arch/x86: Add support for ASan to memory functions

Compiler's instrumentation cannot insert asan memory checks in
case of memory functions like memset, memcpy and memmove as they
are written in assembly.

So, we need to manually check the memory state before performing
each of these operations to ensure that ASan is triggered in case
of bad access.

Change-Id: I2030437636c77aea7cccda8efe050df4b77c15c7
Signed-off-by: Harshit Sharma <harshitsharmajs@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44307
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>

src/arch/x86/memcpy.c

@@ -1,11 +1,19 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #include <string.h>
+#include <stdbool.h>
+#include <asan.h>
 
 void *memcpy(void *dest, const void *src, size_t n)
 {
 	unsigned long d0, d1, d2;
 
+#if (ENV_ROMSTAGE && CONFIG(ASAN_IN_ROMSTAGE)) || \
+		(ENV_RAMSTAGE && CONFIG(ASAN_IN_RAMSTAGE))
+	check_memory_region((unsigned long)src, n, false, _RET_IP_);
+	check_memory_region((unsigned long)dest, n, true, _RET_IP_);
+#endif
+
 	asm volatile(
 #ifdef __x86_64__
 		"rep ; movsd\n\t"

src/arch/x86/memmove.c

@@ -4,12 +4,20 @@
  */
 
 #include <string.h>
+#include <stdbool.h>
+#include <asan.h>
 
 void *memmove(void *dest, const void *src, size_t n)
 {
 	int d0, d1, d2, d3, d4, d5;
 	char *ret = dest;
 
+#if (ENV_ROMSTAGE && CONFIG(ASAN_IN_ROMSTAGE)) || \
+		(ENV_RAMSTAGE && CONFIG(ASAN_IN_RAMSTAGE))
+	check_memory_region((unsigned long)src, n, false, _RET_IP_);
+	check_memory_region((unsigned long)dest, n, true, _RET_IP_);
+#endif
+
 	__asm__ __volatile__(
 		/* Handle more 16bytes in loop */
 		"cmp $0x10, %0\n\t"

src/arch/x86/memset.c

@@ -4,6 +4,8 @@
 
 #include <string.h>
 #include <stdint.h>
+#include <stdbool.h>
+#include <asan.h>
 
 typedef uint32_t op_t;
 
@@ -12,6 +14,11 @@ void *memset(void *dstpp, int c, size_t len)
 	int d0;
 	unsigned long int dstp = (unsigned long int) dstpp;
 
+#if (ENV_ROMSTAGE && CONFIG(ASAN_IN_ROMSTAGE)) || \
+		(ENV_RAMSTAGE && CONFIG(ASAN_IN_RAMSTAGE))
+	check_memory_region((unsigned long)dstpp, len, true, _RET_IP_);
+#endif
+
 	/* This explicit register allocation improves code very much indeed. */
 	register op_t x asm("ax");