--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+#define _GNU_SOURCE
+
+#include <dirent.h>
+#include <sched.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+
+#include <linux/perf_event.h>
+
+#include "../kselftest_harness.h"
+
+#define RB_SIZE 0x3000
+#define AUX_SIZE 0x10000
+#define AUX_OFFS 0x4000
+
+#define HOLE_SIZE 0x1000
+
+/* Reserve space for rb, aux with space for shrink-beyond-vma testing. */
+#define REGION_SIZE (2 * RB_SIZE + 2 * AUX_SIZE)
+#define REGION_AUX_OFFS (2 * RB_SIZE)
+
+#define MAP_BASE 1
+#define MAP_AUX 2
+
+#define EVENT_SRC_DIR "/sys/bus/event_source/devices"
+
+FIXTURE(perf_mmap)
+{
+ int fd;
+ void *ptr;
+ void *region;
+};
+
+FIXTURE_VARIANT(perf_mmap)
+{
+ bool aux;
+ unsigned long ptr_size;
+};
+
+FIXTURE_VARIANT_ADD(perf_mmap, rb)
+{
+ .aux = false,
+ .ptr_size = RB_SIZE,
+};
+
+FIXTURE_VARIANT_ADD(perf_mmap, aux)
+{
+ .aux = true,
+ .ptr_size = AUX_SIZE,
+};
+
+static bool read_event_type(struct dirent *dent, __u32 *type)
+{
+ char typefn[512];
+ FILE *fp;
+ int res;
+
+ snprintf(typefn, sizeof(typefn), "%s/%s/type", EVENT_SRC_DIR, dent->d_name);
+ fp = fopen(typefn, "r");
+ if (!fp)
+ return false;
+
+ res = fscanf(fp, "%u", type);
+ fclose(fp);
+ return res > 0;
+}
+
+FIXTURE_SETUP(perf_mmap)
+{
+ struct perf_event_attr attr = {
+ .size = sizeof(attr),
+ .disabled = 1,
+ .exclude_kernel = 1,
+ .exclude_hv = 1,
+ };
+ struct perf_event_attr attr_ok = {};
+ unsigned int eacces = 0, map = 0;
+ struct perf_event_mmap_page *rb;
+ struct dirent *dent;
+ void *aux, *region;
+ DIR *dir;
+
+ self->ptr = NULL;
+
+ dir = opendir(EVENT_SRC_DIR);
+ if (!dir)
+ SKIP(return, "perf not available.");
+
+ region = mmap(NULL, REGION_SIZE, PROT_NONE, MAP_ANON | MAP_PRIVATE, -1, 0);
+ ASSERT_NE(region, MAP_FAILED);
+ self->region = region;
+
+ // Try to find a suitable event on this system
+ while ((dent = readdir(dir))) {
+ int fd;
+
+ if (!read_event_type(dent, &attr.type))
+ continue;
+
+ fd = syscall(SYS_perf_event_open, &attr, 0, -1, -1, 0);
+ if (fd < 0) {
+ if (errno == EACCES)
+ eacces++;
+ continue;
+ }
+
+ // Check whether the event supports mmap()
+ rb = mmap(region, RB_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, fd, 0);
+ if (rb == MAP_FAILED) {
+ close(fd);
+ continue;
+ }
+
+ if (!map) {
+ // Save the event in case that no AUX capable event is found
+ attr_ok = attr;
+ map = MAP_BASE;
+ }
+
+ if (!variant->aux)
+ continue;
+
+ rb->aux_offset = AUX_OFFS;
+ rb->aux_size = AUX_SIZE;
+
+ // Check whether it supports a AUX buffer
+ aux = mmap(region + REGION_AUX_OFFS, AUX_SIZE, PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_FIXED, fd, AUX_OFFS);
+ if (aux == MAP_FAILED) {
+ munmap(rb, RB_SIZE);
+ close(fd);
+ continue;
+ }
+
+ attr_ok = attr;
+ map = MAP_AUX;
+ munmap(aux, AUX_SIZE);
+ munmap(rb, RB_SIZE);
+ close(fd);
+ break;
+ }
+ closedir(dir);
+
