proper configuration of visudo NOPASSWD for bash backup script

Question

The abstract question is:

If script x calls program y, do I need a NOPASSWD entry in /etc/sudoers for x, y or both x & y? (And can x then call sudo -v without a password?)

Details:

I'm trying to figure out what should go into the /etc/sudoers file to allow a user on Ubuntu (i.e., user ID 1000 who has sudo privileges) to execute a pre-configured full backup without entering a password.

My backup script is: /usr/local/bin/backup
(See below for script.)

The actual backup program called by my script is /opt/storeBackup/bin/storeBackup.pl
(See http://storebackup.org/)

I tried several approaches with visudo but regardless of what I tried, I was still prompted for the password when running the script.

I expected that adding a final line to /etc/sudoers (using visudo) like the following would work:

myuser ALL=(ALL) NOPASSWORD:/usr/local/bin/backup

That didn't work. Neither did this:

myuser ALL=(ALL) NOPASSWORD:/usr/local/bin/backup, /opt/storeBackup/bin/storeBackup.pl

Is the problem due to my script calling sudo -v near the beginning? Or is something else the problem?

To execute the following script, I expect the user to open a terminal and type backup. I want it to be that simple and I don't want them to be prompted for a password at all.

#!/bin/bash

sudo -v
# Keep-alive: update existing sudo time stamp if set, otherwise do nothing.
while true; do sudo -n true; sleep 60; kill -0 "$$" || exit; done 2>/dev/null &

#do a bunch of stuff that could take a while...

#finally, do backup without asking for password:
sudo /opt/storeBackup/bin/storeBackup.pl -f backup.conf

Thanks

Answer 1

I was successful in using the following examples as you've described. Sample scripts:

top.bash

$ cat /tmp/top.bash    
#!/bin/bash

echo "running $0"
sudo -v 
whoami
sudo /tmp/bott.bash

bott.bash

$ more /tmp/bott.bash
#!/bin/bash

echo "running $0"
whoami

Now with the following modification to sudo:

## Allow root to run any commands anywhere 
root    ALL=(ALL)       ALL
sam     ALL=(ALL)       NOPASSWD:/tmp/top.bash

Now as user sam:

$ sudo /tmp/top.bash 
running /tmp/top.bash
root
running /tmp/bott.bash
root

What about running top.bash without sudo?

If I alter the /etc/sudoers file like so:

sam     ALL=(ALL)       NOPASSWD:/tmp/top.bash,/tmp/bott.bash

And then just run /tmp/top.bash as user saml:

$ /tmp/top.bash 
running /tmp/top.bash
sam
running /tmp/bott.bash
root

I get the above. Which is what I would expect.

Answer 2

If you use Ubuntu, you should add your line at the end of /etc/sudoers, so no others lines can override your entry.

# User privilege specification
root    ALL=(ALL:ALL) ALL

# Members of the admin group may gain root privileges
%admin ALL=(ALL) ALL

# Allow members of group sudo to execute any command
%sudo   ALL=(ALL:ALL) ALL

# See sudoers(5) for more information on "#include" directives:

#includedir /etc/sudoers.d

If your entry goes before %sudo entry, it will override your entry, because in Ubuntu, you are in sudo group:

$ id
uid=1000(cuonglm) gid=1000(cuonglm) groups=1000(cuonglm),4(adm),24(cdrom),27(sudo),30(dip),46(plugdev),109(lpadmin),124(sambashare)

And you must allow both your wrapper script and actual script (In your case, it's /usr/local/bin/backup and /opt/storeBackup/bin/storeBackup.pl)

Answer 3

This info is for @slm. (See https://unix.stackexchange.com/a/120159/15010 .) Even with this simple case, it asks for the password.

