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Re: [patch 14/15] PIE: Fix back valgrind --db-attach=yes [fixup]
On Wed, 13 Jan 2010 22:08:21 +0100, Tom Tromey wrote:
> >>>>> "Jan" == Jan Kratochvil <jan.kratochvil@redhat.com> writes:
> Jan> gdb/
> Jan> Support Valgrind attachments broken by the PIE support.
> Jan> * auxv.c: Include gdbcore.h.
> Jan> (procfs_xfer_auxv): Make static. Reduce its comment. Drop its
> Jan> parameters ops, object and annex. Remove their assertions.
> Jan> (ld_so_xfer_auxv, memory_xfer_auxv): New function.
> Jan> * auxv.h (procfs_xfer_auxv): Remove comment. Rename to ...
> Jan> (memory_xfer_auxv): ... here.
> Jan> * linux-nat.c (linux_xfer_partial): Rename procfs_xfer_auxv to
> Jan> memory_xfer_auxv.
> Jan> * procfs.c (procfs_xfer_partial): Likewise.
> Jan> * solib-svr4.c (svr4_relocate_main_executable): New prototype.
> Jan> (svr4_special_symbol_handling): Call svr4_relocate_main_executable.
> Jan> (svr4_solib_create_inferior_hook): Conditionalize the
> Jan> svr4_relocate_main_executable call.
> Jan> gdb/testsuite/
> Jan> * gdb.base/valgrind-db-attach.exp, gdb.base/valgrind-db-attach.c: New.
>
> Ok. Thanks.
Checked-in.
Thanks,
Jan
http://sourceware.org/ml/gdb-cvs/2010-01/msg00125.html
--- src/gdb/ChangeLog 2010/01/14 21:09:04 1.11249
+++ src/gdb/ChangeLog 2010/01/14 21:14:57 1.11250
@@ -1,5 +1,22 @@
2010-01-14 Jan Kratochvil <jan.kratochvil@redhat.com>
+ Support Valgrind attachments broken by the PIE support.
+ * auxv.c: Include gdbcore.h.
+ (procfs_xfer_auxv): Make static. Reduce its comment. Drop its
+ parameters ops, object and annex. Remove their assertions.
+ (ld_so_xfer_auxv, memory_xfer_auxv): New function.
+ * auxv.h (procfs_xfer_auxv): Remove comment. Rename to ...
+ (memory_xfer_auxv): ... here.
+ * linux-nat.c (linux_xfer_partial): Rename procfs_xfer_auxv to
+ memory_xfer_auxv.
+ * procfs.c (procfs_xfer_partial): Likewise.
+ * solib-svr4.c (svr4_relocate_main_executable): New prototype.
+ (svr4_special_symbol_handling): Call svr4_relocate_main_executable.
+ (svr4_solib_create_inferior_hook): Conditionalize the
+ svr4_relocate_main_executable call.
+
+2010-01-14 Jan Kratochvil <jan.kratochvil@redhat.com>
+
* solib-svr4.c (scan_dyntag): Remove variable dyn_addr. New variable
target_section. Find SECT in current_target_sections, gdb_assert it.
(elf_lookup_lib_symbol): Pass the binary file if given symfile_objfile.
