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-rw-r--r--pkg/sentry/platform/kvm/BUILD1
-rw-r--r--pkg/sentry/platform/kvm/address_space.go6
-rw-r--r--pkg/sentry/platform/kvm/context.go10
-rw-r--r--pkg/sentry/platform/kvm/kvm_const_arm64.go11
-rw-r--r--pkg/sentry/platform/kvm/machine_arm64.go72
-rw-r--r--pkg/sentry/platform/kvm/testutil/testutil_arm64.go4
-rw-r--r--pkg/sentry/platform/kvm/testutil/testutil_arm64.s14
-rw-r--r--pkg/sentry/platform/platform.go44
-rw-r--r--pkg/sentry/platform/ptrace/BUILD1
-rw-r--r--pkg/sentry/platform/ptrace/ptrace.go10
-rw-r--r--pkg/sentry/platform/ptrace/subprocess.go6
-rw-r--r--pkg/sentry/platform/ring0/kernel_arm64.go2
-rw-r--r--pkg/sentry/platform/ring0/lib_arm64.go6
-rw-r--r--pkg/sentry/platform/ring0/lib_arm64.s86
14 files changed, 224 insertions, 49 deletions
diff --git a/pkg/sentry/platform/kvm/BUILD b/pkg/sentry/platform/kvm/BUILD
index b5d27a72a..3970dd81d 100644
--- a/pkg/sentry/platform/kvm/BUILD
+++ b/pkg/sentry/platform/kvm/BUILD
@@ -41,6 +41,7 @@ go_library(
deps = [
"//pkg/abi/linux",
"//pkg/atomicbitops",
+ "//pkg/context",
"//pkg/cpuid",
"//pkg/log",
"//pkg/procid",
diff --git a/pkg/sentry/platform/kvm/address_space.go b/pkg/sentry/platform/kvm/address_space.go
index 98a3e539d..af5c5e191 100644
--- a/pkg/sentry/platform/kvm/address_space.go
+++ b/pkg/sentry/platform/kvm/address_space.go
@@ -248,3 +248,9 @@ func (as *addressSpace) Release() {
// Drop all cached machine references.
as.machine.dropPageTables(as.pageTables)
}
+
+// PreFork implements platform.AddressSpace.PreFork.
+func (as *addressSpace) PreFork() {}
+
+// PostFork implements platform.AddressSpace.PostFork.
+func (as *addressSpace) PostFork() {}
diff --git a/pkg/sentry/platform/kvm/context.go b/pkg/sentry/platform/kvm/context.go
index 6507121ea..eb92721fb 100644
--- a/pkg/sentry/platform/kvm/context.go
+++ b/pkg/sentry/platform/kvm/context.go
@@ -15,6 +15,7 @@
package kvm
import (
+ pkgcontext "gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/sentry/arch"
"gvisor.dev/gvisor/pkg/sentry/platform"
"gvisor.dev/gvisor/pkg/sentry/platform/interrupt"
@@ -37,7 +38,8 @@ type context struct {
}
// Switch runs the provided context in the given address space.
-func (c *context) Switch(as platform.AddressSpace, ac arch.Context, _ int32) (*arch.SignalInfo, usermem.AccessType, error) {
+func (c *context) Switch(ctx pkgcontext.Context, mm platform.MemoryManager, ac arch.Context, _ int32) (*arch.SignalInfo, usermem.AccessType, error) {
+ as := mm.AddressSpace()
localAS := as.(*addressSpace)
// Grab a vCPU.
@@ -88,3 +90,9 @@ func (c *context) Interrupt() {
// Release implements platform.Context.Release().
func (c *context) Release() {}
+
+// FloatingPointStateChanged implements platform.Context.FloatingPointStateChanged.
+func (c *context) FloatingPointStateChanged() {}
+
+// PullFullState implements platform.Context.PullFullState.