$ sudo cat /etc/sudoers

tester2 ALL=(ALL) NOPASSWD: /usr/local/bin/backup, /opt/storeBackup/bin/storeBackup.pl

tester2@11038-VirtualBox:~$ sudo -l

Matching Defaults entries for tester2 on this host:
    env_reset,
    secure_path=/usr/local/sbin\:/usr/local/bin\:/usr/sbin\:/usr/bin\:/sbin\:/bin,
    !tty_tickets

User tester2 may run the following commands on this host:
    (ALL : ALL) ALL
    (ALL) NOPASSWD: /usr/local/bin/backup, (ALL) /opt/storeBackup/bin/storeBackup.pl

I'm testing with only one file (this one):
$cat /usr/local/bin/backup

#!/bin/bash

echo "$0"
sudo -v 
whoami

The above file is executable and it is owned by the user (tester2 / id 1000).

And running this commmand strace -s 2000 -o sudo.log /usr/local/bin/backup from tester2's account looks like this (and I entered the password):

execve("/usr/local/bin/backup", ["backup"], [/* 45 vars */]) = 0
brk(0)                                  = 0x9be0000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap2(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb77d3000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=74931, ...}) = 0
mmap2(NULL, 74931, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb77c0000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/i386-linux-gnu/libtinfo.so.5", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0PW\0\0004\0\0\0\210\324\1\0\0\0\0\0004\0 \0\7\0(\0\33\0\32\0\1\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0P\264\1\0P\264\1\0\5\0\0\0\0\20\0\0\1\0\0\0\320\266\1\0\320\306\1\0\320\306\1\0\270\34\0\0| \0\0\6\0\0\0\0\20\0\0\2\0\0\0\264\316\1\0\264\336\1\0\264\336\1\0\310\0\0\0\310\0\0\0\6\0\0\0\4\0\0\0\4\0\0\0\24\1\0\0\24\1\0\0\24\1\0\0$\0\0\0$\0\0\0\4\0\0\0\4\0\0\0P\345td\310\220\1\0\310\220\1\0\310\220\1\0\204\5\0\0\204\5\0\0\4\0\0\0\4\0\0\0Q\345td\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\6\0\0\0\4\0\0\0R\345td\320\266\1\0\320\306\1\0\320\306\1\0000\31\0\0000\31\0\0\4\0\0\0\1\0\0\0\4\0\0\0\24\0\0\0\3\0\0\0GNU\0\261x\200\265F\310?m\300\226\33\327\267y\24\374\371ge4\203\0\0\0007\0\0\0 \0\0\0\n\0\0\0@\20\0\4\2\213\0\224\200\1\220\10\0021\26\270@\0\0 9\20\2448q\262\25}\\\26\244\202\350\3277e:F&\300\212C\6j\0\260H*V$ ,\10\203\1A\20\31\0\21*\200 \24\241\0\fa*(D\10\35\1b!\203\305@\20Y\2\212\20\213\31b@ \200\0\0\204\324\0\24PF\310YI\201. P\201\33\n\241B\2A\272\234\246\n\10 \260\351\24$\217)0N\366@7\0\0\0008\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0:\0\0\0;\0\0\0\0\0\0\0=\0\0\0\0\0\0\0?\0\0\0A\0\0\0C\0\0\0", 512) = 512
fstat64(3, {st_mode=S_IFREG|0644, st_size=121024, ...}) = 0
mmap2(NULL, 124748, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xb77a1000
mmap2(0xb77bd000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1b) = 0xb77bd000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/i386-linux-gnu/libdl.so.2", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0`\n\0\0004\0\0\0t1\0\0\0\0\0\0004\0 \0\t\0(\0 \0\37\0\6\0\0\0004\0\0\0004\0\0\0004\0\0\0 \1\0\0 \1\0\0\5\0\0\0\4\0\0\0\3\0\0\0\307\32\0\0\307\32\0\0\307\32\0\0\23\0\0\0\23\0\0\0\4\0\0\0\1\0\0\0\1\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\\!\0\0\\!\0\0\5\0\0\0\0\20\0\0\1\0\0\0\244.\0\0\244>\0\0\244>\0\0\240\1\0\0\324\1\0\0\6\0\0\0\0\20\0\0\2\0\0\0\300.