> -----Original Message-----
> From: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> Sent: Monday, August 15, 2022 12:18
> To: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>; Lutomirski, Andy
> <luto@xxxxxxxxxx>; Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: x86@xxxxxxxxxx; Kostya Serebryany <kcc@xxxxxxxxxx>; Andrey Ryabinin
> <ryabinin.a.a@xxxxxxxxx>; Andrey Konovalov <andreyknvl@xxxxxxxxx>;
> Alexander Potapenko <glider@xxxxxxxxxx>; Taras Madan
> <tarasmadan@xxxxxxxxxx>; Dmitry Vyukov <dvyukov@xxxxxxxxxx>; H . J . Lu
> <hjl.tools@xxxxxxxxx>; Andi Kleen <ak@xxxxxxxxxxxxxxx>; Edgecombe, Rick P
> <rick.p.edgecombe@xxxxxxxxx>; linux-mm@xxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; Zhang, Weihong <weihong.zhang@xxxxxxxxx>; Kirill A .
> Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> Subject: [PATCHv6 09/11] selftests/x86/lam: Add mmap and SYSCALL test
> cases for linear-address masking
>
> From: Weihong Zhang <weihong.zhang@xxxxxxxxx>
>
> Add mmap and SYSCALL test cases.
>
> SYSCALL test cases:
>
> - LAM supports set metadata in high bits 62:57 (LAM_U57) of a user pointer,
> pass
> the pointer to SYSCALL, SYSCALL can dereference the pointer and return
> correct
> result.
>
> - Disable LAM, pass a pointer with metadata in high bits to SYSCALL,
> SYSCALL returns -1 (EFAULT).
>
> MMAP test cases:
>
> - Enable LAM_U57, MMAP with low address (below bits 47), set metadata
> in high bits of the address, dereference the address should be
> allowed.
>
> - Enable LAM_U57, MMAP with high address (above bits 47), set metadata
> in high bits of the address, dereference the address should be
> allowed.
>
> Signed-off-by: Weihong Zhang <weihong.zhang@xxxxxxxxx>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> ---
> tools/testing/selftests/x86/lam.c | 135 +++++++++++++++++++++++++++++-
> 1 file changed, 132 insertions(+), 3 deletions(-)
>
> diff --git a/tools/testing/selftests/x86/lam.c b/tools/testing/selftests/x86/lam.c
> index 4c6c6dbf7db6..e9e92ab7fea8 100644
> --- a/tools/testing/selftests/x86/lam.c
> +++ b/tools/testing/selftests/x86/lam.c
> @@ -7,6 +7,7 @@
> #include <signal.h>
> #include <setjmp.h>
> #include <sys/mman.h>
> +#include <sys/utsname.h>
> #include <sys/wait.h>
> #include <inttypes.h>
>
> @@ -27,11 +28,18 @@
> /* Specified test function bits */
> #define FUNC_MALLOC 0x1
> #define FUNC_BITS 0x2
> +#define FUNC_MMAP 0x4
> +#define FUNC_SYSCALL 0x8
>
> -#define TEST_MASK 0x3
> +#define TEST_MASK 0xf
> +
> +#define LOW_ADDR (0x1UL << 30)
> +#define HIGH_ADDR (0x3UL << 48)
>
> #define MALLOC_LEN 32
>
> +#define PAGE_SIZE (4 << 10)
> +
> struct testcases {
> unsigned int later;
> int expected; /* 2: SIGSEGV Error; 1: other errors */ @@ -47,6 +55,7
> @@ jmp_buf segv_env; static void segv_handler(int sig) {
> ksft_print_msg("Get segmentation fault(%d).", sig);
> +
> siglongjmp(segv_env, 1);
> }
>
> @@ -59,6 +68,16 @@ static inline int cpu_has_lam(void)
> return (cpuinfo[0] & (1 << 26));
> }
>
> +/* Check 5-level page table feature in CPUID.(EAX=07H,
> +ECX=00H):ECX.[bit 16] */ static inline int cpu_has_la57(void) {
> + unsigned int cpuinfo[4];
> +
> + __cpuid_count(0x7, 0, cpuinfo[0], cpuinfo[1], cpuinfo[2], cpuinfo[3]);
> +
> + return (cpuinfo[2] & (1 << 16));
> +}
> +
> /*
> * Set tagged address and read back untag mask.
> * check if the untagged mask is expected.
