cache.c
@@ -371,8 +371,11 @@ prune_cache (struct database_dyn *table, time_t now, int fd)
serv2str[runp->type], str, dh->timeout);
}
- /* Check whether the entry timed out. */
- if (dh->timeout < now)
+ /* Check whether the entry timed out. Timed out entries
+ will be revalidated. For unusable records, it is still
+ necessary to record that the bucket needs to be scanned
+ again below. */
+ if (dh->timeout < now || !dh->usable)
{
/* This hash bucket could contain entries which need to
be looked at. */
@@ -384,7 +387,7 @@ prune_cache (struct database_dyn *table, time_t now, int fd)
/* We only have to look at the data of the first entries
since the count information is kept in the data part
which is shared. */
- if (runp->first)
+ if (runp->first && dh->usable)
{
/* At this point there are two choices: we reload the
@@ -400,9 +403,6 @@ prune_cache (struct database_dyn *table, time_t now, int fd)
{
/* Remove the value. */
dh->usable = false;
-
- /* We definitely have some garbage entries now. */
- any = true;
}
else
{
@@ -414,18 +414,15 @@ prune_cache (struct database_dyn *table, time_t now, int fd)
time_t timeout = readdfcts[runp->type] (table, runp, dh);
next_timeout = MIN (next_timeout, timeout);
-
- /* If the entry has been replaced, we might need
- cleanup. */
- any |= !dh->usable;
}
}
+
+ /* If the entry has been replaced, we might need cleanup. */
+ any |= !dh->usable;
}
else
- {
- assert (dh->usable);
- next_timeout = MIN (next_timeout, dh->timeout);
- }
+ /* Entry has not timed out and is usable. */
+ next_timeout = MIN (next_timeout, dh->timeout);
run = runp->next;
}

@ -0,0 +1,237 @@
commit d0f07f7df8d9758c838674b70144ac73bcbd1634
Author: Florian Weimer <fweimer@redhat.com>
Date: Tue May 30 13:25:50 2023 +0200
elf: Make more functions available for binding during dlclose (bug 30425)
Previously, after destructors for a DSO have been invoked, ld.so refused
to bind against that DSO in all cases. Relax this restriction somewhat
if the referencing object is itself a DSO that is being unloaded. This
assumes that the symbol reference is not going to be stored anywhere.
The situation in the test case can arise fairly easily with C++ and
objects that are built with different optimization levels and therefore
define different functions with vague linkage.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Conflicts:
elf/Makefile
(usual test differences, link test with -ldl)
diff --git a/elf/Makefile b/elf/Makefile
index 6f0f36cdfe3961e8..ebf46a297d241d8f 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -362,6 +362,7 @@ tests += \
tst-big-note \
tst-debug1 \
tst-deep1 \
+ tst-dlclose-lazy \
tst-dlmodcount \
tst-dlmopen1 \
tst-dlmopen3 \
@@ -711,6 +712,8 @@ modules-names = \
tst-deep1mod2 \
tst-deep1mod3 \
tst-dlmopen1mod \
+ tst-dlclose-lazy-mod1 \
+ tst-dlclose-lazy-mod2 \
tst-dlmopen-dlerror-mod \
tst-dlmopen-gethostbyname-mod \
tst-dlmopen-twice-mod1 \
@@ -2707,6 +2710,12 @@ $(objpfx)tst-dlmopen-twice.out: \
$(objpfx)tst-dlmopen-twice-mod1.so \
$(objpfx)tst-dlmopen-twice-mod2.so
+LDFLAGS-tst-dlclose-lazy-mod1.so = -Wl,-z,lazy,--no-as-needed
+$(objpfx)tst-dlclose-lazy-mod1.so: $(objpfx)tst-dlclose-lazy-mod2.so
+$(objpfx)tst-dlclose-lazy: $(libdl)
+$(objpfx)tst-dlclose-lazy.out: \
+ $(objpfx)tst-dlclose-lazy-mod1.so $(objpfx)tst-dlclose-lazy-mod2.so
+
# The object tst-nodeps1-mod.so has no explicit dependencies on libc.so.
$(objpfx)tst-nodeps1-mod.so: $(objpfx)tst-nodeps1-mod.os
$(LINK.o) -nostartfiles -nostdlib -shared -o $@ $^
diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c
index 47acd134600b44b5..9e8f14b8483f5eba 100644
--- a/elf/dl-lookup.c
+++ b/elf/dl-lookup.c
@@ -380,8 +380,25 @@ do_lookup_x (const char *undef_name, uint_fast32_t new_hash,
if ((type_class & ELF_RTYPE_CLASS_COPY) && map->l_type == lt_executable)
continue;
- /* Do not look into objects which are going to be removed. */
- if (map->l_removed)
+ /* Do not look into objects which are going to be removed,
+ except when the referencing object itself is being removed.