\0\0\300>\0\0\300>\0\0\10\1\0\0\10\1\0\0\6\0\0\0\4\0\0\0\4\0\0\0T\1\0\0T\1\0\0T\1\0\0D\0\0\0D\0\0\0\4\0\0\0\4\0\0\0P\345td\334\32\0\0\334\32\0\0\334\32\0\0\324\0\0\0\324\0\0\0\4\0\0\0\4\0\0\0Q\345td\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\6\0\0\0\4\0\0\0R\345td\244.\0\0\244>\0\0\244>\0\0\\\1\0\0\\\1\0\0\4\0\0\0\1\0\0\0\4\0\0\0\24\0\0\0\3\0\0\0GNU\0;\nY\324X\267\371\341Zj\21\232i,\366\323\307\333C\364\4\0\0\0\20\0\0\0\1\0\0\0GNU\0\0\0\0\0\2\0\0\0\6\0\0\0\30\0\0\0\26\0\0\0\30\0\0\0\4\0\0\0\7\0\0\0\230\0\21\0\0B\0\0\202\0`\10\223(\10\336\30\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\31\0\0\0\0\0\0\0\32\0\0\0\33\0\0\0\0\0\0\0\35\0\0\0\0\0\0\0\0\0\0\0\36\0\0\0 \0\0\0!\0\0\0\0\0\0\0\0\0\0\0\"\0\0\0", 512) = 512
fstat64(3, {st_mode=S_IFREG|0644, st_size=13940, ...}) = 0
mmap2(NULL, 16504, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xb779c000
mmap2(0xb779f000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x2) = 0xb779f000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/i386-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0000\226\1\0004\0\0\0p`\32\0\0\0\0\0004\0 \0\n\0(\0#\0\"\0\6\0\0\0004\0\0\0004\0\0\0004\0\0\0@\1\0\0@\1\0\0\5\0\0\0\4\0\0\0\3\0\0\0h\263\26\0h\263\26\0h\263\26\0\23\0\0\0\23\0\0\0\4\0\0\0\1\0\0\0\1\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\320-\32\0\320-\32\0\5\0\0\0\0\20\0\0\1\0\0\0\3001\32\0\3001\32\0\3001\32\0\34-\0\0\34Y\0\0\6\0\0\0\0\20\0\0\2\0\0\0|M\32\0|M\32\0|M\32\0\360\0\0\0\360\0\0\0\6\0\0\0\4\0\0\0\4\0\0\0t\1\0\0t\1\0\0t\1\0\0D\0\0\0D\0\0\0\4\0\0\0\4\0\0\0\7\0\0\0\3001\32\0\3001\32\0\3001\32\0\10\0\0\0@\0\0\0\4\0\0\0\4\0\0\0P\345td|\263\26\0|\263\26\0|\263\26\0\354v\0\0\354v\0\0\4\0\0\0\4\0\0\0Q\345td\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\6\0\0\0\4\0\0\0R\345td\3001\32\0\3001\32\0\3001\32\0@\36\0\0@\36\0\0\4\0\0\0\1\0\0\0\4\0\0\0\24\0\0\0\3\0\0\0GNU\0\240\rn\0W\32Y\263\23\220\314\370S\322}\320-\37\350\270\4\0\0\0\20\0\0\0\1\0\0\0GNU\0\0\0\0\0\2\0\0\0\6\0\0\0\30\0\0\0\363\3\0\0\t\0\0\0\0\2\0\0\16\0\0\0\2400\20D\200 \2\1\214\3\346\220AE\210\0\204\0\10\0E\200\0`\300\200\0\f\212\f\0\0010\0\10@2\10\256\4\210H6l\240\0260\0&\204\200\216\4\10B$", 512) = 512
fstat64(3, {st_mode=S_IFREG|0755, st_size=1730024, ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb779b000
mmap2(NULL, 1739484, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xb75f2000
mmap2(0xb7795000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1a3) = 0xb7795000
mmap2(0xb7798000, 10972, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xb7798000
close(3)                                = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb75f1000
set_thread_area({entry_number:-1 -> 6, base_addr:0xb75f16c0, limit:1048575, seg_32bit:1, contents:0, read_exec_only:0, limit_in_pages:1, seg_not_present:0, useable:1}) = 0
mprotect(0xb7795000, 8192, PROT_READ)   = 0
mprotect(0xb779f000, 4096, PROT_READ)   = 0
mprotect(0xb77bd000, 8192, PROT_READ)   = 0
mprotect(0x8124000, 4096, PROT_READ)    = 0
mprotect(0xb77f6000, 4096, PROT_READ)   = 0
munmap(0xb77c0000, 74931)               = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
open("/dev/tty", O_RDWR|O_NONBLOCK|O_LARGEFILE) = 3
close(3)                                = 0
brk(0)                                  = 0x9be0000
brk(0x9be1000)                          = 0x9be1000
