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package native
import (
"syscall"
"unsafe"
sys "golang.org/x/sys/unix"
"github.com/go-delve/delve/pkg/proc"
"github.com/go-delve/delve/pkg/proc/amd64util"
"github.com/go-delve/delve/pkg/proc/linutil"
)
func (t *nativeThread) restoreRegisters(savedRegs proc.Registers) error {
sr := savedRegs.(*linutil.AMD64Registers)
var restoreRegistersErr error
t.dbp.execPtraceFunc(func() {
oldRegs := (*sys.PtraceRegs)(sr.Regs)
var currentRegs sys.PtraceRegs
restoreRegistersErr = sys.PtraceGetRegs(t.ID, ¤tRegs)
if restoreRegistersErr != nil {
return
}
// restoreRegisters is only supposed to restore CPU registers, not FS_BASE and GS_BASE
oldRegs.Fs_base = currentRegs.Fs_base
oldRegs.Gs_base = currentRegs.Gs_base
restoreRegistersErr = sys.PtraceSetRegs(t.ID, oldRegs)
if restoreRegistersErr != nil {
return
}
if sr.Fpregset.Xsave != nil {
iov := sys.Iovec{Base: &sr.Fpregset.Xsave[0], Len: uint64(len(sr.Fpregset.Xsave))}
_, _, restoreRegistersErr = syscall.Syscall6(syscall.SYS_PTRACE, sys.PTRACE_SETREGSET, uintptr(t.ID), _NT_X86_XSTATE, uintptr(unsafe.Pointer(&iov)), 0, 0)
return
}
_, _, restoreRegistersErr = syscall.Syscall6(syscall.SYS_PTRACE, sys.PTRACE_SETFPREGS, uintptr(t.ID), uintptr(0), uintptr(unsafe.Pointer(&sr.Fpregset.AMD64PtraceFpRegs)), 0, 0)
})
if restoreRegistersErr == syscall.Errno(0) {
restoreRegistersErr = nil
}
return restoreRegistersErr
}
const debugRegUserOffset = 848 // offset of debug registers in the user struct, see source/arch/x86/kernel/ptrace.c
func (t *nativeThread) withDebugRegisters(f func(*amd64util.DebugRegisters) error) error {
var err error
t.dbp.execPtraceFunc(func() {
debugregs := make([]uint64, 8)
for i := range debugregs {
if i == 4 || i == 5 {
continue
}
_, _, err = sys.Syscall6(sys.SYS_PTRACE, sys.PTRACE_PEEKUSR, uintptr(t.ID), uintptr(debugRegUserOffset+uintptr(i)*unsafe.Sizeof(debugregs[0])), uintptr(unsafe.Pointer(&debugregs[i])), 0, 0)
if err != nil && err != syscall.Errno(0) {
return
}
}
drs := amd64util.NewDebugRegisters(&debugregs[0], &debugregs[1], &debugregs[2], &debugregs[3], &debugregs[6], &debugregs[7])
err = f(drs)
if drs.Dirty {
for i := range debugregs {
if i == 4 || i == 5 {
// Linux will return EIO for DR4 and DR5
continue
}
_, _, err = sys.Syscall6(sys.SYS_PTRACE, sys.PTRACE_POKEUSR, uintptr(t.ID), uintptr(debugRegUserOffset+uintptr(i)*unsafe.Sizeof(debugregs[0])), uintptr(debugregs[i]), 0, 0)
if err != nil && err != syscall.Errno(0) {
return
}
}
}
})
if err == syscall.Errno(0) || err == sys.ESRCH {
err = nil
}
return err
}
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