Don't assume that 4MB can be allocated from stack since there could be smaller
DefaultLimitSTACK= in force, so let's use malloc(). NUL terminate the huge
strings by hand, also ensure termination in test_lz4_decompress_partial() and
optimize the memset() for the string.
Some items in /proc and /etc may not be accessible to poor unprivileged users
due to e.g. SELinux, BOFH or both, so check for EACCES and EPERM.
/var/tmp may be a symlink to /tmp and then path_compare() will always fail, so
let's stick to /tmp like elsewhere.
/tmp may be mounted with noexec option and then trying to execute scripts from
there would fail.
Detect and warn if seccomp is already in use, which could make seccomp test
fail if the syscalls are already blocked.
Unset $TMPDIR so it will not break specifier tests where %T is assumed to be
/tmp and %V /var/tmp.
example.swaps with "(deleted)" does not cause bogus entries in the list now,
but a memleak in libmount instead. The memleaks is not very important since
this code is run just once.
Reported as https://github.com/karelzak/util-linux/issues/596.
$ build/test-umount
...
/* test_swap_list("/proc/swaps") */
path=/var/tmp/swap o= f=0x0 try-ro=no dev=0:0
path=/dev/dm-2 o= f=0x0 try-ro=no dev=0:0
/* test_swap_list("/home/zbyszek/src/systemd/test/test-umount/example.swaps") */
path=/some/swapfile o= f=0x0 try-ro=no dev=0:0
path=/dev/dm-2 o= f=0x0 try-ro=no dev=0:0
==26912==
==26912== HEAP SUMMARY:
==26912== in use at exit: 16 bytes in 1 blocks
==26912== total heap usage: 1,546 allocs, 1,545 frees, 149,008 bytes allocated
==26912==
==26912== 16 bytes in 1 blocks are definitely lost in loss record 1 of 1
==26912== at 0x4C31C15: realloc (vg_replace_malloc.c:785)
==26912== by 0x55C5D8C: _IO_vfscanf (in /usr/lib64/libc-2.26.so)
==26912== by 0x55D8AEC: vsscanf (in /usr/lib64/libc-2.26.so)
==26912== by 0x55D25C3: sscanf (in /usr/lib64/libc-2.26.so)
==26912== by 0x53236D0: mnt_table_parse_stream (in /usr/lib64/libmount.so.1.1.0)
==26912== by 0x53249B6: mnt_table_parse_file (in /usr/lib64/libmount.so.1.1.0)
==26912== by 0x10D157: swap_list_get (umount.c:194)
==26912== by 0x10B06E: test_swap_list (test-umount.c:34)
==26912== by 0x10B24B: main (test-umount.c:56)
==26912==
==26912== LEAK SUMMARY:
==26912== definitely lost: 16 bytes in 1 blocks
==26912== indirectly lost: 0 bytes in 0 blocks
==26912== possibly lost: 0 bytes in 0 blocks
==26912== still reachable: 0 bytes in 0 blocks
==26912== suppressed: 0 bytes in 0 blocks
