Graphics Programs Reference
In-Depth Information
any program to show every system call it makes. In the output below, this is
used to verify that the arguments to
open()
in C match up with the raw sys-
tem calls.
reader@hacking:~/booksrc $ strace ./notetaker test
execve("./notetaker", ["./notetaker", "test"], [/* 27 vars */]) = 0
brk(0) = 0x804a000
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) = 0xb7fe5000
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=70799, ..}) = 0
mmap2(NULL, 70799, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb7fd3000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
open("/lib/tls/i686/cmov/libc.so.6", O_RDONLY) = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\0`\1\000".., 512) = 512
fstat64(3, {st_mode=S_IFREG|0644, st_size=1307104, ..}) = 0
mmap2(NULL, 1312164, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xb7e92000
mmap2(0xb7fcd000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x13b) =
0xb7fcd000
mmap2(0xb7fd0000, 9636, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) =
0xb7fd0000
close(3) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7e91000
set_thread_area({entry_number:-1 -> 6, base_addr:0xb7e916c0, limit:1048575, seg_32bit:1,
contents:0, read_exec_only:0, limit_in_pages:1, seg_not_present:0, useable:1}) = 0
mprotect(0xb7fcd000, 4096, PROT_READ) = 0
munmap(0xb7fd3000, 70799) = 0
brk(0) = 0x804a000
brk(0x806b000) = 0x806b000
fstat64(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 2), ..}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7fe4000
write(1, "[DEBUG] buffer @ 0x804a008: \'t".., 37[DEBUG] buffer @ 0x804a008: 'test'
) = 37
write(1, "[DEBUG] datafile @ 0x804a070: \'/".., 43[DEBUG] datafile @ 0x804a070: '/var/notes'
) = 43
open("/var/notes", O_WRONLY|O_APPEND|O_CREAT, 0600) = -1 EACCES (Permission denied)
dup(2) = 3
fcntl64(3, F_GETFL) = 0x2 (flags O_RDWR)
fstat64(3, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 2), ..}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7fe3000
_llseek(3, 0, 0xbffff4e4, SEEK_CUR) = -1 ESPIPE (Illegal seek)
write(3, "[!!] Fatal Error in main() while".., 65[!!] Fatal Error in main() while opening file:
Permission denied
) = 65
close(3) = 0
munmap(0xb7fe3000, 4096) = 0
exit_group(-1) = ?
Process 21473 detached
reader@hacking:~/booksrc $ grep open notetaker.c
fd = open(datafile, O_WRONLY|O_CREAT|O_APPEND, S_IRUSR|S_IWUSR);
fatal("in main() while opening file");
reader@hacking:~/booksrc $
