diff options
Diffstat (limited to 'pkg/ring0/kernel_amd64.go')
| -rw-r--r-- | pkg/ring0/kernel_amd64.go | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/pkg/ring0/kernel_amd64.go b/pkg/ring0/kernel_amd64.go index 4a4c0ae26..7e55011b5 100644 --- a/pkg/ring0/kernel_amd64.go +++ b/pkg/ring0/kernel_amd64.go @@ -143,6 +143,9 @@ func (c *CPU) init(cpuID int) { // Set mandatory flags. c.registers.Eflags = KernelFlagsSet + + c.hasXSAVE = hasXSAVE + c.hasXSAVEOPT = hasXSAVEOPT } // StackTop returns the kernel's stack address. @@ -248,19 +251,21 @@ func (c *CPU) SwitchToUser(switchOpts SwitchOpts) (vector Vector) { regs.Ss = uint64(Udata) // Ditto. // Perform the switch. - swapgs() // GS will be swapped on return. - WriteGS(uintptr(regs.Gs_base)) // escapes: no. Set application GS. - LoadFloatingPoint(switchOpts.FloatingPointState.BytePointer()) // escapes: no. Copy in floating point. + needIRET := uint64(0) if switchOpts.FullRestore { - vector = iret(c, regs, uintptr(userCR3)) - } else { - vector = sysret(c, regs, uintptr(userCR3)) + needIRET = 1 } - SaveFloatingPoint(switchOpts.FloatingPointState.BytePointer()) // escapes: no. Copy out floating point. - RestoreKernelFPState() // escapes: no. Restore kernel MXCSR. + vector = doSwitchToUser(c, regs, switchOpts.FloatingPointState.BytePointer(), userCR3, needIRET) // escapes: no. return } +func doSwitchToUser( + cpu *CPU, // +0(FP) + regs *arch.Registers, // +8(FP) + fpState *byte, // +16(FP) + userCR3 uint64, // +24(FP) + needIRET uint64) Vector // +32(FP), +40(FP) + var ( sentryXCR0 uintptr sentryXCR0Once sync.Once @@ -287,7 +292,7 @@ func initSentryXCR0() { //go:nosplit func startGo(c *CPU) { // Save per-cpu. - WriteGS(kernelAddr(c.kernelEntry)) + writeGS(kernelAddr(c.kernelEntry)) // // TODO(mpratt): Note that per the note above, this should be done |