diff options
| author | Artur Grabowski <art@cvs.openbsd.org> | 2007-04-13 11:16:09 +0000 |
|---|---|---|
| committer | Artur Grabowski <art@cvs.openbsd.org> | 2007-04-13 11:16:09 +0000 |
| commit | adf58f0350ae4da00f93128ef9598b0eddb3ef7a (patch) | |
| tree | bfef19b230eeda0827875fcf2eb12885cd3c250f /sys/arch/i386 | |
| parent | 4fda9346d2c40dfbb62c38ce9c812f03309128c6 (diff) | |
Move the proc0 stack below the proc0 page tables so that in case we
overflow the stack, we run into the symbol table (not critical) instead
of overwriting the page tables.
From mickey, ok art@, ok toby@
Diffstat (limited to 'sys/arch/i386')
| -rw-r--r-- | sys/arch/i386/i386/locore.s | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/sys/arch/i386/i386/locore.s b/sys/arch/i386/i386/locore.s index 2a1820fed71..fc08292dc61 100644 --- a/sys/arch/i386/i386/locore.s +++ b/sys/arch/i386/i386/locore.s @@ -1,4 +1,4 @@ -/* $OpenBSD: locore.s,v 1.107 2007/04/03 10:14:47 art Exp $ */ +/* $OpenBSD: locore.s,v 1.108 2007/04/13 11:16:08 art Exp $ */ /* $NetBSD: locore.s,v 1.145 1996/05/03 19:41:19 christos Exp $ */ /*- @@ -534,11 +534,11 @@ try586: /* Use the `cpuid' instruction. */ /* * Virtual address space of kernel: * - * text | data | bss | [syms] | page dir | proc0 kstack | Sysmap - * 0 1 2 3 + * text | data | bss | [syms] | proc0 stack | page dir | Sysmap + * 0 1 2 3 */ -#define PROC0PDIR ((0) * NBPG) -#define PROC0STACK ((1) * NBPG) +#define PROC0STACK ((0) * NBPG) +#define PROC0PDIR (( UPAGES) * NBPG) #define SYSMAP ((1+UPAGES) * NBPG) #define TABLESIZE ((1+UPAGES) * NBPG) /* + _C_LABEL(nkpde) * NBPG */ @@ -603,7 +603,7 @@ try586: /* Use the `cpuid' instruction. */ leal (RELOC(_C_LABEL(etext))+PGOFSET),%edx andl $~PGOFSET,%edx - /* Skip over the first 1MB. */ + /* Skip over the first 2MB. */ movl $RELOC(KERNTEXTOFF),%eax movl %eax,%ecx shrl $PGSHIFT,%ecx @@ -657,10 +657,10 @@ try586: /* Use the `cpuid' instruction. */ movl %eax,(PROC0PDIR+PDSLOT_PTE*4)(%esi) # recursive PD slot /* Save phys. addr of PTD, for libkvm. */ - movl %esi,RELOC(_C_LABEL(PTDpaddr)) + leal (PROC0PDIR)(%esi),%eax # phys address of ptd in proc 0 + movl %eax,RELOC(_C_LABEL(PTDpaddr)) /* Load base of page directory and enable mapping. */ - movl %esi,%eax # phys address of ptd in proc 0 movl %eax,%cr3 # load ptd addr into mmu movl %cr0,%eax # get control word # enable paging & NPX emulation @@ -690,7 +690,8 @@ begin: leal (PROC0STACK+KERNBASE)(%esi),%eax movl %eax,_C_LABEL(proc0paddr) leal (USPACE-FRAMESIZE)(%eax),%esp - movl %esi,PCB_CR3(%eax) # pcb->pcb_cr3 + leal (PROC0PDIR)(%esi),%ebx # phys address of ptd in proc 0 + movl %ebx,PCB_CR3(%eax) # pcb->pcb_cr3 xorl %ebp,%ebp # mark end of frames movl _C_LABEL(nkpde),%eax |