| 1 | /* |
| 2 | * SPDX-License-Identifier: GPL-2.0-or-later |
| 3 | * |
| 4 | * This test attempts to execute a magic syscall. The syscall test plugin |
| 5 | * should intercept this and return an expected value. |
| 6 | */ |
| 7 | |
| 8 | #include <stdint.h> |
| 9 | #include <stdio.h> |
| 10 | #include <stdlib.h> |
| 11 | #include <unistd.h> |
| 12 | |
| 13 | int main(int argc, char *argv[]) |
| 14 | { |
| 15 | #ifdef SKIP |
| 16 | return EXIT_SUCCESS; |
| 17 | #endif |
| 18 | /* |
| 19 | * We cannot use a very large magic syscall number, because on some ISAs, |
| 20 | * QEMU will treat it as an illegal instruction and trigger a critical |
| 21 | * exception. For instance, on arm32, the syscall number cannot exceed |
| 22 | * ARM_NR_BASE (0xf0000), as can be seen in |
| 23 | * "linux-user/arm/cpu_loop.c:cpu_loop". |
| 24 | * As well, some arch expect a minimum, like 4000 for mips 32 bits. |
| 25 | * |
| 26 | * Therefore, we pick 4096, which sits between those bounds. It is not |
| 27 | * unused everywhere though: mips 32 bits numbers from 4000, so 4096 is its |
| 28 | * getpriority. This test is unaffected because the filter also requires |
| 29 | * the first argument to be 0x66CCFF, so a real syscall carrying this |
| 30 | * number falls through untouched. This is just a test case, so replace |
| 31 | * this number as needed in the future. |
| 32 | * |
| 33 | * The corresponding syscall filter is implemented in |
| 34 | * "tests/tcg/plugins/syscall.c". |
| 35 | */ |
| 36 | long ret = syscall(4096, 0x66CCFF); |
| 37 | if (ret != 0xFFCC66) { |
| 38 | fprintf(stderr, "Error: unexpected syscall return value %ld\n", ret); |
| 39 | return EXIT_FAILURE; |
| 40 | } |
| 41 | return EXIT_SUCCESS; |
| 42 | } |