/* prmclii3.c: MUTATOR CONTEXT INTEL 386 (LINUX)
*
* $Id: //info.ravenbrook.com/project/mps/master/code/prmclii3.c#17 $
* Copyright (c) 2001-2020 Ravenbrook Limited. See end of file for license.
*
* .purpose: Implement the mutator context module. <design/prmc>.
*
*
* SOURCES
*
* .source.i486: Intel486 Microprocessor Family Programmer's
* Reference Manual
*
* .source.linux.kernel: Linux kernel source files.
*
*
* ASSUMPTIONS
*
* .sp: The stack pointer in the context is ESP.
*
* .assume.regref: The registers in the context can be modified by
* storing into an MRef pointer.
*/
#include "prmcix.h"
#include "prmci3.h"
SRCID(prmclii3, "$Id: //info.ravenbrook.com/project/mps/master/code/prmclii3.c#17 $");
#if !defined(MPS_OS_LI) || !defined(MPS_ARCH_I3)
#error "prmclii3.c is specific to MPS_OS_LI and MPS_ARCH_I3"
#endif
/* Prmci3AddressHoldingReg -- return an address of a register in a context */
MRef Prmci3AddressHoldingReg(MutatorContext context, unsigned int regnum)
{
MRef gregs;
AVERT(MutatorContext, context);
AVER(NONNEGATIVE(regnum));
AVER(regnum <= 7);
/* TODO: The current arrangement of the fix operation (taking a Ref *)
forces us to pun these registers (actually `int` on LII3GC). We can
suppress the warning by casting through `void *` and this might make
it safe, but does it really? RB 2012-09-10 */
AVER(sizeof(void *) == sizeof(*context->ucontext->uc_mcontext.gregs));
gregs = (void *)context->ucontext->uc_mcontext.gregs;
/* .source.i486 */
/* .assume.regref */
/* The register numbers (REG_EAX etc.) are defined in <ucontext.h>
but only if _GNU_SOURCE is defined: see .feature.li in
config.h. */
switch (regnum) {
case 0: return &gregs[REG_EAX];
case 1: return &gregs[REG_ECX];
case 2: return &gregs[REG_EDX];
case 3: return &gregs[REG_EBX];
case 4: return &gregs[REG_ESP];
case 5: return &gregs[REG_EBP];
case 6: return &gregs[REG_ESI];
case 7: return &gregs[REG_EDI];
default:
NOTREACHED;
return NULL; /* Avoids compiler warning. */
}
}
/* Prmci3DecodeFaultContext -- decode fault to find faulting address and IP */
void Prmci3DecodeFaultContext(MRef *faultmemReturn,
Byte **insvecReturn,
MutatorContext context)
{
AVER(faultmemReturn != NULL);
AVER(insvecReturn != NULL);
AVERT(MutatorContext, context);
AVER(context->var == MutatorContextFAULT);
/* .source.linux.kernel (linux/arch/i386/mm/fault.c). */
*faultmemReturn = (MRef)context->info->si_addr;
*insvecReturn = (Byte*)context->ucontext->uc_mcontext.gregs[REG_EIP];
}
/* Prmci3StepOverIns -- modify context to step over instruction */
void Prmci3StepOverIns(MutatorContext context, Size inslen)
{
AVERT(MutatorContext, context);
context->ucontext->uc_mcontext.gregs[REG_EIP] += (unsigned long)inslen;
}
Addr MutatorContextSP(MutatorContext context)
{
AVERT(MutatorContext, context);
return (Addr)context->ucontext->uc_mcontext.gregs[REG_ESP];
}
/* C. COPYRIGHT AND LICENSE
*
* Copyright (C) 2001-2020 Ravenbrook Limited <https://www.ravenbrook.com/>.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/