--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 ARM Limited.
+ * Original author: Mark Brown <broonie@kernel.org>
+ */
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <asm/sigcontext.h>
+#include <asm/hwcap.h>
+
+#include "../../kselftest.h"
+#include "rdvl.h"
+
+#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
+
+#define ARCH_MIN_VL SVE_VL_MIN
+
+struct vec_data {
+ const char *name;
+ unsigned long hwcap_type;
+ unsigned long hwcap;
+ const char *rdvl_binary;
+ int (*rdvl)(void);
+
+ int prctl_get;
+ int prctl_set;
+ const char *default_vl_file;
+
+ int default_vl;
+ int min_vl;
+ int max_vl;
+};
+
+
+static struct vec_data vec_data[] = {
+ {
+ .name = "SVE",
+ .hwcap_type = AT_HWCAP,
+ .hwcap = HWCAP_SVE,
+ .rdvl = rdvl_sve,
+ .rdvl_binary = "./rdvl-sve",
+ .prctl_get = PR_SVE_GET_VL,
+ .prctl_set = PR_SVE_SET_VL,
+ .default_vl_file = "/proc/sys/abi/sve_default_vector_length",
+ },
+};
+
+static int stdio_read_integer(FILE *f, const char *what, int *val)
+{
+ int n = 0;
+ int ret;
+
+ ret = fscanf(f, "%d%*1[\n]%n", val, &n);
+ if (ret < 1 || n < 1) {
+ ksft_print_msg("failed to parse integer from %s\n", what);
+ return -1;
+ }
+
+ return 0;
+}
+
+/* Start a new process and return the vector length it sees */
+static int get_child_rdvl(struct vec_data *data)
+{
+ FILE *out;
+ int pipefd[2];
+ pid_t pid, child;
+ int read_vl, ret;
+
+ ret = pipe(pipefd);
+ if (ret == -1) {
+ ksft_print_msg("pipe() failed: %d (%s)\n",
+ errno, strerror(errno));
+ return -1;
+ }
+
+ fflush(stdout);
+
+ child = fork();
+ if (child == -1) {
+ ksft_print_msg("fork() failed: %d (%s)\n",
+ errno, strerror(errno));
+ close(pipefd[0]);
+ close(pipefd[1]);
+ return -1;
+ }
+
+ /* Child: put vector length on the pipe */
+ if (child == 0) {
+ /*
+ * Replace stdout with the pipe, errors to stderr from
+ * here as kselftest prints to stdout.
+ */
+ ret = dup2(pipefd[1], 1);
+ if (ret == -1) {
+ fprintf(stderr, "dup2() %d\n", errno);
+ exit(EXIT_FAILURE);
+ }
+
+ /* exec() a new binary which puts the VL on stdout */
+ ret = execl(data->rdvl_binary, data->rdvl_binary, NULL);
+ fprintf(stderr, "execl(%s) failed: %d\n",
+ data->rdvl_binary, errno, strerror(errno));
+
+ exit(EXIT_FAILURE);
+ }
+
+ close(pipefd[1]);
+
+ /* Parent; wait for the exit status from the child & verify it */
+ do {
+ pid = wait(&ret);
+ if (pid == -1) {
+ ksft_print_msg("wait() failed: %d (%s)\n",
+ errno, strerror(errno));
+ close(pipefd[0]);
+ return -1;
+ }
+ } while (pid != child);
+
+ assert(pid == child);
+
+ if (!WIFEXITED(ret)) {
+ ksft_print_msg("child exited abnormally\n");
+ close(pipefd[0]);
+ return -1;
+ }
+
+ if (WEXITSTATUS(ret) != 0) {
+ ksft_print_msg("child returned error %d\n",
+ WEXITSTATUS(ret));
+ close(pipefd[0]);
+ return -1;
+ }
+
+ out = fdopen(pipefd[0], "r");
+ if (!out) {
+ ksft_print_msg("failed to open child stdout\n");
+ close(pipefd[0]);
+ return -1;
+ }
+
+ ret = stdio_read_integer(out, "child", &read_vl);
+ fclose(out);
+ if (ret != 0)
+ return ret;
+
+ return read_vl;
+}
+
+static int file_read_integer(const char *name, int *val)
+{
+ FILE *f;
+ int ret;
+
+ f = fopen(name, "r");
+ if (!f) {
+ ksft_test_result_fail("Unable to open %s: %d (%s)\n",
+ name, errno,
+ strerror(errno));
+ return -1;
+ }
+
+ ret = stdio_read_integer(f, name, val);
+ fclose(f);
+
+ return ret;
+}
+
+static int file_write_integer(const char *name, int val)
+{
+ FILE *f;
+ int ret;
+
+ f = fopen(name, "w");
+ if (!f) {
+ ksft_test_result_fail("Unable to open %s: %d (%s)\n",
+ name, errno,
+ strerror(errno));
+ return -1;
+ }
+
+ fprintf(f, "%d", val);
+ fclose(f);
+ if (ret < 0) {
+ ksft_test_result_fail("Error writing %d to %s\n",
+ val, name);
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * Verify that we can read the default VL via proc, checking that it
+ * is set in a freshly spawned child.
