[v2,02/14] elf: Add a DTV setup test [BZ #27136]
Commit Message
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
---
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
Comments
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.
@@ -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)
new file mode 100644
@@ -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>
new file mode 100644
@@ -0,0 +1,2 @@
+void missing_symbol (void);
+void f (void) {missing_symbol ();}