--- src/gdb/auxv.c 2010/01/01 07:31:30 1.24
+++ src/gdb/auxv.c 2010/01/14 21:14:59 1.25
@@ -25,6 +25,7 @@
#include "inferior.h"
#include "valprint.h"
#include "gdb_assert.h"
+#include "gdbcore.h"
#include "auxv.h"
#include "elf/common.h"
@@ -33,15 +34,11 @@
#include <fcntl.h>
-/* This function is called like a to_xfer_partial hook, but must be
- called with TARGET_OBJECT_AUXV. It handles access via
- /proc/PID/auxv, which is a common method for native targets. */
+/* This function handles access via /proc/PID/auxv, which is a common method
+ for native targets. */
-LONGEST
-procfs_xfer_auxv (struct target_ops *ops,
- enum target_object object,
- const char *annex,
- gdb_byte *readbuf,
+static LONGEST
+procfs_xfer_auxv (gdb_byte *readbuf,
const gdb_byte *writebuf,
ULONGEST offset,
LONGEST len)
@@ -50,9 +47,6 @@
int fd;
LONGEST n;
- gdb_assert (object == TARGET_OBJECT_AUXV);
- gdb_assert (readbuf || writebuf);
-
pathname = xstrprintf ("/proc/%d/auxv", PIDGET (inferior_ptid));
fd = open (pathname, writebuf != NULL ? O_WRONLY : O_RDONLY);
xfree (pathname);
@@ -72,6 +66,143 @@
return n;
}
+/* This function handles access via ld.so's symbol `_dl_auxv'. */
+
+static LONGEST
+ld_so_xfer_auxv (gdb_byte *readbuf,
+ const gdb_byte *writebuf,
+ ULONGEST offset,
+ LONGEST len)
+{
+ struct minimal_symbol *msym;
+ CORE_ADDR data_address, pointer_address;
+ struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
+ size_t ptr_size = TYPE_LENGTH (ptr_type);
+ size_t auxv_pair_size = 2 * ptr_size;
+ gdb_byte *ptr_buf = alloca (ptr_size);
+ LONGEST retval;
+ size_t block;
+
+ msym = lookup_minimal_symbol ("_dl_auxv", NULL, NULL);
+ if (msym == NULL)
+ return -1;
+
+ if (MSYMBOL_SIZE (msym) != ptr_size)
+ return -1;
+
+ /* POINTER_ADDRESS is a location where the `_dl_auxv' variable resides.
+ DATA_ADDRESS is the inferior value present in `_dl_auxv', therefore the
+ real inferior AUXV address. */
+
+ pointer_address = SYMBOL_VALUE_ADDRESS (msym);
+
+ data_address = read_memory_typed_address (pointer_address, ptr_type);
+
+ /* Possibly still not initialized such as during an inferior startup. */
+ if (data_address == 0)
+ return -1;
+
+ data_address += offset;
+
+ if (writebuf != NULL)
+ {
+ if (target_write_memory (data_address, writebuf, len) == 0)
+ return len;
+ else
+ return -1;
+ }
+
+ /* Stop if trying to read past the existing AUXV block. The final AT_NULL
+ was already returned before. */
+
+ if (offset >= auxv_pair_size)
+ {
+ if (target_read_memory (data_address - auxv_pair_size, ptr_buf,
+ ptr_size) != 0)
+ return -1;
+
+ if (extract_typed_address (ptr_buf, ptr_type) == AT_NULL)
+ return 0;
+ }
+
+ retval = 0;
+ block = 0x400;
+ gdb_assert (block % auxv_pair_size == 0);
+
+ while (len > 0)
+ {
+ if (block > len)
+ block = len;
+
+ /* Reading sizes smaller than AUXV_PAIR_SIZE is not supported. Tails
+ unaligned to AUXV_PAIR_SIZE will not be read during a call (they
+ should be completed during next read with new/extended buffer). */
+
+ block &= -auxv_pair_size;
+ if (block == 0)
+ return retval;
+
+ if (target_read_memory (data_address, readbuf, block) != 0)
+ {
+ if (block <= auxv_pair_size)
+ return retval;
+
+ block = auxv_pair_size;
+ continue;
+ }
+
+ data_address += block;
+ len -= block;
+
+ /* Check terminal AT_NULL. This function is being called indefinitely
+ being extended its READBUF until it returns EOF (0). */
+
+ while (block >= auxv_pair_size)
+ {
+ retval += auxv_pair_size;
+
+ if (extract_typed_address (readbuf, ptr_type) == AT_NULL)
