diff options
| author |   tedu <tedu@openbsd.org> | 2013-04-17 17:46:53 +0000 |
|---|---|---|
| committer | tedu <tedu@openbsd.org> | 2013-04-17 17:46:53 +0000 |
| commit | 0725b15dd2eea23bdd90c6c9f10fcc5f909ddd32 (patch) | |
| tree | 4537413e392a91ed26ae2cbb8ea9d8f55479ddf7 | |
| parent | check that the pool we are about to init isn't already on the list in (diff) | |
| download | wireguard-openbsd-0725b15dd2eea23bdd90c6c9f10fcc5f909ddd32.tar.xz wireguard-openbsd-0725b15dd2eea23bdd90c6c9f10fcc5f909ddd32.zip | |
do not permanently avoid the BRKSIZ gap in the heap for mmap. after some
allocations have been made, open it up. this is a variation on a previous
change that was lost in the great uvm map rewrite. allows some platforms,
notably i386, to fully utilize their address space.
| -rw-r--r-- | sys/uvm/uvm_map.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/sys/uvm/uvm_map.c b/sys/uvm/uvm_map.c index f73e968538c..40b50993d66 100644 --- a/sys/uvm/uvm_map.c +++ b/sys/uvm/uvm_map.c @@ -1,4 +1,4 @@ -/* $OpenBSD: uvm_map.c,v 1.159 2013/02/10 19:19:30 beck Exp $ */ +/* $OpenBSD: uvm_map.c,v 1.160 2013/04/17 17:46:53 tedu Exp $ */ /* $NetBSD: uvm_map.c,v 1.86 2000/11/27 08:40:03 chs Exp $ */ /* @@ -3641,6 +3641,7 @@ vaddr_t uvm_map_hint(struct vmspace *vm, vm_prot_t prot) { vaddr_t addr; + vaddr_t spacing; #ifdef __i386__ /* @@ -3654,10 +3655,18 @@ uvm_map_hint(struct vmspace *vm, vm_prot_t prot) return (round_page(addr)); } #endif - /* start malloc/mmap after the brk */ - addr = (vaddr_t)vm->vm_daddr + BRKSIZ; + + spacing = (MIN((256 * 1024 * 1024), BRKSIZ) - 1); + + /* + * Start malloc/mmap after the brk. + * If the random spacing area has been used up, + * the brk area becomes fair game for mmap as well. + */ + if (vm->vm_dused < spacing >> PAGE_SHIFT) + addr = (vaddr_t)vm->vm_daddr + BRKSIZ; #if !defined(__vax__) - addr += arc4random() & (MIN((256 * 1024 * 1024), BRKSIZ) - 1); + addr += arc4random() & spacing; #endif return (round_page(addr)); } |