+
+ The second part covers the situation when an object lazily
+ binds to another object while running its destructor, but the
+ destructor of the other object has already run, so that
+ dlclose has set l_removed. It may not always be obvious how
+ to avoid such a scenario to programmers creating DSOs,
+ particularly if C++ vague linkage is involved and triggers
+ symbol interposition.
+
+ Accepting these to-be-removed objects makes the lazy and
+ BIND_NOW cases more similar. (With BIND_NOW, the symbol is
+ resolved early, before the destructor call, so the issue does
+ not arise.). Behavior matches the constructor scenario: the
+ implementation allows binding to symbols of objects whose
+ constructors have not run. In fact, not doing this would be
+ mostly incompatible with symbol interposition. */
+ if (map->l_removed && !(undef_map != NULL && undef_map->l_removed))
continue;
/* Print some debugging info if wanted. */
diff --git a/elf/tst-dlclose-lazy-mod1.c b/elf/tst-dlclose-lazy-mod1.c
new file mode 100644
index 0000000000000000..8439dc1925cc8b41
--- /dev/null
+++ b/elf/tst-dlclose-lazy-mod1.c
@@ -0,0 +1,36 @@
+/* Lazy binding during dlclose. Directly loaded module.
+ Copyright (C) 2023 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+/* This function is called from exported_function below. It is only
+ defined in this module. The weak attribute mimics how G++
+ implements vague linkage for C++. */
+void __attribute__ ((weak))
+lazily_bound_exported_function (void)
+{
+}
+
+/* Called from tst-dlclose-lazy-mod2.so. */
+void
+exported_function (int call_it)
+{
+ if (call_it)
+ /* Previous to the fix this would crash when called during dlclose
+ since symbols from the DSO were no longer available for binding
+ (bug 30425) after the DSO started being closed by dlclose. */
+ lazily_bound_exported_function ();
+}
diff --git a/elf/tst-dlclose-lazy-mod2.c b/elf/tst-dlclose-lazy-mod2.c
new file mode 100644
index 0000000000000000..767f69ffdb23a685
--- /dev/null
+++ b/elf/tst-dlclose-lazy-mod2.c
@@ -0,0 +1,49 @@
+/* Lazy binding during dlclose. Indirectly loaded module.
+ Copyright (C) 2023 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+void
+exported_function (int ignored)
+{
+ /* This function is interposed from tst-dlclose-lazy-mod1.so and
+ thus never called. */
+ abort ();
+}
+
+static void __attribute__ ((constructor))
+init (void)
+{
+ puts ("info: tst-dlclose-lazy-mod2.so constructor called");
+
+ /* Trigger lazy binding to the definition in
+ tst-dlclose-lazy-mod1.so, but not for
+ lazily_bound_exported_function in that module. */
+ exported_function (0);
+}
+
+static void __attribute__ ((destructor))
+fini (void)
+{
+ puts ("info: tst-dlclose-lazy-mod2.so destructor called");
+
+ /* Trigger the lazily_bound_exported_function call in
+ exported_function in tst-dlclose-lazy-mod1.so. */
+ exported_function (1);
+}
diff --git a/elf/tst-dlclose-lazy.c b/elf/tst-dlclose-lazy.c
new file mode 100644
index 0000000000000000..976a6bb6f64fa981
--- /dev/null
+++ b/elf/tst-dlclose-lazy.c
@@ -0,0 +1,47 @@
+/* Test lazy binding during dlclose (bug 30425).
+ Copyright (C) 2023 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+/* This test re-creates a situation that can arise naturally for C++
+ applications due to the use of vague linkage and differences in the
+ set of compiler-emitted functions. A function in
+ tst-dlclose-lazy-mod1.so (exported_function) interposes a function
+ in tst-dlclose-lazy-mod2.so. This function is called from the
+ destructor in tst-dlclose-lazy-mod2.so, after the destructor for
+ tst-dlclose-lazy-mod1.so has already completed. Prior to the fix
+ for bug 30425, this would lead to a lazy binding failure in
+ tst-dlclose-lazy-mod1.so because dlclose had already marked the DSO
+ as unavailable for binding (by setting l_removed). */
+
+#include <dlfcn.h>
+#include <support/xdlfcn.h>
+#include <support/check.h>
+
+int
+main (void)
+{
+ /* Load tst-dlclose-lazy-mod1.so, indirectly loading
+ tst-dlclose-lazy-mod2.so. */
+ void *handle = xdlopen ("tst-dlclose-lazy-mod1.so", RTLD_GLOBAL | RTLD_LAZY);
+
+ /* Invoke the destructor of tst-dlclose-lazy-mod2.so, which calls
+ into tst-dlclose-lazy-mod1.so after its destructor has been
+ called. */
+ xdlclose (handle);
+
+ return 0;
+}

@ -0,0 +1,27 @@
commit ecc7c3deb9f347649c2078fcc0f94d4cedf92d60
Author: Florian Weimer <fweimer@redhat.com>
Date: Tue Jan 2 14:36:17 2024 +0100
libio: Check remaining buffer size in _IO_wdo_write (bug 31183)
The multibyte character needs to fit into the remaining buffer space,
not the already-written buffer space. Without the fix, we were never
moving the write pointer from the start of the buffer, always using
the single-character fallback buffer.