+ */
+static void proc_read_default(struct vec_data *data)
+{
+ int default_vl, child_vl, ret;
+
+ ret = file_read_integer(data->default_vl_file, &default_vl);
+ if (ret != 0)
+ return;
+
+ /* Is this the actual default seen by new processes? */
+ child_vl = get_child_rdvl(data);
+ if (child_vl != default_vl) {
+ ksft_test_result_fail("%s is %d but child VL is %d\n",
+ data->default_vl_file,
+ default_vl, child_vl);
+ return;
+ }
+
+ ksft_test_result_pass("%s default vector length %d\n", data->name,
+ default_vl);
+ data->default_vl = default_vl;
+}
+
+/* Verify that we can write a minimum value and have it take effect */
+static void proc_write_min(struct vec_data *data)
+{
+ int ret, new_default, child_vl;
+
+ if (geteuid() != 0) {
+ ksft_test_result_skip("Need to be root to write to /proc\n");
+ return;
+ }
+
+ ret = file_write_integer(data->default_vl_file, ARCH_MIN_VL);
+ if (ret != 0)
+ return;
+
+ /* What was the new value? */
+ ret = file_read_integer(data->default_vl_file, &new_default);
+ if (ret != 0)
+ return;
+
+ /* Did it take effect in a new process? */
+ child_vl = get_child_rdvl(data);
+ if (child_vl != new_default) {
+ ksft_test_result_fail("%s is %d but child VL is %d\n",
+ data->default_vl_file,
+ new_default, child_vl);
+ return;
+ }
+
+ ksft_test_result_pass("%s minimum vector length %d\n", data->name,
+ new_default);
+ data->min_vl = new_default;
+
+ file_write_integer(data->default_vl_file, data->default_vl);
+}
+
+/* Verify that we can write a maximum value and have it take effect */
+static void proc_write_max(struct vec_data *data)
+{
+ int ret, new_default, child_vl;
+
+ if (geteuid() != 0) {
+ ksft_test_result_skip("Need to be root to write to /proc\n");
+ return;
+ }
+
+ /* -1 is accepted by the /proc interface as the maximum VL */
+ ret = file_write_integer(data->default_vl_file, -1);
+ if (ret != 0)
+ return;
+
+ /* What was the new value? */
+ ret = file_read_integer(data->default_vl_file, &new_default);
+ if (ret != 0)
+ return;
+
+ /* Did it take effect in a new process? */
+ child_vl = get_child_rdvl(data);
+ if (child_vl != new_default) {
+ ksft_test_result_fail("%s is %d but child VL is %d\n",
+ data->default_vl_file,
+ new_default, child_vl);
+ return;
+ }
+
+ ksft_test_result_pass("%s maximum vector length %d\n", data->name,
+ new_default);
+ data->max_vl = new_default;
+
+ file_write_integer(data->default_vl_file, data->default_vl);
+}
+
+/* Can we read back a VL from prctl? */
+static void prctl_get(struct vec_data *data)
+{
+ int ret;
+
+ ret = prctl(data->prctl_get);
+ if (ret == -1) {
+ ksft_test_result_fail("%s prctl() read failed: %d (%s)\n",
+ data->name, errno, strerror(errno));
+ return;
+ }
+
+ /* Mask out any flags */
+ ret &= PR_SVE_VL_LEN_MASK;
+
+ /* Is that what we can read back directly? */
+ if (ret == data->rdvl())
+ ksft_test_result_pass("%s current VL is %d\n",
+ data->name, ret);
+ else
+ ksft_test_result_fail("%s prctl() VL %d but RDVL is %d\n",
+ data->name, ret, data->rdvl());
+}
+
+/* Does the prctl let us set the VL we already have? */
+static void prctl_set_same(struct vec_data *data)
+{
+ int cur_vl = data->rdvl();
+ int ret;
+
+ ret = prctl(data->prctl_set, cur_vl);
+ if (ret < 0) {
+ ksft_test_result_fail("%s prctl set failed: %d (%s)\n",