open("/usr/lib/locale/locale-archive", O_RDONLY|O_LARGEFILE|O_CLOEXEC) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=4447600, ...}) = 0
mmap2(NULL, 2097152, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb73f1000
mmap2(NULL, 262144, PROT_READ, MAP_PRIVATE, 3, 0x2bd) = 0xb73b1000
mmap2(NULL, 4096, PROT_READ, MAP_PRIVATE, 3, 0x43a) = 0xb73b0000
close(3)                                = 0
brk(0x9be2000)                          = 0x9be2000
brk(0x9be3000)                          = 0x9be3000
getuid32()                              = 1000
getgid32()                              = 1000
geteuid32()                             = 1000
getegid32()                             = 1000
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
time(NULL)                              = 1395267410
brk(0x9be4000)                          = 0x9be4000
open("/proc/meminfo", O_RDONLY|O_CLOEXEC) = 3
fstat64(3, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb73af000
read(3, "MemTotal:        2061512 kB\nMemFree:          161556 kB\nBuffers:           23816 kB\nCached:          1229076 kB\nSwapCached:            0 kB\nActive:          1038852 kB\nInactive:         792548 kB\nActive(anon):     447940 kB\nInactive(anon):   161448 kB\nActive(file):     590912 kB\nInactive(file):   631100 kB\nUnevictable:           0 kB\nMlocked:               0 kB\nHighTotal:       1183688 kB\nHighFree:          14988 kB\nLowTotal:         877824 kB\nLowFree:          146568 kB\nSwapTotal:       2095100 kB\nSwapFree:        2095028 kB\nDirty:                60 kB\nWriteback:             0 kB\nAnonPages:        578540 kB\nMapped:           156860 kB\nShmem:             30880 kB\nSlab:              48428 kB\nSReclaimable:      36208 kB\nSUnreclaim:        12220 kB\nKernelStack:        2672 kB\nPageTables:         8804 kB\nNFS_Unstable:          0 kB\nBounce:                0 kB\nWritebackTmp:          0 kB\nCommitLimit:     3125856 kB\nCommitted_AS:    1922516 kB\nVmallocTotal:     122880 kB\nVmallocUsed:       28356 kB\nVmallocChunk:   ", 1024) = 1024
close(3)                                = 0
munmap(0xb73af000, 4096)                = 0
brk(0x9be5000)                          = 0x9be5000
rt_sigaction(SIGCHLD, {SIG_DFL, [], SA_RESTART}, {SIG_DFL, [], 0}, 8) = 0
rt_sigaction(SIGCHLD, {SIG_DFL, [], SA_RESTART}, {SIG_DFL, [], SA_RESTART}, 8) = 0
rt_sigaction(SIGINT, {SIG_DFL, [], 0}, {SIG_DFL, [], 0}, 8) = 0
rt_sigaction(SIGINT, {SIG_DFL, [], 0}, {SIG_DFL, [], 0}, 8) = 0
rt_sigaction(SIGQUIT, {SIG_DFL, [], 0}, {SIG_DFL, [], 0}, 8) = 0
rt_sigaction(SIGQUIT, {SIG_DFL, [], 0}, {SIG_DFL, [], 0}, 8) = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
rt_sigaction(SIGQUIT, {SIG_IGN, [], 0}, {SIG_DFL, [], 0}, 8) = 0
uname({sys="Linux", node="11038-VirtualBox", ...}) = 0
brk(0x9be6000)                          = 0x9be6000
brk(0x9be7000)                          = 0x9be7000
stat64("/home/tester2", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
stat64(".", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
getpid()                                = 8307
open("/usr/lib/i386-linux-gnu/gconv/gconv-modules.cache", O_RDONLY) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=26256, ...}) = 0
mmap2(NULL, 26256, PROT_READ, MAP_SHARED, 3, 0) = 0xb73a9000
close(3)                                = 0
brk(0x9be8000)                          = 0x9be8000
