Files
linux/tools/testing/selftests/arm64/mte/check_user_mem.c
Andre Przywara 46cb11b17c kselftest/arm64: mte: user_mem: Fix write() warning
Out of the box Ubuntu's 20.04 compiler warns about missing return value
checks for write() (sys)calls.

Make GCC happy by checking whether we actually managed to write "val".

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Mark Brown <broone@kernel.org>
Link: https://lore.kernel.org/r/20210319165334.29213-5-andre.przywara@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-03-24 15:43:01 +00:00

117 lines
3.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2020 ARM Limited
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ucontext.h>
#include <unistd.h>
#include <sys/mman.h>
#include "kselftest.h"
#include "mte_common_util.h"
#include "mte_def.h"
static size_t page_sz;
static int check_usermem_access_fault(int mem_type, int mode, int mapping)
{
int fd, i, err;
char val = 'A';
size_t len, read_len;
void *ptr, *ptr_next;
err = KSFT_FAIL;
len = 2 * page_sz;
mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG);
fd = create_temp_file();
if (fd == -1)
return KSFT_FAIL;
for (i = 0; i < len; i++)
if (write(fd, &val, sizeof(val)) != sizeof(val))
return KSFT_FAIL;
lseek(fd, 0, 0);
ptr = mte_allocate_memory(len, mem_type, mapping, true);
if (check_allocated_memory(ptr, len, mem_type, true) != KSFT_PASS) {
close(fd);
return KSFT_FAIL;
}
mte_initialize_current_context(mode, (uintptr_t)ptr, len);
/* Copy from file into buffer with valid tag */
read_len = read(fd, ptr, len);
mte_wait_after_trig();
if (cur_mte_cxt.fault_valid || read_len < len)
goto usermem_acc_err;
/* Verify same pattern is read */
for (i = 0; i < len; i++)
if (*(char *)(ptr + i) != val)
break;
if (i < len)
goto usermem_acc_err;
/* Tag the next half of memory with different value */
ptr_next = (void *)((unsigned long)ptr + page_sz);
ptr_next = mte_insert_new_tag(ptr_next);
mte_set_tag_address_range(ptr_next, page_sz);
lseek(fd, 0, 0);
/* Copy from file into buffer with invalid tag */
read_len = read(fd, ptr, len);
mte_wait_after_trig();
/*
* Accessing user memory in kernel with invalid tag should fail in sync
* mode without fault but may not fail in async mode as per the
* implemented MTE userspace support in Arm64 kernel.
*/
if (mode == MTE_SYNC_ERR &&
!cur_mte_cxt.fault_valid && read_len < len) {
err = KSFT_PASS;
} else if (mode == MTE_ASYNC_ERR &&
!cur_mte_cxt.fault_valid && read_len == len) {
err = KSFT_PASS;
}
usermem_acc_err:
mte_free_memory((void *)ptr, len, mem_type, true);
close(fd);
return err;
}
int main(int argc, char *argv[])
{
int err;
page_sz = getpagesize();
if (!page_sz) {
ksft_print_msg("ERR: Unable to get page size\n");
return KSFT_FAIL;
}
err = mte_default_setup();
if (err)
return err;
/* Register signal handlers */
mte_register_signal(SIGSEGV, mte_default_handler);
/* Set test plan */
ksft_set_plan(4);
evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_SYNC_ERR, MAP_PRIVATE),
"Check memory access from kernel in sync mode, private mapping and mmap memory\n");
evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_SYNC_ERR, MAP_SHARED),
"Check memory access from kernel in sync mode, shared mapping and mmap memory\n");
evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_ASYNC_ERR, MAP_PRIVATE),
"Check memory access from kernel in async mode, private mapping and mmap memory\n");
evaluate_test(check_usermem_access_fault(USE_MMAP, MTE_ASYNC_ERR, MAP_SHARED),
"Check memory access from kernel in async mode, shared mapping and mmap memory\n");
mte_restore_setup();
ksft_print_cnts();
return ksft_get_fail_cnt() == 0 ? KSFT_PASS : KSFT_FAIL;
}