+func (c *context) PullFullState(as platform.AddressSpace, ac arch.Context) {}
diff --git a/pkg/sentry/platform/kvm/kvm_const_arm64.go b/pkg/sentry/platform/kvm/kvm_const_arm64.go
index 6f0539c29..fdc599477 100644
--- a/pkg/sentry/platform/kvm/kvm_const_arm64.go
+++ b/pkg/sentry/platform/kvm/kvm_const_arm64.go
@@ -116,6 +116,17 @@ const (
// Arm64: Exception Syndrome Register EL1.
const (
+ _ESR_ELx_EC_SHIFT = 26
+ _ESR_ELx_EC_MASK = 0x3F << _ESR_ELx_EC_SHIFT
+
+ _ESR_ELx_EC_IMP_DEF = 0x1f
+ _ESR_ELx_EC_IABT_LOW = 0x20
+ _ESR_ELx_EC_IABT_CUR = 0x21
+ _ESR_ELx_EC_PC_ALIGN = 0x22
+
+ _ESR_ELx_CM = 1 << 8
+ _ESR_ELx_WNR = 1 << 6
+
_ESR_ELx_FSC = 0x3F
_ESR_SEGV_MAPERR_L0 = 0x4
diff --git a/pkg/sentry/platform/kvm/machine_arm64.go b/pkg/sentry/platform/kvm/machine_arm64.go
index f3bf973de..9db171af9 100644
--- a/pkg/sentry/platform/kvm/machine_arm64.go
+++ b/pkg/sentry/platform/kvm/machine_arm64.go
@@ -125,71 +125,59 @@ func nonCanonical(addr uint64, signal int32, info *arch.SignalInfo) (usermem.Acc
return usermem.NoAccess, platform.ErrContextSignal
}
+// isInstructionAbort returns true if it is an instruction abort.
+//
+//go:nosplit
+func isInstructionAbort(code uint64) bool {
+ value := (code & _ESR_ELx_EC_MASK) >> _ESR_ELx_EC_SHIFT
+ return value == _ESR_ELx_EC_IABT_LOW
+}
+
+// isWriteFault returns whether it is a write fault.
+//
+//go:nosplit
+func isWriteFault(code uint64) bool {
+ if isInstructionAbort(code) {
+ return false
+ }
+
+ return (code & _ESR_ELx_WNR) != 0
+}
+
// fault generates an appropriate fault return.
//
//go:nosplit
func (c *vCPU) fault(signal int32, info *arch.SignalInfo) (usermem.AccessType, error) {
+ bluepill(c) // Probably no-op, but may not be.
faultAddr := c.GetFaultAddr()
code, user := c.ErrorCode()
+ if !user {
+ // The last fault serviced by this CPU was not a user
+ // fault, so we can't reliably trust the faultAddr or
+ // the code provided here. We need to re-execute.
+ return usermem.NoAccess, platform.ErrContextInterrupt
+ }
+
// Reset the pointed SignalInfo.
*info = arch.SignalInfo{Signo: signal}
info.SetAddr(uint64(faultAddr))
- read := true
- write := false
- execute := true
-
ret := code & _ESR_ELx_FSC
switch ret {
case _ESR_SEGV_MAPERR_L0, _ESR_SEGV_MAPERR_L1, _ESR_SEGV_MAPERR_L2, _ESR_SEGV_MAPERR_L3:
info.Code = 1 //SEGV_MAPERR
- read = false
- write = true
- execute = false
case _ESR_SEGV_ACCERR_L1, _ESR_SEGV_ACCERR_L2, _ESR_SEGV_ACCERR_L3, _ESR_SEGV_PEMERR_L1, _ESR_SEGV_PEMERR_L2, _ESR_SEGV_PEMERR_L3:
info.Code = 2 // SEGV_ACCERR.
- read = true
- write = false
- execute = false
default:
info.Code = 2
}
- if !user {
- read = true
- write = false
- execute = true
-
- }
accessType := usermem.AccessType{
- Read: read,
- Write: write,
- Execute: execute,
+ Read: !isWriteFault(uint64(code)),
+ Write: isWriteFault(uint64(code)),
+ Execute: isInstructionAbort(uint64(code)),
}
return accessType, platform.ErrContextSignal
}
-
-// retryInGuest runs the given function in guest mode.
