On Mon, Feb 25, 2013 at 8:51 PM, Roland Mainz <[email protected]> wrote:
> On Fri, Feb 22, 2013 at 10:14 PM, Glenn Fowler <[email protected]> wrote:
>>
>> On Thu, 21 Feb 2013 04:19:00 +0100 Roland Mainz wrote:
>>> On Mon, Feb 18, 2013 at 5:51 PM, Glenn Fowler <[email protected]> wrote:
>>> >
>>> > 2013-02-14 alpha posted to www.research.att.com/download/alpha/
>>> >         INIT.2013-02-14.tgz
>>> >         ast-ksh.2013-02-14.tgz
>>> > this is a work in progress
>>> > there are known problems on some architectures
>>
>>> On SuSE 12.2 Linux/AMD64/64bit I get a couple of valgrind hits in the
>>> spawnvex subsystem:
>>> -- snip --
>>> $ valgrind --track-origins=yes --read-var-info=yes  ~/bin/ksh -c 'ls -l ; 
>>> true'
>>> ==19925== Memcheck, a memory error detector
>>> ==19925== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
>>> ==19925== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
>>> ==19925== Command: /home/test001/bin/ksh -c ls\ -l\ ;\ true
>>> ==19925==
>>> [snip]
>>> ==19925==
>>> ==19925== Conditional jump or move depends on uninitialised value(s)
>>> ==19925==    at 0x4DC865: spawnvex (spawnvex.c:1100)
>>> ==19925==    by 0x4653D3: _spawnveg (path.c:151)
>>> ==19925==    by 0x468973: path_spawn (path.c:1228)
>>> ==19925==    by 0x480B4A: sh_ntfork (xec.c:3824)
>>> ==19925==    by 0x479F15: sh_exec (xec.c:1675)
>>> ==19925==    by 0x47BC7A: sh_exec (xec.c:2200)
>>> ==19925==    by 0x40F0D5: exfile (main.c:588)
>>> ==19925==    by 0x40E29A: sh_main (main.c:360)
>>> ==19925==    by 0x40D450: main (pmain.c:45)
>>> ==19925==  Uninitialised value was created by a stack allocation
>>> ==19925==    at 0x4DC6C2: spawnvex (spawnvex.c:793)
> [snip]
>>
>> roland, I'm having line sync probs between my src and the valgrind lines
>> can you identify the varialble that is claimed to be uninitialized
>> thanks
>
> valgrind hits and line numbers for ast-ksh.2013-02-22 look like this:
> -- snip --
> $ valgrind --track-origins=yes --read-var-info=yes
> ./arch/linux.i386-64/bin/ksh -c 'ls -l ; true'
> ==2409== Memcheck, a memory error detector
> ==2409== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
> ==2409== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
> ==2409== Command: ./arch/linux.i386-64/bin/ksh -c ls\ -l\ ;\ true
> ==2409==
> [snip]
> ==2409==
> ==2409== Conditional jump or move depends on uninitialised value(s)
> ==2409==    at 0x4DC851: spawnvex (spawnvex.c:1100)
> ==2409==    by 0x4653BF: _spawnveg (path.c:151)
> ==2409==    by 0x46895F: path_spawn (path.c:1228)
> ==2409==    by 0x480B36: sh_ntfork (xec.c:3824)
> ==2409==    by 0x479F01: sh_exec (xec.c:1675)
> ==2409==    by 0x47BC66: sh_exec (xec.c:2200)
> ==2409==    by 0x40F0D5: exfile (main.c:588)
> ==2409==    by 0x40E29A: sh_main (main.c:360)
> ==2409==    by 0x40D450: main (pmain.c:45)
> ==2409==  Uninitialised value was created by a stack allocation
> ==2409==    at 0x4DC6AE: spawnvex (spawnvex.c:793)
> ==2409==
> ==2409== Conditional jump or move depends on uninitialised value(s)
> ==2409==    at 0x4DCC77: spawnvex (spawnvex.c:1193)
> ==2409==    by 0x4653BF: _spawnveg (path.c:151)
> ==2409==    by 0x46895F: path_spawn (path.c:1228)
> ==2409==    by 0x480B36: sh_ntfork (xec.c:3824)
> ==2409==    by 0x479F01: sh_exec (xec.c:1675)
> ==2409==    by 0x47BC66: sh_exec (xec.c:2200)
> ==2409==    by 0x40F0D5: exfile (main.c:588)
> ==2409==    by 0x40E29A: sh_main (main.c:360)
> ==2409==    by 0x40D450: main (pmain.c:45)
> ==2409==  Uninitialised value was created by a stack allocation
> ==2409==    at 0x4DC6AE: spawnvex (spawnvex.c:793)
> ==2409==
> ==2410== Conditional jump or move depends on uninitialised value(s)
> ==2410==    at 0x4DC8AB: spawnvex (spawnvex.c:1118)
> ==2410==    by 0x4653BF: _spawnveg (path.c:151)
> ==2410==    by 0x46895F: path_spawn (path.c:1228)
> ==2410==    by 0x480B36: sh_ntfork (xec.c:3824)
> ==2410==    by 0x479F01: sh_exec (xec.c:1675)
> ==2410==    by 0x47BC66: sh_exec (xec.c:2200)
> ==2410==    by 0x40F0D5: exfile (main.c:588)
> ==2410==    by 0x40E29A: sh_main (main.c:360)
> ==2410==    by 0x40D450: main (pmain.c:45)
> ==2410==  Uninitialised value was created by a stack allocation
> ==2410==    at 0x4DC6AE: spawnvex (spawnvex.c:793)
> ==2410==
> total 1536
> drwxr-xr-x 3 test001 users    4096 Feb 24 23:06 arch