Fixes commit 04b76b5aa8b2d1d19066e42dd1 ("Don't error out writing
a multibyte character to an unbuffered stream (bug 17522)").
diff --git a/libio/wfileops.c b/libio/wfileops.c
index d3deb34ba058ca39..6a6421f8880f9356 100644
--- a/libio/wfileops.c
+++ b/libio/wfileops.c
@@ -57,7 +57,7 @@ _IO_wdo_write (FILE *fp, const wchar_t *data, size_t to_do)
char mb_buf[MB_LEN_MAX];
char *write_base, *write_ptr, *buf_end;
- if (fp->_IO_write_ptr - fp->_IO_write_base < sizeof (mb_buf))
+ if (fp->_IO_buf_end - fp->_IO_write_ptr < sizeof (mb_buf))
{
/* Make sure we have room for at least one multibyte
character. */

@ -132,7 +132,7 @@ end \
Summary: The GNU libc libraries Summary: The GNU libc libraries
Name: glibc Name: glibc
Version: %{glibcversion} Version: %{glibcversion}
Release: %{glibcrelease}.7 Release: %{glibcrelease}.12
# In general, GPLv2+ is used by programs, LGPLv2+ is used for # In general, GPLv2+ is used by programs, LGPLv2+ is used for
# libraries. # libraries.
@ -1053,6 +1053,14 @@ Patch865: glibc-RHEL-2435.patch
Patch866: glibc-RHEL-2435-2.patch Patch866: glibc-RHEL-2435-2.patch
Patch867: glibc-RHEL-2423.patch Patch867: glibc-RHEL-2423.patch
Patch868: glibc-RHEL-3036.patch Patch868: glibc-RHEL-3036.patch
Patch869: glibc-RHEL-21522-1.patch
Patch870: glibc-RHEL-21522-2.patch
Patch871: glibc-RHEL-21522-3.patch
Patch872: glibc-RHEL-21522-4.patch
Patch873: glibc-RHEL-21519.patch
Patch874: glibc-RHEL-22441.patch
Patch875: glibc-RHEL-22846.patch
Patch876: glibc-RHEL-22847.patch
############################################################################## ##############################################################################
# Continued list of core "glibc" package information: # Continued list of core "glibc" package information:
@ -2883,6 +2891,21 @@ fi
%files -f compat-libpthread-nonshared.filelist -n compat-libpthread-nonshared %files -f compat-libpthread-nonshared.filelist -n compat-libpthread-nonshared
%changelog %changelog
* Mon Jan 29 2024 Florian Weimer <fweimer@redhat.com> - 2.28-236.12
- Re-enable output buffering for wide stdio streams (RHEL-22847)
* Mon Jan 29 2024 Florian Weimer <fweimer@redhat.com> - 2.28-236.11
- Avoid lazy binding failures during dlclose (RHEL-22846)
* Fri Jan 26 2024 Florian Weimer <fweimer@redhat.com> - 2.28-236.10
- nscd: Skip unusable entries in first pass in prune_cache (RHEL-22441)
* Fri Jan 26 2024 Florian Weimer <fweimer@redhat.com> - 2.28-236.9
- Fix force-first handling in dlclose (RHEL-21519)
* Fri Jan 26 2024 Florian Weimer <fweimer@redhat.com> - 2.28-236.8
- Improve compatibility between underlinking and IFUNC resolvers (RHEL-21522)
* Wed Sep 20 2023 Siddhesh Poyarekar <siddhesh@redhat.com> - 2.28-236.7 * Wed Sep 20 2023 Siddhesh Poyarekar <siddhesh@redhat.com> - 2.28-236.7
- CVE-2023-4911 glibc: buffer overflow in ld.so leading to privilege escalation (RHEL-3036) - CVE-2023-4911 glibc: buffer overflow in ld.so leading to privilege escalation (RHEL-3036)

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