OpenE2K
/
binutils-gdb
12
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Fix "Remote 'g' packet reply is too long" problems with multiple inferiors 

When debugging two inferiors (or more) against gdbserver, and the
inferiors have different architectures, such as e.g., on x86_64
GNU/Linux and one inferior is 64-bit while the other is 32-bit, then
GDB can get confused with the different architectures in a couple
spots.

In both cases I ran into, GDB incorrectly ended up using the
architecture of whatever happens to be the selected inferior instead
of the architecture of some other given inferior:

#1 - When parsing the expedited registers in stop replies.

#2 - In the default implementation of the target_thread_architecture
     target method.

These resulted in instances of the infamous "Remote 'g' packet reply
is too long" error.  For example, with the test added in this commit,
we get:

~~~
  Continuing.
  Remote 'g' packet reply is too long (expected 440 bytes, got 816 bytes): ad064000000000000[snip]
  (gdb) FAIL: gdb.multi/multi-arch.exp: inf1 event with inf2 selected: continue to hello_loop

  c
  Continuing.
  Truncated register 50 in remote 'g' packet
  (gdb) PASS: gdb.multi/multi-arch.exp: inf2 event with inf1 selected: c
~~~

This commit fixes that.

gdb/ChangeLog:
2017-10-04  Pedro Alves  <palves@redhat.com>

	* remote.c (get_remote_arch_state): New 'gdbarch' parameter.  Use
	it instead of target_gdbarch.
	(get_remote_state, get_remote_packet_size): Adjust
	get_remote_arch_state calls, passing down target_gdbarch
	explicitly.
	(packet_reg_from_regnum, packet_reg_from_pnum): New parameter
	'gdbarch' and use it instead of target_gdbarch.
	(get_memory_packet_size): Adjust get_remote_arch_state calls,
	passing down target_gdbarch explicitly.
	(struct stop_reply) <arch>: New field.
	(remote_parse_stop_reply): Use the stopped thread's architecture,
	not the current inferior's.  Save the architecture in the
	stop_reply.
	(process_stop_reply): Use the stop reply's architecture.
	(process_g_packet, remote_fetch_registers)
	(remote_prepare_to_store, store_registers_using_G)
	(remote_store_registers): Adjust get_remote_arch_state calls,
	using the regcache's architecture.
	(remote_get_trace_status): Adjust get_remote_arch_state calls,
	passing down target_gdbarch explicitly.
	* spu-multiarch.c (spu_thread_architecture): Defer to the target
	beneath instead of calling target_gdbarch.
	* target.c (default_thread_architecture): Use the specified
	inferior's architecture, instead of the current inferior's
	architecture (via target_gdbarch).

gdb/testsuite/ChangeLog:
2017-10-04  Pedro Alves  <palves@redhat.com>

	* gdb.multi/hangout.c: Include <unistd.h>.
	(hangout_loop): New function.
	(main): Call alarm.  Call hangout_loop in a loop.
	* gdb.multi/hello.c: Include <unistd.h>.
	(hello_loop): New function.
	(main): Call alarm.  Call hangout_loop in a loop.
	* gdb.multi/multi-arch.exp: Test running to a breakpoint one
	inferior with the other selected.
This commit is contained in:
Pedro Alves 2017-10-04 18:21:10 +01:00
parent ed4227b7c6
commit 5cd63fda03
8 changed files with 169 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
gdb/ChangeLog
View File

@ -1,3 +1,31 @@
2017-10-04 Pedro Alves <palves@redhat.com>
* remote.c (get_remote_arch_state): New 'gdbarch' parameter. Use
it instead of target_gdbarch.
(get_remote_state, get_remote_packet_size): Adjust
get_remote_arch_state calls, passing down target_gdbarch
explicitly.
(packet_reg_from_regnum, packet_reg_from_pnum): New parameter
'gdbarch' and use it instead of target_gdbarch.
(get_memory_packet_size): Adjust get_remote_arch_state calls,
passing down target_gdbarch explicitly.
(struct stop_reply) <arch>: New field.
(remote_parse_stop_reply): Use the stopped thread's architecture,
not the current inferior's. Save the architecture in the
stop_reply.
(process_stop_reply): Use the stop reply's architecture.
(process_g_packet, remote_fetch_registers)
(remote_prepare_to_store, store_registers_using_G)
(remote_store_registers): Adjust get_remote_arch_state calls,
using the regcache's architecture.
(remote_get_trace_status): Adjust get_remote_arch_state calls,
passing down target_gdbarch explicitly.
* spu-multiarch.c (spu_thread_architecture): Defer to the target
beneath instead of calling target_gdbarch.
* target.c (default_thread_architecture): Use the specified
inferior's architecture, instead of the current inferior's
architecture (via target_gdbarch).
2017-10-04 Pedro Alves <palves@redhat.com>
* regcache.c (get_thread_arch_regcache): Remove null_ptid special