> drwxr-xr-x 2 test001 users    4096 Feb 24 23:07 bin
> -rw-r--r-- 1 test001 users 1537649 Feb 25 02:29 buildlog.log
> drwxr-xr-x 3 test001 users    4096 Feb 24 23:04 lib
> -rw-r--r-- 1 test001 users     854 Feb 23 08:20 README
> drwxr-xr-x 4 test001 users    4096 Feb 24 23:04 src
> drwxr-xr-x 3 test001 users    4096 Feb 25 05:29 tmp
> -rw-r--r-- 1 test001 users    3851 Feb 24 23:06 tmp_gnulinux_builtin_header.h
> -- snip --
>
> First hit is:
> -- snip --
> ==2461== Conditional jump or move depends on uninitialised value(s)
> ==2461==    at 0x4DC851: spawnvex (spawnvex.c:1100)
> ==2461==    by 0x4653BF: _spawnveg (path.c:151)
> ==2461==    by 0x46895F: path_spawn (path.c:1228)
> ==2461==    by 0x480B36: sh_ntfork (xec.c:3824)
> ==2461==    by 0x479F01: sh_exec (xec.c:1675)
> ==2461==    by 0x47BC66: sh_exec (xec.c:2200)
> ==2461==    by 0x40F0D5: exfile (main.c:588)
> ==2461==    by 0x40E29A: sh_main (main.c:360)
> ==2461==    by 0x40D450: main (pmain.c:45)
> ==2461==  Uninitialised value was created by a stack allocation
> ==2461==    at 0x4DC6AE: spawnvex (spawnvex.c:793)
> -- snip --
> ... which seems to be the |flags| variable in line 1100:
> -- snip --
>   1097                          fcntl(msg[1], F_SETFD, FD_CLOEXEC);
>   1098                  }
>   1099  #endif
>   1100                  if (!(flags & SPAWN_FOREGROUND))
>   1101                          sigcritical(SIG_REG_EXEC|SIG_REG_PROC);
>   1102  #if _lib_vfork
>   1103  #if _lib_fork
>   1104                  if (nx.flags & SPAWN_VFORK)
> -- snip --
>
>
> 2nd hit is:
> -- snip --
> ==2461== Conditional jump or move depends on uninitialised value(s)
> ==2461==    at 0x4DC851: spawnvex (spawnvex.c:1100)
> ==2461==    by 0x4653BF: _spawnveg (path.c:151)
> ==2461==    by 0x46895F: path_spawn (path.c:1228)
> ==2461==    by 0x480B36: sh_ntfork (xec.c:3824)
> ==2461==    by 0x479F01: sh_exec (xec.c:1675)
> ==2461==    by 0x47BC66: sh_exec (xec.c:2200)
> ==2461==    by 0x40F0D5: exfile (main.c:588)
> ==2461==    by 0x40E29A: sh_main (main.c:360)
> ==2461==    by 0x40D450: main (pmain.c:45)
> ==2461==  Uninitialised value was created by a stack allocation
> ==2461==    at 0x4DC6AE: spawnvex (spawnvex.c:793)
> -- snip --
> ... again it seems to be the |flags| variable in line 1118:
> -- snip --
>   1117                  {
>   1118                          if (!(flags & SPAWN_FOREGROUND))
>   1119                                  sigcritical(0);
>   1120                          if (vex && (n = spawnvex_apply(vex, 0, 
> SPAWN_FRAME|SPAWN_NOCALL)))
>   1121                                  errno = n;
> -- snip --
>
>
> 3rd (and last) hit is this one:
> -- snip --
> ==2461== Conditional jump or move depends on uninitialised value(s)
> ==2461==    at 0x4DCC77: spawnvex (spawnvex.c:1193)
> ==2461==    by 0x4653BF: _spawnveg (path.c:151)
> ==2461==    by 0x46895F: path_spawn (path.c:1228)
> ==2461==    by 0x480B36: sh_ntfork (xec.c:3824)
> ==2461==    by 0x479F01: sh_exec (xec.c:1675)
> ==2461==    by 0x47BC66: sh_exec (xec.c:2200)
> ==2461==    by 0x40F0D5: exfile (main.c:588)
> ==2461==    by 0x40E29A: sh_main (main.c:360)
> ==2461==    by 0x40D450: main (pmain.c:45)
> ==2461==  Uninitialised value was created by a stack allocation
> ==2461==    at 0x4DC6AE: spawnvex (spawnvex.c:793)
> ==2461==
> -- snip --
> ... which relates to this code in line 1193:
> -- snip --
>   1192                  }
>   1193                  if (!(flags & SPAWN_FOREGROUND))
>   1194                          sigcritical(0);
>   1195                  if (pid != -1 && vex)
> -- snip --
>
> ... short summary: It's the |flags| variable which is uninitalised in
> some usage cases.
>
> The frustrating part is that the --track-origins=yes option of
> valgrind points to line 793:
> -- snip --
>    791  pid_t
>    792  spawnvex(const char* path, char* const argv[], char* const
> envv[], Spawnvex_t* vex)
>    793  {
>    794
> -- snip --
> This is the beginning of the function, IMO useless and frustrating
> because the binary was explicitly created with -g -ggdb and optimiser
> disabled.

ping! ... is there a patch for the valgrind hits yet (well, I can
"silence" the warnings via initalising the |flags| variable myself...
but I'm not 100% sure whether this is the correct "fix") ?

----

Bye,
Roland

-- 
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