zenithsiz/ftmemsim-valgrind
1
0
Fork 0
mirror of https://github.com/Zenithsiz/ftmemsim-valgrind.git synced 2026-02-03 10:05:29 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Fix 326462 Refactor vgdb to isolate invoker stuff into separate module

Browse Source 
vgdb.c contained (conditionally compiled) "invoker" code to have ptrace syscalls
used to allow gdb/vgdb to connect to a valgrind process blocked in a syscall.
This "invoker" code is ptrace based.
Not all platforms are using ptrace.
=> refactor vgdb so as allow invoker code to be added more cleanly
for non ptrace based platforms (e.g. Darwin, Solaris).

* add file vgdb.h for:
   - definition of the vgdb-invoker interface
   - common declarations between vgdb.c and vgdb-invoker implementations
* move ptrace related code from vgdb.c to new file vgdb-invoker-ptrace.c
* new file vgdb-invoker-none.c containing an empty invoker implementation
  used on platforms that do not (yet) have a invoker implementation
  (e.g. android and darwin).
* modified Makefile.am to use one of the vgdb-invoker-*.c file depending
  on the platform.
* small changes related to changing ptraceinvoker to invoker in various files:
  gdbserver_tests/make_local_links, gdbserver_tests/nlcontrolc.vgtest,
  gdbserver_tests/mcinvokeRU.vgtest, gdbserver_tests/nlsigvgdb.vgtest  
  gdbserver_tests/mcinvokeWS.vgtest, coregrind/m_gdbserver/README_DEVELOPERS

Patch from Ivo Raisr, slightly modified



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13743
This commit is contained in:
Philippe Waroquiers 2013-12-01 14:56:28 +00:00
parent e9b6e1c9be
commit b8ed3a5b65
12 changed files with 1134 additions and 1009 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
NEWS
View File

@ -24,7 +24,7 @@ To see details of a given bug, visit
https://bugs.kde.org/show_bug.cgi?id=XXXXXX
where XXXXXX is the bug number as listed below.
326462 Refactor vgdb to isolate invoker stuff into separate module
326983 Clear direction flag after tests on amd64.
327238 Callgrind Assertion 'passed <= last_bb->cjmp_count' failed
327837 dwz compressed alternate .debug_info and .debug_str not read correctly

15
coregrind/Makefile.am
View File

@ -59,7 +59,22 @@ valgrind_CFLAGS += -static
valgrind_LDFLAGS += -Wl,-z,noexecstack
endif
vgdb_SOURCES = vgdb.c
if VGCONF_OS_IS_LINUX
if VGCONF_PLATVARIANT_IS_ANDROID
vgdb_SOURCES += vgdb-invoker-none.c
else
vgdb_SOURCES += vgdb-invoker-ptrace.c
endif
endif
if VGCONF_OS_IS_DARWIN
# Some darwin specific stuff is needed as ptrace is not
# fully supported on MacOS. Till we find someone courageous
# having access to Darwin, 'none' implementation is used.
vgdb_SOURCES += vgdb-invoker-none.c
endif
vgdb_CPPFLAGS = $(AM_CPPFLAGS_PRI)
vgdb_CFLAGS = $(AM_CFLAGS_PRI)
vgdb_CCASFLAGS = $(AM_CCASFLAGS_PRI)

11
coregrind/m_gdbserver/README_DEVELOPERS
View File

@ -165,7 +165,7 @@ will check after 100ms if the characters it has written have been read
by valgrind. If not, vgdb will force the invocation of the gdbserver
code inside the valgrind process.
This forced invocation is implemented using the ptrace system call:
On Linux, this forced invocation is implemented using the ptrace system call:
using ptrace, vgdb will cause the valgrind process to call the
gdbserver code.
@ -272,10 +272,12 @@ Then adapt the set of functions needed to initialize the structure
Optional but heavily recommended:
To have a proper wake up of a Valgrind process with all threads
blocked in a system call, some architecture specific code
has to be done in vgdb.c : search for PTRACEINVOKER processor symbol
to see what has to be completed.
has to be done in vgdb-invoker-*.c.
Typically, for a linux system supporting ptrace, you have to modify
vgdb-invoker-ptrace.c.
For Linux based platforms, all the ptrace calls should be ok.
For Linux based platforms, all the ptrace calls in vgdb-invoker-ptrace.c
should be ok.
The only thing needed is the code needed to "push a dummy call" on the stack,
i.e. assign the relevant registers in the struct user_regs_struct, and push
values on the stack according to the ABI.
@ -337,7 +339,6 @@ TODO and/or additional nice things to have
(such as search leaks)?
* currently jump(s) and inferior call(s) are somewhat dangerous
when called from a block not yet instrumented : instead
of continuing till the next Imark, where there will be a

