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1#!/bin/sh
2# SPDX-License-Identifier: GPL-2.0-or-later
3# Copyright (C) 2017 Red Hat, Inc.
4# Regression test if the vsyscall and vdso VMA regions are reported correctly.
5#
6# While [vsyscall] is mostly deprecated with newer systems, there is
7# still plenty of kernels compiled with CONFIG_LEGACY_VSYSCALL_NATIVE and
8# CONFIG_LEGACY_VSYSCALL_EMULATE (see linux/arch/x86/Kconfig for option
9# descriptions). First part of the test will check eligible kernels for
10# regression for a bug fixed by commit 103efcd9aac1 (fix perms/range of
11# vsyscall vma in /proc/*/maps).
12#
13# Second part of test checks [vdso] VMA permissions (fixed with commits
14# b6558c4a2378 (fix [vdso] page permissions) and e5b97dde514f (Add
15# VM_ALWAYSDUMP)). As a consequence of this bug, VMAs were not included
16# in core dumps which resulted in eg. incomplete backtraces and invalid
17# core dump files created by gdb.
18
19TST_SETUP=setup
20TST_CLEANUP=cleanup
21TST_TESTFUNC=vma_report_check
22TST_NEEDS_ROOT=1
23TST_NEEDS_TMPDIR=1
24TST_NEEDS_CMDS="gdb"
25
26. tst_test.sh
27
28CORE_LIMIT=$(ulimit -c)
29CORE_PATTERN=$(cat /proc/sys/kernel/core_pattern)
30
31setup()
32{
33	ulimit -c unlimited
34	echo "core" > /proc/sys/kernel/core_pattern
35}
36
37cleanup()
38{
39	ulimit -c "$CORE_LIMIT"
40	echo "$CORE_PATTERN" > /proc/sys/kernel/core_pattern
41}
42
43vma_report_check()
44{
45	if [ $(uname -m) = "x86_64" ]; then
46		if LINE=$(grep "vsyscall" /proc/self/maps); then
47			RIGHT="ffffffffff600000-ffffffffff601000[[:space:]][r-]-xp"
48			if echo "$LINE" | grep -q "$RIGHT"; then
49				tst_res TPASS "[vsyscall] reported correctly"
50			else
51				tst_res TFAIL "[vsyscall] reporting wrong"
52			fi
53		fi
54	fi
55
56	rm -rf core*
57	{ vma05_vdso; } > /dev/null 2>&1
58	TRACE=$(gdb -silent -ex="thread apply all backtrace" -ex="quit"\
59		vma05_vdso ./core* 2> /dev/null)
60	if echo "$TRACE" | grep -qF "??"; then
61		tst_res TFAIL "[vdso] bug not patched"
62	else
63		tst_res TPASS "[vdso] backtrace complete"
64	fi
65}
66
67tst_run
68