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diff --git a/share/man/man9/contigmalloc.9 b/share/man/man9/contigmalloc.9
--- a/share/man/man9/contigmalloc.9
+++ b/share/man/man9/contigmalloc.9
@@ -23,7 +23,7 @@
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
-.Dd October 30, 2018
+.Dd July 22, 2024
.Dt CONTIGMALLOC 9
.Os
.Sh NAME
@@ -113,6 +113,13 @@
.Fn contigmalloc
or
.Fn contigmalloc_domainset .
+Its use is deprecated in favor of
+.Xr free 9
+which no longer requires the caller to know the
+.Fa size
+and also accepts
+.Dv NULL
+as an address.
.Sh IMPLEMENTATION NOTES
The
.Fn contigmalloc
diff --git a/sys/kern/kern_malloc.c b/sys/kern/kern_malloc.c
--- a/sys/kern/kern_malloc.c
+++ b/sys/kern/kern_malloc.c
@@ -116,6 +116,16 @@
#define DEBUG_REDZONE_ARG
#endif
+typedef enum {
+ SLAB_COOKIE_SLAB_PTR = 0x0,
+ SLAB_COOKIE_MALLOC_LARGE = 0x1,
+ SLAB_COOKIE_CONTIG_MALLOC = 0x2,
+} slab_cookie_t;
+#define SLAB_COOKIE_MASK 0x3
+#define SLAB_COOKIE_SHIFT 2
+#define GET_SLAB_COOKIE(_slab) \
+ ((slab_cookie_t)(uintptr_t)(_slab) & SLAB_COOKIE_MASK)
+
/*
* When realloc() is called, if the new size is sufficiently smaller than
* the old size, realloc() will allocate a new, smaller block to avoid
@@ -451,6 +461,21 @@
* If M_NOWAIT is set, this routine will not block and return NULL if
* the allocation fails.
*/
+#define IS_CONTIG_MALLOC(_slab) \
+ (GET_SLAB_COOKIE(_slab) == SLAB_COOKIE_CONTIG_MALLOC)
+#define CONTIG_MALLOC_SLAB(_size) \
+ ((void *)(((_size) << SLAB_COOKIE_SHIFT) | SLAB_COOKIE_CONTIG_MALLOC))
+static inline size_t
+contigmalloc_size(uma_slab_t slab)
+{
+ uintptr_t va;
+
+ KASSERT(IS_CONTIG_MALLOC(slab),
+ ("%s: called on non-contigmalloc allocation: %p", __func__, slab));
+ va = (uintptr_t)slab;
+ return (va >> SLAB_COOKIE_SHIFT);
+}
+
void *
contigmalloc(unsigned long size, struct malloc_type *type, int flags,
vm_paddr_t low, vm_paddr_t high, unsigned long alignment,
@@ -460,8 +485,11 @@
ret = (void *)kmem_alloc_contig(size, flags, low, high, alignment,
boundary, VM_MEMATTR_DEFAULT);
- if (ret != NULL)
+ if (ret != NULL) {
+ /* Use low bits unused for slab pointers. */
+ vsetzoneslab((uintptr_t)ret, NULL, CONTIG_MALLOC_SLAB(size));
malloc_type_allocated(type, round_page(size));
+ }
return (ret);
}
@@ -474,25 +502,28 @@
ret = (void *)kmem_alloc_contig_domainset(ds, size, flags, low, high,
alignment, boundary, VM_MEMATTR_DEFAULT);
- if (ret != NULL)
+ if (ret != NULL) {
+ /* Use low bits unused for slab pointers. */
+ vsetzoneslab((uintptr_t)ret, NULL, CONTIG_MALLOC_SLAB(size));
malloc_type_allocated(type, round_page(size));
+ }
return (ret);
}
/*
- * contigfree:
+ * contigfree (deprecated).
*
* Free a block of memory allocated by contigmalloc.
*
* This routine may not block.
*/
void
-contigfree(void *addr, unsigned long size, struct malloc_type *type)
+contigfree(void *addr, unsigned long size __unused, struct malloc_type *type)
{
-
- kmem_free(addr, size);
- malloc_type_freed(type, round_page(size));
+ free(addr, type);
}
+#undef IS_CONTIG_MALLOC
+#undef CONTIG_MALLOC_SLAB
#ifdef MALLOC_DEBUG
static int
@@ -562,22 +593,19 @@
/*
* Handle large allocations and frees by using kmem_malloc directly.
