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Diffstat (limited to 'private/ntos/rtl/mips/chkstk.s')
| -rw-r--r-- | private/ntos/rtl/mips/chkstk.s | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/private/ntos/rtl/mips/chkstk.s b/private/ntos/rtl/mips/chkstk.s new file mode 100644 index 000000000..6de5018b7 --- /dev/null +++ b/private/ntos/rtl/mips/chkstk.s @@ -0,0 +1,88 @@ +// TITLE("Runtime Stack Checking") +//++ +// +// Copyright (c) 1991 Microsoft Corporation +// +// Module Name: +// +// chkstk.s +// +// Abstract: +// +// This module implements runtime stack checking. +// +// Author: +// +// David N. Cutler (davec) 14-Mar-1991 +// +// Environment: +// +// User mode. +// +// Revision History: +// +//-- + +#include "ksmips.h" + + SBTTL("Check Stack") +//++ +// +// ULONG +// _RtlCheckStack ( +// IN ULONG Allocation +// ) +// +// Routine Description: +// +// This function provides runtime stack checking for local allocations +// that are more than a page and for storage dynamically allocated with +// the alloca function. Stack checking consists of probing downward in +// the stack a page at a time. If the current stack commitment is exceeded, +// then the system will automatically attempt to expand the stack. If the +// attempt succeeds, then another page is committed. Otherwise, a stack +// overflow exception is raised. It is the responsiblity of the caller to +// handle this exception. +// +// N.B. This routine is called using a calling sequence that assumes that +// all registers are preserved. +// +// Arguments: +// +// Allocation (t8) - Supplies the size of the allocation on the stack. +// +// Return Value: +// +// None. +// +//-- + + NESTED_ENTRY(_RtlCheckStack, 0, ra) + + sw t7,0(sp) // save temporary register + sw t8,4(sp) // save allocation size + sw t9,8(sp) // save temporary register + + PROLOGUE_END + + .set noreorder + .set noat + li t9,UsPcr // get address of user PCR + lw t9,PcTeb(t9) // get address of environment block + subu t8,sp,t8 // compute new bottom of stack + lw t9,TeStackLimit(t9) // get low stack address + sltu t7,t8,t9 // new stack address within limits? + beq zero,t7,20f // if eq, stack within limits + li t7,~(PAGE_SIZE - 1) // set address mask + and t8,t8,t7 // round down new stack address +10: subu t9,t9,PAGE_SIZE // compute next address to check + bne t8,t9,10b // if ne, more pages to probe + sw zero,0(t9) // check stack address +20: lw t7,0(sp) // restore temporary register + lw t8,4(sp) // restore allocation size + j ra // return + lw t9,8(sp) // restore temporary register + .set at + .set reorder + + .end _RtlCheckStack |