diff options
Diffstat (limited to 'pkg/sentry/platform/ring0/kernel_amd64.go')
| -rw-r--r-- | pkg/sentry/platform/ring0/kernel_amd64.go | 21 |
1 files changed, 5 insertions, 16 deletions
diff --git a/pkg/sentry/platform/ring0/kernel_amd64.go b/pkg/sentry/platform/ring0/kernel_amd64.go index 37d5484e1..c828af654 100644 --- a/pkg/sentry/platform/ring0/kernel_amd64.go +++ b/pkg/sentry/platform/ring0/kernel_amd64.go @@ -20,20 +20,6 @@ import ( "encoding/binary" ) -const ( - // KernelFlagsSet should always be set in the kernel. - KernelFlagsSet = _RFLAGS_RESERVED - - // UserFlagsSet are always set in userspace. - UserFlagsSet = _RFLAGS_RESERVED | _RFLAGS_IF - - // KernelFlagsClear should always be clear in the kernel. - KernelFlagsClear = _RFLAGS_IF | _RFLAGS_NT | _RFLAGS_IOPL - - // UserFlagsClear are always cleared in userspace. - UserFlagsClear = _RFLAGS_NT | _RFLAGS_IOPL -) - // init initializes architecture-specific state. func (k *Kernel) init(opts KernelOpts) { // Save the root page tables. @@ -85,6 +71,9 @@ func (c *CPU) init() { c.registers.Ss = uint64(Kdata) c.registers.Fs = uint64(Kdata) c.registers.Gs = uint64(Kdata) + + // Set mandatory flags. + c.registers.Eflags = KernelFlagsSet } // StackTop returns the kernel's stack address. @@ -119,7 +108,7 @@ func (c *CPU) TSS() (uint64, uint16, *SegmentDescriptor) { // //go:nosplit func (c *CPU) CR0() uint64 { - return _CR0_PE | _CR0_PG | _CR0_ET + return _CR0_PE | _CR0_PG | _CR0_AM | _CR0_ET } // CR4 returns the CPU's CR4 value. @@ -240,7 +229,7 @@ func start(c *CPU) { // Set the syscall target. wrmsr(_MSR_LSTAR, kernelFunc(sysenter)) - wrmsr(_MSR_SYSCALL_MASK, _RFLAGS_STEP|_RFLAGS_IF|_RFLAGS_DF|_RFLAGS_IOPL|_RFLAGS_AC|_RFLAGS_NT) + wrmsr(_MSR_SYSCALL_MASK, KernelFlagsClear|_RFLAGS_DF) // NOTE: This depends on having the 64-bit segments immediately // following the 32-bit user segments. This is simply the way the |