[Patch]Fix the args' output of syscall execve

[Cai Fei]

Hi,

Martin Hunt wrote:
> On Thu, 2007-08-16 at 10:00 -0400, Frank Ch. Eigler wrote:
>   
>> Martin Hunt <hunt@redhat.com> writes:
>>
>> strace -f sh -c ls |& grep exec
>> execve("/bin/sh", ["sh", "-c", "ls"], [/* 53 vars */]) = 0
>> execve("/bin/ls", ["ls"...], [/* 52 vars */]) = 0
>>     
>
> Looks OK for trivial cases, but compare
>
> strace way:
>
> [pid 11943] execve("/usr/bin/g++", ["g++"..., "-DHAVE_CONFIG_H"...,
> "-I."..., "-I."..., "-I."..., "-DBINDIR=\"/usr/local/bin\""...,
> "-DPKGDATADIR=\"/usr/local/share/s"..., "-DPKGLIBDIR=
> \"/usr/local/libexec/"..., "-Wall"..., "-Wextra"..., "-Werror"...,
> "-g"..., "-O2"..., "-MT"..., "stap-staptree.o"..., "-MD"..., ...], [/*
> 43 vars */]) = 0
>
> [pid 11944] execve("/usr/libexec/gcc/i386-redhat-linux/4.1.2/cc1plus",
> ["/usr/libexec/gcc/i386-redhat-lin"..., "-quiet"..., "-I."..., "-I."...,
> "-I."..., "-MD"..., "stap-staptree.d"..., "-MF"...,
> ".deps/stap-staptree.Tpo"..., "-MP"..., "-MT"..., "stap-staptree.o"...,
> "-MQ"..., "stap-staptree.o"..., "-D_GNU_SOURCE"...,
> "-DHAVE_CONFIG_H"..., ...], [/* 45 vars */]) = 0
>
>
> systemtap script:
>
> [pid 12965] /usr/bin/g++ -DHAVE_CONFIG_H -I. -I. -I.
> -DBINDIR="/usr/local/bin" -DPKGDATADIR="/usr/local/share/systemtap"
> -DPKGLIBDIR="/usr/local/libexec/systemtap" -Wall -Wextra -Werror -g -O2
> -MT stap-parse.o -MD -MP -MF .deps/stap-parse.Tpo -c -o stap-parse.o
> parse.cxx
>
> [pid 12966] /usr/libexec/gcc/i386-redhat-linux/4.1.2/cc1plus -quiet -I.
> -I. -I. -MD stap-parse.d -MF .deps/stap-parse.Tpo -MP -MT stap-parse.o
> -MQ stap-parse.o -D_GNU_SOURCE -DHAVE_CONFIG_H -DBINDIR="/usr/local/bin"
> -DPKGDATADIR="/usr/local/share/systemtap"
> -DPKGLIBDIR="/usr/local/libexec/systemtap" parse.cxx -quiet -dumpbase
> parse.cxx -mtune=generic -auxbase-strip stap-parse.o -g -O2 -Wall
> -Wextra -Werror -o /tmp/ccUmZrhr.s
I read the new syscalls.stp and aux_syscalls.stp.
The argv[0]'th entry is usually the path name, but for various reasons 
the invoker may want to override that.
In this kind of situation, if the invoker uses args but not argstr for 
tracing that, he will not get the message.