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Do not map the trap vectors into the kernel's address space. They are

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only used in real mode and keeping them mapped only serves to make NULL
a valid address, which results in silent NULL pointer deferences.

Suggested by:   Patrick Kerharo
Obtained from:	projects/ppc64
This commit is contained in:
Nathan Whitehorn 2009-10-23 14:27:40 +00:00
parent 0f3e215954
commit e2ee8728ee
2 changed files with 13 additions and 6 deletions
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10
sys/powerpc/aim/mmu_oea64.c
View File

@ -868,15 +868,17 @@ moea64_bridge_bootstrap(mmu_t mmup, vm_offset_t kernelstart, vm_offset_t kernele
ENABLE_TRANS(msr);
/*
* Map certain important things, like ourselves and the exception
* vectors
* Map certain important things, like ourselves.
*
* NOTE: We do not map the exception vector space. That code is
* used only in real mode, and leaving it unmapped allows us to
* catch NULL pointer deferences, instead of making NULL a valid
* address.
*/
DISABLE_TRANS(msr);
for (pa = kernelstart & ~PAGE_MASK; pa < kernelend; pa += PAGE_SIZE)
moea64_kenter(mmup, pa, pa);
for (pa = EXC_RSVD; pa < EXC_LAST; pa += PAGE_SIZE)
moea64_kenter(mmup, pa, pa);
ENABLE_TRANS(msr);
if (!ofw_real_mode) {

9
sys/powerpc/aim/trap_subr.S
View File

@ -275,10 +275,16 @@ CNAME(restorebridgesize) = .-CNAME(restorebridge)
/*
* Processor reset exception handler. These are typically
* the first instructions the processor executes after a
* software reset.
* software reset. We do this in two bits so that we are
* not still hanging around in the trap handling region
* once the MMU is turned on.
*/
.globl CNAME(rstcode), CNAME(rstsize)
CNAME(rstcode):
ba cpu_reset
CNAME(rstsize) = . - CNAME(rstcode)
cpu_reset:
bl 1f
.space 124
@ -296,7 +302,6 @@ CNAME(rstcode):
/* Should not be reached */
9:
b 9b
CNAME(rstsize) = . - CNAME(rstcode)
#endif
/*