6e976fbb4b
The idea of this template was to distinguish types which should grow/shrink based on the native size of the ABI in question. Or in other words, if the ABI was 32 bit, the type should also be 32 bit, or 64 bit and 64 bit. Unfortunately, I had intended for Addr to be a conforming type (since local pointers would be conforming), but uint64_t not to be. Since Addr is defined as a typedef of uint64_t, the compiler would make *both* types conforming, giving incorrect behavior on 32 bit systems. Local pointers will need to be handled in a different way, likely with the VPtr template, so that they will be treated correctly and not like an explicitly 64 bit data type. Change-Id: Idfdd5351260b48bb531a1926b93e0478a297826d Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40495 Reviewed-by: Gabe Black <gabe.black@gmail.com> Maintainer: Gabe Black <gabe.black@gmail.com> Tested-by: kokoro <noreply+kokoro@google.com>
110 lines
3.6 KiB
C++
110 lines
3.6 KiB
C++
/*
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* Copyright 2019 Google, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met: redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer;
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* redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution;
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* neither the name of the copyright holders nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef __SIM_SYSCALL_ABI_HH__
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#define __SIM_SYSCALL_ABI_HH__
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#include "base/bitfield.hh"
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#include "base/types.hh"
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#include "cpu/thread_context.hh"
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#include "sim/guest_abi.hh"
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#include "sim/syscall_return.hh"
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class SyscallDesc;
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struct GenericSyscallABI
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{
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using State = int;
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};
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struct GenericSyscallABI64 : public GenericSyscallABI
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{
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using UintPtr = uint64_t;
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};
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struct GenericSyscallABI32 : public GenericSyscallABI
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{
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using UintPtr = uint32_t;
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// Is this argument too big for a single register?
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template <typename T, typename Enabled=void>
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struct IsWide : public std::false_type {};
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template <typename T>
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struct IsWide<T, std::enable_if_t<(sizeof(T) > sizeof(UintPtr))>> :
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public std::true_type
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{};
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// Read two registers and merge them into one value.
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static uint64_t
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mergeRegs(ThreadContext *tc, RegIndex low_idx, RegIndex high_idx)
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{
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RegVal low = tc->readIntReg(low_idx);
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RegVal high = tc->readIntReg(high_idx);
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return insertBits(low, 63, 32, high);
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}
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};
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namespace GuestABI
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{
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// For 64 bit systems, return syscall args directly.
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template <typename ABI, typename Arg>
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struct Argument<ABI, Arg,
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typename std::enable_if_t<
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std::is_base_of<GenericSyscallABI64, ABI>::value &&
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std::is_integral<Arg>::value>>
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{
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static Arg
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get(ThreadContext *tc, typename ABI::State &state)
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{
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panic_if(state >= ABI::ArgumentRegs.size(),
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"Ran out of syscall argument registers.");
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return tc->readIntReg(ABI::ArgumentRegs[state++]);
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}
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};
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// For 32 bit systems, return small enough syscall args directly. Large
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// arguments aren't handled generically.
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template <typename ABI, typename Arg>
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struct Argument<ABI, Arg,
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typename std::enable_if_t<std::is_integral<Arg>::value &&
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!ABI::template IsWide<Arg>::value>>
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{
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static Arg
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get(ThreadContext *tc, typename ABI::State &state)
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{
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panic_if(state >= ABI::ArgumentRegs.size(),
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"Ran out of syscall argument registers.");
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return bits(tc->readIntReg(ABI::ArgumentRegs[state++]), 31, 0);
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}
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};
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} // namespace GuestABI
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#endif // __SIM_SYSCALL_ABI_HH__
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