Module Name: src
Committed By: joerg
Date: Sat Feb 6 13:54:48 UTC 2021
Modified Files:
src/sys/kern: subr_kmem.c
Log Message:
Do not cast memcpy arguments when the intention is unaligned access.
The standard is pretty explicit that misaligned pointers is UB and LLVM
does exploit the promised alignment on SPARC, resulting in kernel
crashes during early boot.
To generate a diff of this commit:
cvs rdiff -u -r1.81 -r1.82 src/sys/kern/subr_kmem.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/subr_kmem.c
diff -u src/sys/kern/subr_kmem.c:1.81 src/sys/kern/subr_kmem.c:1.82
--- src/sys/kern/subr_kmem.c:1.81 Sun Jan 24 17:29:11 2021
+++ src/sys/kern/subr_kmem.c Sat Feb 6 13:54:48 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_kmem.c,v 1.81 2021/01/24 17:29:11 thorpej Exp $ */
+/* $NetBSD: subr_kmem.c,v 1.82 2021/02/06 13:54:48 joerg Exp $ */
/*
* Copyright (c) 2009-2020 The NetBSD Foundation, Inc.
@@ -78,7 +78,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.81 2021/01/24 17:29:11 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.82 2021/02/06 13:54:48 joerg Exp $");
#ifdef _KERNEL_OPT
#include "opt_kmem.h"
@@ -505,7 +505,7 @@ kmem_tmpbuf_free(void *buf, size_t size,
static void
kmem_size_set(void *p, size_t sz)
{
- memcpy((size_t *)((uintptr_t)p + sz), &sz, sizeof(size_t));
+ memcpy((char *)p + sz, &sz, sizeof(size_t));
}
static void
@@ -513,13 +513,13 @@ kmem_size_check(void *p, size_t sz)
{
size_t hsz;
- memcpy(&hsz, (size_t *)((uintptr_t)p + sz), sizeof(size_t));
+ memcpy(&hsz, (char *)p + sz, sizeof(size_t));
if (hsz != sz) {
panic("kmem_free(%p, %zu) != allocated size %zu; overwrote?",
p, sz, hsz);
}
- memset((size_t *)((uintptr_t)p + sz), 0xff, sizeof(size_t));
+ memset((char *)p + sz, 0xff, sizeof(size_t));
}
#endif /* defined(KMEM_SIZE) */
