[linux] Make malloc and linux_umalloc valgrindable

Make the allocators used by malloc and linux_umalloc valgrindable.
Include valgrind headers in the codebase to avoid a build dependency
on valgrind.

Signed-off-by: Piotr Jaroszyński <p.jaroszynski@gmail.com>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 31 insertions, 3 deletions

diff --git a/src/interface/linux/linux_umalloc.c b/src/interface/linux/linux_umalloc.c
index 5167d382..aa0052c5 100644
--- a/src/interface/linux/linux_umalloc.c
+++ b/src/interface/linux/linux_umalloc.c
@@ -18,6 +18,8 @@
 
 FILE_LICENCE(GPL2_OR_LATER);
 
+#include <valgrind/memcheck.h>
+
 /** @file
  *
  * iPXE user memory allocation API for linux
@@ -56,7 +58,9 @@ static void * linux_realloc(void *ptr, size_t size)
 	/* Check whether we have a valid pointer */
 	if (ptr != NULL && ptr != NOWHERE) {
 		mdptr = ptr - SIZE_MD;
+		VALGRIND_MAKE_MEM_DEFINED(mdptr, SIZE_MD);
 		md = *mdptr;
+		VALGRIND_MAKE_MEM_NOACCESS(mdptr, SIZE_MD);
 
 		/* Check for poison in the metadata */
 		if (md.poison != POISON) {
@@ -78,32 +82,56 @@ static void * linux_realloc(void *ptr, size_t size)
 		if (mdptr) {
 			if (linux_munmap(mdptr, md.size))
 				DBG("linux_realloc munmap failed: %s\n", linux_strerror(linux_errno));
+			VALGRIND_FREELIKE_BLOCK(ptr, sizeof(*mdptr));
 		}
 		return NOWHERE;
 	}
 
 	if (ptr) {
-		/* ptr is pointing to an already allocated memory, mremap() it with new size */
+		char *vbits = NULL;
+
+		if (RUNNING_ON_VALGRIND > 0)
+			vbits = linux_realloc(NULL, min(size, md.size));
+
+/* prevent an unused variable warning when building w/o valgrind support */
+#ifndef NVALGRIND
+		VALGRIND_GET_VBITS(ptr, vbits, min(size, md.size));
+#endif
+
+		VALGRIND_FREELIKE_BLOCK(ptr, SIZE_MD);
+
 		mdptr = linux_mremap(mdptr, md.size + SIZE_MD, size + SIZE_MD, MREMAP_MAYMOVE);
 		if (mdptr == MAP_FAILED) {
 			DBG("linux_realloc mremap failed: %s\n", linux_strerror(linux_errno));
 			return NULL;
 		}
-
 		ptr = ((void *)mdptr) + SIZE_MD;
+
+		VALGRIND_MALLOCLIKE_BLOCK(ptr, size, SIZE_MD, 0);
+/* prevent an unused variable warning when building w/o valgrind support */
+#ifndef NVALGRIND
+		VALGRIND_SET_VBITS(ptr, vbits, min(size, md.size));
+#endif
+
+		if (RUNNING_ON_VALGRIND > 0)
+			linux_realloc(vbits, 0);
 	} else {
-		/* allocate new memory with mmap() */
 		mdptr = linux_mmap(NULL, size + SIZE_MD, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 		if (mdptr == MAP_FAILED) {
 			DBG("linux_realloc mmap failed: %s\n", linux_strerror(linux_errno));
 			return NULL;
 		}
 		ptr = ((void *)mdptr) + SIZE_MD;
+		VALGRIND_MALLOCLIKE_BLOCK(ptr, size, SIZE_MD, 0);
 	}
 
 	/* Update the metadata */
+	VALGRIND_MAKE_MEM_DEFINED(mdptr, SIZE_MD);
 	mdptr->poison = POISON;
 	mdptr->size = size;
+	VALGRIND_MAKE_MEM_NOACCESS(mdptr, SIZE_MD);
+	// VALGRIND_MALLOCLIKE_BLOCK ignores redzones currently, make our own
+	VALGRIND_MAKE_MEM_NOACCESS(ptr + size, SIZE_MD);
 
 	return ptr;
 }