+ return retval;
+
+ readbuf += auxv_pair_size;
+ block -= auxv_pair_size;
+ }
+ }
+
+ return retval;
+}
+
+/* This function is called like a to_xfer_partial hook, but must be
+ called with TARGET_OBJECT_AUXV. It handles access to AUXV. */
+
+LONGEST
+memory_xfer_auxv (struct target_ops *ops,
+ enum target_object object,
+ const char *annex,
+ gdb_byte *readbuf,
+ const gdb_byte *writebuf,
+ ULONGEST offset,
+ LONGEST len)
+{
+ gdb_assert (object == TARGET_OBJECT_AUXV);
+ gdb_assert (readbuf || writebuf);
+
+ /* ld_so_xfer_auxv is the only function safe for virtual executables being
+ executed by valgrind's memcheck. As using ld_so_xfer_auxv is problematic
+ during inferior startup GDB does call it only for attached processes. */
+
+ if (current_inferior ()->attach_flag != 0)
+ {
+ LONGEST retval;
+
+ retval = ld_so_xfer_auxv (readbuf, writebuf, offset, len);
+ if (retval != -1)
+ return retval;
+ }
+
+ return procfs_xfer_auxv (readbuf, writebuf, offset, len);
+}
+
/* Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
Return 0 if *READPTR is already at the end of the buffer.
Return -1 if there is insufficient buffer for a whole entry.
--- src/gdb/auxv.h 2010/01/01 07:31:30 1.10
+++ src/gdb/auxv.h 2010/01/14 21:14:59 1.11
@@ -43,11 +43,7 @@
/* Print the contents of the target's AUXV on the specified file. */
extern int fprint_target_auxv (struct ui_file *file, struct target_ops *ops);
-/* This function is called like a to_xfer_partial hook, but must be
- called with TARGET_OBJECT_AUXV. It handles access via
- /proc/PID/auxv, which is a common method for native targets. */
-
-extern LONGEST procfs_xfer_auxv (struct target_ops *ops,
+extern LONGEST memory_xfer_auxv (struct target_ops *ops,
enum target_object object,
const char *annex,
gdb_byte *readbuf,
--- src/gdb/linux-nat.c 2010/01/12 21:40:24 1.160
+++ src/gdb/linux-nat.c 2010/01/14 21:14:59 1.161
@@ -5009,7 +5009,7 @@
LONGEST xfer;
if (object == TARGET_OBJECT_AUXV)
- return procfs_xfer_auxv (ops, object, annex, readbuf, writebuf,
+ return memory_xfer_auxv (ops, object, annex, readbuf, writebuf,
offset, len);
if (object == TARGET_OBJECT_OSDATA)
--- src/gdb/procfs.c 2010/01/09 04:44:02 1.124
+++ src/gdb/procfs.c 2010/01/14 21:15:00 1.125
@@ -4387,7 +4387,7 @@
#ifdef NEW_PROC_API
case TARGET_OBJECT_AUXV:
- return procfs_xfer_auxv (ops, object, annex, readbuf, writebuf,
+ return memory_xfer_auxv (ops, object, annex, readbuf, writebuf,
offset, len);
#endif
--- src/gdb/solib-svr4.c 2010/01/14 21:09:04 1.113
+++ src/gdb/solib-svr4.c 2010/01/14 21:15:00 1.114
@@ -50,6 +50,7 @@
static struct link_map_offsets *svr4_fetch_link_map_offsets (void);
static int svr4_have_link_map_offsets (void);
+static void svr4_relocate_main_executable (void);
/* Link map info to include in an allocated so_list entry */
@@ -1540,6 +1541,7 @@
static void
svr4_special_symbol_handling (void)
{
+ svr4_relocate_main_executable ();
}
/* Decide if the objfile needs to be relocated. As indicated above,
@@ -1729,7 +1731,8 @@
info = get_svr4_info ();
/* Relocate the main executable if necessary. */
- svr4_relocate_main_executable ();
+ if (current_inferior ()->attach_flag == 0)
+ svr4_relocate_main_executable ();
if (!svr4_have_link_map_offsets ())
return;
--- src/gdb/testsuite/ChangeLog 2010/01/14 21:11:59 1.2087
+++ src/gdb/testsuite/ChangeLog 2010/01/14 21:15:00 1.2088
@@ -1,5 +1,9 @@
2010-01-14 Jan Kratochvil <jan.kratochvil@redhat.com>
+ * gdb.base/valgrind-db-attach.exp, gdb.base/valgrind-db-attach.c: New.