56
coregrind/vgdb-invoker-none.c Normal file
View File

@ -0,0 +1,56 @@
/*--------------------------------------------------------------------*/
/*--- Empty implementation of vgdb invoker subsystem. ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Valgrind, a dynamic binary instrumentation
framework.
Copyright (C) 2011-2013 Philippe Waroquiers
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 2 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, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307, USA.
The GNU General Public License is contained in the file COPYING.
*/
#include "vgdb.h"
#include <stdio.h>
#include <sys/time.h>
void invoker_restrictions_msg(void)
{
fprintf(stderr,
"Note: vgdb invoker not implemented on this platform.\n"
"For more info: read user manual section"
" 'Limitations of the Valgrind gdbserver'.\n");
}
void invoker_cleanup_restore_and_detach(void *v_pid)
{
DEBUG(1, "invoker_cleanup_restore_and_detach");
}
Bool invoker_invoke_gdbserver(pid_t pid)
{
DEBUG(2, "invoker_invoke_gdbserver not implemented\n");
/* Returning True signals to not retry (too soon) to invoke. */
return True;
}
void invoker_valgrind_dying(void)
{
}

917
coregrind/vgdb-invoker-ptrace.c Normal file
View File

@ -0,0 +1,917 @@
/*--------------------------------------------------------------------*/
/*--- Implementation of vgdb invoker subsystem via ptrace() calls. ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Valgrind, a dynamic binary instrumentation
framework.
Copyright (C) 2011-2013 Philippe Waroquiers
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 2 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, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307, USA.
The GNU General Public License is contained in the file COPYING.
*/
#include "config.h"
#include "vgdb.h"
#include "pub_core_threadstate.h"
#include <alloca.h>
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ptrace.h>
#include <sys/time.h>
#include <sys/user.h>
#include <sys/wait.h>
#if VEX_HOST_WORDSIZE == 8
typedef Addr64 CORE_ADDR;
#elif VEX_HOST_WORDSIZE == 4
typedef Addr32 CORE_ADDR;
#else
# error "unexpected wordsize"
#endif
#if VEX_HOST_WORDSIZE == 8
typedef Addr64 PTRACE_XFER_TYPE;
typedef void* PTRACE_ARG3_TYPE;
#elif VEX_HOST_WORDSIZE == 4
typedef Addr32 PTRACE_XFER_TYPE;
typedef void* PTRACE_ARG3_TYPE;
#else
# error "unexpected wordsize"
#endif
/* True if we have continued pid_of_save_regs after PTRACE_ATTACH. */
static Bool pid_of_save_regs_continued = False;
/* True when loss of connection indicating that the Valgrind
process is dying. */
static Bool dying = False;
/* ptrace_(read|write)_memory are modified extracts of linux-low.c
from gdb 6.6. Copyrighted FSF */
/* Copy LEN bytes from valgrind memory starting at MEMADDR
to vgdb memory starting at MYADDR. */
static
int ptrace_read_memory (pid_t inferior_pid, CORE_ADDR memaddr,
void *myaddr, size_t len)
{
register int i;
/* Round starting address down to longword boundary. */
register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
/* Round ending address up; get number of longwords that makes. */
register int count
= (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
/ sizeof (PTRACE_XFER_TYPE);
/* Allocate buffer of that many longwords. */
register PTRACE_XFER_TYPE *buffer
= (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
/* Read all the longwords */
for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) {
errno = 0;
buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid,
(PTRACE_ARG3_TYPE) addr, 0);
if (errno)
return errno;
}
/* Copy appropriate bytes out of the buffer. */
memcpy (myaddr,
(char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), len);
return 0;
}
/* Copy LEN bytes of data from vgdb memory at MYADDR
to valgrind memory at MEMADDR.
On failure (cannot write the valgrind memory)
returns the value of errno. */
__attribute__((unused)) /* not used on all platforms */
static
int ptrace_write_memory (pid_t inferior_pid, CORE_ADDR memaddr,
const void *myaddr, size_t len)
{
register int i;
/* Round starting address down to longword boundary. */
register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
/* Round ending address up; get number of longwords that makes. */
register int count
= (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
