Date: Wed, 22 Aug 2012 17:16:05 +0000 (UTC) From: Matthew D Fleming <mdf@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-8@freebsd.org Subject: svn commit: r239566 - in stable/8/sys: kern vm Message-ID: <201208221716.q7MHG5vq065777@svn.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: mdf Date: Wed Aug 22 17:16:05 2012 New Revision: 239566 URL: http://svn.freebsd.org/changeset/base/239566 Log: MFC r238502: Fix a bug with memguard(9) on 32-bit architectures without a VM_KMEM_MAX_SIZE. The code was not taking into account the size of the kernel_map, which the kmem_map is allocated from, so it could produce a sub-map size too large to fit. The simplest solution is to ignore VM_KMEM_MAX entirely and base the memguard map's size off the kernel_map's size, since this is always relevant and always smaller. Found by: Justin Hibbits Modified: stable/8/sys/kern/kern_malloc.c stable/8/sys/vm/memguard.c stable/8/sys/vm/memguard.h stable/8/sys/vm/vm_map.h Directory Properties: stable/8/sys/ (props changed) stable/8/sys/amd64/include/xen/ (props changed) stable/8/sys/boot/ (props changed) stable/8/sys/cddl/ (props changed) stable/8/sys/cddl/contrib/opensolaris/ (props changed) stable/8/sys/compat/ (props changed) stable/8/sys/contrib/dev/acpica/ (props changed) stable/8/sys/contrib/pf/ (props changed) stable/8/sys/dev/ (props changed) stable/8/sys/dev/e1000/ (props changed) stable/8/sys/dev/sound/ (props changed) stable/8/sys/dev/sound/pci/ (props changed) stable/8/sys/dev/virtio/ (props changed) stable/8/sys/kern/ (props changed) stable/8/sys/sys/ (props changed) stable/8/sys/vm/ (props changed) Modified: stable/8/sys/kern/kern_malloc.c ============================================================================== --- stable/8/sys/kern/kern_malloc.c Wed Aug 22 17:13:00 2012 (r239565) +++ stable/8/sys/kern/kern_malloc.c Wed Aug 22 17:16:05 2012 (r239566) @@ -646,7 +646,7 @@ kmeminit(void *dummy) init_param3(vm_kmem_size / PAGE_SIZE); #ifdef DEBUG_MEMGUARD - tmp = memguard_fudge(vm_kmem_size, vm_kmem_size_max); + tmp = memguard_fudge(vm_kmem_size, kernel_map); #else tmp = vm_kmem_size; #endif Modified: stable/8/sys/vm/memguard.c ============================================================================== --- stable/8/sys/vm/memguard.c Wed Aug 22 17:13:00 2012 (r239565) +++ stable/8/sys/vm/memguard.c Wed Aug 22 17:16:05 2012 (r239566) @@ -156,16 +156,18 @@ SYSCTL_ULONG(_vm_memguard, OID_AUTO, fre * the kmem_map. The memguard memory will be a submap. */ unsigned long -memguard_fudge(unsigned long km_size, unsigned long km_max) +memguard_fudge(unsigned long km_size, const struct vm_map *parent_map) { - u_long mem_pgs = cnt.v_page_count; + u_long mem_pgs, parent_size; vm_memguard_divisor = 10; TUNABLE_INT_FETCH("vm.memguard.divisor", &vm_memguard_divisor); + parent_size = vm_map_max(parent_map) - vm_map_min(parent_map) + + PAGE_SIZE; /* Pick a conservative value if provided value sucks. */ if ((vm_memguard_divisor <= 0) || - ((km_size / vm_memguard_divisor) == 0)) + ((parent_size / vm_memguard_divisor) == 0)) vm_memguard_divisor = 10; /* * Limit consumption of physical pages to @@ -174,20 +176,19 @@ memguard_fudge(unsigned long km_size, un * This prevents memguard's page promotions from completely * using up memory, since most malloc(9) calls are sub-page. */ + mem_pgs = cnt.v_page_count; memguard_physlimit = (mem_pgs / vm_memguard_divisor) * PAGE_SIZE; /* * We want as much KVA as we can take safely. Use at most our - * allotted fraction of kmem_max. Limit this to twice the - * physical memory to avoid using too much memory as pagetable - * pages. + * allotted fraction of the parent map's size. Limit this to + * twice the physical memory to avoid using too much memory as + * pagetable pages (size must be multiple of PAGE_SIZE). */ - memguard_mapsize = km_max / vm_memguard_divisor; - /* size must be multiple of PAGE_SIZE */ - memguard_mapsize = round_page(memguard_mapsize); + memguard_mapsize = round_page(parent_size / vm_memguard_divisor); if (memguard_mapsize / (2 * PAGE_SIZE) > mem_pgs) memguard_mapsize = mem_pgs * 2 * PAGE_SIZE; - if (km_size + memguard_mapsize > km_max) - return (km_max); + if (km_size + memguard_mapsize > parent_size) + memguard_mapsize = 0; return (km_size + memguard_mapsize); } Modified: stable/8/sys/vm/memguard.h ============================================================================== --- stable/8/sys/vm/memguard.h Wed Aug 22 17:13:00 2012 (r239565) +++ stable/8/sys/vm/memguard.h Wed Aug 22 17:16:05 2012 (r239566) @@ -35,7 +35,7 @@ struct malloc_type; struct vm_map; #ifdef DEBUG_MEMGUARD -unsigned long memguard_fudge(unsigned long, unsigned long); +unsigned long memguard_fudge(unsigned long, const struct vm_map *); void memguard_init(struct vm_map *); void *memguard_alloc(unsigned long, int); void *memguard_realloc(void *, unsigned long, struct malloc_type *, int); Modified: stable/8/sys/vm/vm_map.h ============================================================================== --- stable/8/sys/vm/vm_map.h Wed Aug 22 17:13:00 2012 (r239565) +++ stable/8/sys/vm/vm_map.h Wed Aug 22 17:16:05 2012 (r239566) @@ -198,13 +198,13 @@ struct vm_map { #ifdef _KERNEL static __inline vm_offset_t -vm_map_max(vm_map_t map) +vm_map_max(const struct vm_map *map) { return (map->max_offset); } static __inline vm_offset_t -vm_map_min(vm_map_t map) +vm_map_min(const struct vm_map *map) { return (map->min_offset); }
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201208221716.q7MHG5vq065777>