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/*
* Check decoding of modify_ldt syscall.
*
* Copyright (c) 2018-2021 The strace developers.
* All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "tests.h"
#include "scno.h"
#if defined __NR_modify_ldt && defined HAVE_STRUCT_USER_DESC
# include <errno.h>
# include <stdio.h>
# include <unistd.h>
# include "print_user_desc.c"
static void
printrc(long rc)
{
# ifdef __x86_64__
/*
* Hopefully, we don't expect EPERM to be returned,
* otherwise we can't distinguish it on x32.
*/
if (rc != -1) {
int err = -rc;
/* Thanks, long return type of syscall(2) */
printf("%lld", zero_extend_signed_to_ull(rc));
if (err > 0 && err < 0x1000) {
errno = err;
printf(" %s (%m)", errno2name());
}
}
else
# endif
{
printf("%s", sprintrc(rc));
}
puts("");
}
int
main(void)
{
static const kernel_ulong_t bogus_func =
(kernel_ulong_t) 0xbadc0dedda7a1057ULL;
static const kernel_ulong_t bogus_bytecount =
(kernel_ulong_t) 0xdeadfacefa57beefULL;
TAIL_ALLOC_OBJECT_CONST_PTR(struct user_desc, us);
TAIL_ALLOC_OBJECT_CONST_PTR(unsigned int, bogus_int);
long rc;
fill_memory(us, sizeof(*us));
rc = syscall(__NR_modify_ldt, 0, 0, 0);
printf("modify_ldt(0, NULL, 0) = ");
printrc(rc);
rc = syscall(__NR_modify_ldt, bogus_func, (kernel_long_t) -1,
bogus_bytecount);
printf("modify_ldt(%d, %#llx, %llu) = ",
(int) bogus_func,
zero_extend_signed_to_ull((kernel_long_t) -1),
(unsigned long long) bogus_bytecount);
printrc(rc);
rc = syscall(__NR_modify_ldt, bogus_func, us + 1, 0);
printf("modify_ldt(%d, %p, 0) = ", (int) bogus_func, us + 1);
printrc(rc);
rc = syscall(__NR_modify_ldt, bogus_func, us, 42);
printf("modify_ldt(%d, %p, 42) = ", (int) bogus_func, us);
printrc(rc);
rc = syscall(__NR_modify_ldt, bogus_func, us + 1, sizeof(*us));
printf("modify_ldt(%d, %p, %zu) = ",
(int) bogus_func, us + 1, sizeof(*us));
printrc(rc);
/*
* print_user_desc handles entry_number field in a special way for
* get_thread_area syscall, so let's also check here that we don't
* retrieve it accidentally.
*/
rc = syscall(__NR_modify_ldt, bogus_func, bogus_int, sizeof(*us));
printf("modify_ldt(%d, %p, %zu) = ",
(int) bogus_func, bogus_int, sizeof(*us));
printrc(rc);
rc = syscall(__NR_modify_ldt, bogus_func, us, sizeof(*us));
printf("modify_ldt(%d, ", (int) bogus_func);
print_user_desc(us, NULL);
printf(", %zu) = ", sizeof(*us));
printrc(rc);
fill_memory_ex(us, sizeof(*us), 0x55, 80);
us->entry_number = -1;
us->base_addr = 0;
us->limit = 0;
rc = syscall(__NR_modify_ldt, bogus_func, us, sizeof(*us));
printf("modify_ldt(%d, ", (int) bogus_func);
print_user_desc(us, "-1");
printf(", %zu) = ", sizeof(*us));
printrc(rc);
puts("+++ exited with 0 +++");
return 0;
}
#else
SKIP_MAIN_UNDEFINED("__NR_modify_ldt && HAVE_STRUCT_USER_DESC");
#endif
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