getppid()                               = 8306
gettimeofday({1395267410, 397418}, NULL) = 0
brk(0x9be9000)                          = 0x9be9000
brk(0x9bea000)                          = 0x9bea000
getpgrp()                               = 8306
rt_sigaction(SIGCHLD, {0x8085410, [], SA_RESTART}, {SIG_DFL, [], SA_RESTART}, 8) = 0
getrlimit(RLIMIT_NPROC, {rlim_cur=15942, rlim_max=15942}) = 0
brk(0x9beb000)                          = 0x9beb000
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
open("/usr/local/bin/backup", O_RDONLY|O_LARGEFILE) = 3
ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfad4848) = -1 ENOTTY (Inappropriate ioctl for device)
_llseek(3, 0, [0], SEEK_CUR)            = 0
read(3, "#!/bin/bash\n\necho \"$0\"\n\nsudo -v\nwhoami\n\n", 80) = 40
_llseek(3, 0, [0], SEEK_SET)            = 0
getrlimit(RLIMIT_NOFILE, {rlim_cur=1024, rlim_max=4*1024}) = 0
fcntl64(255, F_GETFD)                   = -1 EBADF (Bad file descriptor)
dup2(3, 255)                            = 255
close(3)                                = 0
fcntl64(255, F_SETFD, FD_CLOEXEC)       = 0
fcntl64(255, F_GETFL)                   = 0x8000 (flags O_RDONLY|O_LARGEFILE)
fstat64(255, {st_mode=S_IFREG|0755, st_size=40, ...}) = 0
_llseek(255, 0, [0], SEEK_CUR)          = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
read(255, "#!/bin/bash\n\necho \"$0\"\n\nsudo -v\nwhoami\n\n", 40) = 40
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
brk(0x9bec000)                          = 0x9bec000
write(1, "/usr/local/bin/backup\n", 22) = 22
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
stat64(".", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
stat64("/usr/local/sbin/sudo", 0xbfad4600) = -1 ENOENT (No such file or directory)
stat64("/usr/local/bin/sudo", 0xbfad4600) = -1 ENOENT (No such file or directory)
stat64("/usr/sbin/sudo", 0xbfad4600)    = -1 ENOENT (No such file or directory)
stat64("/usr/bin/sudo", {st_mode=S_IFREG|S_ISUID|0755, st_size=69708, ...}) = 0
stat64("/usr/bin/sudo", {st_mode=S_IFREG|S_ISUID|0755, st_size=69708, ...}) = 0
geteuid32()                             = 1000
getegid32()                             = 1000
getuid32()                              = 1000
getgid32()                              = 1000
access("/usr/bin/sudo", X_OK)           = 0
stat64("/usr/bin/sudo", {st_mode=S_IFREG|S_ISUID|0755, st_size=69708, ...}) = 0
geteuid32()                             = 1000
getegid32()                             = 1000
getuid32()                              = 1000
getgid32()                              = 1000
access("/usr/bin/sudo", R_OK)           = 0
stat64("/usr/bin/sudo", {st_mode=S_IFREG|S_ISUID|0755, st_size=69708, ...}) = 0
stat64("/usr/bin/sudo", {st_mode=S_IFREG|S_ISUID|0755, st_size=69708, ...}) = 0
geteuid32()                             = 1000
getegid32()                             = 1000
getuid32()                              = 1000
getgid32()                              = 1000
access("/usr/bin/sudo", X_OK)           = 0
stat64("/usr/bin/sudo", {st_mode=S_IFREG|S_ISUID|0755, st_size=69708, ...}) = 0
geteuid32()                             = 1000
getegid32()                             = 1000
getuid32()                              = 1000
getgid32()                              = 1000
