52 lines
1.3 KiB
C
52 lines
1.3 KiB
C
/*
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* tasking-stack.c
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*
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* Created on: Sep 7, 2011
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* Author: Tiberiu
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*/
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#include <memory-add.h>
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uint32 InitialStack;
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void TaskingSetInitialStack(uint32 addr)
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{
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InitialStack = addr;
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}
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void TaskingMoveStack (uint32 newstart, uint32 size)
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{
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uint32 i;
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for (i = newstart; i >= newstart-size; i-= 0x1000)
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MemPhAllocFrame(PagingGetPage(i, 1, CurrentDirectory), 0, 1);
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// Flush TLB by rewriting cr3
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uint32 t;
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asm volatile ("mov %%cr3, %0" : "=r" (t));
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asm volatile ("mov %0, %%cr3" : : "r" (t));
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// Read old esp, ebp regs
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uint32 oldStackPointer, oldBasePointer;
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asm volatile ("mov %%esp, %0" : "=r"(oldStackPointer));
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asm volatile ("mov %%ebp, %0" : "=r"(oldBasePointer));
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uint32 offset = newstart - InitialStack;
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uint32 newStackPointer = oldStackPointer + offset;
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uint32 newBasePointer = oldBasePointer + offset;
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// Copy stack content
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memcpy((void*)newStackPointer, (void*)oldStackPointer, InitialStack-oldStackPointer);
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// (Attempt to) change EBP addresses in new stack
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for (i = newstart; i > newstart - size; i-=4)
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{
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uint32 *temp = (uint32*)i;
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if (oldStackPointer < *temp && *temp < InitialStack)
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*temp += offset;
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}
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// Set stack pointers to new stack
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asm volatile ("mov %0, %%esp" : : "r" (newStackPointer));
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asm volatile ("mov %0, %%ebp" : : "r" (newBasePointer));
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}
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