+ if (!map) {
+ if (!eacces)
+ SKIP(return, "No mappable perf event found.");
+ else
+ SKIP(return, "No permissions for perf_event_open()");
+ }
+
+ self->fd = syscall(SYS_perf_event_open, &attr_ok, 0, -1, -1, 0);
+ ASSERT_NE(self->fd, -1);
+
+ rb = mmap(region, RB_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, self->fd, 0);
+ ASSERT_NE(rb, MAP_FAILED);
+
+ if (!variant->aux) {
+ self->ptr = rb;
+ return;
+ }
+
+ if (map != MAP_AUX)
+ SKIP(return, "No AUX event found.");
+
+ rb->aux_offset = AUX_OFFS;
+ rb->aux_size = AUX_SIZE;
+ aux = mmap(region + REGION_AUX_OFFS, AUX_SIZE, PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_FIXED, self->fd, AUX_OFFS);
+ ASSERT_NE(aux, MAP_FAILED);
+ self->ptr = aux;
+}
+
+FIXTURE_TEARDOWN(perf_mmap)
+{
+ ASSERT_EQ(munmap(self->region, REGION_SIZE), 0);
+ if (self->fd != -1)
+ ASSERT_EQ(close(self->fd), 0);
+}
+
+TEST_F(perf_mmap, remap)
+{
+ void *tmp, *ptr = self->ptr;
+ unsigned long size = variant->ptr_size;
+
+ // Test the invalid remaps
+ ASSERT_EQ(mremap(ptr, size, HOLE_SIZE, MREMAP_MAYMOVE), MAP_FAILED);
+ ASSERT_EQ(mremap(ptr + HOLE_SIZE, size, HOLE_SIZE, MREMAP_MAYMOVE), MAP_FAILED);
+ ASSERT_EQ(mremap(ptr + size - HOLE_SIZE, HOLE_SIZE, size, MREMAP_MAYMOVE), MAP_FAILED);
+ // Shrink the end of the mapping such that we only unmap past end of the VMA,
+ // which should succeed and poke a hole into the PROT_NONE region
+ ASSERT_NE(mremap(ptr + size - HOLE_SIZE, size, HOLE_SIZE, MREMAP_MAYMOVE), MAP_FAILED);
+
+ // Remap the whole buffer to a new address
+ tmp = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+ ASSERT_NE(tmp, MAP_FAILED);
+
+ // Try splitting offset 1 hole size into VMA, this should fail
+ ASSERT_EQ(mremap(ptr + HOLE_SIZE, size - HOLE_SIZE, size - HOLE_SIZE,
+ MREMAP_MAYMOVE | MREMAP_FIXED, tmp), MAP_FAILED);
+ // Remapping the whole thing should succeed fine
+ ptr = mremap(ptr, size, size, MREMAP_MAYMOVE | MREMAP_FIXED, tmp);
+ ASSERT_EQ(ptr, tmp);
+ ASSERT_EQ(munmap(tmp, size), 0);
+}
+
+TEST_F(perf_mmap, unmap)
+{
+ unsigned long size = variant->ptr_size;
+
+ // Try to poke holes into the mappings
+ ASSERT_NE(munmap(self->ptr, HOLE_SIZE), 0);
+ ASSERT_NE(munmap(self->ptr + HOLE_SIZE, HOLE_SIZE), 0);
+ ASSERT_NE(munmap(self->ptr + size - HOLE_SIZE, HOLE_SIZE), 0);
+}
+
+TEST_F(perf_mmap, map)
+{
+ unsigned long size = variant->ptr_size;
+
+ // Try to poke holes into the mappings by mapping anonymous memory over it
+ ASSERT_EQ(mmap(self->ptr, HOLE_SIZE, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0), MAP_FAILED);
+ ASSERT_EQ(mmap(self->ptr + HOLE_SIZE, HOLE_SIZE, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0), MAP_FAILED);
+ ASSERT_EQ(mmap(self->ptr + size - HOLE_SIZE, HOLE_SIZE, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0), MAP_FAILED);
+}
+
+TEST_HARNESS_MAIN
projects / users / dwmw2 / linux.git / commitdiff