access("/usr/bin/sudo", R_OK)           = 0
rt_sigprocmask(SIG_BLOCK, [INT CHLD], [], 8) = 0
_llseek(255, -8, [32], SEEK_CUR)        = 0
clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0xb75f1728) = 8308
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGINT, {0x80829d0, [], 0}, {SIG_DFL, [], 0}, 8) = 0
waitpid(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0) = 8308
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
--- SIGCHLD (Child exited) @ 0 (0) ---
waitpid(-1, 0xbfad4038, WNOHANG)        = -1 ECHILD (No child processes)
sigreturn()                             = ? (mask now [])
rt_sigaction(SIGINT, {SIG_DFL, [], 0}, {0x80829d0, [], 0}, 8) = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
read(255, "whoami\n\n", 40)             = 8
stat64(".", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
stat64("/usr/local/sbin/whoami", 0xbfad4600) = -1 ENOENT (No such file or directory)
stat64("/usr/local/bin/whoami", 0xbfad4600) = -1 ENOENT (No such file or directory)
stat64("/usr/sbin/whoami", 0xbfad4600)  = -1 ENOENT (No such file or directory)
stat64("/usr/bin/whoami", {st_mode=S_IFREG|0755, st_size=22060, ...}) = 0
stat64("/usr/bin/whoami", {st_mode=S_IFREG|0755, st_size=22060, ...}) = 0
geteuid32()                             = 1000
getegid32()                             = 1000
getuid32()                              = 1000
getgid32()                              = 1000
access("/usr/bin/whoami", X_OK)         = 0
stat64("/usr/bin/whoami", {st_mode=S_IFREG|0755, st_size=22060, ...}) = 0
geteuid32()                             = 1000
getegid32()                             = 1000
getuid32()                              = 1000
getgid32()                              = 1000
access("/usr/bin/whoami", R_OK)         = 0
stat64("/usr/bin/whoami", {st_mode=S_IFREG|0755, st_size=22060, ...}) = 0
stat64("/usr/bin/whoami", {st_mode=S_IFREG|0755, st_size=22060, ...}) = 0
geteuid32()                             = 1000
getegid32()                             = 1000
getuid32()                              = 1000
getgid32()                              = 1000
access("/usr/bin/whoami", X_OK)         = 0
stat64("/usr/bin/whoami", {st_mode=S_IFREG|0755, st_size=22060, ...}) = 0
geteuid32()                             = 1000
getegid32()                             = 1000
getuid32()                              = 1000
getgid32()                              = 1000
access("/usr/bin/whoami", R_OK)         = 0
rt_sigprocmask(SIG_BLOCK, [INT CHLD], [], 8) = 0
_llseek(255, -1, [39], SEEK_CUR)        = 0
clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0xb75f1728) = 8309
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGINT, {0x80829d0, [], 0}, {SIG_DFL, [], 0}, 8) = 0
waitpid(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0) = 8309
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
--- SIGCHLD (Child exited) @ 0 (0) ---
waitpid(-1, 0xbfad4038, WNOHANG)        = -1 ECHILD (No child processes)
sigreturn()                             = ? (mask now [])
rt_sigaction(SIGINT, {SIG_DFL, [], 0}, {0x80829d0, [], 0}, 8) = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
read(255, "\n", 40)                     = 1
rt_sigprocmask(SIG_BLOCK, NULL, [], 8)  = 0
read(255, "", 40)                       = 0
exit_group(0)                           = ?