100
gdb/remote.c
View File

@ -654,11 +654,11 @@ remote_get_noisy_reply ()
static struct gdbarch_data *remote_gdbarch_data_handle;
static struct remote_arch_state *
get_remote_arch_state (void)
get_remote_arch_state (struct gdbarch *gdbarch)
{
gdb_assert (target_gdbarch () != NULL);
gdb_assert (gdbarch != NULL);
return ((struct remote_arch_state *)
gdbarch_data (target_gdbarch (), remote_gdbarch_data_handle));
gdbarch_data (gdbarch, remote_gdbarch_data_handle));
}
/* Fetch the global remote target state. */
@ -671,7 +671,7 @@ get_remote_state (void)
function which calls getpkt also needs to be mindful of changes
to rs->buf, but this call limits the number of places which run
into trouble. */
get_remote_arch_state ();
get_remote_arch_state (target_gdbarch ());
return get_remote_state_raw ();
}
@ -878,7 +878,7 @@ static long
get_remote_packet_size (void)
{
struct remote_state *rs = get_remote_state ();
struct remote_arch_state *rsa = get_remote_arch_state ();
remote_arch_state *rsa = get_remote_arch_state (target_gdbarch ());
if (rs->explicit_packet_size)
return rs->explicit_packet_size;
@ -887,9 +887,10 @@ get_remote_packet_size (void)
}
static struct packet_reg *
packet_reg_from_regnum (struct remote_arch_state *rsa, long regnum)
packet_reg_from_regnum (struct gdbarch *gdbarch, struct remote_arch_state *rsa,
long regnum)
{
if (regnum < 0 && regnum >= gdbarch_num_regs (target_gdbarch ()))
if (regnum < 0 && regnum >= gdbarch_num_regs (gdbarch))
return NULL;
else
{
@ -901,11 +902,12 @@ packet_reg_from_regnum (struct remote_arch_state *rsa, long regnum)
}
static struct packet_reg *
packet_reg_from_pnum (struct remote_arch_state *rsa, LONGEST pnum)
packet_reg_from_pnum (struct gdbarch *gdbarch, struct remote_arch_state *rsa,
LONGEST pnum)
{
int i;
for (i = 0; i < gdbarch_num_regs (target_gdbarch ()); i++)
for (i = 0; i < gdbarch_num_regs (gdbarch); i++)
{
struct packet_reg *r = &rsa->regs[i];
@ -1049,7 +1051,7 @@ static long
get_memory_packet_size (struct memory_packet_config *config)
{
struct remote_state *rs = get_remote_state ();
struct remote_arch_state *rsa = get_remote_arch_state ();
remote_arch_state *rsa = get_remote_arch_state (target_gdbarch ());
long what_they_get;
if (config->fixed_p)
@ -6364,6 +6366,9 @@ typedef struct stop_reply
struct target_waitstatus ws;
/* The architecture associated with the expedited registers. */
gdbarch *arch;
/* Expedited registers. This makes remote debugging a bit more
efficient for those targets that provide critical registers as
part of their normal status mechanism (as another roundtrip to
@ -6838,7 +6843,7 @@ strprefix (const char *p, const char *pend, const char *prefix)
static void
remote_parse_stop_reply (char *buf, struct stop_reply *event)
{
struct remote_arch_state *rsa = get_remote_arch_state ();
remote_arch_state *rsa = NULL;
ULONGEST addr;
const char *p;
int skipregs = 0;
@ -7018,9 +7023,47 @@ Packet: '%s'\n"),
reason. */
if (p_temp == p1)
{
struct packet_reg *reg = packet_reg_from_pnum (rsa, pnum);
/* If we haven't parsed the event's thread yet, find
it now, in order to find the architecture of the
reported expedited registers. */
if (event->ptid == null_ptid)
{
const char *thr = strstr (p1 + 1, ";thread:");
if (thr != NULL)
event->ptid = read_ptid (thr + strlen (";thread:"),
NULL);
else
event->ptid = magic_null_ptid;
}
if (rsa == NULL)
{
inferior *inf = (event->ptid == null_ptid
? NULL
: find_inferior_ptid (event->ptid));
/* If this is the first time we learn anything
about this process, skip the registers
included in this packet, since we don't yet
know which architecture to use to parse them.
We'll determine the architecture later when
we process the stop reply and retrieve the
target description, via
remote_notice_new_inferior ->
post_create_inferior. */
if (inf == NULL)
{
p = strchrnul (p1 + 1, ';');
p++;
continue;
}
event->arch = inf->gdbarch;
rsa = get_remote_arch_state (event->arch);
}
packet_reg *reg
= packet_reg_from_pnum (event->arch, rsa, pnum);
cached_reg_t cached_reg;
struct gdbarch *gdbarch = target_gdbarch ();
