I got a gdb backtrace for the openat syscall of /etc/passwd. This is with glibc 2.31:
#0 __GI___open64_nocancel (file=0x7ffff7df715e "/etc/passwd", oflag=524288)
at ../sysdeps/unix/sysv/linux/open64_nocancel.c:45
#1 0x00007ffff7e82185 in __GI__IO_file_open (fp=fp@entry=0x5555555596b0,
filename=<optimized out>, posix_mode=<optimized out>, prot=prot@entry=438,
read_write=8, is32not64=<optimized out>) at fileops.c:186
#2 0x00007ffff7e822aa in _IO_new_file_fopen (fp=fp@entry=0x5555555596b0,
filename=filename@entry=0x7ffff7df715e "/etc/passwd", mode=<optimized out>,
mode@entry=0x7ffff7df7003 "rce", is32not64=is32not64@entry=1) at
fileops.c:281
#3 0x00007ffff7e75c09 in __fopen_internal (
filename=filename@entry=0x7ffff7df715e "/etc/passwd",
mode=mode@entry=0x7ffff7df7003 "rce", is32=is32@entry=1) at iofopen.c:75
#4 0x00007ffff7e75c8a in _IO_new_fopen (
filename=filename@entry=0x7ffff7df715e "/etc/passwd",
mode=mode@entry=0x7ffff7df7003 "rce") at iofopen.c:86
#5 0x00007ffff7df37a0 in internal_setent (stream=<synthetic pointer>)
at nss_files/files-XXX.c:77
#6 _nss_files_getpwnam_r (name=0x7fffffffe38a "root", result=0x7fffffffdf10,
buffer=0x5555555592a0 "", buflen=1024, errnop=0x7ffff7fc74c0)
at nss_files/files-pwd.c:32
#7 0x00007ffff7ecb4f3 in __getpwnam_r (name=0x7fffffffe38a "root",
resbuf=0x7fffffffdf10,
buffer=0x5555555592a0 "", buflen=1024, result=<optimized out>)
at ../nss/getXXbyYY_r.c:315
#8 0x0000555555555266 in main (argc=2, argv=0x7fffffffe058) at test.c:30
fopen gets called here:
https://sources.debian.org/src/glibc/2.31-17/nss/nss_files/files-XXX.c/#L77
This is with glibc 2.32:
#0 __GI___open64_nocancel (file=0x7ffff7db104f "/etc/passwd", oflag=524288)
at ../sysdeps/unix/sysv/linux/open64_nocancel.c:45
#1 0x00007ffff7e369d5 in __GI__IO_file_open (fp=fp@entry=0x5555555596b0,
filename=<optimized out>,
posix_mode=<optimized out>, prot=prot@entry=438, read_write=8,
is32not64=<optimized out>) at fileops.c:186
#2 0x00007ffff7e36afa in _IO_new_file_fopen (fp=fp@entry=0x5555555596b0,
filename=filename@entry=0x7ffff7db104f "/etc/passwd", mode=<optimized out>,
mode@entry=0x7ffff7f3f08e "rce",
is32not64=is32not64@entry=1) at fileops.c:281
#3 0x00007ffff7e2a829 in __fopen_internal
(filename=filename@entry=0x7ffff7db104f "/etc/passwd",
mode=mode@entry=0x7ffff7f3f08e "rce", is32=is32@entry=1) at iofopen.c:75
#4 0x00007ffff7e2a8aa in _IO_new_fopen (filename=filename@entry=0x7ffff7db104f
"/etc/passwd",
mode=mode@entry=0x7ffff7f3f08e "rce") at iofopen.c:86
#5 0x00007ffff7ed7dbe in __GI___nss_files_fopen
(path=path@entry=0x7ffff7db104f "/etc/passwd")
at nss_files_fopen.c:27
#6 0x00007ffff7dac3cc in internal_setpwent (ent=ent@entry=0x7fffffffde70,
stayopen=stayopen@entry=0,
needent=needent@entry=0) at nss_compat/compat-pwd.c:227
#7 0x00007ffff7dad76a in _nss_compat_getpwnam_r (name=0x7fffffffe479 "josch",
pwd=0x7fffffffe020,
buffer=0x5555555592a0 "", buflen=1024, errnop=0x7ffff7f7c4c8) at
nss_compat/compat-pwd.c:829
#8 0x00007ffff7e801e3 in __getpwnam_r (name=0x7fffffffe479 "josch",
resbuf=0x7fffffffe020,
buffer=0x5555555592a0 "", buflen=1024, result=<optimized out>) at
../nss/getXXbyYY_r.c:315
#9 0x0000555555555266 in main (argc=2, argv=0x7fffffffe168) at test.c:30
fopen gets called here:
https://sources.debian.org/src/glibc/2.32-2/nss/nss_files_fopen.c/#L27
But why is the fopen of 2.32 different from the one in 2.31?
signature.asc
Description: signature
