?????????Щshell???!??????????????????????????\.
????-e trace=set
???????????????? ????.????:-e trace=open??close??rean??write???????????????????.?????set=all.
????-e trace=file
??????????й????????????????.
????-e trace=process
??????????й??????????????.
????-e trace=network
???????????????й????????????.
????-e strace=signal
????????????????????й?? ??????
????-e trace=ipc
????????????????????й????????
????-e abbrev=set
?????趨 strace????????????????.-v ???? abbrev=none.????abbrev=all.
????-e raw=set
??????? ??????????????????????????.
????-e signal=set
?????????????????.????all.?? signal=!SIGIO(????signal=!io)???????????SIGIO???.
????-e read=set
????????????????ж??? ??????.????:
????-e read=3??5
????-e write=set
???????д?????????е?????.
????-o filename
??????strace?????д?????filename
????-p pid
????????????????pid.
????-s strsize
??????????????????????.????32.?????????????.
????-u username
??????username ??UID??GID??б??????????
???????????
?????????????÷???
????strace -o output.txt -T -tt -e trace=all -p 28979
?????????????? ????28979????????????????-e trace=all???????????????????????????????????????????????????????????????????output.txt??????檔
????strace????
??????strace???????
????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? ??????????????????????????????????????????????????????????
?????????????????????strace????????????? ????????strace?????????????á???????????????????????????????????????????е??????strace??????????е?PID?? ?棩??
???????????????????????????????KDE?????????
??????????????? ???KDE????????????KDE????????????????κ??а???????????
????_KDE_IceTransSocketCreateListener: failed to bind listener
????_KDE_IceTransSocketUNIXCreateListener: ...SocketCreateListener() failed
????_KDE_IceTransMakeAllCOTSServerListeners: failed to create listener for local
????Cannot establish any listening sockets DCOPServer self-test failed.
?????? ????????????????????????壬????????KDE????????????????????????????????????????????????????ICEЭ?饗Inter Client Exchange???й???????????????????KDE???????????
?????????????strace?????????? dcopserver????????????????
????strace -f -F -o ~/dcop-strace.txt dcopserver
???????? -f -F??????strace??????fork??vfork??????????-o????????strace???д??~/dcop-strace.txt?? ?棬dcopserver???????????????
??????γ????????????????????????dcop-strace.txt????????к?? ???????????????????г???????й??????￡?
27207 mkdir("/tmp/.ICE-unix"?? 0777) = -1 EEXIST (File exists)
27207 lstat64("/tmp/.ICE-unix"?? {st_mode=S_IFDIR|S_ISVTX|0755?? st_size=4096?? ...}) = 0
27207 unlink("/tmp/.ICE-unix/dcop27207-1066844596") = -1 ENOENT (No such file or directory)
27207 bind(3?? {sin_family=AF_UNIX?? path="/tmp/.ICE-unix/dcop27207-1066844596"}?? 38) = -1 EACCES (Permission denied)
27207 write(2?? "_KDE_IceTrans"?? 13) = 13
27207 write(2?? "SocketCreateListener: failed to "...?? 46) = 46
27207 close(3) = 0 27207 write(2?? "_KDE_IceTrans"?? 13) = 13
27207 write(2?? "SocketUNIXCreateListener: ...Soc"...?? 59) = 59
27207 umask(0) = 0 27207 write(2?? "_KDE_IceTrans"?? 13) = 13
27207 write(2?? "MakeAllCOTSServerListeners: fail"...?? 64) = 64
27207 write(2?? "Cannot establish any listening s"...?? 39) = 39
???????е??????????????????/tmp/.ICE-unix????????0777????????????????????????????????????????lstat64????? ?????????????????????????0755??????????????????????д??????????????????????????0777??????????????????????????? 0755???????????????????unlink????????????????????????????????????????????????????????????????????????????
?????????????????????????????????????/tmp/.ICE-unix/dcop27207-1066844596????????????????????. ICE_unix??????????鶼??root??????????????????д?????????root????????????????潨????????????????????0777?? ??????????п????????У????????????????????????й????????
????????????????chmod 0777 /tmp/.ICE-unix???KDE?????????????????????????strace???и?????????????????????????????????У?????鰱?? ??????????
?????????????chmod 0777?????????????????????????ó???????????д?????????????λ(sticky bit)?????????????λ??????????????????????д??????????????????????????/tmp????????????????????λ??KDE??????????? ???????chmod +t /tmp/.ICE-unix??.ICE_unix???????λ??
?????????????????
????starce ???????????????????????????????????????????????ldd?????????????????????????????????λ?á????????????????????????? ??glibc?汾??2.2????磩???????????????bug??ldd?????????????????????·??????????????????????г?????????????? ??/lib/ld-linux.so.2???????????????????????????????????/etc/ld.so.conf?? /etc/ld.so.cache???????￡?????/etc/ld.so.cache?????????glibc 2.3.2?汾???????????????????ld-linux?????bug???????????
??????????????ldd??????????г??????????????г? ??????????dlopen??????????????????????????????????Щ????????ldd?г????????glibc????????NSS??Name Server Switch???????????????????NSS????????????????ó???????????????????????ó?????????????NSS??glibc???? ??dlopen???????NSS???????????????????????????????????????????????????????????????????????ID??????????????????
????whoami????????????????????????????????Щ?????????г??????????????????????????????whoami???????? ??????￡?
????# whoami
????root
????????????????????? ??glibc??????и?????????????ID??????NSS?????????????????nss???????????????????
????# mv /lib/libnss_files.so.2 /lib/libnss_files.so.2.backup
????# whoami
????whoami: cannot find username for UID 0
??????????????????????whoami??????????ldd????????????????????????
????# ldd /usr/bin/whoami
????libc.so.6 => /lib/libc.so.6 (0x4001f000)
????/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)
???????????whoami????Libc.so.6??ld-linux.so.2??????и???????whoami????????????????????strace???? whoami????????
strace -o whoami-strace.txt whoami
open("/lib/libnss_files.so.2"?? O_RDONLY) = -1 ENOENT (No such file or directory)
open("/lib/i686/mmx/libnss_files.so.2"?? O_RDONLY) = -1 ENOENT (No such file or directory)
stat64("/lib/i686/mmx"?? 0xbffff190) = -1 ENOENT (No such file or directory)
open("/lib/i686/libnss_files.so.2"?? O_RDONLY) = -1 ENOENT (No such file or directory)
stat64("/lib/i686"?? 0xbffff190) = -1 ENOENT (No such file or directory)
open("/lib/mmx/libnss_files.so.2"?? O_RDONLY) = -1 ENOENT (No such file or directory)
stat64("/lib/mmx"?? 0xbffff190) = -1 ENOENT (No such file or directory)
open("/lib/libnss_files.so.2"?? O_RDONLY) = -1 ENOENT (No such file or directory)
stat64("/lib"?? {st_mode=S_IFDIR|0755?? st_size=2352?? ...}) = 0
open("/usr/lib/i686/mmx/libnss_files.so.2"?? O_RDONLY) = -1 ENOENT (No such file or directory)
stat64("/usr/lib/i686/mmx"?? 0xbffff190) = -1 ENOENT (No such file or directory)
open("/usr/lib/i686/libnss_files.so.2"?? O_RDONLY) = -1 ENOENT (No such file or directory)
?????????????????????????libnss.so.2???????????????????????strace???????????????????????????????????????????? ?????????libnss.so.2???????????????λ????????
????????strace????????????????
???????????????????????????????strace??????Щ??????????á????磬???????????configure?????????е?????????????????? ????execve????strace????execve??????????????
????strace -f -o configure-strace.txt -e execve ./configure