ftmemsim-valgrind/coregrind/m_clientstate.c
Philippe Waroquiers 51c6c85e22 The semantic of the stack bounds is not consistent or is not described.
At various places, there were either some assumption that the 'end'
boundary (highest address) was either not included, included,
or was the highest addressable word, or the highest addressable byte.
This e.g. was very visible when doing:
  ./vg-in-place -d -d ./helgrind/tests/tc01_simple_race|&grep regi
giving
  --24040:2:stacks     register 0xBEDB4000-0xBEDB4FFF as stack 0
  --24040:2:stacks     register 0x402C000-0x4A2C000 as stack 1
showing that the main stack end was (on x86) not the highest word
but the highest byte, while for the thread 1, the registered end
was a byte not part of the stack.

The attached patch ensures that stack bounds semantic are documented and
consistent. Also, some of the stack handling code is factorised.

The convention that the patch ensures and documents is:
start is the lowest addressable byte, end is the highest addressable byte.
(the words 'min' and 'max' have been kept when already used, as this wording is 
consistent with the new semantic of start/end).

In various debug log, used brackets [ and ] to make clear that
both bounds are included.

The code to guess and register the client stack was duplicated
in all the platform specific syswrap-<plat>-<os>.c files.
Code has been factorised in syswrap-generic.c

The patch has been regression tested on
   x86, amd64, ppc32/64, s390x.
It has been compiled and one test run on arm64.
Not compiled/not tested on darwin, android, mips32/64, arm


More in details, the patch does the following:

coregrind/pub_core_aspacemgr.h
include/valgrind.h
include/pub_tool_machine.h
coregrind/pub_core_scheduler.h
coregrind/pub_core_stacks.h
  - document start/end semantic in various functions
 also in pub_tool_machine.h:
  - replaces unclear 'bottommost address' by 'lowest address'
    (unclear as stack bottom is or at least can be interpreted as
     the 'functional' bottom of the stack, which is the highest
      address for 'stack growing downwards').
coregrind/pub_core_initimg.h
  replace unclear clstack_top by clstack_end
coregrind/m_main.c
  updated to clstack_end

coregrind/pub_core_threadstate.h
  renamed client_stack_highest_word to client_stack_highest_byte
coregrind/m_scheduler/scheduler.c
  computes client_stack_highest_byte as the highest addressable byte
  Update comments in call to VG_(show_sched_status)
coregrind/m_machine.c
coregrind/m_stacktrace.c
  updated to client_stack_highest_byte, and switched 
    stack_lowest/highest_word to stack_lowest/highest_byte accordingly

coregrind/m_stacks.c
  clarify semantic of start/end,
  added a comment to indicate why we invert start/end in register call
  (note that the code find_stack_by_addr was already assuming that
  end was included as the checks were doing e.g.
    sp >= i->start && sp <= i->end

coregrind/pub_core_clientstate.h
coregrind/m_clientstate.c
  renames Addr  VG_(clstk_base) to Addr  VG_(clstk_start_base)
    (start to indicate it is the lowest address, base suffix kept
     to indicate it is the initial lowest address).

coregrind/m_initimg/initimg-darwin.c
   updated to  VG_(clstk_start_base)
   replace unclear iicii.clstack_top by iicii.clstack_end
   updated clstack_max_size computation according to both bounds included.

coregrind/m_initimg/initimg-linux.c
   updated to  VG_(clstk_start_base)
   updated VG_(clstk_end) computation according to both bounds included.
   replace unclear iicii.clstack_top by iicii.clstack_end

coregrind/pub_core_aspacemgr.h
  extern Addr VG_(am_startup) : clarify semantic of the returned value
coregrind/m_aspacemgr/aspacemgr-linux.c
   removed a copy of a comment that was already in pub_core_aspacemgr.h
     (avoid double maintenance)
   renamed unclear suggested_clstack_top to suggested_clstack_end
    (note that here, it looks like suggested_clstack_top was already
     the last addressable byte)

* factorisation of the stack guessing and registration causes
  mechanical changes in the following files:
      coregrind/m_syswrap/syswrap-ppc64-linux.c
      coregrind/m_syswrap/syswrap-x86-darwin.c
      coregrind/m_syswrap/syswrap-amd64-linux.c
      coregrind/m_syswrap/syswrap-arm-linux.c
      coregrind/m_syswrap/syswrap-generic.c
      coregrind/m_syswrap/syswrap-mips64-linux.c
      coregrind/m_syswrap/syswrap-ppc32-linux.c
      coregrind/m_syswrap/syswrap-amd64-darwin.c
      coregrind/m_syswrap/syswrap-mips32-linux.c
      coregrind/m_syswrap/priv_syswrap-generic.h
      coregrind/m_syswrap/syswrap-x86-linux.c
      coregrind/m_syswrap/syswrap-s390x-linux.c
      coregrind/m_syswrap/syswrap-darwin.c
      coregrind/m_syswrap/syswrap-arm64-linux.c
 Some files to look at more in details:
  syswrap-darwin.c : the handling of sysctl(kern.usrstack) looked
    buggy to me, and has probably be made correct by the fact that
     VG_(clstk_end) is now the last addressable byte. However,unsure
    about this, as I could not find any documentation about 
    sysctl(kern.usrstack). I only find several occurences on the web,
    showing that the result of this is page aligned, which I guess
    means it must be 1+ the last addressable byte.
  syswrap-x86-darwin.c and syswrap-amd64-darwin.c
   I suspect the code that was computing client_stack_highest_word
   was wrong, and the patch makes it correct.
  syswrap-mips64-linux.c
    not sure what to do for this code. This is the only code
    that was guessing the stack differently from others.
    Kept (almost) untouched. To be discussed with mips maintainers.

