diff options
| author | Ted Unangst <tedu@cvs.openbsd.org> | 2003-09-02 17:57:13 +0000 |
|---|---|---|
| committer | Ted Unangst <tedu@cvs.openbsd.org> | 2003-09-02 17:57:13 +0000 |
| commit | 19f0226468354b35e700ee241500e85bd0673028 (patch) | |
| tree | 1c6d8d0d6c0399fcc9bb34cdf3245b8cf175d4bf /sys | |
| parent | dca278092808b64fa28f9aff61e9fa3d687c2f86 (diff) | |
add a random offset to uvm_map_hint. this has the primary effect of
scattering ld.so and libraries around, although all mmaps will also
have some jitter too. better version after some discussion with drahn
testing/ok deraadt henning marcm otto pb
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/uvm/uvm_map.c | 19 | ||||
| -rw-r--r-- | sys/uvm/uvm_mmap.c | 4 |
2 files changed, 17 insertions, 6 deletions
diff --git a/sys/uvm/uvm_map.c b/sys/uvm/uvm_map.c index 2c6b39d066a..68948b16881 100644 --- a/sys/uvm/uvm_map.c +++ b/sys/uvm/uvm_map.c @@ -1,4 +1,4 @@ -/* $OpenBSD: uvm_map.c,v 1.60 2003/06/29 17:31:12 avsm Exp $ */ +/* $OpenBSD: uvm_map.c,v 1.61 2003/09/02 17:57:12 tedu Exp $ */ /* $NetBSD: uvm_map.c,v 1.86 2000/11/27 08:40:03 chs Exp $ */ /* @@ -79,6 +79,8 @@ #include <sys/pool.h> #include <sys/kernel.h> +#include <dev/rndvar.h> + #ifdef SYSVSHM #include <sys/shm.h> #endif @@ -1078,16 +1080,25 @@ uvm_map_spacefits(vm_map_t map, vaddr_t *phint, vsize_t length, vaddr_t uvm_map_hint(struct proc *p, vm_prot_t prot) { + vaddr_t addr; + #ifdef __i386__ /* * If executable skip first two pages, otherwise start * after data + heap region. */ if ((prot & VM_PROT_EXECUTE) && - ((vaddr_t)p->p_vmspace->vm_daddr >= I386_MAX_EXE_ADDR)) - return (round_page(PAGE_SIZE*2)); + ((vaddr_t)p->p_vmspace->vm_daddr >= I386_MAX_EXE_ADDR)) { + addr = (PAGE_SIZE*2) + + (arc4random() & (I386_MAX_EXE_ADDR / 2 - 1)); + return (round_page(addr)); + } +#endif + addr = (vaddr_t)p->p_vmspace->vm_daddr + MAXDSIZ; +#ifndef __vax__ + addr += arc4random() & (256 * 1024 * 1024 - 1); #endif - return (round_page((vaddr_t)p->p_vmspace->vm_daddr + MAXDSIZ)); + return (round_page(addr)); } /* diff --git a/sys/uvm/uvm_mmap.c b/sys/uvm/uvm_mmap.c index 2ddb6286b96..523f7e22e90 100644 --- a/sys/uvm/uvm_mmap.c +++ b/sys/uvm/uvm_mmap.c @@ -1,4 +1,4 @@ -/* $OpenBSD: uvm_mmap.c,v 1.52 2003/09/01 18:06:44 henning Exp $ */ +/* $OpenBSD: uvm_mmap.c,v 1.53 2003/09/02 17:57:12 tedu Exp $ */ /* $NetBSD: uvm_mmap.c,v 1.49 2001/02/18 21:19:08 chs Exp $ */ /* @@ -451,7 +451,7 @@ sys_mmap(p, v, retval) if (addr == 0) addr = uvm_map_hint(p, prot); else if (!(flags & MAP_TRYFIXED) && - addr < uvm_map_hint(p, prot)) + addr < (vaddr_t)p->p_vmspace->vm_daddr) addr = uvm_map_hint(p, prot); } |