/ sizeof (PTRACE_XFER_TYPE);
/* Allocate buffer of that many longwords. */
register PTRACE_XFER_TYPE *buffer
= (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
if (debuglevel >= 1) {
DEBUG (1, "Writing ");
for (i = 0; i < len; i++)
PDEBUG (1, "%02x", ((const unsigned char*)myaddr)[i]);
PDEBUG(1, " to %p\n", (void *) memaddr);
}
/* Fill start and end extra bytes of buffer with existing memory data. */
buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid,
(PTRACE_ARG3_TYPE) addr, 0);
if (count > 1) {
buffer[count - 1]
= ptrace (PTRACE_PEEKTEXT, inferior_pid,
(PTRACE_ARG3_TYPE) (addr + (count - 1)
* sizeof (PTRACE_XFER_TYPE)),
0);
}
/* Copy data to be written over corresponding part of buffer */
memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
myaddr, len);
/* Write the entire buffer. */
for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) {
errno = 0;
ptrace (PTRACE_POKETEXT, inferior_pid,
(PTRACE_ARG3_TYPE) addr, buffer[i]);
if (errno)
return errno;
}
return 0;
}
/* subset of VG_(threads) needed for vgdb ptrace.
This is initialized when process is attached. */
typedef struct {
ThreadStatus status;
Int lwpid;
}
VgdbThreadState;
static VgdbThreadState vgdb_threads[VG_N_THREADS];
static const
HChar* name_of_ThreadStatus ( ThreadStatus status )
{
switch (status) {
case VgTs_Empty: return "VgTs_Empty";
case VgTs_Init: return "VgTs_Init";
case VgTs_Runnable: return "VgTs_Runnable";
case VgTs_WaitSys: return "VgTs_WaitSys";
case VgTs_Yielding: return "VgTs_Yielding";
case VgTs_Zombie: return "VgTs_Zombie";
default: return "VgTs_???";
}
}
static
char *status_image (int status)
{
static char result[256];
int sz = 0;
#define APPEND(...) sz += snprintf (result+sz, 256 - sz - 1, __VA_ARGS__)
result[0] = 0;
if (WIFEXITED(status))
APPEND ("WIFEXITED %d ", WEXITSTATUS(status));
if (WIFSIGNALED(status)) {
APPEND ("WIFSIGNALED %d ", WTERMSIG(status));
if (WCOREDUMP(status)) APPEND ("WCOREDUMP ");
}
if (WIFSTOPPED(status))
APPEND ("WIFSTOPPED %d ", WSTOPSIG(status));
#ifdef WIFCONTINUED
if (WIFCONTINUED(status))
APPEND ("WIFCONTINUED ");
#endif
return result;
#undef APPEND
}
/* Wait till the process pid is reported as stopped with signal_expected.
If other signal(s) than signal_expected are received, waitstopped
will pass them to pid, waiting for signal_expected to stop pid.
Returns True when process is in stopped state with signal_expected.
Returns False if a problem was encountered while waiting for pid
to be stopped.
If pid is reported as being dead/exited, waitstopped will return False.
*/
static
Bool waitstopped (pid_t pid, int signal_expected, const char *msg)
{
pid_t p;
int status = 0;
int signal_received;
int res;
while (1) {
DEBUG(1, "waitstopped %s before waitpid signal_expected %d\n",
msg, signal_expected);
p = waitpid(pid, &status, __WALL);
DEBUG(1, "after waitpid pid %d p %d status 0x%x %s\n", pid, p,
status, status_image (status));
if (p != pid) {
ERROR(errno, "%s waitpid pid %d in waitstopped %d status 0x%x %s\n",
msg, pid, p, status, status_image (status));
return False;
}
if (WIFEXITED(status)) {
shutting_down = True;
return False;
}
assert (WIFSTOPPED(status));
signal_received = WSTOPSIG(status);
if (signal_received == signal_expected)
break;
/* pid received a signal which is not the signal we are waiting for.
We continue pid, transmitting this signal. */
DEBUG(1, "waitstopped PTRACE_CONT with signal %d\n", signal_received);
res = ptrace (PTRACE_CONT, pid, NULL, signal_received);
if (res != 0) {
ERROR(errno, "waitstopped PTRACE_CONT\n");
return False;
}
}
return True;
}
/* Stops the given pid, wait for the process to be stopped.
Returns True if succesful, False otherwise.
msg is used in tracing and error reporting. */
static
Bool stop (pid_t pid, const char *msg)
{
long res;
DEBUG(1, "%s SIGSTOP pid %d\n", msg, pid);
res = kill (pid, SIGSTOP);
if (res != 0) {
ERROR(errno, "%s SIGSTOP pid %d %ld\n", msg, pid, res);
return False;
}
return waitstopped (pid, SIGSTOP, msg);
}
/* Attaches to given pid, wait for the process to be stopped.
Returns True if succesful, False otherwise.
msg is used in tracing and error reporting. */
static
Bool attach (pid_t pid, const char *msg)
{
long res;
static Bool output_error = True;
static Bool initial_attach = True;
