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

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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
This commit is contained in:
Weihong Zhang
2023-03-12 14:26:08 +03:00
committed by Dave Hansen
parent 3de9745c12
commit e67876962e
1 changed files with 140 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files
tools/testing/selftests/x86/lam.c
+140 -4
View File
@@ -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();