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authorMike Gulick <mike.gulick@mathworks.com>2017-10-30 18:13:44 -0400
committerSimon Marchi <simon.marchi@ericsson.com>2018-01-17 12:54:59 -0500
commit416675305692976aca45860e24b963982a2e682a (patch)
tree5999c0ba0fccc5fdffa709272d61b791747b3abd /gdb
parent4d9b86e17505063c96a01d40cdf5b4fc2080a798 (diff)
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Fix gdb segv when objfile can't be opened
This fixes PR 16577. This patch changes gdb_bfd_map_section to issue a warning rather than an error if it is unable to read the object file, and sets the size of the section/frame that it attempted to read to 0 on error. The description of gdb_bfd_map_section states that it will try to read or map the contents of the section SECT, and if successful, the section data is returned and *SIZE is set to the size of the section data. This function was throwing an error and leaving *SIZE as-is. Setting the section size to 0 indicates to dwarf2_build_frame_info that there is no data to read, otherwise it will try to read from an invalid frame pointer. Changing the error to a warning allows this to be handled gracefully. Additionally, the error was clobbering the breakpoint output indicating the current frame (function name, arguments, source file, and line number). E.g. Thread 3 "foo" hit Breakpoint 1, BFD: reopening /tmp/jna-1013829440/jna2973250704389291330.tmp: No such file or directory BFD: reopening /tmp/jna-1013829440/jna2973250704389291330.tmp: No such file or directory (gdb) While the "BFD: reopening ..." messages will still appear interspersed in the breakpoint output, the current frame info is now displayed: Thread 3 "foo" hit Breakpoint 1, BFD: reopening /tmp/jna-1013829440/jna1875755897659885075.tmp: No such file or directory BFD: reopening /tmp/jna-1013829440/jna1875755897659885075.tmp: No such file or directory warning: Can't read data for section '.eh_frame' in file '/tmp/jna-1013829440/jna1875755897659885075.tmp' do_something () at file.cpp:80 80 { (gdb)
Diffstat (limited to 'gdb')
-rw-r--r--gdb/ChangeLog8
-rw-r--r--gdb/gdb_bfd.c12
-rw-r--r--gdb/gdb_bfd.h17
-rw-r--r--gdb/testsuite/ChangeLog8
-rw-r--r--gdb/testsuite/gdb.base/solib-vanish-lib1.c24
-rw-r--r--gdb/testsuite/gdb.base/solib-vanish-lib2.c22
-rw-r--r--gdb/testsuite/gdb.base/solib-vanish-main.c75
-rw-r--r--gdb/testsuite/gdb.base/solib-vanish.exp107
8 files changed, 261 insertions, 12 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index bfd3492..76e6548 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,11 @@
+2017-10-30 Mike Gulick <mgulick@mathworks.com>
+
+ PR gdb/16577
+ * gdb_bfd.c (gdb_bfd_map_section): If unable to read object file, issue
+ a warning instead of throwing an error, set section size to 0 and return
+ NULL.
+ * gdb_bfd.h (gdb_bfd_map_section): Update description.
+
2018-01-17 Simon Marchi <simon.marchi@ericsson.com>
* nat/linux-ptrace.h (linux_ptrace_attach_fail_reason): Return
diff --git a/gdb/gdb_bfd.c b/gdb/gdb_bfd.c
index 80ddd42..02b1375 100644
--- a/gdb/gdb_bfd.c
+++ b/gdb/gdb_bfd.c
@@ -702,9 +702,15 @@ gdb_bfd_map_section (asection *sectp, bfd_size_type *size)
data = NULL;
if (!bfd_get_full_section_contents (abfd, sectp, &data))
- error (_("Can't read data for section '%s' in file '%s'"),
- bfd_get_section_name (abfd, sectp),
- bfd_get_filename (abfd));
+ {
+ warning (_("Can't read data for section '%s' in file '%s'"),
+ bfd_get_section_name (abfd, sectp),
+ bfd_get_filename (abfd));
+ /* Set size to 0 to prevent further attempts to read the invalid
+ section. */
+ *size = 0;
+ return (const gdb_byte *) NULL;
+ }
descriptor->data = data;
done:
diff --git a/gdb/gdb_bfd.h b/gdb/gdb_bfd.h
index ea3fdeb..2e4ac2c 100644
--- a/gdb/gdb_bfd.h
+++ b/gdb/gdb_bfd.h
@@ -115,15 +115,14 @@ void gdb_bfd_mark_parent (bfd *child, bfd *parent);
void gdb_bfd_record_inclusion (bfd *includer, bfd *includee);
-/* Try to read or map the contents of the section SECT. If
- successful, the section data is returned and *SIZE is set to the
- size of the section data; this may not be the same as the size
- according to bfd_get_section_size if the section was compressed.