// For a ptrace_scope protected system, we do not want to output
// repetitively attach error. We will output once an error
// for the initial_attach. Once the 1st attach has succeeded, we
// again show all errors.
DEBUG(1, "%s PTRACE_ATTACH pid %d\n", msg, pid);
res = ptrace (PTRACE_ATTACH, pid, NULL, NULL);
if (res != 0) {
if (output_error || debuglevel > 0) {
ERROR(errno, "%s PTRACE_ATTACH pid %d %ld\n", msg, pid, res);
if (initial_attach)
output_error = False;
}
return False;
}
initial_attach = False;
output_error = True;
return waitstopped(pid, SIGSTOP, msg);
}
/* once we are attached to the pid, get the list of threads and stop
them all.
Returns True if all threads properly suspended, False otherwise. */
static
Bool acquire_and_suspend_threads (pid_t pid)
{
int i;
int rw;
Bool pid_found = False;
Addr vgt;
int sz_tst;
int off_status;
int off_lwpid;
int nr_live_threads = 0;
if (shared32 != NULL) {
vgt = shared32->threads;
sz_tst = shared32->sizeof_ThreadState;
off_status = shared32->offset_status;
off_lwpid = shared32->offset_lwpid;
}
else if (shared64 != NULL) {
vgt = shared64->threads;
sz_tst = shared64->sizeof_ThreadState;
off_status = shared64->offset_status;
off_lwpid = shared64->offset_lwpid;
} else {
assert (0);
}
/* note: the entry 0 is unused */
for (i = 1; i < VG_N_THREADS; i++) {
vgt += sz_tst;
rw = ptrace_read_memory(pid, vgt+off_status,
&(vgdb_threads[i].status),
sizeof(ThreadStatus));
if (rw != 0) {
ERROR(rw, "status ptrace_read_memory\n");
return False;
}
rw = ptrace_read_memory(pid, vgt+off_lwpid,
&(vgdb_threads[i].lwpid),
sizeof(Int));
if (rw != 0) {
ERROR(rw, "lwpid ptrace_read_memory\n");
return False;
}
if (vgdb_threads[i].status != VgTs_Empty) {
DEBUG(1, "found tid %d status %s lwpid %d\n",
i, name_of_ThreadStatus(vgdb_threads[i].status),
vgdb_threads[i].lwpid);
nr_live_threads++;
if (vgdb_threads[i].lwpid <= 1) {
if (vgdb_threads[i].lwpid == 0
&& vgdb_threads[i].status == VgTs_Init) {
DEBUG(1, "not set lwpid tid %d status %s lwpid %d\n",
i, name_of_ThreadStatus(vgdb_threads[i].status),
vgdb_threads[i].lwpid);
} else {
ERROR(1, "unexpected lwpid tid %d status %s lwpid %d\n",
i, name_of_ThreadStatus(vgdb_threads[i].status),
vgdb_threads[i].lwpid);
}
/* in case we have a VtTs_Init thread with lwpid not yet set,
we try again later. */
return False;
}
if (vgdb_threads[i].lwpid == pid) {
assert (!pid_found);
assert (i == 1);
pid_found = True;
} else {
if (!attach(vgdb_threads[i].lwpid, "attach_thread")) {
ERROR(0, "ERROR attach pid %d tid %d\n",
vgdb_threads[i].lwpid, i);
return False;
}
}
}
}
/* If we found no thread, it means the process is stopping, and
we better do not force anything to happen during that. */
if (nr_live_threads > 0)
return True;
else
return False;
}
static
void detach_from_all_threads (pid_t pid)
{
int i;
long res;
Bool pid_found = False;
/* detach from all the threads */
for (i = 1; i < VG_N_THREADS; i++) {
if (vgdb_threads[i].status != VgTs_Empty) {
if (vgdb_threads[i].status == VgTs_Init
&& vgdb_threads[i].lwpid == 0) {
DEBUG(1, "skipping PTRACE_DETACH pid %d tid %d status %s\n",
vgdb_threads[i].lwpid, i,
name_of_ThreadStatus (vgdb_threads[i].status));
} else {
if (vgdb_threads[i].lwpid == pid) {
assert (!pid_found);
pid_found = True;
}
DEBUG(1, "PTRACE_DETACH pid %d tid %d status %s\n",
vgdb_threads[i].lwpid, i,
name_of_ThreadStatus (vgdb_threads[i].status));
res = ptrace (PTRACE_DETACH, vgdb_threads[i].lwpid, NULL, NULL);
if (res != 0) {
ERROR(errno, "PTRACE_DETACH pid %d tid %d status %s res %ld\n",
vgdb_threads[i].lwpid, i,
name_of_ThreadStatus (vgdb_threads[i].status),
res);
}
}
}
}
if (!pid_found && pid) {
/* No threads are live. Process is busy stopping.
We need to detach from pid explicitely. */
DEBUG(1, "no thread live => PTRACE_DETACH pid %d\n", pid);
res = ptrace (PTRACE_DETACH, pid, NULL, NULL);
if (res != 0)
ERROR(errno, "PTRACE_DETACH pid %d res %ld\n", pid, res);
}
}
// if > 0, pid for which registers have to be restored.
static int pid_of_save_regs = 0;
static struct user user_save;
// The below indicates if ptrace_getregs (and ptrace_setregs) can be used.
// Note that some linux versions are defining PTRACE_GETREGS but using
// it gives back EIO.
// has_working_ptrace_getregs can take the following values:
// -1 : PTRACE_GETREGS is defined
// runtime check not yet done.