+ data->name, errno, strerror(errno));
+ return;
+ }
+
+ if (cur_vl != data->rdvl())
+ ksft_test_result_pass("%s current VL is %d\n",
+ data->name, ret);
+ else
+ ksft_test_result_fail("%s prctl() VL %d but RDVL is %d\n",
+ data->name, ret, data->rdvl());
+}
+
+/* Can we set a new VL for this process? */
+static void prctl_set(struct vec_data *data)
+{
+ int ret;
+
+ if (data->min_vl == data->max_vl) {
+ ksft_test_result_skip("%s only one VL supported\n",
+ data->name);
+ return;
+ }
+
+ /* Try to set the minimum VL */
+ ret = prctl(data->prctl_set, data->min_vl);
+ if (ret < 0) {
+ ksft_test_result_fail("%s prctl set failed for %d: %d (%s)\n",
+ data->name, data->min_vl,
+ errno, strerror(errno));
+ return;
+ }
+
+ if ((ret & PR_SVE_VL_LEN_MASK) != data->min_vl) {
+ ksft_test_result_fail("%s prctl set %d but return value is %d\n",
+ data->name, data->min_vl, data->rdvl());
+ return;
+ }
+
+ if (data->rdvl() != data->min_vl) {
+ ksft_test_result_fail("%s set %d but RDVL is %d\n",
+ data->name, data->min_vl, data->rdvl());
+ return;
+ }
+
+ /* Try to set the maximum VL */
+ ret = prctl(data->prctl_set, data->max_vl);
+ if (ret < 0) {
+ ksft_test_result_fail("%s prctl set failed for %d: %d (%s)\n",
+ data->name, data->max_vl,
+ errno, strerror(errno));
+ return;
+ }
+
+ if ((ret & PR_SVE_VL_LEN_MASK) != data->max_vl) {
+ ksft_test_result_fail("%s prctl() set %d but return value is %d\n",
+ data->name, data->max_vl, data->rdvl());
+ return;
+ }
+
+ /* The _INHERIT flag should not be present when we read the VL */
+ ret = prctl(data->prctl_get);
+ if (ret == -1) {
+ ksft_test_result_fail("%s prctl() read failed: %d (%s)\n",
+ data->name, errno, strerror(errno));
+ return;
+ }
+
+ if (ret & PR_SVE_VL_INHERIT) {
+ ksft_test_result_fail("%s prctl() reports _INHERIT\n",
+ data->name);
+ return;
+ }
+
+ ksft_test_result_pass("%s prctl() set min/max\n", data->name);
+}
+
+/* If we didn't request it a new VL shouldn't affect the child */
+static void prctl_set_no_child(struct vec_data *data)
+{
+ int ret, child_vl;
+
+ if (data->min_vl == data->max_vl) {
+ ksft_test_result_skip("%s only one VL supported\n",
+ data->name);
+ return;
+ }
+
+ ret = prctl(data->prctl_set, data->min_vl);
+ if (ret < 0) {
+ ksft_test_result_fail("%s prctl set failed for %d: %d (%s)\n",
+ data->name, data->min_vl,
+ errno, strerror(errno));
+ return;
+ }
+
+ /* Ensure the default VL is different */
+ ret = file_write_integer(data->default_vl_file, data->max_vl);
+ if (ret != 0)
+ return;
+
+ /* Check that the child has the default we just set */
+ child_vl = get_child_rdvl(data);
+ if (child_vl != data->max_vl) {
+ ksft_test_result_fail("%s is %d but child VL is %d\n",
+ data->default_vl_file,
+ data->max_vl, child_vl);
+ return;
+ }
+
+ ksft_test_result_pass("%s vector length used default\n", data->name);
+
+ file_write_integer(data->default_vl_file, data->default_vl);
+}
+
+/* If we didn't request it a new VL shouldn't affect the child */
+static void prctl_set_for_child(struct vec_data *data)
+{
+ int ret, child_vl;
+
+ if (data->min_vl == data->max_vl) {
+ ksft_test_result_skip("%s only one VL supported\n",
+ data->name);
+ return;
+ }
+
+ ret = prctl(data->prctl_set, data->min_vl | PR_SVE_VL_INHERIT);
+ if (ret < 0) {
+ ksft_test_result_fail("%s prctl set failed for %d: %d (%s)\n",