- The returned section data is associated with the BFD and will be
- destroyed when the BFD is destroyed. There is no other way to free
- it; for temporary uses of section data, see
- bfd_malloc_and_get_section. SECT may not have relocations. This
- function will throw on error. */
+/* Try to read or map the contents of the section SECT. If successful, the
+ section data is returned and *SIZE is set to the size of the section data;
+ this may not be the same as the size according to bfd_get_section_size if the
+ section was compressed. The returned section data is associated with the BFD
+ and will be destroyed when the BFD is destroyed. There is no other way to
+ free it; for temporary uses of section data, see bfd_malloc_and_get_section.
+ SECT may not have relocations. If there is an error reading the section,
+ this issues a warning, sets *SIZE to 0, and returns NULL. */
const gdb_byte *gdb_bfd_map_section (asection *section, bfd_size_type *size);
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index cd99b84..2eaec1c 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2017-10-30 Mike Gulick <mgulick@mathworks.com>
+
+ PR gdb/16577
+ * gdb.base/solib-vanish.exp: New.
+ * gdb.base/solib-vanish-main.c: New.
+ * gdb.base/solib-vanish-lib1.c: New.
+ * gdb.base/solib-vanish-lib2.c: New.
+
2018-01-17 Yao Qi <yao.qi@linaro.org>
* gdb.compile/compile.exp: Match the address printed for
diff --git a/gdb/testsuite/gdb.base/solib-vanish-lib1.c b/gdb/testsuite/gdb.base/solib-vanish-lib1.c
new file mode 100644
index 0000000..68c78ec
--- /dev/null
+++ b/gdb/testsuite/gdb.base/solib-vanish-lib1.c
@@ -0,0 +1,24 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ 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/>. */
+
+extern int bar (int);
+
+int
+foo (int x)
+{
+ return bar (x);
+}
diff --git a/gdb/testsuite/gdb.base/solib-vanish-lib2.c b/gdb/testsuite/gdb.base/solib-vanish-lib2.c
new file mode 100644
index 0000000..78fb4e2
--- /dev/null
+++ b/gdb/testsuite/gdb.base/solib-vanish-lib2.c
@@ -0,0 +1,22 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ 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/>. */
+
+int
+bar (int y)
+{
+ return y + 1; /* break here */
+}
diff --git a/gdb/testsuite/gdb.base/solib-vanish-main.c b/gdb/testsuite/gdb.base/solib-vanish-main.c
new file mode 100644
index 0000000..a00ee17
--- /dev/null
+++ b/gdb/testsuite/gdb.base/solib-vanish-main.c
@@ -0,0 +1,75 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ 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/>. */
+
+#include <dlfcn.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int
+main ()
+{
+ void *handle;
+ int (*foo) (int);
+ char *error;
+ char *dest = VANISH_LIB ".renamed";
+
+ /* Open library. */
+ handle = dlopen (VANISH_LIB, RTLD_NOW);
+ if (!handle)
+ {
+ fprintf (stderr, "%s\n", dlerror ());
+ exit (EXIT_FAILURE);
+ }
+
+ /* Clear any existing error */
+ dlerror ();
+
+ /* Simulate deleting file by renaming it. */
+ if (rename (VANISH_LIB, dest) == -1)
+ {
+ error = strerror (errno);
+ fprintf (stderr, "rename %s -> %s: %s\n", VANISH_LIB, dest, error);
+ exit (EXIT_FAILURE);
+ }
+
+ /* Get function pointer. */
+ foo = dlsym (handle, "foo");
+ error = dlerror ();
+ if (error != NULL)
+ {
+ fprintf (stderr, "%s\n", error);
+ exit (EXIT_FAILURE);
