Comment 9 for bug 1755499

Looking at the termination of t_immutable test program:

ARM:
mprotect(0xffff86092000, 4096, PROT_READ) = 0
mprotect(0xffff860b3000, 4096, PROT_READ) = 0
munmap(0xffff86295000, 38279) = 0
openat(AT_FDCWD, "/etc/passwd", O_RDONLY|O_CLOEXEC) = 4
lseek(4, 0, SEEK_CUR) = 0
fstat(4, {st_mode=S_IFREG|0644, st_size=1682, ...}) = 0
mmap(NULL, 1682, PROT_READ, MAP_SHARED, 4, 0) = 0xffff8629e000
lseek(4, 1682, SEEK_SET) = 1682
munmap(0xffff8629e000, 1682) = 0
close(4) = 0
dup(2) = 4
fcntl(4, F_GETFL) = 0x20002 (flags O_RDWR|0x20000)
fstat(4, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 0), ...}) = 0
write(4, "acl: Function not implemented\n", 30acl: Function not implemented
) = 30
close(4) = 0
exit_group(1) = ?
+++ exited with 1 +++

x86 at same place:
mprotect(0x7f677e46f000, 4096, PROT_READ) = 0
mprotect(0x7f677e67d000, 4096, PROT_READ) = 0
munmap(0x7f677f097000, 165753) = 0
openat(AT_FDCWD, "/etc/passwd", O_RDONLY|O_CLOEXEC) = 4
lseek(4, 0, SEEK_CUR) = 0
fstat(4, {st_mode=S_IFREG|0644, st_size=3023, ...}) = 0
mmap(NULL, 3023, PROT_READ, MAP_SHARED, 4, 0) = 0x7f677f0bf000
lseek(4, 3023, SEEK_SET) = 3023
munmap(0x7f677f0bf000, 3023) = 0
close(4) = 0
fsetxattr(3, "system.posix_acl_access", "\2\0\0\0\1\0\6\0\377\377\377\377\2\0\6\0\376\377\0\0\4\0\6\0\377\377\377\377\20\0\6", 44, 0) = -1 EOPNOTSUPP (Operation not supported)
fsetxattr(3, "trusted.test", "readonly", 8, XATTR_CREATE) = 0
fsetxattr(3, "user.test", "readonly", 8, XATTR_CREATE) = 0
..etc

So it's something different in the test program in the acl handling side