// 0 : PTRACE_GETREGS runtime check has failed.
// 1 : PTRACE_GETREGS defined and runtime check ok.
#ifdef HAVE_PTRACE_GETREGS
static int has_working_ptrace_getregs = -1;
#endif
/* Get the registers from pid into regs.
regs_bsz value gives the length of *regs.
Returns True if all ok, otherwise False. */
static
Bool getregs (pid_t pid, void *regs, long regs_bsz)
{
DEBUG(1, "getregs regs_bsz %ld\n", regs_bsz);
# ifdef HAVE_PTRACE_GETREGS
if (has_working_ptrace_getregs) {
// Platforms having GETREGS
long res;
DEBUG(1, "getregs PTRACE_GETREGS\n");
res = ptrace (PTRACE_GETREGS, pid, NULL, regs);
if (res == 0) {
if (has_working_ptrace_getregs == -1) {
// First call to PTRACE_GETREGS succesful =>
has_working_ptrace_getregs = 1;
DEBUG(1, "detected a working PTRACE_GETREGS\n");
}
assert (has_working_ptrace_getregs == 1);
return True;
}
else if (has_working_ptrace_getregs == 1) {
// We had a working call, but now it fails.
// This is unexpected.
ERROR(errno, "PTRACE_GETREGS %ld\n", res);
return False;
} else {
// Check this is the first call:
assert (has_working_ptrace_getregs == -1);
if (errno == EIO) {
DEBUG(1, "detected a broken PTRACE_GETREGS with EIO\n");
has_working_ptrace_getregs = 0;
// Fall over to the PTRACE_PEEKUSER case.
} else {
ERROR(errno, "broken PTRACE_GETREGS unexpected errno %ld\n", res);
return False;
}
}
}
# endif
// We assume PTRACE_PEEKUSER is defined everywhere.
{
# ifdef PT_ENDREGS
long peek_bsz = PT_ENDREGS;
assert (peek_bsz <= regs_bsz);
# else
long peek_bsz = regs_bsz-1;
# endif
char *pregs = (char *) regs;
long offset;
errno = 0;
DEBUG(1, "getregs PTRACE_PEEKUSER(s) peek_bsz %ld\n", peek_bsz);
for (offset = 0; offset < peek_bsz; offset = offset + sizeof(long)) {
*(long *)(pregs+offset) = ptrace(PTRACE_PEEKUSER, pid, offset, NULL);
if (errno != 0) {
ERROR(errno, "PTRACE_PEEKUSER offset %ld\n", offset);
return False;
}
}
return True;
}
// If neither PTRACE_GETREGS not PTRACE_PEEKUSER have returned,
// then we are in serious trouble.
assert (0);
}
/* Set the registers of pid to regs.
regs_bsz value gives the length of *regs.
Returns True if all ok, otherwise False. */
static
Bool setregs (pid_t pid, void *regs, long regs_bsz)
{
DEBUG(1, "setregs regs_bsz %ld\n", regs_bsz);
// Note : the below is checking for GETREGS, not SETREGS
// as if one is defined and working, the other one should also work.
# ifdef HAVE_PTRACE_GETREGS
if (has_working_ptrace_getregs) {
// Platforms having SETREGS
long res;
// setregs can never be called before getregs has done a runtime check.
assert (has_working_ptrace_getregs == 1);
DEBUG(1, "setregs PTRACE_SETREGS\n");
res = ptrace (PTRACE_SETREGS, pid, NULL, regs);
if (res != 0) {
ERROR(errno, "PTRACE_SETREGS %ld\n", res);
return False;
}
return True;
}
# endif
{
char *pregs = (char *) regs;
long offset;
long res;
# ifdef PT_ENDREGS
long peek_bsz = PT_ENDREGS;
assert (peek_bsz <= regs_bsz);
# else
long peek_bsz = regs_bsz-1;
# endif
errno = 0;
DEBUG(1, "setregs PTRACE_POKEUSER(s) %ld\n", peek_bsz);
for (offset = 0; offset < peek_bsz; offset = offset + sizeof(long)) {
res = ptrace(PTRACE_POKEUSER, pid, offset, *(long*)(pregs+offset));
if (errno != 0) {
ERROR(errno, "PTRACE_POKEUSER offset %ld res %ld\n", offset, res);
return False;
}
}
return True;
}
// If neither PTRACE_SETREGS not PTRACE_POKEUSER have returned,
// then we are in serious trouble.
assert (0);
}
/* Restore the registers to the saved value, then detaches from all threads */
static
void restore_and_detach (pid_t pid)
{
if (pid_of_save_regs) {
/* In case the 'main pid' has been continued, we need to stop it
before resetting the registers. */
if (pid_of_save_regs_continued) {
pid_of_save_regs_continued = False;
if (!stop(pid_of_save_regs, "sigstop before reset regs"))
DEBUG(0, "Could not sigstop before reset");
}
DEBUG(1, "setregs restore registers pid %d\n", pid_of_save_regs);
if (!setregs(pid_of_save_regs, &user_save.regs, sizeof(user_save.regs))) {
ERROR(errno, "setregs restore registers pid %d after cont\n",
pid_of_save_regs);
}
pid_of_save_regs = 0;
} else {
DEBUG(1, "PTRACE_SETREGS restore registers: no pid\n");
}
detach_from_all_threads(pid);
}
Bool invoker_invoke_gdbserver (pid_t pid)
{
long res;
Bool stopped;
struct user user_mod;
Addr sp;
/* A specific int value is passed to invoke_gdbserver, to check
