gdb/testsuite/gdb.base/libsegfault.exp

# Copyright 2017-2018 Free Software Foundation, Inc.

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# This file is part of the gdb testsuite.

# Test that GDB tolerates being started with libSegFault.so preloaded
# with LD_PRELOAD, and that GDB warns about a custom SIGSEGV custom
# handler.  See PR gdb/18653
# <https://sourceware.org/bugzilla/show_bug.cgi?id=18653#c7>.

# We cannot expect remote hosts to see environment variables set on
# the local machine.
if { [is_remote host] } {
    unsupported "can't set environment variables on remote host"
    return -1
}

# Spawn GDB with LIB preloaded with LD_PRELOAD.  CMDLINE_OPTS are
# command line options passed to GDB.

proc gdb_spawn_with_ld_preload {lib cmdline_opts} {
    global env

    save_vars { env(LD_PRELOAD) } {
	if { ![info exists env(LD_PRELOAD) ]
	     || $env(LD_PRELOAD) == "" } {
	    set env(LD_PRELOAD) "$lib"
	} else {
	    append env(LD_PRELOAD) ":$lib"
	}

	gdb_spawn_with_cmdline_opts $cmdline_opts
    }
}

proc test_libsegfault {} {
    global gdb_prompt

    set libsegfault "libSegFault.so"

    # When started normally, if libSegFault.so is preloaded, GDB
    # should warn about not being able to propagate the signal
    # disposition of SIGSEGV.
    gdb_exit
    gdb_spawn_with_ld_preload $libsegfault ""

    set test "gdb emits custom handler warning"
    gdb_test_multiple "" $test {
	-re "cannot be preloaded.*\r\n$gdb_prompt $" {
	    # Glibc 2.22 outputs:
	    # ERROR: ld.so: object 'libSegFault.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored.
	    untested "cannot preload libSegFault.so"
	    return
	}
	-re "Found custom handler.*won't be propagated.*\r\n$gdb_prompt $" {
	    pass $test
	}
    }

    # "-q" should disable the warning, though.
    gdb_exit
    gdb_spawn_with_ld_preload $libsegfault "-q"

    set test "quiet suppresses custom handler warning"
    gdb_test_multiple "" $test {
	-re "^$gdb_prompt $" {
	    pass $test
	}
    }
}

test_libsegfault