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Fix floating point register reads x86_64 linux on targets with no AVX support 

Summary:
On for 64-bit targets, the correct register set to read the fxsave are is
NT_PRFPREG (only 32-bit targets need NT_PRXFPREG, presumably for historic
reasons). Reference:
<https://github.com/torvalds/linux/blob/v4.8/arch/x86/kernel/ptrace.c#L1261>.

Reviewers: tberghammer, valentinagiusti

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D27161

llvm-svn: 288038
This commit is contained in:
Pavel Labath 2016-11-28 15:51:47 +00:00
parent 3def9e11e2
commit 6ec13991f5
1 changed files with 14 additions and 3 deletions
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17
lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp
View File

@ -20,6 +20,8 @@
#include "Plugins/Process/Utility/RegisterContextLinux_i386.h"
#include "Plugins/Process/Utility/RegisterContextLinux_x86_64.h"
#include <linux/elf.h>
using namespace lldb_private;
using namespace lldb_private::process_linux;
@ -218,6 +220,12 @@ static const RegisterSet g_reg_sets_x86_64[k_num_register_sets] = {
#define NT_PRXFPREG 0x46e62b7f
#endif
// On x86_64 NT_PRFPREG is used to access the FXSAVE area. On i386, we need to
// use NT_PRXFPREG.
static inline unsigned int fxsr_regset(const ArchSpec &arch) {
return arch.GetAddressByteSize() == 8 ? NT_PRFPREG : NT_PRXFPREG;
}
// ----------------------------------------------------------------------------
// Required MPX define.
// ----------------------------------------------------------------------------
@ -852,8 +860,9 @@ bool NativeRegisterContextLinux_x86_64::IsFPR(uint32_t reg_index) const {
Error NativeRegisterContextLinux_x86_64::WriteFPR() {
switch (m_xstate_type) {
case XStateType::FXSAVE:
return WriteRegisterSet(&m_iovec, sizeof(m_fpr.xstate.xsave),
NT_PRXFPREG);
return WriteRegisterSet(
&m_iovec, sizeof(m_fpr.xstate.xsave),
fxsr_regset(GetRegisterInfoInterface().GetTargetArchitecture()));
case XStateType::XSAVE:
return WriteRegisterSet(&m_iovec, sizeof(m_fpr.xstate.xsave),
NT_X86_XSTATE);
@ -957,7 +966,9 @@ Error NativeRegisterContextLinux_x86_64::ReadFPR() {
return error;
}
}
error = ReadRegisterSet(&m_iovec, sizeof(m_fpr.xstate.xsave), NT_PRXFPREG);
error = ReadRegisterSet(
&m_iovec, sizeof(m_fpr.xstate.xsave),
fxsr_regset(GetRegisterInfoInterface().GetTargetArchitecture()));
if (!error.Fail()) {
m_xstate_type = XStateType::FXSAVE;
return error;