Module Name: src
Committed By: maxv
Date: Tue Jul 1 12:08:33 UTC 2014
Modified Files:
src/sys/kern: subr_kmem.c
Log Message:
1) Define a malloc(9)-like kmem_header structure for KMEM_SIZE. It is in
fact more consistent, and more flexible (eg if we want to add new fields).
2) When I say "page" I actually mean "kmem page". It may not be clear, so
replace it by "memory chunk" (suggested by lars@).
3) Minor changes for KMEM_REDZONE.
To generate a diff of this commit:
cvs rdiff -u -r1.56 -r1.57 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:1.56 src/sys/kern/subr_kmem.c:1.57
--- src/sys/kern/subr_kmem.c:1.56 Wed Jun 25 16:35:12 2014
+++ src/sys/kern/subr_kmem.c Tue Jul 1 12:08:33 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_kmem.c,v 1.56 2014/06/25 16:35:12 maxv Exp $ */
+/* $NetBSD: subr_kmem.c,v 1.57 2014/07/01 12:08:33 maxv Exp $ */
/*-
* Copyright (c) 2009 The NetBSD Foundation, Inc.
@@ -62,15 +62,15 @@
/*
* KMEM_SIZE: detect alloc/free size mismatch bugs.
- * Prefix each allocations with a fixed-sized header and record the exact
- * user-requested allocation size in it. When freeing, compare it with
- * kmem_free's "size" argument.
+ * Prefix each allocations with a fixed-sized, aligned header and record
+ * the exact user-requested allocation size in it. When freeing, compare
+ * it with kmem_free's "size" argument.
*/
/*
* KMEM_REDZONE: detect overrun bugs.
- * Add a 2-byte pattern (allocate one more page if needed) at the end
- * of each allocated buffer. Check this pattern on kmem_free.
+ * Add a 2-byte pattern (allocate one more memory chunk if needed) at the
+ * end of each allocated buffer. Check this pattern on kmem_free.
*
* KMEM_POISON: detect modify-after-free bugs.
* Fill freed (in the sense of kmem_free) memory with a garbage pattern.
@@ -90,7 +90,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.56 2014/06/25 16:35:12 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.57 2014/07/01 12:08:33 maxv Exp $");
#include <sys/param.h>
#include <sys/callback.h>
@@ -167,7 +167,7 @@ static pool_cache_t kmem_cache_big[KMEM_
static size_t kmem_cache_big_maxidx __read_mostly;
#if defined(DIAGNOSTIC) && defined(_HARDKERNEL)
-#define KMEM_SIZE
+#define KMEM_SIZE
#endif /* defined(DIAGNOSTIC) */
#if defined(DEBUG) && defined(_HARDKERNEL)
@@ -187,8 +187,8 @@ static void kmem_poison_check(void *, si
#if defined(KMEM_REDZONE)
#define REDZONE_SIZE 2
-static void kmem_redzone_fill(void *p, size_t sz);
-static void kmem_redzone_check(void *p, size_t sz);
+static void kmem_redzone_fill(void *, size_t);
+static void kmem_redzone_check(void *, size_t);
#else /* defined(KMEM_REDZONE) */
#define REDZONE_SIZE 0
#define kmem_redzone_fill(p, sz) /* nothing */
@@ -196,7 +196,10 @@ static void kmem_redzone_check(void *p,
#endif /* defined(KMEM_REDZONE) */
#if defined(KMEM_SIZE)
-#define SIZE_SIZE kmem_roundup_size(sizeof(size_t))
+struct kmem_header {
+ size_t size;
+} __aligned(KMEM_ALIGN);
+#define SIZE_SIZE sizeof(struct kmem_header)
static void kmem_size_set(void *, size_t);
static void kmem_size_check(void *, size_t);
#else
@@ -243,8 +246,8 @@ kmem_intr_alloc(size_t requested_size, k
#ifdef KMEM_REDZONE
if (size - requested_size < REDZONE_SIZE) {
- /* If there isn't enough space in the page padding,
- * allocate one more page for the red zone. */
+ /* If there isn't enough space in the padding, allocate
+ * one more memory chunk for the red zone. */
allocsz += kmem_roundup_size(REDZONE_SIZE);
}
#endif
@@ -537,18 +540,23 @@ kmem_poison_check(void *p, size_t sz)
static void
kmem_size_set(void *p, size_t sz)
{
- memcpy(p, &sz, sizeof(sz));
+ struct kmem_header *hd;
+ hd = (struct kmem_header *)p;
+ hd->size = sz;
}
static void
kmem_size_check(void *p, size_t sz)
{
- size_t psz;
+ struct kmem_header *hd;
+ size_t hsz;
- memcpy(&psz, p, sizeof(psz));
- if (psz != sz) {
+ hd = (struct kmem_header *)p;
+ hsz = hd->size;
+
+ if (hsz != sz) {
panic("kmem_free(%p, %zu) != allocated size %zu",
- (const uint8_t *)p + SIZE_SIZE, sz, psz);
+ (const uint8_t *)p + SIZE_SIZE, sz, hsz);
}
}
#endif /* defined(KMEM_SIZE) */
@@ -582,7 +590,7 @@ kmem_redzone_check(void *p, size_t sz)
const uint8_t *ep;
cp = (uint8_t *)p + sz;
- ep = (uint8_t *)p + sz + REDZONE_SIZE;
+ ep = cp + REDZONE_SIZE;
while (cp < ep) {
const uint8_t expected = kmem_redzone_pattern(cp);
