svn commit: r365383 - in stable/12: share/man/man9 sys/compat/linuxkpi/common/include/linux sys/kern sys/sys sys/vm
Vladimir Kondratyev
wulf at FreeBSD.org
Sun Sep 6 17:40:37 UTC 2020
Author: wulf
Date: Sun Sep 6 17:40:35 2020
New Revision: 365383
URL: https://svnweb.freebsd.org/changeset/base/365383
Log:
MFC r364964: LinuxKPI: Implement ksize() function.
In Linux, ksize() gets the actual amount of memory allocated for a given
object. This commit adds malloc_usable_size() to FreeBSD KPI which does
the same. It also maps LinuxKPI ksize() to newly created function.
ksize() function is used by drm-kmod.
Reviewed by: hselasky, kib
Differential Revision: https://reviews.freebsd.org/D26215
Modified:
stable/12/share/man/man9/malloc.9
stable/12/sys/compat/linuxkpi/common/include/linux/slab.h
stable/12/sys/kern/kern_malloc.c
stable/12/sys/sys/malloc.h
stable/12/sys/vm/memguard.c
stable/12/sys/vm/memguard.h
Directory Properties:
stable/12/ (props changed)
Modified: stable/12/share/man/man9/malloc.9
==============================================================================
--- stable/12/share/man/man9/malloc.9 Sun Sep 6 15:44:09 2020 (r365382)
+++ stable/12/share/man/man9/malloc.9 Sun Sep 6 17:40:35 2020 (r365383)
@@ -29,7 +29,7 @@
.\" $NetBSD: malloc.9,v 1.3 1996/11/11 00:05:11 lukem Exp $
.\" $FreeBSD$
.\"
-.Dd October 30, 2018
+.Dd August 28, 2020
.Dt MALLOC 9
.Os
.Sh NAME
@@ -53,6 +53,8 @@
.Fn realloc "void *addr" "size_t size" "struct malloc_type *type" "int flags"
.Ft void *
.Fn reallocf "void *addr" "size_t size" "struct malloc_type *type" "int flags"
+.Ft size_t
+.Fn malloc_usable_size "const void *addr"
.Fn MALLOC_DECLARE type
.In sys/param.h
.In sys/malloc.h
@@ -138,6 +140,13 @@ function is identical to
.Fn realloc
except that it
will free the passed pointer when the requested memory cannot be allocated.
+.Pp
+The
+.Fn malloc_usable_size
+function returns the usable size of the allocation pointed to by
+.Fa addr .
+The return value may be larger than the size that was requested during
+allocation.
.Pp
Unlike its standard C library counterpart
.Pq Xr malloc 3 ,
Modified: stable/12/sys/compat/linuxkpi/common/include/linux/slab.h
==============================================================================
--- stable/12/sys/compat/linuxkpi/common/include/linux/slab.h Sun Sep 6 15:44:09 2020 (r365382)
+++ stable/12/sys/compat/linuxkpi/common/include/linux/slab.h Sun Sep 6 17:40:35 2020 (r365383)
@@ -154,6 +154,12 @@ kfree(const void *ptr)
free(__DECONST(void *, ptr), M_KMALLOC);
}
+static inline size_t
+ksize(const void *ptr)
+{
+ return (malloc_usable_size(ptr));
+}
+
extern struct linux_kmem_cache *linux_kmem_cache_create(const char *name,
size_t size, size_t align, unsigned flags, linux_kmem_ctor_t *ctor);
Modified: stable/12/sys/kern/kern_malloc.c
==============================================================================
--- stable/12/sys/kern/kern_malloc.c Sun Sep 6 15:44:09 2020 (r365382)
+++ stable/12/sys/kern/kern_malloc.c Sun Sep 6 17:40:35 2020 (r365383)
@@ -867,6 +867,41 @@ reallocf(void *addr, size_t size, struct malloc_type *
return (mem);
}
+/*
+ * malloc_usable_size: returns the usable size of the allocation.
+ */
+size_t
+malloc_usable_size(const void *addr)
+{
+#ifndef DEBUG_REDZONE
+ uma_slab_t slab;
+#endif
+ u_long size;
+
+ if (addr == NULL)
+ return (0);
+
+#ifdef DEBUG_MEMGUARD
+ if (is_memguard_addr(__DECONST(void *, addr)))
+ return (memguard_get_req_size(addr));
+#endif
+
+#ifdef DEBUG_REDZONE
+ size = redzone_get_size(__DECONST(void *, addr));
+#else
+ slab = vtoslab((vm_offset_t)addr & (~UMA_SLAB_MASK));
+ if (slab == NULL)
+ panic("malloc_usable_size: address %p(%p) is not allocated.\n",
+ addr, (void *)((u_long)addr & (~UMA_SLAB_MASK)));
+
+ if (!(slab->us_flags & UMA_SLAB_MALLOC))
+ size = slab->us_keg->uk_size;
+ else
+ size = slab->us_size;
+#endif
+ return (size);
+}
+
#ifndef __sparc64__
CTASSERT(VM_KMEM_SIZE_SCALE >= 1);
#endif
Modified: stable/12/sys/sys/malloc.h
==============================================================================
--- stable/12/sys/sys/malloc.h Sun Sep 6 15:44:09 2020 (r365382)
+++ stable/12/sys/sys/malloc.h Sun Sep 6 17:40:35 2020 (r365383)
@@ -244,6 +244,7 @@ void malloc_type_allocated(struct malloc_type *type, u
void malloc_type_freed(struct malloc_type *type, unsigned long size);
void malloc_type_list(malloc_type_list_func_t *, void *);
void malloc_uninit(void *);
+size_t malloc_usable_size(const void *);
void *realloc(void *addr, size_t size, struct malloc_type *type, int flags)
__result_use_check __alloc_size(2);
void *reallocf(void *addr, size_t size, struct malloc_type *type, int flags)
Modified: stable/12/sys/vm/memguard.c
==============================================================================
--- stable/12/sys/vm/memguard.c Sun Sep 6 15:44:09 2020 (r365382)
+++ stable/12/sys/vm/memguard.c Sun Sep 6 17:40:35 2020 (r365383)
@@ -503,3 +503,9 @@ memguard_cmp_zone(uma_zone_t zone)
*/
return (strcmp(zone->uz_name, vm_memguard_desc) == 0);
}
+
+unsigned long
+memguard_get_req_size(const void *addr)
+{
+ return (*v2sizep(trunc_page((uintptr_t)addr)));
+}
Modified: stable/12/sys/vm/memguard.h
==============================================================================
--- stable/12/sys/vm/memguard.h Sun Sep 6 15:44:09 2020 (r365382)
+++ stable/12/sys/vm/memguard.h Sun Sep 6 17:40:35 2020 (r365383)
@@ -43,6 +43,7 @@ void memguard_init(struct vmem *);
void *memguard_alloc(unsigned long, int);
void *memguard_realloc(void *, unsigned long, struct malloc_type *, int);
void memguard_free(void *);
+unsigned long memguard_get_req_size(const void *);
int memguard_cmp_mtp(struct malloc_type *, unsigned long);
int memguard_cmp_zone(uma_zone_t);
int is_memguard_addr(void *);
@@ -52,6 +53,7 @@ int is_memguard_addr(void *);
#define memguard_alloc(size, flags) NULL
#define memguard_realloc(a, s, mtp, f) NULL
#define memguard_free(addr) do { } while (0)
+#define memguard_get_req_size(addr) 0
#define memguard_cmp_mtp(mtp, size) 0
#define memguard_cmp_zone(zone) 0
#define is_memguard_addr(addr) 0
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