+
+2010-01-14 Jan Kratochvil <jan.kratochvil@redhat.com>
+
* gdb.base/break-interp-lib.c: Include unistd.h, assert.h and stdio.h.
(libfunc): New parameter action. Implement also selectable "sleep".
* gdb.base/break-interp-main.c: Include assert.h.
--- src/gdb/testsuite/gdb.base/valgrind-db-attach.c
+++ src/gdb/testsuite/gdb.base/valgrind-db-attach.c 2010-01-14 21:15:38.712924000 +0000
@@ -0,0 +1,30 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2009 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 <stdlib.h>
+
+int main()
+{
+ void *p;
+
+ p = malloc (1);
+ if (p == NULL)
+ return 1;
+ free (p);
+ free (p); /* double-free */
+ return 0;
+}
--- src/gdb/testsuite/gdb.base/valgrind-db-attach.exp
+++ src/gdb/testsuite/gdb.base/valgrind-db-attach.exp 2010-01-14 21:15:39.281560000 +0000
@@ -0,0 +1,76 @@
+# Copyright 2009 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/>.
+
+set test valgrind-db-attach
+set srcfile $test.c
+set executable $test
+set binfile ${objdir}/${subdir}/${executable}
+if {[build_executable $test.exp $executable $srcfile {debug}] == -1} {
+ return -1
+}
+
+gdb_exit
+
+# remote_spawn breaks the command on each whitespace despite possible quoting.
+# Use backslash-escaped whitespace there instead:
+
+set db_command "--db-command=$GDB $INTERNAL_GDBFLAGS $GDBFLAGS [host_info gdb_opts] %f %p"
+regsub -all " " $db_command "\\ " db_command
+
+set test "spawn valgrind"
+set cmd "valgrind --db-attach=yes $db_command $binfile"
+set res [remote_spawn host $cmd];
+if { $res < 0 || $res == "" } {
+ verbose -log "Spawning $cmd failed."
+ setup_xfail *-*-*
+ fail $test
+ return -1
+}
+pass $test
+# Declare GDB now as running.
+set gdb_spawn_id -1
+
+set test "valgrind started"
+# The trailing '.' differs for different memcheck versions.
+gdb_test_multiple "" $test {
+ -re "Memcheck, a memory error detector\\.?\r\n" {
+ pass $test
+ }
+ -re "valgrind: failed to start tool 'memcheck' for platform '.*': No such file or directory" {
+ setup_xfail *-*-*
+ fail $test
+ return -1
+ }
+}
+
+set double_free [gdb_get_line_number "double-free"]
+
+gdb_test_multiple "" $test {
+ -re "Invalid free\\(\\) / delete / delete\\\[\\\]\r\n.*: main \\(${srcfile}:$double_free\\)\r\n.*---- Attach to debugger \\? --- \[^\r\n\]* ---- " {
+ send_gdb "y\r"
+ }
+ -re "---- Attach to debugger \\? --- \[^\r\n\]* ---- " {
+ send_gdb "n\r"
+ exp_continue
+ }
+}
+
+gdb_test "" "" "eat first prompt"
+
+# Initialization from default_gdb_start.
+gdb_test "set height 0"
+gdb_test "set width 0"
+
+gdb_test "bt" "in main \\(.*\\) at .*${srcfile}:$double_free"