From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755163AbdKNNoK (ORCPT ); Tue, 14 Nov 2017 08:44:10 -0500 Received: from mga06.intel.com ([134.134.136.31]:64690 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753905AbdKNNoC (ORCPT ); Tue, 14 Nov 2017 08:44:02 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.44,395,1505804400"; d="scan'208";a="2117737" From: "Kirill A. Shutemov" To: Ingo Molnar , x86@kernel.org, Thomas Gleixner , "H. Peter Anvin" Cc: Linus Torvalds , Andy Lutomirski , Nicholas Piggin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv2 2/2] x86/selftests: Add test for mapping placement for 5-level paging Date: Tue, 14 Nov 2017 16:43:22 +0300 Message-Id: <20171114134322.40321-2-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.15.0 In-Reply-To: <20171114134322.40321-1-kirill.shutemov@linux.intel.com> References: <20171114134322.40321-1-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With 5-level paging, we have 56-bit virtual address space available for userspace. But we don't want to expose userspace to addresses above 47-bits, unless it asked specifically for it. We use mmap(2) hint address as a way for kernel to know if it's okay to allocate virtual memory above 47-bit. Let's add a self-test that covers few corner cases of the interface. Signed-off-by: Kirill A. Shutemov --- tools/testing/selftests/x86/5lvl.c | 53 ++++++++++++++++++++++++++++++++++++ tools/testing/selftests/x86/Makefile | 2 +- 2 files changed, 54 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/x86/5lvl.c diff --git a/tools/testing/selftests/x86/5lvl.c b/tools/testing/selftests/x86/5lvl.c new file mode 100644 index 000000000000..94610fd13ba2 --- /dev/null +++ b/tools/testing/selftests/x86/5lvl.c @@ -0,0 +1,53 @@ +#include +#include + +#define PAGE_SIZE 4096 +#define SIZE (2 * PAGE_SIZE) +#define LOW_ADDR ((void *) (1UL << 30)) +#define HIGH_ADDR ((void *) (1UL << 50)) +#define TASK_SIZE ((void *) (1UL << 47)) + +int main(int argc, char **argv) +{ + void *p; + + p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + printf("mmap(NULL): %p %s\n", p, p > TASK_SIZE ? "FAILED!" : ""); + + p = mmap(LOW_ADDR, SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + printf("mmap(%p): %p %s\n", LOW_ADDR, p, + p > TASK_SIZE ? "FAILED!" : ""); + + p = mmap(HIGH_ADDR, SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + printf("mmap(%p): %p\n", HIGH_ADDR, p); + + p = mmap(HIGH_ADDR, SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + printf("mmap(%p) again: %p\n", HIGH_ADDR, p); + + p = mmap(HIGH_ADDR, SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); + printf("mmap(%p, MAP_FIXED): %p\n", HIGH_ADDR, p); + + p = mmap((void *)-1, SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + printf("mmap(-1): %p\n", p); + + p = mmap((void *)-1, SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + printf("mmap(-1) again: %p\n", p); + + p = mmap(TASK_SIZE - PAGE_SIZE, SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + printf("mmap(%p, %d): %p %s\n", TASK_SIZE - PAGE_SIZE, SIZE, p, + p > TASK_SIZE ? "FAILED!" : ""); + + p = mmap(TASK_SIZE - PAGE_SIZE, SIZE, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); + printf("mmap(TASK_SIZE - PAGE_SIZE, MAP_FIXED): %p\n", p); + + return 0; +} diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index 7b1adeee4b0f..939a337128db 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -11,7 +11,7 @@ TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt ptrace_sysc TARGETS_C_32BIT_ONLY := entry_from_vm86 syscall_arg_fault test_syscall_vdso unwind_vdso \ test_FCMOV test_FCOMI test_FISTTP \ vdso_restorer -TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip +TARGETS_C_64BIT_ONLY := fsgsbase sysret_rip 5lvl TARGETS_C_32BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_32BIT_ONLY) TARGETS_C_64BIT_ALL := $(TARGETS_C_BOTHBITS) $(TARGETS_C_64BIT_ONLY) -- 2.15.0