everything goes according to the plan. */
const int check = 0x8BADF00D; // ate bad food.
const Addr bad_return = 0;
// A bad return address will be pushed on the stack.
// The function invoke_gdbserver cannot return. If ever it returns, a NULL
// address pushed on the stack should ensure this is detected.
/* Not yet attached. If problem, vgdb can abort,
no cleanup needed. */
DEBUG(1, "attach to 'main' pid %d\n", pid);
if (!attach(pid, "attach main pid")) {
ERROR(0, "error attach main pid %d\n", pid);
return False;
}
/* Now, we are attached. If problem, detach and return. */
if (!acquire_and_suspend_threads(pid)) {
detach_from_all_threads(pid);
/* if the pid does not exist anymore, we better stop */
if (kill(pid, 0) != 0)
XERROR (errno, "invoke_gdbserver: check for pid %d existence failed\n",
pid);
return False;
}
if (!getregs(pid, &user_mod.regs, sizeof(user_mod.regs))) {
detach_from_all_threads(pid);
return False;
}
user_save = user_mod;
#if defined(VGA_x86)
sp = user_mod.regs.esp;
#elif defined(VGA_amd64)
sp = user_mod.regs.rsp;
if (shared32 != NULL) {
/* 64bit vgdb speaking with a 32bit executable.
To have system call restart properly, we need to sign extend rax.
For more info:
web search '[patch] Fix syscall restarts for amd64->i386 biarch'
e.g. http://sourceware.org/ml/gdb-patches/2009-11/msg00592.html */
*(long *)&user_save.regs.rax = *(int*)&user_save.regs.rax;
DEBUG(1, "Sign extending %8.8lx to %8.8lx\n",
user_mod.regs.rax, user_save.regs.rax);
}
#elif defined(VGA_arm)
sp = user_mod.regs.uregs[13];
#elif defined(VGA_ppc32)
sp = user_mod.regs.gpr[1];
#elif defined(VGA_ppc64)
sp = user_mod.regs.gpr[1];
#elif defined(VGA_s390x)
sp = user_mod.regs.gprs[15];
#elif defined(VGA_mips32)
long long *p = (long long *)user_mod.regs;
sp = p[29];
#elif defined(VGA_mips64)
sp = user_mod.regs[29];
#else
I_die_here : (sp) architecture missing in vgdb.c
#endif
// the magic below is derived from spying what gdb sends to
// the (classical) gdbserver when invoking a C function.
if (shared32 != NULL) {
// vgdb speaking with a 32bit executable.
#if defined(VGA_x86) || defined(VGA_amd64)
const int regsize = 4;
int rw;
/* push check arg on the stack */
sp = sp - regsize;
DEBUG(1, "push check arg ptrace_write_memory\n");
assert(regsize == sizeof(check));
rw = ptrace_write_memory(pid, sp,
&check,
regsize);
if (rw != 0) {
ERROR(rw, "push check arg ptrace_write_memory");
detach_from_all_threads(pid);
return False;
}
sp = sp - regsize;
DEBUG(1, "push bad_return return address ptrace_write_memory\n");
// Note that for a 64 bits vgdb, only 4 bytes of NULL bad_return
// are written.
rw = ptrace_write_memory(pid, sp,
&bad_return,
regsize);
if (rw != 0) {
ERROR(rw, "push bad_return return address ptrace_write_memory");
detach_from_all_threads(pid);
return False;
}
#if defined(VGA_x86)
/* set ebp, esp, eip and orig_eax to invoke gdbserver */
// compiled in 32bits, speaking with a 32bits exe
user_mod.regs.ebp = sp; // bp set to sp
user_mod.regs.esp = sp;
user_mod.regs.eip = shared32->invoke_gdbserver;
user_mod.regs.orig_eax = -1L;
#elif defined(VGA_amd64)
/* set ebp, esp, eip and orig_eax to invoke gdbserver */
// compiled in 64bits, speaking with a 32bits exe
user_mod.regs.rbp = sp; // bp set to sp
user_mod.regs.rsp = sp;
user_mod.regs.rip = shared32->invoke_gdbserver;
user_mod.regs.orig_rax = -1L;
#else
I_die_here : not x86 or amd64 in x86/amd64 section/
#endif
#elif defined(VGA_ppc32) || defined(VGA_ppc64)
user_mod.regs.nip = shared32->invoke_gdbserver;
user_mod.regs.trap = -1L;
/* put check arg in register 3 */
user_mod.regs.gpr[3] = check;
/* put NULL return address in Link Register */
user_mod.regs.link = bad_return;
#elif defined(VGA_arm)
/* put check arg in register 0 */
user_mod.regs.uregs[0] = check;
/* put NULL return address in Link Register */
user_mod.regs.uregs[14] = bad_return;
user_mod.regs.uregs[15] = shared32->invoke_gdbserver;
#elif defined(VGA_s390x)
XERROR(0, "(fn32) s390x has no 32bits implementation");
#elif defined(VGA_mips32)
/* put check arg in register 4 */
p[4] = check;
/* put NULL return address in ra */
p[31] = bad_return;
p[34] = shared32->invoke_gdbserver;
p[25] = shared32->invoke_gdbserver;
/* make stack space for args */
p[29] = sp - 32;
#elif defined(VGA_mips64)
assert(0); // cannot vgdb a 32 bits executable with a 64 bits exe
