glibc/elf/dso-sort-tests-1.def

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elf: Testing infrastructure for ld.so DSO sorting (BZ #17645) This is the first of a 2-part patch set that fixes slow DSO sorting behavior in the dynamic loader, as reported in BZ #17645. In order to facilitate such a large modification to the dynamic loader, this first patch implements a testing framework for validating shared object sorting behavior, to enable comparison between old/new sorting algorithms, and any later enhancements. This testing infrastructure consists of a Python script scripts/dso-ordering-test.py' which takes in a description language, consisting of strings that describe a set of link dependency relations between DSOs, and generates testcase programs and Makefile fragments to automatically test the described situation, for example: a->b->c->d # four objects linked one after another a->[bc]->d;b->c # a depends on b and c, which both depend on d, # b depends on c (b,c linked to object a in fixed order) a->b->c;{+a;%a;-a} # a, b, c serially dependent, main program uses # dlopen/dlsym/dlclose on object a a->b->c;{}!->[abc] # a, b, c serially dependent; multiple tests generated # to test all permutations of a, b, c ordering linked # to main program (Above is just a short description of what the script can do, more documentation is in the script comments.) Two files containing several new tests, elf/dso-sort-tests-[12].def are added, including test scenarios for BZ #15311 and Redhat issue #1162810 [1]. Due to the nature of dynamic loader tests, where the sorting behavior and test output occurs before/after main(), generating testcases to use support/test-driver.c does not suffice to control meaningful timeout for ld.so. Therefore a new utility program 'support/test-run-command', based on test-driver.c/support_test_main.c has been added. This does the same testcase control, but for a program specified through a command-line rather than at the source code level. This utility is used to run the dynamic loader testcases generated by dso-ordering-test.py. [1] https://bugzilla.redhat.com/show_bug.cgi?id=1162810 Signed-off-by: Chung-Lin Tang <cltang@codesourcery.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-10-21 13:41:21 +00:00
# DSO sorting test descriptions.
# This file is to be processed by ../scripts/dso-ordering-test.py, see usage
# in elf/Makefile for how it is executed.
# We test both dynamic loader sorting algorithms
tunable_option: glibc.rtld.dynamic_sort=1
tunable_option: glibc.rtld.dynamic_sort=2
# Sequence of single dependencies with no cycles.
tst-dso-ordering1: a->b->c
output: c>b>a>{}<a<b<c
# Sequence including 2 dependent DSOs not at the end of the graph.
tst-dso-ordering2: a->b->[cd]->e
output: e>d>c>b>a>{}<a<b<c<d<e
# Complex order with 3 "layers" of full dependencies
tst-dso-ordering3: a->[bc]->[def]->[gh]->i
output: i>h>g>f>e>d>c>b>a>{}<a<b<c<d<e<f<g<h<i
# Sequence including 2 dependent DSOs at the end of the graph.
# Additionally the same dependencies appear in two paths.
tst-dso-ordering4: a->b->[de];a->c->d->e
output: e>d>c>b>a>{}<a<b<c<d<e
# Test that b->c cross link is respected correctly
tst-dso-ordering5: a!->[bc]->d;b->c
output: d>c>b>a>{}<a<b<c<d
# First DSO fully dependent on 4 DSOs, with another DSO at the end of chain.
tst-dso-ordering6: a->[bcde]->f
output: f>e>d>c>b>a>{}<a<b<c<d<e<f
# Sequence including 2 dependent and 3 dependent DSOs, and one of the
# dependent DSOs is dependent on an earlier DSO.
tst-dso-ordering7: a->[bc];b->[cde];e->f
output: f>e>d>c>b>a>{}<a<b<c<d<e<f
# Sequence where the DSO c is unerlinked and calls a function in DSO a which
# is technically a cycle. The main executable depends on the first two DSOs.
# Note: This test has unspecified behavior.
tst-dso-ordering8: a->b->c=>a;{}->[ba]
output: c>b>a>{}<a<b<c
# Generate the permutation of DT_NEEDED order between the main binary and
# all 5 DSOs; all link orders should produce exact same init/fini ordering
tst-dso-ordering9: a->b->c->d->e;{}!->[abcde]
output: e>d>c>b>a>{}<a<b<c<d<e
# Test if init/fini ordering behavior is proper, despite main program with
# an soname that may cause confusion
tst-dso-ordering10: {}->a->b->c;soname({})=c
output: b>a>{}<a<b
# Complex example from Bugzilla #15311, under-linked and with circular
# 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 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.
elf: Testing infrastructure for ld.so DSO sorting (BZ #17645) This is the first of a 2-part patch set that fixes slow DSO sorting behavior in the dynamic loader, as reported in BZ #17645. In order to facilitate such a large modification to the dynamic loader, this first patch implements a testing framework for validating shared object sorting behavior, to enable comparison between old/new sorting algorithms, and any later enhancements. This testing infrastructure consists of a Python script scripts/dso-ordering-test.py' which takes in a description language, consisting of strings that describe a set of link dependency relations between DSOs, and generates testcase programs and Makefile fragments to automatically test the described situation, for example: a->b->c->d # four objects linked one after another a->[bc]->d;b->c # a depends on b and c, which both depend on d, # b depends on c (b,c linked to object a in fixed order) a->b->c;{+a;%a;-a} # a, b, c serially dependent, main program uses # dlopen/dlsym/dlclose on object a a->b->c;{}!->[abc] # a, b, c serially dependent; multiple tests generated # to test all permutations of a, b, c ordering linked # to main program (Above is just a short description of what the script can do, more documentation is in the script comments.) Two files containing several new tests, elf/dso-sort-tests-[12].def are added, including test scenarios for BZ #15311 and Redhat issue #1162810 [1]. Due to the nature of dynamic loader tests, where the sorting behavior and test output occurs before/after main(), generating testcases to use support/test-driver.c does not suffice to control meaningful timeout for ld.so. Therefore a new utility program 'support/test-run-command', based on test-driver.c/support_test_main.c has been added. This does the same testcase control, but for a program specified through a command-line rather than at the source code level. This utility is used to run the dynamic loader testcases generated by dso-ordering-test.py. [1] https://bugzilla.redhat.com/show_bug.cgi?id=1162810 Signed-off-by: Chung-Lin Tang <cltang@codesourcery.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-10-21 13:41:21 +00:00
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<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).
# Final destructor order is indeterminate due to the cycle.
tst-bz28937: {+a;+b;-b;+c;%c};a->a1;a->a2;a2->a;b->b1;c->a1;c=>a1
output(glibc.rtld.dynamic_sort=1): {+a[a2>a1>a>];+b[b1>b>];-b[<b<b1];+c[c>];%c(a1());}<a<a2<c<a1
output(glibc.rtld.dynamic_sort=2): {+a[a2>a1>a>];+b[b1>b>];-b[<b<b1];+c[c>];%c(a1());}<a2<a<c<a1