[PATCH RFC v3 2/2] selftests/mm: Create ADDR_LIMIT_47BIT test
From: Charlie Jenkins <hidden>
Date: 2024-09-05 21:16:19
Also in:
linux-alpha, linux-arch, linux-kselftest, linux-mips, linux-mm, linux-s390, linux-sh, lkml, loongarch, sparclinux
Subsystem:
kernel selftest framework, memory management - misc, the rest · Maintainers:
Shuah Khan, Andrew Morton, David Hildenbrand, Linus Torvalds
Add a selftest for the ADDR_LIMIT_47BIT personality flag that mmaps until it runs out of space and ensures no addresses are allocated above 47 bits. Signed-off-by: Charlie Jenkins <redacted> --- tools/testing/selftests/mm/.gitignore | 1 + tools/testing/selftests/mm/Makefile | 1 + tools/testing/selftests/mm/map_47bit_personality.c | 34 ++++++++++++++++++++++ 3 files changed, 36 insertions(+)
diff --git a/tools/testing/selftests/mm/.gitignore b/tools/testing/selftests/mm/.gitignore
index da030b43e43b..918ef05e180d 100644
--- a/tools/testing/selftests/mm/.gitignore
+++ b/tools/testing/selftests/mm/.gitignore@@ -32,6 +32,7 @@ mlock-random-test virtual_address_range gup_test va_128TBswitch +map_47bit_personality map_fixed_noreplace write_to_hugetlbfs hmm-tests
diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
index cfad627e8d94..2e95fd545409 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_47bit_personality TEST_GEN_FILES += map_fixed_noreplace TEST_GEN_FILES += map_hugetlb TEST_GEN_FILES += map_populate
diff --git a/tools/testing/selftests/mm/map_47bit_personality.c b/tools/testing/selftests/mm/map_47bit_personality.c
new file mode 100644
index 000000000000..453412990c21
--- /dev/null
+++ b/tools/testing/selftests/mm/map_47bit_personality.c@@ -0,0 +1,34 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test the ADDR_LIMIT_47BIT personality flag. + */ +#include <sys/syscall.h> +#include <sys/mman.h> +#include <errno.h> +#include "../kselftest.h" + +#define LENGTH (100000000) + +#define ADDR_LIMIT_47BIT 0x10000000 +#define BIT47 1UL << 47 + +/* + * Map memory with ADDR_LIMIT_47BIT until no memory left. Ensure that all returned + * addresses are below 47 bits. + */ +int main(int argc, char **argv) +{ + void *addr; + + syscall(__NR_personality, ADDR_LIMIT_47BIT); + + do { + addr = mmap(0, LENGTH, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + } while (addr != MAP_FAILED && (unsigned long)addr < BIT47); + + if (errno == ENOMEM) + ksft_test_result_pass("ADDR_LIMIT_47BIT works\n"); + else + ksft_test_result_fail("mmap returned address above 47 bits with ADDR_LIMIT_47BIT with addr: %p and err: %s\n", + addr, strerror(errno)); +}
--
2.45.0