Message ID | 0b160a0060cd209a33496da51f915258ec5dd9a5.1618301209.git.szabolcs.nagy@arm.com |
---|---|
State | New |
Headers | show |
Series | Dynamic TLS related data race fixes | expand |
On 13/04/2021 05:18, Szabolcs Nagy via Libc-alpha wrote: > 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. > > -- > v2: > - moved from nptl/ to elf/ > - dlopen a different set of existing modules. > - code style fixes (!= NULL etc). > - moved after bug fix patch LGTM, with just a small suggestion below? Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> > --- > 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 0bef49e53d..b1344f1133 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 \ Ok. > @@ -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. Ok. > @@ -1924,3 +1926,9 @@ $(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 Ok. > new file mode 100644 > index 0000000000..a378c1fa08 > --- /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 > + <http://www.gnu.org/licenses/>. */ > + > +#include <dlfcn.h> > +#include <pthread.h> > +#include <stdio.h> > +#include <stdlib.h> > +#include <support/check.h> > +#include <support/xdlfcn.h> > +#include <support/xthread.h> > + > +#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[100]; > + snprintf (buf, sizeof buf, "tst-tls-manydynamic%02dmod.so", i); > + mod[i] = xdlopen (buf, RTLD_LAZY); > +} Maybe xasprintf here? > + > +static void > +unload_mod (int i) > +{ > + if (mod[i] != NULL) > + xdlclose (mod[i]); > + mod[i] = NULL; > +} > + > +static void > +access (int i) > +{ > + char buf[100]; > + snprintf (buf, sizeof buf, "tls_global_%02d", i); Same as before. > + 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; > +} > + > +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 <support/test-driver.c> Ok. > 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 ();} > Ok.
The 04/14/2021 15:06, Adhemerval Zanella wrote: > On 13/04/2021 05:18, Szabolcs Nagy via Libc-alpha wrote: > > 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. > > > > -- > > v2: > > - moved from nptl/ to elf/ > > - dlopen a different set of existing modules. > > - code style fixes (!= NULL etc). > > - moved after bug fix patch > > LGTM, with just a small suggestion below? > > Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> thanks > > +{ > > + char buf[100]; > > + snprintf (buf, sizeof buf, "tst-tls-manydynamic%02dmod.so", i); > > + mod[i] = xdlopen (buf, RTLD_LAZY); > > +} > > Maybe xasprintf here? committed with this change, but made a mistake committed patches are attached.
diff --git a/elf/Makefile b/elf/Makefile index 0bef49e53d..b1344f1133 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. @@ -1924,3 +1926,9 @@ $(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..a378c1fa08 --- /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 + <http://www.gnu.org/licenses/>. */ + +#include <dlfcn.h> +#include <pthread.h> +#include <stdio.h> +#include <stdlib.h> +#include <support/check.h> +#include <support/xdlfcn.h> +#include <support/xthread.h> + +#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[100]; + snprintf (buf, sizeof buf, "tst-tls-manydynamic%02dmod.so", i); + mod[i] = xdlopen (buf, RTLD_LAZY); +} + +static void +unload_mod (int i) +{ + if (mod[i] != NULL) + xdlclose (mod[i]); + mod[i] = NULL; +} + +static void +access (int i) +{ + char buf[100]; + snprintf (buf, sizeof buf, "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; +} + +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 <support/test-driver.c> 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 ();}