if (reg == NULL)
error (_("Remote sent bad register number %s: %s\n\
@ -7029,13 +7072,13 @@ Packet: '%s'\n"),
cached_reg.num = reg->regnum;
cached_reg.data = (gdb_byte *)
xmalloc (register_size (gdbarch, reg->regnum));
xmalloc (register_size (event->arch, reg->regnum));
p = p1 + 1;
fieldsize = hex2bin (p, cached_reg.data,
register_size (gdbarch, reg->regnum));
register_size (event->arch, reg->regnum));
p += 2 * fieldsize;
if (fieldsize < register_size (gdbarch, reg->regnum))
if (fieldsize < register_size (event->arch, reg->regnum))
warning (_("Remote reply is too short: %s"), buf);
VEC_safe_push (cached_reg_t, event->regcache, &cached_reg);
@ -7251,7 +7294,7 @@ process_stop_reply (struct stop_reply *stop_reply,
if (stop_reply->regcache)
{
struct regcache *regcache
= get_thread_arch_regcache (ptid, target_gdbarch ());
= get_thread_arch_regcache (ptid, stop_reply->arch);
cached_reg_t *reg;
int ix;
@ -7608,7 +7651,7 @@ process_g_packet (struct regcache *regcache)
{
struct gdbarch *gdbarch = get_regcache_arch (regcache);
struct remote_state *rs = get_remote_state ();
struct remote_arch_state *rsa = get_remote_arch_state ();
remote_arch_state *rsa = get_remote_arch_state (gdbarch);
int i, buf_len;
char *p;
char *regs;
@ -7742,7 +7785,8 @@ static void
remote_fetch_registers (struct target_ops *ops,
struct regcache *regcache, int regnum)
{
struct remote_arch_state *rsa = get_remote_arch_state ();
struct gdbarch *gdbarch = get_regcache_arch (regcache);
remote_arch_state *rsa = get_remote_arch_state (gdbarch);
int i;
set_remote_traceframe ();
@ -7750,7 +7794,7 @@ remote_fetch_registers (struct target_ops *ops,
if (regnum >= 0)
{
struct packet_reg *reg = packet_reg_from_regnum (rsa, regnum);
packet_reg *reg = packet_reg_from_regnum (gdbarch, rsa, regnum);
gdb_assert (reg != NULL);
@ -7776,7 +7820,7 @@ remote_fetch_registers (struct target_ops *ops,
fetch_registers_using_g (regcache);
for (i = 0; i < gdbarch_num_regs (get_regcache_arch (regcache)); i++)
for (i = 0; i < gdbarch_num_regs (gdbarch); i++)
if (!rsa->regs[i].in_g_packet)
if (!fetch_register_using_p (regcache, &rsa->regs[i]))
{
@ -7792,7 +7836,7 @@ remote_fetch_registers (struct target_ops *ops,
static void
remote_prepare_to_store (struct target_ops *self, struct regcache *regcache)
{
struct remote_arch_state *rsa = get_remote_arch_state ();
remote_arch_state *rsa = get_remote_arch_state (regcache->arch ());
int i;
/* Make sure the entire registers array is valid. */
@ -7858,7 +7902,7 @@ static void
store_registers_using_G (const struct regcache *regcache)
{
struct remote_state *rs = get_remote_state ();
struct remote_arch_state *rsa = get_remote_arch_state ();
remote_arch_state *rsa = get_remote_arch_state (regcache->arch ());
gdb_byte *regs;
char *p;
@ -7897,7 +7941,8 @@ static void
remote_store_registers (struct target_ops *ops,
struct regcache *regcache, int regnum)
{
struct remote_arch_state *rsa = get_remote_arch_state ();
struct gdbarch *gdbarch = regcache->arch ();
remote_arch_state *rsa = get_remote_arch_state (gdbarch);
int i;
set_remote_traceframe ();
@ -7905,7 +7950,7 @@ remote_store_registers (struct target_ops *ops,
if (regnum >= 0)
{
struct packet_reg *reg = packet_reg_from_regnum (rsa, regnum);
packet_reg *reg = packet_reg_from_regnum (gdbarch, rsa, regnum);
gdb_assert (reg != NULL);
@ -7929,7 +7974,7 @@ remote_store_registers (struct target_ops *ops,
store_registers_using_G (regcache);
for (i = 0; i < gdbarch_num_regs (get_regcache_arch (regcache)); i++)
for (i = 0; i < gdbarch_num_regs (gdbarch); i++)
if (!rsa->regs[i].in_g_packet)
if (!store_register_using_P (regcache, &rsa->regs[i]))
/* See above for why we do not issue an error here. */
@ -12697,7 +12742,8 @@ remote_get_trace_status (struct target_ops *self, struct trace_status *ts)
if (packet_support (PACKET_qTStatus) == PACKET_DISABLE)
return -1;
trace_regblock_size = get_remote_arch_state ()->sizeof_g_packet;
trace_regblock_size
= get_remote_arch_state (target_gdbarch ())->sizeof_g_packet;
putpkt ("qTStatus");

