From: Zenghui Yu Date: Thu, 24 Jun 2021 07:09:31 +0000 (+0800) Subject: KVM: selftests: Fix mapping length truncation in m{,un}map() X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=309505dd5685;p=uclinux-h8%2Flinux.git KVM: selftests: Fix mapping length truncation in m{,un}map() max_mem_slots is now declared as uint32_t. The result of (0x200000 * 32767) is unexpectedly truncated to be 0xffe00000, whilst we actually need to allocate about, 63GB. Cast max_mem_slots to size_t in both mmap() and munmap() to fix the length truncation. We'll otherwise see the failure on arm64 thanks to the access_ok() checking in __kvm_set_memory_region(), as the unmapped VA happen to go beyond the task's allowed address space. # ./set_memory_region_test Allowed number of memory slots: 32767 Adding slots 0..32766, each memory region with 2048K size ==== Test Assertion Failure ==== set_memory_region_test.c:391: ret == 0 pid=94861 tid=94861 errno=22 - Invalid argument 1 0x00000000004015a7: test_add_max_memory_regions at set_memory_region_test.c:389 2 (inlined by) main at set_memory_region_test.c:426 3 0x0000ffffb8e67bdf: ?? ??:0 4 0x00000000004016db: _start at :? KVM_SET_USER_MEMORY_REGION IOCTL failed, rc: -1 errno: 22 slot: 2615 Fixes: 3bf0fcd75434 ("KVM: selftests: Speed up set_memory_region_test") Signed-off-by: Zenghui Yu Message-Id: <20210624070931.565-1-yuzenghui@huawei.com> Signed-off-by: Paolo Bonzini --- diff --git a/tools/testing/selftests/kvm/set_memory_region_test.c b/tools/testing/selftests/kvm/set_memory_region_test.c index 978f5b5f4dc0..d8812f27648c 100644 --- a/tools/testing/selftests/kvm/set_memory_region_test.c +++ b/tools/testing/selftests/kvm/set_memory_region_test.c @@ -376,7 +376,7 @@ static void test_add_max_memory_regions(void) pr_info("Adding slots 0..%i, each memory region with %dK size\n", (max_mem_slots - 1), MEM_REGION_SIZE >> 10); - mem = mmap(NULL, MEM_REGION_SIZE * max_mem_slots + alignment, + mem = mmap(NULL, (size_t)max_mem_slots * MEM_REGION_SIZE + alignment, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); TEST_ASSERT(mem != MAP_FAILED, "Failed to mmap() host"); mem_aligned = (void *)(((size_t) mem + alignment - 1) & ~(alignment - 1)); @@ -401,7 +401,7 @@ static void test_add_max_memory_regions(void) TEST_ASSERT(ret == -1 && errno == EINVAL, "Adding one more memory slot should fail with EINVAL"); - munmap(mem, MEM_REGION_SIZE * max_mem_slots + alignment); + munmap(mem, (size_t)max_mem_slots * MEM_REGION_SIZE + alignment); munmap(mem_extra, MEM_REGION_SIZE); kvm_vm_free(vm); }