> @@ -204,6 +223,68 @@ static int handle_malloc(struct testcases *test)
> return ret;
> }
>
> +static int handle_mmap(struct testcases *test) {
> + void *ptr;
> + unsigned int flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED;
> + int ret = 0;
> +
> + if (test->later == 0 && test->lam != 0)
> + if (set_lam(test->lam) != 0)
> + return 1;
> +
> + ptr = mmap((void *)test->addr, PAGE_SIZE, PROT_READ |
> PROT_WRITE,
> + flags, -1, 0);
> + if (ptr == MAP_FAILED) {
> + if (test->addr == HIGH_ADDR)
> + if (!cpu_has_la57())
> + return 3; /* unsupport LA57 */
> + return 1;
> + }
> +
> + if (test->later != 0 && test->lam != 0)
> + if (set_lam(test->lam) != 0)
> + ret = 1;
> +
> + if (ret == 0) {
> + if (sigsetjmp(segv_env, 1) == 0) {
> + signal(SIGSEGV, segv_handler);
> + ret = handle_lam_test(ptr, test->lam);
> + } else {
> + ret = 2;
> + }
> + }
> +
> + munmap(ptr, PAGE_SIZE);
> + return ret;
> +}
> +
> +static int handle_syscall(struct testcases *test) {
> + struct utsname unme, *pu;
> + int ret = 0;
> +
> + if (test->later == 0 && test->lam != 0)
> + if (set_lam(test->lam) != 0)
> + return 1;
> +
> + if (sigsetjmp(segv_env, 1) == 0) {
> + signal(SIGSEGV, segv_handler);
> + pu = (struct utsname *)get_metadata((uint64_t)&unme, test-
> >lam);
> + ret = uname(pu);
> + if (ret < 0)
> + ret = 1;
> + } else {
> + ret = 2;
> + }
> +
> + if (test->later != 0 && test->lam != 0)
> + if (set_lam(test->lam) != -1 && ret == 0)
> + ret = 1;
> +
> + return ret;
> +}
> +
> static int fork_test(struct testcases *test) {
> int ret, child_ret;
> @@ -259,7 +340,6 @@ static struct testcases malloc_cases[] = {
> },
> };
>
> -
> static struct testcases bits_cases[] = {
> {
> .test_func = handle_max_bits,
> @@ -267,11 +347,54 @@ static struct testcases bits_cases[] = {
> },
> };
>
> +static struct testcases syscall_cases[] = {
> + {
> + .later = 0,
> + .lam = LAM_U57_BITS,
> + .test_func = handle_syscall,
> + .msg = "SYSCALL: LAM_U57. syscall with metadata\n",
> + },
> + {
> + .later = 1,
> + .expected = 1,
> + .lam = LAM_U57_BITS,
> + .test_func = handle_syscall,
> + .msg = "SYSCALL:[Negtive] Disable LAM. Dereferencing pointer
[Hu, Robert]
Trivial, Negtive --> Negative.
> with metadata.\n",
> + },
> +};
> +
> +static struct testcases mmap_cases[] = {
[Hu, Robert]
Can mmap also have negative case?
> + {
> + .later = 1,
> + .expected = 0,
> + .lam = LAM_U57_BITS,
> + .addr = HIGH_ADDR,
> + .test_func = handle_mmap,
> + .msg = "MMAP: First mmap high address, then set
> LAM_U57.\n",
> + },
> + {
> + .later = 0,
> + .expected = 0,
> + .lam = LAM_U57_BITS,
> + .addr = HIGH_ADDR,
> + .test_func = handle_mmap,
> + .msg = "MMAP: First LAM_U57, then High address.\n",
> + },
> + {
> + .later = 0,
> + .expected = 0,
> + .lam = LAM_U57_BITS,
> + .addr = LOW_ADDR,
> + .test_func = handle_mmap,
> + .msg = "MMAP: First LAM_U57, then Low address.\n",
> + },
> +};
> +
> static void cmd_help(void)
> {
> printf("usage: lam [-h] [-t test list]\n");
> printf("\t-t test list: run tests specified in the test list, default:0x%x\n",
> TEST_MASK);
> - printf("\t\t0x1:malloc; 0x2:max_bits;\n");
> + printf("\t\t0x1:malloc; 0x2:max_bits; 0x4:mmap; 0x8:syscall.\n");
> printf("\t-h: help\n");
> }
>
> @@ -311,6 +434,12 @@ int main(int argc, char **argv)
> if (tests & FUNC_BITS)
> run_test(bits_cases, ARRAY_SIZE(bits_cases));
>
> + if (tests & FUNC_MMAP)
> + run_test(mmap_cases, ARRAY_SIZE(mmap_cases));
> +
> + if (tests & FUNC_SYSCALL)
> + run_test(syscall_cases, ARRAY_SIZE(syscall_cases));
> +
> ksft_set_plan(tests_cnt);
>
> return ksft_exit_pass();
> --
> 2.35.1
