// SPDX-License-Identifier: GPL-2.0 #include <linux/init.h>#include <linux/kernel.h>#include <linux/printk.h>#include <linux/random.h>#include <linux/types.h> #include "encoding.h" #define ITERS_PER_TEST 2000 /* Test requirements. */static bool test_requires(void){	/* random should be initialized for the below tests */	return prandom_u32() + prandom_u32() != 0;} /* * Test watchpoint encode and decode: check that encoding some access's info, * and then subsequent decode preserves the access's info. */static bool test_encode_decode(void){	int i; 	for (i = 0; i < ITERS_PER_TEST; ++i) {		size_t size = prandom_u32_max(MAX_ENCODABLE_SIZE) + 1;		bool is_write = !!prandom_u32_max(2);		unsigned long addr; 		prandom_bytes(&addr, sizeof(addr));		if (WARN_ON(!check_encodable(addr, size)))			return false; 		/* Encode and decode */		{			const long encoded_watchpoint =				encode_watchpoint(addr, size, is_write);			unsigned long verif_masked_addr;			size_t verif_size;			bool verif_is_write; 			/* Check special watchpoints */			if (WARN_ON(decode_watchpoint(				    INVALID_WATCHPOINT, &verif_masked_addr,				    &verif_size, &verif_is_write)))				return false;			if (WARN_ON(decode_watchpoint(				    CONSUMED_WATCHPOINT, &verif_masked_addr,				    &verif_size, &verif_is_write)))				return false; 			/* Check decoding watchpoint returns same data */			if (WARN_ON(!decode_watchpoint(				    encoded_watchpoint, &verif_masked_addr,				    &verif_size, &verif_is_write)))				return false;			if (WARN_ON(verif_masked_addr !=				    (addr & WATCHPOINT_ADDR_MASK)))				goto fail;			if (WARN_ON(verif_size != size))				goto fail;			if (WARN_ON(is_write != verif_is_write))				goto fail; 			continue;fail:			pr_err("%s fail: %s %zu bytes @ %lx -> encoded: %lx -> %s %zu bytes @ %lx\n",			       __func__, is_write ? "write" : "read", size,			       addr, encoded_watchpoint,			       verif_is_write ? "write" : "read", verif_size,			       verif_masked_addr);			return false;		}	} 	return true;} /* Test access matching function. */static bool test_matching_access(void){	if (WARN_ON(!matching_access(10, 1, 10, 1)))		return false;	if (WARN_ON(!matching_access(10, 2, 11, 1)))		return false;	if (WARN_ON(!matching_access(10, 1, 9, 2)))		return false;	if (WARN_ON(matching_access(10, 1, 11, 1)))		return false;	if (WARN_ON(matching_access(9, 1, 10, 1)))		return false; 	/*	 * An access of size 0 could match another access, as demonstrated here.	 * Rather than add more comparisons to 'matching_access()', which would	 * end up in the fast-path for *all* checks, check_access() simply	 * returns for all accesses of size 0.	 */	if (WARN_ON(!matching_access(8, 8, 12, 0)))		return false; 	return true;} static int __init kcsan_selftest(void){	int passed = 0;	int total = 0; #define RUN_TEST(do_test)                                                      \	do {                                                                   \		++total;                                                       \		if (do_test())                                                 \			++passed;                                              \		else                                                           \			pr_err("KCSAN selftest: " #do_test " failed");         \	} while (0) 	RUN_TEST(test_requires);	RUN_TEST(test_encode_decode);	RUN_TEST(test_matching_access); 	pr_info("KCSAN selftest: %d/%d tests passed\n", passed, total);	if (passed != total)		panic("KCSAN selftests failed");	return 0;}postcore_initcall(kcsan_selftest);