coregrind/pub_core_libcassert.h
coregrind/m_libcassert.c
  * void VG_(show_sched_status):
     renamed Bool valgrind_stack_usage to Bool stack_usage
     if stack_usage, shows both the valgrind stack usage and
     the client stack boundaries
coregrind/m_scheduler/scheduler.c
coregrind/m_gdbserver/server.c
coregrind/m_gdbserver/remote-utils.c
   Updated comments in callers to VG_(show_sched_status)



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14392
2014-08-29 22:53:19 +00:00

119 lines
4.5 KiB
C

/*--------------------------------------------------------------------*/
/*--- A home for miscellaneous bits of information which pertain ---*/
/*--- to the client's state. ---*/
/*--- m_clientstate.c ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Valgrind, a dynamic binary instrumentation
framework.
Copyright (C) 2000-2013 Julian Seward
jseward@acm.org
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 "pub_core_basics.h"
#include "pub_core_vki.h"
#include "pub_core_xarray.h"
#include "pub_core_clientstate.h"
/*-----------------------------------------------------------------*/
/*--- ---*/
/*--- Basic globals about the address space. ---*/
/*--- ---*/
/*-----------------------------------------------------------------*/
/* Client address space, lowest to highest (see top of ume.c) */
// TODO: get rid of as many of these as possible.
/* ***Initial*** lowest address of the stack segment of the main thread.
The main stack will grow if needed but VG_(clstk_start_base) will
not be changed according to the growth. */
Addr VG_(clstk_start_base) = 0;
/* Initial highest address of the stack segment of the main thread. */
Addr VG_(clstk_end) = 0;
UWord VG_(clstk_id) = 0;
/* linux only: where is the client auxv ? */
/* This is set up as part of setup_client_stack in initimg-linux.c. */
UWord* VG_(client_auxv) = NULL;
Addr VG_(brk_base) = 0; /* start of brk */
Addr VG_(brk_limit) = 0; /* current brk */
/* A fd which refers to the client executable. */
Int VG_(cl_exec_fd) = -1;
/* A fd which refers to the fake /proc/<pid>/cmdline in /tmp. */
Int VG_(cl_cmdline_fd) = -1;
/* A fd which refers to the fake /proc/<pid>/auxv in /tmp. */
Int VG_(cl_auxv_fd) = -1;
// Command line pieces, after they have been extracted from argv in
// m_main.main(). The payload vectors are allocated in VG_AR_CORE
// (the default arena). They are never freed.
/* Args for the client. */
XArray* /* of HChar* */ VG_(args_for_client) = NULL;
/* Args for V (augments, then those from the launcher). */
XArray* /* of HChar* */ VG_(args_for_valgrind) = NULL;
/* How many of the above not to pass on at execve time? */
Int VG_(args_for_valgrind_noexecpass) = 0;
/* The name of the client executable, as specified on the command
line. */
const HChar* VG_(args_the_exename) = NULL;
// Client's original rlimit data and rlimit stack
struct vki_rlimit VG_(client_rlimit_data);
struct vki_rlimit VG_(client_rlimit_stack);
// Name of the launcher, as extracted from VALGRIND_LAUNCHER at
// startup.
HChar* VG_(name_of_launcher) = NULL;
/* Application-visible file descriptor limits */
Int VG_(fd_soft_limit) = -1;
Int VG_(fd_hard_limit) = -1;
/* Useful addresses extracted from the client */
/* Where is the __libc_freeres_wrapper routine we made? */
Addr VG_(client___libc_freeres_wrapper) = 0;
/* x86-linux only: where is glibc's _dl_sysinfo_int80 function?
Finding it isn't essential, but knowing where it is does sometimes
help produce better back traces. See big comment in
VG_(get_StackTrace) in m_stacktrace.c for further info. */
Addr VG_(client__dl_sysinfo_int80) = 0;
/* Address of the (internal) glibc nptl pthread stack cache size,
declared as:
static size_t stack_cache_actsize;
in nptl/allocatestack.c */
SizeT* VG_(client__stack_cache_actsize__addr) = 0;
/*--------------------------------------------------------------------*/
/*--- end ---*/
/*--------------------------------------------------------------------*/