*/
-static inline bool
-malloc_large_slab(uma_slab_t slab)
-{
- uintptr_t va;
-
- va = (uintptr_t)slab;
- return ((va & 1) != 0);
-}
-
+#define IS_MALLOC_LARGE(_slab) \
+ (GET_SLAB_COOKIE(_slab) == SLAB_COOKIE_MALLOC_LARGE)
+#define MALLOC_LARGE_SLAB(_size) \
+ ((void *)(((_size) << SLAB_COOKIE_SHIFT) | SLAB_COOKIE_MALLOC_LARGE))
static inline size_t
malloc_large_size(uma_slab_t slab)
{
uintptr_t va;
va = (uintptr_t)slab;
- return (va >> 1);
+ KASSERT(IS_MALLOC_LARGE(slab),
+ ("%s: called on non-malloc_large allocation: %p", __func__, slab));
+ return (va >> SLAB_COOKIE_SHIFT);
}
static caddr_t __noinline
@@ -589,8 +617,8 @@
size = roundup(size, PAGE_SIZE);
va = kmem_malloc_domainset(policy, size, flags);
if (va != NULL) {
- /* The low bit is unused for slab pointers. */
- vsetzoneslab((uintptr_t)va, NULL, (void *)((size << 1) | 1));
+ /* Use low bits unused for slab pointers. */
+ vsetzoneslab((uintptr_t)va, NULL, MALLOC_LARGE_SLAB(size));
uma_total_inc(size);
}
malloc_type_allocated(mtp, va == NULL ? 0 : size);
@@ -613,6 +641,8 @@
kmem_free(addr, size);
uma_total_dec(size);
}
+#undef IS_MALLOC_LARGE
+#undef MALLOC_LARGE_SLAB
/*
* malloc:
@@ -914,18 +944,30 @@
vtozoneslab((vm_offset_t)addr & (~UMA_SLAB_MASK), &zone, &slab);
if (slab == NULL)
- panic("free: address %p(%p) has not been allocated.\n",
+ panic("free: address %p(%p) has not been allocated",
addr, (void *)((u_long)addr & (~UMA_SLAB_MASK)));
- if (__predict_true(!malloc_large_slab(slab))) {
+ switch (GET_SLAB_COOKIE(slab)) {
+ case __predict_true(SLAB_COOKIE_SLAB_PTR):
size = zone->uz_size;
#if defined(INVARIANTS) && !defined(KASAN)
free_save_type(addr, mtp, size);
#endif
uma_zfree_arg(zone, addr, slab);
- } else {
+ break;
+ case SLAB_COOKIE_MALLOC_LARGE:
size = malloc_large_size(slab);
free_large(addr, size);
+ break;
+ case SLAB_COOKIE_CONTIG_MALLOC:
+ size = contigmalloc_size(slab);
+ kmem_free(addr, size);
+ size = round_page(size);
+ break;
+ default:
+ panic("%s: addr %p slab %p with unknown cookie %d", __func__,
+ addr, slab, GET_SLAB_COOKIE(slab));
+ /* NOTREACHED */
}
malloc_type_freed(mtp, size);
}
@@ -957,7 +999,8 @@
panic("free: address %p(%p) has not been allocated.\n",
addr, (void *)((u_long)addr & (~UMA_SLAB_MASK)));
- if (__predict_true(!malloc_large_slab(slab))) {
+ switch (GET_SLAB_COOKIE(slab)) {
+ case __predict_true(SLAB_COOKIE_SLAB_PTR):
size = zone->uz_size;
#if defined(INVARIANTS) && !defined(KASAN)
free_save_type(addr, mtp, size);
@@ -965,11 +1008,22 @@
kasan_mark(addr, size, size, 0);
explicit_bzero(addr, size);
uma_zfree_arg(zone, addr, slab);
- } else {
+ break;
+ case SLAB_COOKIE_MALLOC_LARGE:
size = malloc_large_size(slab);
kasan_mark(addr, size, size, 0);
explicit_bzero(addr, size);
free_large(addr, size);
+ break;
+ case SLAB_COOKIE_CONTIG_MALLOC:
+ size = round_page(contigmalloc_size(slab));
+ explicit_bzero(addr, size);
+ kmem_free(addr, size);
+ break;
+ default:
+ panic("%s: addr %p slab %p with unknown cookie %d", __func__,
+ addr, slab, GET_SLAB_COOKIE(slab));
+ /* NOTREACHED */
}
malloc_type_freed(mtp, size);
}
@@ -1016,10 +1070,20 @@
("realloc: address %p out of range", (void *)addr));
/* Get the size of the original block */
- if (!malloc_large_slab(slab))
+ switch (GET_SLAB_COOKIE(slab)) {
+ case __predict_true(SLAB_COOKIE_SLAB_PTR):
alloc = zone->uz_size;
- else
+ break;
+ case SLAB_COOKIE_MALLOC_LARGE:
alloc = malloc_large_size(slab);
+ break;
+ default:
+#ifdef INVARIANTS
+ panic("%s: called for addr %p of unsupported allocation type; "
+ "slab %p cookie %d", __func__, addr, slab, GET_SLAB_COOKIE(slab));
+#endif
+ return (NULL);
+ }
/* Reuse the original block if appropriate */
if (size <= alloc &&
@@ -1101,10 +1165,18 @@
panic("malloc_usable_size: address %p(%p) is not allocated.\n",
addr, (void *)((u_long)addr & (~UMA_SLAB_MASK)));
- if (!malloc_large_slab(slab))
+ switch (GET_SLAB_COOKIE(slab)) {
+ case __predict_true(SLAB_COOKIE_SLAB_PTR):
size = zone->uz_size;
- else
+ break;
+ case SLAB_COOKIE_MALLOC_LARGE:
size = malloc_large_size(slab);
+ break;
+ default:
+ __assert_unreachable();
+ size = 0;
+ break;
+ }
#endif
/*

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