From 9ef9e6a6a0dd8f948708cb67c9afcfd0be40cb0a Mon Sep 17 00:00:00 2001 From: Keith Seitz Date: Mon, 8 Feb 2016 12:57:22 -0800 Subject: [PATCH] breakpoints/19546: Fix crash after updating breakpoints One of the last checks update_breakpoints_after_exec does while looping over the list of breakpoints is check that the breakpoint has a valid location spec. It uses event_location_empty_p to check if the location spec is "empty", and if it is, the breakpoint is deleted. momentary_breakpoint types rely on setting the breakpoint structure's location spec to NULL, thereby causing an update to delete the breakpoint. However, event_location_empty_p assumed that locations were never NULL. As a result, GDB would crash dereferencing a NULL pointer whenever update_breakpoints_after_exec would encounter a momentary_breakpoint. This patch creates a new wrapper/helper function which tests that the given breakpoint's location spec is non-NULL and if it is not "empty" or "unspecified." gdb/ChangeLog PR breakpoints/19546 * breakpoint.c (breakpoint_event_location_empty_p): New function. (update_breakpoints_after_exec, bkpt_re_set): Use this new function instead of event_location_empty_p. gdb/testsuite/ChangeLog PR breakpoints/19546 * gdb.base/infcall-exec.c: New file. * gdb.base/infcall-exec2.c: New file. * gdb.base/infcall-exec.exp: New file. --- gdb/ChangeLog | 7 ++++ gdb/breakpoint.c | 12 +++++-- gdb/testsuite/ChangeLog | 7 ++++ gdb/testsuite/gdb.base/infcall-exec.c | 28 +++++++++++++++ gdb/testsuite/gdb.base/infcall-exec.exp | 48 +++++++++++++++++++++++++ gdb/testsuite/gdb.base/infcall-exec2.c | 22 ++++++++++++ 6 files changed, 122 insertions(+), 2 deletions(-) create mode 100644 gdb/testsuite/gdb.base/infcall-exec.c create mode 100644 gdb/testsuite/gdb.base/infcall-exec.exp create mode 100644 gdb/testsuite/gdb.base/infcall-exec2.c diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 04daf07eef1..e10f54b2ea4 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +2016-02-09 Keith Seitz + + PR breakpoints/19546 + * breakpoint.c (breakpoint_event_location_empty_p): New function. + (update_breakpoints_after_exec, bkpt_re_set): Use this new function + instead of event_location_empty_p. + 2016-02-09 Keith Seitz * mi/mi-cmd-break.c (mi_cmd_break_insert_1): Use diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index c0598611382..f99a7ab46dd 100644 --- a/gdb/breakpoint.c +++ b/gdb/breakpoint.c @@ -3764,6 +3764,14 @@ create_exception_master_breakpoint (void) } } +/* Does B have a location spec? */ + +static int +breakpoint_event_location_empty_p (const struct breakpoint *b) +{ + return b->location != NULL && event_location_empty_p (b->location); +} + void update_breakpoints_after_exec (void) { @@ -3878,7 +3886,7 @@ update_breakpoints_after_exec (void) /* Without a symbolic address, we have little hope of the pre-exec() address meaning the same thing in the post-exec() a.out. */ - if (event_location_empty_p (b->location)) + if (breakpoint_event_location_empty_p (b)) { delete_breakpoint (b); continue; @@ -13063,7 +13071,7 @@ static void bkpt_re_set (struct breakpoint *b) { /* FIXME: is this still reachable? */ - if (event_location_empty_p (b->location)) + if (breakpoint_event_location_empty_p (b)) { /* Anything without a location can't be re-set. */ delete_breakpoint (b); diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index c4e082a23a4..c2e346613a3 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,10 @@ +2016-02-09 Keith Seitz + + PR breakpoints/19546 + * gdb.base/infcall-exec.c: New file. + * gdb.base/infcall-exec2.c: New file. + * gdb.base/infcall-exec.exp: New file. + 2016-02-09 Keith Seitz * gdb.guile/scm-breakpoint.exp (test_bkpt_address): New procedure. diff --git a/gdb/testsuite/gdb.base/infcall-exec.c b/gdb/testsuite/gdb.base/infcall-exec.c new file mode 100644 index 00000000000..6617934a491 --- /dev/null +++ b/gdb/testsuite/gdb.base/infcall-exec.c @@ -0,0 +1,28 @@ +/* This test program is part of GDB, the GNU debugger. + + Copyright 2016 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 . */ + +#include + +int +main (int argc, char ** argv) +{ + const char *prog = "inf-exec2"; + + execlp (prog, prog, (char *) 0); + + return 0; +} diff --git a/gdb/testsuite/gdb.base/infcall-exec.exp b/gdb/testsuite/gdb.base/infcall-exec.exp new file mode 100644 index 00000000000..7b937fc33ca --- /dev/null +++ b/gdb/testsuite/gdb.base/infcall-exec.exp @@ -0,0 +1,48 @@ +# Copyright 2016 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 . + +# Test an inferior function call which execs a new program. +# This is a test for breakpoints/19546. + +standard_testfile + +set testfile2 "infcall-exec2" +set srcfile2 "${testfile2}.c" +set binfile2 [standard_output_file $testfile2] + +# Build the two executables for the test. +if {[gdb_compile $srcdir/$subdir/$srcfile $binfile executable debug] != ""} { + untested "could not build $binfile" + return -1 +} +if {[gdb_compile $srcdir/$subdir/$srcfile2 $binfile2 executable debug] != ""} { + untested "could not build $binfile2" + return -1 +} + +clean_restart $binfile + +if {![runto_main]} { + untested "could not run to main" + return -1 +} + +set expected_result "process $decimal is executing new program: $binfile2" +append expected_result "\[\r\n\]+.*" +append expected_result "Breakpoint 1, main .*at .*$srcfile2:$decimal" +append expected_result ".*" + +gdb_test "call execlp \(\"$binfile2\", \"$binfile2\", \(char \*\)0\)" \ + $expected_result "call execlp" diff --git a/gdb/testsuite/gdb.base/infcall-exec2.c b/gdb/testsuite/gdb.base/infcall-exec2.c new file mode 100644 index 00000000000..bb2a008bdb2 --- /dev/null +++ b/gdb/testsuite/gdb.base/infcall-exec2.c @@ -0,0 +1,22 @@ +/* This test program is part of GDB, the GNU debugger. + + Copyright 2016 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 . */ + +int +main (int argc, char ** argv) +{ + return 0; +} -- 2.30.2