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sim-se: Different HWCAP for ArmProcess32/64
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AArch32 and AArch64 have different HWCAP flags in Linux, but we are
currently using AArch32 HWCAP flags to initialize the aux vector of both
AArch32 and AArch64 binaries.

This patch also fixes a bug that was introduced by running in SE mode a
target binary compiled with glibc > 2.18. Using AArch32 flags
resulted on CPUID flag being set for AArch64. This incorrectly tells
libc that emulation of the midr_el1 is supported.
In FullSystem this might work, but since we are in Syscall Emulation
there is no OS behind emulating the mrs midr_el1 instruction.

By separating AArch32 flags from AArch64 flags we are turning off the
CPUID hwcap flag in SE mode.

Change-Id: I9f651957ba9d19dc2bc06606de070c6586f0f9fa
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/12884
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
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giactra committed Oct 2, 2018
1 parent 352d666 commit 6efe7e1
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Showing 2 changed files with 85 additions and 37 deletions.
103 changes: 67 additions & 36 deletions src/arch/arm/process.cc
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2010, 2012 ARM Limited
* Copyright (c) 2010, 2012, 2018 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
Expand Down Expand Up @@ -142,6 +142,71 @@ ArmProcess64::initState()
}
}

uint32_t
ArmProcess32::armHwcapImpl() const
{
enum ArmCpuFeature {
Arm_Swp = 1 << 0,
Arm_Half = 1 << 1,
Arm_Thumb = 1 << 2,
Arm_26Bit = 1 << 3,
Arm_FastMult = 1 << 4,
Arm_Fpa = 1 << 5,
Arm_Vfp = 1 << 6,
Arm_Edsp = 1 << 7,
Arm_Java = 1 << 8,
Arm_Iwmmxt = 1 << 9,
Arm_Crunch = 1 << 10,
Arm_ThumbEE = 1 << 11,
Arm_Neon = 1 << 12,
Arm_Vfpv3 = 1 << 13,
Arm_Vfpv3d16 = 1 << 14
};

return Arm_Swp | Arm_Half | Arm_Thumb | Arm_FastMult |
Arm_Vfp | Arm_Edsp | Arm_ThumbEE | Arm_Neon |
Arm_Vfpv3 | Arm_Vfpv3d16;
}

uint32_t
ArmProcess64::armHwcapImpl() const
{
// In order to know what these flags mean, please refer to Linux
// /Documentation/arm64/elf_hwcaps.txt text file.
enum ArmCpuFeature {
Arm_Fp = 1 << 0,
Arm_Asimd = 1 << 1,
Arm_Evtstrm = 1 << 2,
Arm_Aes = 1 << 3,
Arm_Pmull = 1 << 4,
Arm_Sha1 = 1 << 5,
Arm_Sha2 = 1 << 6,
Arm_Crc32 = 1 << 7,
Arm_Atomics = 1 << 8,
Arm_Fphp = 1 << 9,
Arm_Asimdhp = 1 << 10,
Arm_Cpuid = 1 << 11,
Arm_Asimdrdm = 1 << 12,
Arm_Jscvt = 1 << 13,
Arm_Fcma = 1 << 14,
Arm_Lrcpc = 1 << 15,
Arm_Dcpop = 1 << 16,
Arm_Sha3 = 1 << 17,
Arm_Sm3 = 1 << 18,
Arm_Sm4 = 1 << 19,
Arm_Asimddp = 1 << 20,
Arm_Sha512 = 1 << 21,
Arm_Sve = 1 << 22,
Arm_Asimdfhm = 1 << 23,
Arm_Dit = 1 << 24,
Arm_Uscat = 1 << 25,
Arm_Ilrcpc = 1 << 26,
Arm_Flagm = 1 << 27
};

return Arm_Fp | Arm_Asimd | Arm_Evtstrm | Arm_Crc32;
}

template <class IntType>
void
ArmProcess::argsInit(int pageSize, IntRegIndex spIndex)
Expand All @@ -166,47 +231,13 @@ ArmProcess::argsInit(int pageSize, IntRegIndex spIndex)
// load object file into target memory
objFile->loadSections(initVirtMem);

enum ArmCpuFeature {
Arm_Swp = 1 << 0,
Arm_Half = 1 << 1,
Arm_Thumb = 1 << 2,
Arm_26Bit = 1 << 3,
Arm_FastMult = 1 << 4,
Arm_Fpa = 1 << 5,
Arm_Vfp = 1 << 6,
Arm_Edsp = 1 << 7,
Arm_Java = 1 << 8,
Arm_Iwmmxt = 1 << 9,
Arm_Crunch = 1 << 10,
Arm_ThumbEE = 1 << 11,
Arm_Neon = 1 << 12,
Arm_Vfpv3 = 1 << 13,
Arm_Vfpv3d16 = 1 << 14
};

//Setup the auxilliary vectors. These will already have endian conversion.
//Auxilliary vectors are loaded only for elf formatted executables.
ElfObject * elfObject = dynamic_cast<ElfObject *>(objFile);
if (elfObject) {

if (objFile->getOpSys() == ObjectFile::Linux) {
IntType features =
Arm_Swp |
Arm_Half |
Arm_Thumb |
// Arm_26Bit |
Arm_FastMult |
// Arm_Fpa |
Arm_Vfp |
Arm_Edsp |
// Arm_Java |
// Arm_Iwmmxt |
// Arm_Crunch |
Arm_ThumbEE |
Arm_Neon |
Arm_Vfpv3 |
Arm_Vfpv3d16 |
0;
IntType features = armHwcap<IntType>();

//Bits which describe the system hardware capabilities
//XXX Figure out what these should be
Expand Down
19 changes: 18 additions & 1 deletion src/arch/arm/process.hh
Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2012 ARM Limited
* Copyright (c) 2012, 2018 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
Expand Down Expand Up @@ -61,6 +61,17 @@ class ArmProcess : public Process
ObjectFile::Arch _arch);
template<class IntType>
void argsInit(int pageSize, ArmISA::IntRegIndex spIndex);

template<class IntType>
IntType armHwcap() const
{
return static_cast<IntType>(armHwcapImpl());
}

/**
* AT_HWCAP is 32-bit wide on AArch64 as well so we can
* safely return an uint32_t */
virtual uint32_t armHwcapImpl() const = 0;
};

class ArmProcess32 : public ArmProcess
Expand All @@ -71,6 +82,9 @@ class ArmProcess32 : public ArmProcess

void initState();

/** AArch32 AT_HWCAP */
uint32_t armHwcapImpl() const override;

public:

ArmISA::IntReg getSyscallArg(ThreadContext *tc, int &i, int width);
Expand All @@ -87,6 +101,9 @@ class ArmProcess64 : public ArmProcess

void initState();

/** AArch64 AT_HWCAP */
uint32_t armHwcapImpl() const override;

public:

ArmISA::IntReg getSyscallArg(ThreadContext *tc, int &i, int width);
Expand Down

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