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3d5e2ca85f
This was achieved by partially undoing changelist 24817, including an accidental corruption of eventgen.pl. Copied from Perforce Change: 24877 ServerID: perforce.ravenbrook.com
59 lines
1.7 KiB
C
59 lines
1.7 KiB
C
/* impl.c.sslii3: LINUX/INTEL STACK SCANNING
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*
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* $Id$
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* $HopeName: MMsrc!sslii3.c(trunk.2) $
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* Copyright (c) 2001 Ravenbrook Limited.
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*
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* This scans the stack and fixes the registers which may contain
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* roots. See design.mps.thread-manager
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*
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* The registers edi, esi, ebx are the registers defined to be preserved
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* across function calls and therefore may contain roots.
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* These are pushed on the stack for scanning.
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*
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* SOURCES
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*
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* .source.callees.saves: Set of callee-saved registers taken from
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* CALL_USED_REGISTERS in <gcc-sources>/config/i386/i386.h.
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*
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* ASSUMPTIONS
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*
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* .assume.align: The stack pointer is assumed to be aligned on a word
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* boundary.
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*
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* .assume.asm.stack: The compiler must not do wacky things with the
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* stack pointer around a call since we need to ensure that the
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* callee-save regs are visible during TraceScanArea.
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*
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* .assume.asm.order: The volatile modifier should prevent movement
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* of code, which might break .assume.asm.stack.
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*
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*/
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#include "mpm.h"
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SRCID(sslii3, "$Id$");
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/* .assume.asm.order */
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#define ASMV(x) __asm__ volatile (x)
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Res StackScan(ScanState ss, Addr *stackBot)
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{
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Addr *stackTop;
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Res res;
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/* .assume.asm.stack */
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ASMV("push %ebx"); /* These registers are callee-saved */
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ASMV("push %esi"); /* and so may contain roots. They are pushed */
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ASMV("push %edi"); /* for scanning. See .source.callees.saves. */
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ASMV("mov %%esp, %0" : "=r" (stackTop) :); /* stackTop = esp */
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AVER(AddrIsAligned((Addr)stackTop, sizeof(Addr))); /* .assume.align */
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res = TraceScanArea(ss, stackTop, stackBot);
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ASMV("add $12, %esp"); /* pop 3 regs to restore the stack pointer */
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return res;
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}
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