selftests/x86/lam: Add mmap and SYSCALL test cases for linear-address masking

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@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20230312112612.31869-14-kirill.shutemov%40linux.intel.com

diff --git a/tools/testing/selftests/x86/lam.c b/tools/testing/selftests/x86/lam.c
index 268c1d2..39ebfc5 100644 (file)
--- 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>
 
@@ -29,11 +30,18 @@
 /* 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 */
@@ -49,6 +57,7 @@ jmp_buf segv_env;
 static void segv_handler(int sig)
 {
        ksft_print_msg("Get segmentation fault(%d).", sig);
+
        siglongjmp(segv_env, 1);
 }
 
@@ -61,6 +70,16 @@ 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.
@@ -213,6 +232,68 @@ 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 *)set_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;
@@ -241,13 +322,20 @@ static void run_test(struct testcases *test, int count)
                struct testcases *t = test + i;
 
                /* fork a process to run test case */
+               tests_cnt++;
                ret = fork_test(t);
+
+               /* return 3 is not support LA57, the case should be skipped */
+               if (ret == 3) {
+                       ksft_test_result_skip(t->msg);
+                       continue;
+               }
+
                if (ret != 0)
                        ret = (t->expected == ret);
                else
                        ret = !(t->expected);
 
-               tests_cnt++;
                ksft_test_result(ret, t->msg);
        }
 }
@@ -268,7 +356,6 @@ static struct testcases malloc_cases[] = {
        },
 };
 
-
 static struct testcases bits_cases[] = {
        {
                .test_func = handle_max_bits,
@@ -276,11 +363,54 @@ 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:[Negative] Disable LAM. Dereferencing pointer with metadata.\n",
+       },
+};
+
+static struct testcases mmap_cases[] = {
+       {
+               .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");
 }
 
@@ -320,6 +450,12 @@ 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();