#else
I_die_here : architecture missing in vgdb.c
#endif
}
else if (shared64 != NULL) {
#if defined(VGA_x86)
assert(0); // cannot vgdb a 64 bits executable with a 32 bits exe
#elif defined(VGA_amd64)
// vgdb speaking with a 64 bit executable.
const int regsize = 8;
int rw;
/* give check arg in rdi */
user_mod.regs.rdi = check;
/* push return address on stack : return to breakaddr */
sp = sp - regsize;
DEBUG(1, "push bad_return return address ptrace_write_memory\n");
rw = ptrace_write_memory(pid, sp,
&bad_return,
sizeof(bad_return));
if (rw != 0) {
ERROR(rw, "push bad_return return address ptrace_write_memory");
detach_from_all_threads(pid);
return False;
}
/* set rbp, rsp, rip and orig_rax to invoke gdbserver */
user_mod.regs.rbp = sp; // bp set to sp
user_mod.regs.rsp = sp;
user_mod.regs.rip = shared64->invoke_gdbserver;
user_mod.regs.orig_rax = -1L;
#elif defined(VGA_arm)
assert(0); // cannot vgdb a 64 bits executable with a 32 bits exe
#elif defined(VGA_ppc32)
assert(0); // cannot vgdb a 64 bits executable with a 32 bits exe
#elif defined(VGA_ppc64)
Addr64 func_addr;
Addr64 toc_addr;
int rw;
rw = ptrace_read_memory(pid, shared64->invoke_gdbserver,
&func_addr,
sizeof(Addr64));
if (rw != 0) {
ERROR(rw, "ppc64 read func_addr\n");
detach_from_all_threads(pid);
return False;
}
rw = ptrace_read_memory(pid, shared64->invoke_gdbserver+8,
&toc_addr,
sizeof(Addr64));
if (rw != 0) {
ERROR(rw, "ppc64 read toc_addr\n");
detach_from_all_threads(pid);
return False;
}
// We are not pushing anything on the stack, so it is not
// very clear why the sp has to be decreased, but it seems
// needed. The ppc64 ABI might give some lights on this ?
user_mod.regs.gpr[1] = sp - 220;
user_mod.regs.gpr[2] = toc_addr;
user_mod.regs.nip = func_addr;
user_mod.regs.trap = -1L;
/* put check arg in register 3 */
user_mod.regs.gpr[3] = check;
/* put bad_return return address in Link Register */
user_mod.regs.link = bad_return;
#elif defined(VGA_s390x)
/* put check arg in register r2 */
user_mod.regs.gprs[2] = check;
/* bad_return Return address is in r14 */
user_mod.regs.gprs[14] = bad_return;
/* minimum stack frame */
sp = sp - 160;
user_mod.regs.gprs[15] = sp;
/* set program counter */
user_mod.regs.psw.addr = shared64->invoke_gdbserver;
#elif defined(VGA_mips32)
assert(0); // cannot vgdb a 64 bits executable with a 32 bits exe
#elif defined(VGA_mips64)
/* put check arg in register 4 */
user_mod.regs[4] = check;
/* put NULL return address in ra */
user_mod.regs[31] = bad_return;
user_mod.regs[34] = shared64->invoke_gdbserver;
user_mod.regs[25] = shared64->invoke_gdbserver;
#else
I_die_here: architecture missing in vgdb.c
#endif
}
else {
assert(0);
}
if (!setregs(pid, &user_mod.regs, sizeof(user_mod.regs))) {
detach_from_all_threads(pid);
return False;
}
/* Now that we have modified the registers, we set
pid_of_save_regs to indicate that restore_and_detach
must restore the registers in case of cleanup. */
pid_of_save_regs = pid;
pid_of_save_regs_continued = False;
/* We PTRACE_CONT-inue pid.
Either gdbserver will be invoked directly (if all
threads are interruptible) or gdbserver will be
called soon by the scheduler. In the first case,
pid will stop on the break inserted above when
gdbserver returns. In the 2nd case, the break will
be encountered directly. */
DEBUG(1, "PTRACE_CONT to invoke\n");
res = ptrace (PTRACE_CONT, pid, NULL, NULL);
if (res != 0) {
ERROR(errno, "PTRACE_CONT\n");
restore_and_detach(pid);
return False;
}
pid_of_save_regs_continued = True;
/* Wait for SIGSTOP generated by m_gdbserver.c give_control_back_to_vgdb */
stopped = waitstopped (pid, SIGSTOP,
"waitpid status after PTRACE_CONT to invoke");
if (stopped) {
/* Here pid has properly stopped on the break. */
pid_of_save_regs_continued = False;
restore_and_detach(pid);
return True;
} else {
/* Whatever kind of problem happened. We shutdown. */
shutting_down = True;
return False;
}
}
void invoker_cleanup_restore_and_detach(void *v_pid)
{
DEBUG(1, "invoker_cleanup_restore_and_detach dying: %d\n", dying);
if (!dying)
restore_and_detach(*(int*)v_pid);
}
void invoker_restrictions_msg(void)
{
}
void invoker_valgrind_dying(void)
{
/* Avoid messing up with registers of valgrind when it is dying. */
pid_of_save_regs_continued = False;
dying = True;
}