3
gdb/spu-multiarch.c
View File

@ -121,7 +121,8 @@ spu_thread_architecture (struct target_ops *ops, ptid_t ptid)
if (parse_spufs_run (ptid, &spufs_fd, &spufs_addr))
return spu_gdbarch (spufs_fd);
return target_gdbarch ();
target_ops *beneath = find_target_beneath (ops);
return beneath->to_thread_architecture (beneath, ptid);
}
/* Override the to_region_ok_for_hw_watchpoint routine. */

4
gdb/target.c
View File

@ -3137,7 +3137,9 @@ default_watchpoint_addr_within_range (struct target_ops *target,
static struct gdbarch *
default_thread_architecture (struct target_ops *ops, ptid_t ptid)
{
return target_gdbarch ();
inferior *inf = find_inferior_ptid (ptid);
gdb_assert (inf != NULL);
return inf->gdbarch;
}
static int

11
gdb/testsuite/ChangeLog
View File

@ -1,3 +1,14 @@
2017-10-04 Pedro Alves <palves@redhat.com>
* gdb.multi/hangout.c: Include <unistd.h>.
(hangout_loop): New function.
(main): Call alarm. Call hangout_loop in a loop.
* gdb.multi/hello.c: Include <unistd.h>.
(hello_loop): New function.
(main): Call alarm. Call hangout_loop in a loop.
* gdb.multi/multi-arch.exp: Test running to a breakpoint one
inferior with the other selected.
2017-10-04 Simon Marchi <simon.marchi@ericsson.com>
* gdb.mi/list-thread-groups-available.exp: New file.

14
gdb/testsuite/gdb.multi/hangout.c
View File

@ -16,14 +16,28 @@
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <stdio.h>
#include <unistd.h>
static void
hangout_loop (void)
{
}
int
main(int argc, char *argv[])
{
int i;
alarm (30);
for (i = 0; i < argc; ++i)
{
printf("Arg %d is %s\n", i, argv[i]);
}
while (1)
{
hangout_loop ();
usleep (20);
}
}

15
gdb/testsuite/gdb.multi/hello.c
View File

@ -16,6 +16,7 @@
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <stdlib.h>
#include <unistd.h>
short hglob = 1;
@ -37,15 +38,27 @@ hello(int x)
return x + 45;
}
static void
hello_loop (void)
{
}
int
main()
{
int tmpx;
alarm (30);
bar();
tmpx = hello(glob);
commonfun();
glob = tmpx;
commonfun();
}
while (1)
{
hello_loop ();
usleep (20);
}
}

24
gdb/testsuite/gdb.multi/multi-arch.exp
View File

@ -96,3 +96,27 @@ if ![runto_main] then {
gdb_test "info inferiors" \
"Executable.*${exec1}.*${exec2}.*"
# Now select inferior 2, and trigger an event in inferior 1. This
# tries to check that GDB doesn't incorrectly uses the architecture of
# inferior 2 when parsing the expedited registers in a stop reply for
# inferior 1 (when remote debugging).
gdb_test_no_output "set schedule-multiple on"
with_test_prefix "inf1 event with inf2 selected" {
gdb_test "inferior 2" "Switching to inferior 2.*thread 2\.1.*main.*${srcfile2}.*"
gdb_test "b hello_loop" "Breakpoint .* at .*${srcfile1}.*"
gdb_test "c" " hello_loop.*" "continue to hello_loop"
}
delete_breakpoints
# Same, but the other way around: select inferior 1 and trigger an
# event in inferior 2.
with_test_prefix "inf2 event with inf1 selected" {
gdb_test "inferior 1" "Switching to inferior 1.*thread 1\.1.*hello_loop.*${srcfile1}.*"
gdb_test "b hangout_loop" "Breakpoint .* at .*${srcfile2}.*"
gdb_test "c" " hangout_loop.*" "continue to hangout_loop"
}