From 8f85075a2e9c26ff7486d4bbaf358999807d215c Mon Sep 17 00:00:00 2001 From: Szabolcs Nagy Date: Thu, 31 Dec 2020 12:24:38 +0000 Subject: [PATCH] elf: Add a DTV setup test [BZ #27136] The test dlopens a large number of modules with TLS, they are reused from an existing test. The test relies on the reuse of slotinfo entries after dlclose, without bug 27135 fixed this needs a failing dlopen. With a slotinfo list that has non-monotone increasing generation counters, bug 27136 can trigger. Reviewed-by: Adhemerval Zanella --- elf/Makefile | 10 ++++- elf/tst-tls20.c | 98 ++++++++++++++++++++++++++++++++++++++++++ elf/tst-tls20mod-bad.c | 2 + 3 files changed, 109 insertions(+), 1 deletion(-) create mode 100644 elf/tst-tls20.c create mode 100644 elf/tst-tls20mod-bad.c diff --git a/elf/Makefile b/elf/Makefile index de659655dc..c531470ede 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -222,7 +222,8 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \ tst-audit14 tst-audit15 tst-audit16 \ tst-single_threaded tst-single_threaded-pthread \ tst-tls-ie tst-tls-ie-dlmopen argv0test \ - tst-glibc-hwcaps tst-glibc-hwcaps-prepend tst-glibc-hwcaps-mask + tst-glibc-hwcaps tst-glibc-hwcaps-prepend tst-glibc-hwcaps-mask \ + tst-tls20 # reldep9 tests-internal += loadtest unload unload2 circleload1 \ neededtest neededtest2 neededtest3 neededtest4 \ @@ -344,6 +345,7 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \ libmarkermod2-1 libmarkermod2-2 \ libmarkermod3-1 libmarkermod3-2 libmarkermod3-3 \ libmarkermod4-1 libmarkermod4-2 libmarkermod4-3 libmarkermod4-4 \ + tst-tls20mod-bad # Most modules build with _ISOMAC defined, but those filtered out # depend on internal headers. @@ -1922,3 +1924,9 @@ $(objpfx)tst-rtld-help.out: $(objpfx)ld.so fi; \ (exit $$status); \ $(evaluate-test) + +# Reuses tst-tls-many-dynamic-modules +tst-tls20mod-bad.so-no-z-defs = yes +$(objpfx)tst-tls20: $(libdl) $(shared-thread-library) +$(objpfx)tst-tls20.out: $(objpfx)tst-tls20mod-bad.so \ + $(tst-tls-many-dynamic-modules:%=$(objpfx)%.so) diff --git a/elf/tst-tls20.c b/elf/tst-tls20.c new file mode 100644 index 0000000000..ac5f8c8d39 --- /dev/null +++ b/elf/tst-tls20.c @@ -0,0 +1,98 @@ +/* Test dtv setup if entries don't have monotone increasing generation. + Copyright (C) 2021 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 + . */ + +#include +#include +#include +#include +#include +#include +#include + +#define NMOD 100 +static void *mod[NMOD]; + +static void +load_fail (void) +{ + /* Expected to fail because of a missing symbol. */ + void *m = dlopen ("tst-tls20mod-bad.so", RTLD_NOW); + if (m != NULL) + FAIL_EXIT1 ("dlopen of tst-tls20mod-bad.so succeeded\n"); +} + +static void +load_mod (int i) +{ + char *buf = xasprintf ("tst-tls-manydynamic%02dmod.so", i); + mod[i] = xdlopen (buf, RTLD_LAZY); + free (buf); +} + +static void +unload_mod (int i) +{ + if (mod[i] != NULL) + xdlclose (mod[i]); + mod[i] = NULL; +} + +static void +access (int i) +{ + char *buf = xasprintf ("tls_global_%02d", i); + dlerror (); + int *p = dlsym (mod[i], buf); + printf ("mod[%d]: &tls = %p\n", i, p); + if (p == NULL) + FAIL_EXIT1 ("dlsym failed: %s\n", dlerror ()); + ++*p; + free (buf); +} + +static void * +start (void *a) +{ + for (int i = 0; i < NMOD; i++) + if (mod[i] != NULL) + access (i); + return 0; +} + +static int +do_test (void) +{ + int i; + + for (i = 0; i < NMOD; i++) + { + load_mod (i); + /* Bump the generation of mod[0] without using new dtv slot. */ + unload_mod (0); + load_fail (); /* Ensure GL(dl_tls_dtv_gaps) is true: see bug 27135. */ + load_mod (0); + /* Access TLS in all loaded modules. */ + pthread_t t = xpthread_create (0, start, 0); + xpthread_join (t); + } + for (i = 0; i < NMOD; i++) + unload_mod (i); + return 0; +} + +#include diff --git a/elf/tst-tls20mod-bad.c b/elf/tst-tls20mod-bad.c new file mode 100644 index 0000000000..c1aed8ea7d --- /dev/null +++ b/elf/tst-tls20mod-bad.c @@ -0,0 +1,2 @@ +void missing_symbol (void); +void f (void) {missing_symbol ();} -- 2.43.5