+ data->name, data->min_vl,
+ errno, strerror(errno));
+ return;
+ }
+
+ /* The _INHERIT flag should be present when we read the VL */
+ ret = prctl(data->prctl_get);
+ if (ret == -1) {
+ ksft_test_result_fail("%s prctl() read failed: %d (%s)\n",
+ data->name, errno, strerror(errno));
+ return;
+ }
+ if (!(ret & PR_SVE_VL_INHERIT)) {
+ ksft_test_result_fail("%s prctl() does not report _INHERIT\n",
+ data->name);
+ return;
+ }
+
+ /* Ensure the default VL is different */
+ ret = file_write_integer(data->default_vl_file, data->max_vl);
+ if (ret != 0)
+ return;
+
+ /* Check that the child inherited our VL */
+ child_vl = get_child_rdvl(data);
+ if (child_vl != data->min_vl) {
+ ksft_test_result_fail("%s is %d but child VL is %d\n",
+ data->default_vl_file,
+ data->min_vl, child_vl);
+ return;
+ }
+
+ ksft_test_result_pass("%s vector length was inherited\n", data->name);
+
+ file_write_integer(data->default_vl_file, data->default_vl);
+}
+
+/* _ONEXEC takes effect only in the child process */
+static void prctl_set_onexec(struct vec_data *data)
+{
+ int ret, child_vl;
+
+ if (data->min_vl == data->max_vl) {
+ ksft_test_result_skip("%s only one VL supported\n",
+ data->name);
+ return;
+ }
+
+ /* Set a known value for the default and our current VL */
+ ret = file_write_integer(data->default_vl_file, data->max_vl);
+ if (ret != 0)
+ return;
+
+ ret = prctl(data->prctl_set, data->max_vl);
+ if (ret < 0) {
+ ksft_test_result_fail("%s prctl set failed for %d: %d (%s)\n",
+ data->name, data->min_vl,
+ errno, strerror(errno));
+ return;
+ }
+
+ /* Set a different value for the child to have on exec */
+ ret = prctl(data->prctl_set, data->min_vl | PR_SVE_SET_VL_ONEXEC);
+ if (ret < 0) {
+ ksft_test_result_fail("%s prctl set failed for %d: %d (%s)\n",
+ data->name, data->min_vl,
+ errno, strerror(errno));
+ return;
+ }
+
+ /* Our current VL should stay the same */
+ if (data->rdvl() != data->max_vl) {
+ ksft_test_result_fail("%s VL changed by _ONEXEC prctl()\n",
+ data->name);
+ return;
+ }
+
+ /* Check that the child inherited our VL */
+ child_vl = get_child_rdvl(data);
+ if (child_vl != data->min_vl) {
+ ksft_test_result_fail("Set %d _ONEXEC but child VL is %d\n",
+ data->min_vl, child_vl);
+ return;
+ }
+
+ ksft_test_result_pass("%s vector length set on exec\n", data->name);
+
+ file_write_integer(data->default_vl_file, data->default_vl);
+}
+
+typedef void (*test_type)(struct vec_data *);
+
+static const test_type tests[] = {
+ /*
+ * The default/min/max tests must be first and in this order
+ * to provide data for other tests.
+ */
+ proc_read_default,
+ proc_write_min,
+ proc_write_max,
+
+ prctl_get,
+ prctl_set,
+ prctl_set_no_child,
+ prctl_set_for_child,
+ prctl_set_onexec,
+};
+
+int main(void)
+{
+ int i, j;
+
+ ksft_print_header();
+ ksft_set_plan(ARRAY_SIZE(tests) * ARRAY_SIZE(vec_data));
+
+ for (i = 0; i < ARRAY_SIZE(vec_data); i++) {
+ struct vec_data *data = &vec_data[i];
+ unsigned long supported;
+
+ supported = getauxval(data->hwcap_type) & data->hwcap;
+
+ for (j = 0; j < ARRAY_SIZE(tests); j++) {
+ if (supported)
+ tests[j](data);
+ else
+ ksft_test_result_skip("%s not supported\n",
+ data->name);
+ }
+ }
+
+ ksft_exit_pass();
+}
projects / users / dwmw2 / linux.git / commitdiff