Add a selftest for MAP_BELOW_HINT that maps until it runs out of space below the hint address.
Signed-off-by: Charlie Jenkins charlie@rivosinc.com --- tools/testing/selftests/mm/Makefile | 1 + tools/testing/selftests/mm/map_below_hint.c | 32 +++++++++++++++++++++++++++++ 2 files changed, 33 insertions(+)
diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile index cfad627e8d94..4e2de85267b5 100644 --- a/tools/testing/selftests/mm/Makefile +++ b/tools/testing/selftests/mm/Makefile @@ -50,6 +50,7 @@ TEST_GEN_FILES += hugepage-shm TEST_GEN_FILES += hugepage-vmemmap TEST_GEN_FILES += khugepaged TEST_GEN_FILES += madv_populate +TEST_GEN_FILES += map_below_hint TEST_GEN_FILES += map_fixed_noreplace TEST_GEN_FILES += map_hugetlb TEST_GEN_FILES += map_populate diff --git a/tools/testing/selftests/mm/map_below_hint.c b/tools/testing/selftests/mm/map_below_hint.c new file mode 100644 index 000000000000..55d6cbf90645 --- /dev/null +++ b/tools/testing/selftests/mm/map_below_hint.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test the MAP_BELOW_HINT mmap flag. + */ +#include <sys/mman.h> +#include <errno.h> +#include "../kselftest.h" + +#define ADDR (1 << 20) +#define LENGTH (ADDR / 10000) + +#define MAP_BELOW_HINT 0x8000000 /* Not defined in all libc */ + +/* + * Map memory with MAP_BELOW_HINT until no memory left. Ensure that all returned + * addresses are below the hint. + */ +int main(int argc, char **argv) +{ + void *addr; + + do { + addr = mmap((void *)ADDR, LENGTH, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_BELOW_HINT, -1, 0); + } while (addr != MAP_FAILED && (unsigned long)addr <= ADDR); + + if (errno == ENOMEM) + ksft_test_result_pass("MAP_BELOW_HINT works\n"); + else + ksft_test_result_fail("mmap returned address above hint with MAP_BELOW_HINT with error: %s\n", + strerror(errno)); +}