+ }
+
+ /* Call function. */
+ (*foo) (1);
+
+ /* Close and exit. */
+ dlclose (handle);
+
+ /* Put VANISH_LIB back where we found it. */
+ if (rename (dest, VANISH_LIB) == -1)
+ {
+ error = strerror (errno);
+ fprintf (stderr, "rename %s -> %s: %s\n", dest, VANISH_LIB, error);
+ exit (EXIT_FAILURE);
+ }
+
+ exit (EXIT_SUCCESS);
+}
diff --git a/gdb/testsuite/gdb.base/solib-vanish.exp b/gdb/testsuite/gdb.base/solib-vanish.exp
new file mode 100644
index 0000000..928ca4e
--- /dev/null
+++ b/gdb/testsuite/gdb.base/solib-vanish.exp
@@ -0,0 +1,107 @@
+# 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 test case verifies that GDB gracefully handles a shared library file
+# vanishing after being dlopen'ed. This consists of three nested function calls:
+#
+# main() -> foo() -> bar()
+#
+# where:
+# - foo exists in solib-vanish-lib1.so, which is dlopen'ed by main()
+# - bar exists in solib-vanish-lib2.so, which is dynamically linked into
+# solib-vanish-lib1.so
+#
+# Immediately after dlopen'ing solib-vanish-lib1.so, the so file is moved aside
+# by renaming. The main executable and solib-vanish-lib2.so are still
+# accessible.
+#
+# If a breakpoint is set on bar(), gdb throws an error when this breakpoint is
+# hit:
+#
+# (gdb) r
+# Starting program: /local/gdb/git/pr_16577_repro/simple/solib-vanish-main
+#
+# Breakpoint 1, BFD: reopening ./solib-vanish-lib1.so: No such file or directory
+#
+# BFD: reopening ./solib-vanish-lib1.so: No such file or directory
+#
+# (gdb)
+#
+# Notice that this does not print the current frame, i.e.:
+# bar (y=1) at solib-vanish-lib2.c:19
+# 19 return y + 1; /* break here */
+# (gdb)
+#
+# The current gdb git tip segfaults if we then try to step:
+# (gdb) n
+# Segmentation fault
+
+# This test verifies that:
+# 1) GDB does not segfault when stepping
+# 2) The stack frame is printed
+
+if { [skip_shlib_tests] } {
+ return 0
+}
+
+# Library 2
+set lib2name "solib-vanish-lib2"
+set srcfile_lib2 ${srcdir}/${subdir}/${lib2name}.c
+set binfile_lib2 [standard_output_file ${lib2name}.so]
+set lib2_flags {debug}
+
+# Library 1
+set lib1name "solib-vanish-lib1"
+set srcfile_lib1 ${srcdir}/${subdir}/${lib1name}.c
+set binfile_lib1 [standard_output_file ${lib1name}.so]
+set lib1_flags [list debug shlib=${binfile_lib2}]
+
+# Main program
+set testfile "solib-vanish-main"
+set srcfile ${srcdir}/${subdir}/${testfile}.c
+set executable ${testfile}
+set binfile [standard_output_file ${executable}]
+set bin_flags [list debug shlib_load additional_flags=-DVANISH_LIB=\"${binfile_lib1}\"]
+
+if { [gdb_compile_shlib ${srcfile_lib2} ${binfile_lib2} $lib2_flags] != ""
+ || [gdb_compile_shlib ${srcfile_lib1} ${binfile_lib1} $lib1_flags] != ""
+ || [gdb_compile ${srcfile} ${binfile} executable $bin_flags] != "" } {
+ untested "failed to compile"
+ return -1
+}
+
+clean_restart $testfile
+
+if { ![runto_main] } {
+ fail "can't run to main"
+ return
+}
+
+delete_breakpoints
+
+set lib2_lineno [gdb_get_line_number "break here" ${srcfile_lib2}]
+
+gdb_breakpoint "${lib2name}.c:${lib2_lineno}" {allow-pending}
+
+# Verify that both the location and source code are displayed
+gdb_continue_to_breakpoint "bar" \
+ ".*/${lib2name}.c:${lib2_lineno}.*break here.*"
+
+# This should not segfault
+gdb_test "next" \
+ "" \
+ "next succeeds"
+