[PATCH] btrace, vdso: add vdso target sections

Markus Metzger
2014-04-04T08:53:15Z

When loading symbols for the vdso, also add its sections to target_sections.

This fixes an issue with record btrace where vdso instructions could not be
disassembled during replay.

2014-04-04 Markus Metzger <markus.t.metzger@intel.com>

* symfile-mem.c (symbol_file_add_from_memory): Add add_sections
parameter. Add BFD sections. Adjust all callers.
(struct symbol_file_add_from_memory_args): Add add_sections field.

testsuite/
* gdb.btrace/vdso.c: New.
* gdb.btrace/vdso.exp: New.

---
gdb/symfile-mem.c | 33 ++++++++++++++++++++++++----
gdb/testsuite/gdb.btrace/vdso.c | 30 +++++++++++++++++++++++++
gdb/testsuite/gdb.btrace/vdso.exp | 46 +++++++++++++++++++++++++++++++++++++++
3 files changed, 105 insertions(+), 4 deletions(-)
create mode 100644 gdb/testsuite/gdb.btrace/vdso.c
create mode 100644 gdb/testsuite/gdb.btrace/vdso.exp

diff --git a/gdb/symfile-mem.c b/gdb/symfile-mem.c
index 3f09c4d..6f67cd8 100644
--- a/gdb/symfile-mem.c
+++ b/gdb/symfile-mem.c
@@ -80,10 +80,12 @@ target_read_memory_bfd (bfd_vma memaddr, bfd_byte *myaddr, bfd_size_type len)
non-zero, is the known size of the object. TEMPL is a bfd
representing the target's format. NAME is the name to use for this
symbol file in messages; it can be NULL or a malloc-allocated string
- which will be attached to the BFD. */
+ which will be attached to the BFD. If ADD_SECTIONS is non-zero,
+ add the sections of the loaded BFD. */
static struct objfile *
symbol_file_add_from_memory (struct bfd *templ, CORE_ADDR addr,
- size_t size, char *name, int from_tty)
+ size_t size, char *name, int add_sections,
+ int from_tty)
{
struct objfile *objf;
struct bfd *nbfd;
@@ -131,6 +133,27 @@ symbol_file_add_from_memory (struct bfd *templ, CORE_ADDR addr,
from_tty ? SYMFILE_VERBOSE : 0,
sai, OBJF_SHARED, NULL);

+ if (add_sections)
+ {
+ struct target_section *sections, *sections_end, *tsec;
+
+ sections = NULL;
+ sections_end = NULL;
+ make_cleanup (xfree, sections);
+
+ if (build_section_table (nbfd, &sections, &sections_end) == 0)
+ {
+ /* Adjust the target section addresses by the load address. */
+ for (tsec = sections; tsec != sections_end; ++tsec)
+ {
+ tsec->addr += loadbase;
+ tsec->endaddr += loadbase;
+ }
+
+ add_target_sections (&nbfd, sections, sections_end);
+ }
+ }
+
/* This might change our ideas about frames already looked at. */
reinit_frame_cache ();

@@ -159,7 +182,7 @@ add_symbol_file_from_memory_command (char *args, int from_tty)
error (_("Must use symbol-file or exec-file "
"before add-symbol-file-from-memory."));

- symbol_file_add_from_memory (templ, addr, 0, NULL, from_tty);
+ symbol_file_add_from_memory (templ, addr, 0, NULL, 0, from_tty);
}

/* Arguments for symbol_file_add_from_memory_wrapper. */
@@ -171,6 +194,7 @@ struct symbol_file_add_from_memory_args
size_t size;
char *name;
int from_tty;
+ int add_sections;
};

/* Wrapper function for symbol_file_add_from_memory, for
@@ -182,7 +206,7 @@ symbol_file_add_from_memory_wrapper (struct ui_out *uiout, void *data)
struct symbol_file_add_from_memory_args *args = data;

symbol_file_add_from_memory (args->bfd, args->sysinfo_ehdr, args->size,
- args->name, args->from_tty);
+ args->name, args->add_sections, args->from_tty);
return 0;
}

@@ -247,6 +271,7 @@ add_vsyscall_page (struct target_ops *target, int from_tty)
vsyscall DSO was not triggered by the user, even if the user
typed "run" at the TTY. */
args.from_tty = 0;
+ args.add_sections = 1;
catch_exceptions (current_uiout, symbol_file_add_from_memory_wrapper,
&args, RETURN_MASK_ALL);
}
diff --git a/gdb/testsuite/gdb.btrace/vdso.c b/gdb/testsuite/gdb.btrace/vdso.c
new file mode 100644
index 0000000..3e73071
--- /dev/null
+++ b/gdb/testsuite/gdb.btrace/vdso.c
@@ -0,0 +1,30 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2014 Free Software Foundation, Inc.
+
+ Contributed by Intel Corp. <markus.t.metzger@intel.com>
+
+ 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 <sys/time.h>
+
+int
+main (void)
+{
+ struct timeval tv;
+
+ gettimeofday (&tv, 0);
+
+ return 0;
+}
diff --git a/gdb/testsuite/gdb.btrace/vdso.exp b/gdb/testsuite/gdb.btrace/vdso.exp
new file mode 100644
index 0000000..2f415ff
--- /dev/null
+++ b/gdb/testsuite/gdb.btrace/vdso.exp
@@ -0,0 +1,46 @@
+# This testcase is part of GDB, the GNU debugger.
+#
+# Copyright 2014 Free Software Foundation, Inc.
+#
+# Contributed by Intel Corp. <markus.t.metzger@intel.com>
+#
+# 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/>.
+#
+#
+# Test that we can access the vdso memory during replay for stepping.
+
+# check for btrace support
+if { [skip_btrace_tests] } { return -1 }
+
+# start inferior
+standard_testfile
+if [prepare_for_testing $testfile.exp $testfile $srcfile] {
+ return -1
+}
+if ![runto_main] {
+ return -1
+}
+
+# trace the test code
+gdb_test_no_output "record btrace"
+gdb_test "next"
+
+# start replaying
+gdb_test "reverse-stepi"
+
+# disassemble the code around the current PC
+gdb_test "disassemble \$pc, +10" [join [list \
+ ".*" \
+ "End of assembler dump\." \
+ ] "\r\n"]
--
1.8.3.1