1023
coregrind/vgdb.c
View File

File diff suppressed because it is too large Load Diff

103
coregrind/vgdb.h Normal file
View File

@ -0,0 +1,103 @@
/*--------------------------------------------------------------------*/
/*--- Declarations common for vgdb and implementations ---*/
/*--- of vgdb-invoker. vgdb.h ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Valgrind, a dynamic binary instrumentation
framework.
Copyright (C) 2011-2013 Philippe Waroquiers
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 2 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, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307, USA.
The GNU General Public License is contained in the file COPYING.
*/
#ifndef __VGDB_H
#define __VGDB_H
#include "pub_core_basics.h"
#include "pub_core_vki.h"
#include "pub_core_gdbserver.h"
#include <sys/types.h>
extern int debuglevel;
extern struct timeval dbgtv;
/* if level <= debuglevel, print timestamp, then print provided by debug info */
#define DEBUG(level, ...) (level <= debuglevel ? \
gettimeofday(&dbgtv, NULL), \
fprintf(stderr, "%ld.%6.6ld ", \
(long int)dbgtv.tv_sec, \
(long int)dbgtv.tv_usec), \
fprintf(stderr, __VA_ARGS__),fflush(stderr) \
: 0)
/* same as DEBUG but does not print time stamp info */
#define PDEBUG(level, ...) (level <= debuglevel ? \
fprintf(stderr, __VA_ARGS__),fflush(stderr) \
: 0)
/* if errno != 0,
report the errno and fprintf the ... varargs on stderr. */
#define ERROR(errno, ...) ((errno == 0 ? 0 : perror("syscall failed")), \
fprintf(stderr, __VA_ARGS__), \
fflush(stderr))
/* same as ERROR, but also exits with status 1 */
#define XERROR(errno, ...) ((errno == 0 ? 0 : perror("syscall failed")), \
fprintf(stderr, __VA_ARGS__), \
fflush(stderr), \
exit(1))
/* Will be set to True when any condition indicating we have to shutdown
is encountered. */
extern Bool shutting_down;
extern VgdbShared32 *shared32;
extern VgdbShared64 *shared64;
/*--------------------------------------------------------------------*/
/*--- Below is vgdb-invoker interface which must be implemented by ---*/
/*--- all vgdb-invoker implementations. ---*/
/*--------------------------------------------------------------------*/
/* Possibly produces additional usage information documenting the
invoker restrictions. */
void invoker_restrictions_msg(void);
/* Restore the registers to the saved value, then detaches from all threads.
Used as a cleanup handler for thread cancellation. */
void invoker_cleanup_restore_and_detach(void *v_pid);
/* Ensures that the gdbserver code is invoked by pid.
If an error occurs, resets the valgrind process
to the state it had before being invoked.
Returns True if invoke successful, False otherwise. */
Bool invoker_invoke_gdbserver(pid_t pid);
/* Called when connection with valgrind is lost. In case we
have lost the connection, it means that Valgrind has closed the
connection and is busy exiting. We can't and don't have to stop it in
this case. */
void invoker_valgrind_dying(void);
#endif // __VGDB_H
/*--------------------------------------------------------------------*/
/*--- end ---*/
/*--------------------------------------------------------------------*/

6
gdbserver_tests/make_local_links
View File

@ -99,11 +99,11 @@ ln -f -s ../coregrind/vgdb gdbserver_tests/vgdb
# if ptrace not implemented in vgdb or OS restricts the initial attach,
# some tests would block for a loooonnnng time.
if gdbserver_tests/vgdb --help 2>&1 |
grep -e 'ptrace invoker not implemented' > /dev/null
grep -e 'invoker not implemented' > /dev/null
then
rm -f gdbserver_tests/vgdb.ptraceinvoker
rm -f gdbserver_tests/vgdb.invoker
else
touch gdbserver_tests/vgdb.ptraceinvoker
touch gdbserver_tests/vgdb.invoker
fi
# cleanup the possibly big garbage previously collected output

4
gdbserver_tests/mcinvokeRU.vgtest
View File

@ -4,8 +4,8 @@ prog: sleepers
args: 1 0 1000000000 B-B-B-B-
vgopts: --tool=memcheck --vgdb=yes --vgdb-prefix=./vgdb-prefix-mcinvokeRU
stderr_filter: filter_make_empty
# as the Valgrind process is always busy, we do not need the vgdb.ptraceinvoker prereq.
# We even disable ptrace invoker to avoid spurious attach error message
# as the Valgrind process is always busy, we do not need the vgdb.invoker prereq.
# We even disable invoker to avoid spurious attach error message
# on kernels where ptrace is restricted.
progB: invoker
argsB: 10 --vgdb-prefix=./vgdb-prefix-mcinvokeRU --max-invoke-ms=0 --wait=60 -c v.wait 0

2
gdbserver_tests/mcinvokeWS.vgtest
View File

@ -4,7 +4,7 @@ prog: sleepers
args: 1 10000000 0 -S-S-S-S
vgopts: --tool=memcheck --vgdb=yes --vgdb-prefix=./vgdb-prefix-mcinvokeWS
stderr_filter: filter_make_empty
prereq: test -f vgdb.ptraceinvoker
prereq: test -f vgdb.invoker
progB: invoker
argsB: 10 --vgdb-prefix=./vgdb-prefix-mcinvokeWS --wait=60 -c v.wait 0
# if the --wait is not enough, the test will fail or block

2
gdbserver_tests/nlcontrolc.vgtest
View File

@ -10,7 +10,7 @@ prog: sleepers
args: 1000000000 1000000000 1000000000 BSBSBSBS
vgopts: --tool=none --vgdb=yes --vgdb-error=0 --vgdb-prefix=./vgdb-prefix-nlcontrolc
stderr_filter: filter_stderr
prereq: test -e gdb -a -f vgdb.ptraceinvoker
prereq: test -e gdb -a -f vgdb.invoker
progB: gdb
argsB: --quiet -l 60 --nx ./sleepers
stdinB: nlcontrolc.stdinB.gdb

2
gdbserver_tests/nlsigvgdb.vgtest
View File

@ -7,7 +7,7 @@ prog: sleepers
args: 1 10000000 0 -S-S-S-S
vgopts: --tool=none --vgdb=yes --vgdb-error=0 --vgdb-prefix=./vgdb-prefix-nlsigvgdb
stderr_filter: filter_stderr
prereq: test -e gdb -a -f vgdb.ptraceinvoker
prereq: test -e gdb -a -f vgdb.invoker
progB: gdb
argsB: --quiet -l 60 --nx ./sleepers
stdinB: nlsigvgdb.stdinB.gdb