Register a syscall filter callback in tests/tcg/plugins/sycall.c, returns a specific value for a magic system call number, and check it in tests/tcg/multiarch/test-plugin-syscall-filter.c.
Signed-off-by: Ziyang Zhang <[email protected]> Co-authored-by: Mingyuan Xia <[email protected]> --- tests/tcg/multiarch/Makefile.target | 4 ++- .../multiarch/test-plugin-syscall-filter.c | 35 +++++++++++++++++++ tests/tcg/plugins/syscall.c | 19 ++++++++++ 3 files changed, 57 insertions(+), 1 deletion(-) create mode 100644 tests/tcg/multiarch/test-plugin-syscall-filter.c diff --git a/tests/tcg/multiarch/Makefile.target b/tests/tcg/multiarch/Makefile.target index f5b4d2b813..4005e3a8a9 100644 --- a/tests/tcg/multiarch/Makefile.target +++ b/tests/tcg/multiarch/Makefile.target @@ -202,8 +202,10 @@ run-plugin-test-plugin-mem-access-with-libmem.so: \ CHECK_PLUGIN_OUTPUT_COMMAND= \ $(SRC_PATH)/tests/tcg/multiarch/check-plugin-output.sh \ $(QEMU) $< +run-plugin-test-plugin-syscall-filter-with-libsyscall.so: -EXTRA_RUNS_WITH_PLUGIN += run-plugin-test-plugin-mem-access-with-libmem.so +EXTRA_RUNS_WITH_PLUGIN += run-plugin-test-plugin-mem-access-with-libmem.so \ + run-plugin-test-plugin-syscall-filter-with-libsyscall.so endif # Update TESTS diff --git a/tests/tcg/multiarch/test-plugin-syscall-filter.c b/tests/tcg/multiarch/test-plugin-syscall-filter.c new file mode 100644 index 0000000000..caa2063a46 --- /dev/null +++ b/tests/tcg/multiarch/test-plugin-syscall-filter.c @@ -0,0 +1,35 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * This test attempts to execute a magic syscall. The syscall test plugin + * should intercept this and return an expected value. + */ + +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> + +int main(int argc, char *argv[]) +{ + /* + * We cannot use a very large magic syscall number, because on some ISAs, + * QEMU will treat it as an illegal instruction and trigger a critical + * exception. For instance, on arm32, the syscall number cannot exceed + * ARM_NR_BASE (0xf0000), as can be seen in + * "linux-user/arm/cpu_loop.c:cpu_loop". + * + * Therefore, we pick 2048 because, as of now, no ISA in Linux uses this + * number. This is just a test case; replace this number as needed in the + * future. + * + * The corresponding syscall filter is implemented in + * "tests/tcg/plugins/syscall.c". + */ + long ret = syscall(2048, 0x66CCFF); + if (ret != 0xFFCC66) { + fprintf(stderr, "Error: unexpected syscall return value %ld\n", ret); + return EXIT_FAILURE; + } + return EXIT_SUCCESS; +} diff --git a/tests/tcg/plugins/syscall.c b/tests/tcg/plugins/syscall.c index 42801f5c86..e7d4e9b589 100644 --- a/tests/tcg/plugins/syscall.c +++ b/tests/tcg/plugins/syscall.c @@ -170,6 +170,24 @@ static void vcpu_syscall_ret(qemu_plugin_id_t id, unsigned int vcpu_idx, } } +static bool vcpu_syscall_filter(qemu_plugin_id_t id, unsigned int vcpu_index, + int64_t num, uint64_t a1, uint64_t a2, + uint64_t a3, uint64_t a4, uint64_t a5, + uint64_t a6, uint64_t a7, uint64_t a8, + uint64_t *sysret) +{ + /* Special syscall to test the filter functionality. */ + if (num == 2048 && a1 == 0x66CCFF) { + *sysret = 0xFFCC66; + + if (!statistics) { + qemu_plugin_outs("magic syscall filtered, set magic return\n"); + } + return true; + } + return false; +} + static void print_entry(gpointer val, gpointer user_data) { SyscallStats *entry = (SyscallStats *) val; @@ -255,6 +273,7 @@ QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id, qemu_plugin_register_vcpu_syscall_cb(id, vcpu_syscall); qemu_plugin_register_vcpu_syscall_ret_cb(id, vcpu_syscall_ret); + qemu_plugin_register_vcpu_syscall_filter_cb(id, vcpu_syscall_filter); qemu_plugin_register_atexit_cb(id, plugin_exit, NULL); return 0; } -- 2.34.1