-//
-// If the function does not complete in guest mode (due to execution of a
-// system call due to a GC stall, for example), then it will be retried. The
-// given function must be idempotent as a result of the retry mechanism.
-func (m *machine) retryInGuest(fn func()) {
- c := m.Get()
- defer m.Put(c)
- for {
- c.ClearErrorCode() // See below.
- bluepill(c) // Force guest mode.
- fn() // Execute the given function.
- _, user := c.ErrorCode()
- if user {
- // If user is set, then we haven't bailed back to host
- // mode via a kernel exception or system call. We
- // consider the full function to have executed in guest
- // mode and we can return.
- break
- }
- }
-}
diff --git a/pkg/sentry/platform/kvm/testutil/testutil_arm64.go b/pkg/sentry/platform/kvm/testutil/testutil_arm64.go
index ca902c8c1..4dad877ba 100644
--- a/pkg/sentry/platform/kvm/testutil/testutil_arm64.go
+++ b/pkg/sentry/platform/kvm/testutil/testutil_arm64.go
@@ -56,5 +56,9 @@ func CheckTestRegs(regs *arch.Registers, full bool) (err error) {
err = addRegisterMismatch(err, fmt.Sprintf("R%d", i), regs.Regs[i], need)
}
}
+ // Check tls.
+ if need := ^uint64(11); regs.TPIDR_EL0 != need {
+ err = addRegisterMismatch(err, "tpdir_el0", regs.TPIDR_EL0, need)
+ }
return
}
diff --git a/pkg/sentry/platform/kvm/testutil/testutil_arm64.s b/pkg/sentry/platform/kvm/testutil/testutil_arm64.s
index 07658144e..6caf7282d 100644
--- a/pkg/sentry/platform/kvm/testutil/testutil_arm64.s
+++ b/pkg/sentry/platform/kvm/testutil/testutil_arm64.s
@@ -52,6 +52,8 @@ start:
TEXT ·FloatingPointWorks(SB),NOSPLIT,$0-8
NO_LOCAL_POINTERS
+ // gc will touch fpsimd, so we should test it.
+ // such as in <runtime.deductSweepCredit>.
FMOVD $(9.9), F0
MOVD $SYS_GETPID, R8 // getpid
SVC
@@ -102,11 +104,15 @@ isNaN:
TEXT ·TwiddleRegsSyscall(SB),NOSPLIT,$0
TWIDDLE_REGS()
+ MSR R10, TPIDR_EL0
+ // Trapped in el0_svc.
SVC
RET // never reached
TEXT ·TwiddleRegsFault(SB),NOSPLIT,$0
- TWIDDLE_REGS()
- // Branch to Register branches unconditionally to an address in <Rn>.
- JMP (R4) // <=> br x4, must fault
- RET // never reached
+ TWIDDLE_REGS()
+ MSR R10, TPIDR_EL0
+ // Trapped in el0_ia.
+ // Branch to Register branches unconditionally to an address in <Rn>.
+ JMP (R6) // <=> br x6, must fault
+ RET // never reached
diff --git a/pkg/sentry/platform/platform.go b/pkg/sentry/platform/platform.go
index 4b13eec30..3f99afdd1 100644
--- a/pkg/sentry/platform/platform.go
+++ b/pkg/sentry/platform/platform.go
@@ -22,6 +22,7 @@ import (
"os"
"gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/seccomp"
"gvisor.dev/gvisor/pkg/sentry/arch"
"gvisor.dev/gvisor/pkg/sentry/memmap"
@@ -114,6 +115,17 @@ func (NoCPUPreemptionDetection) PreemptAllCPUs() error {
panic("This platform does not support CPU preemption detection")
}
+// MemoryManager represents an abstraction above the platform address space
+// which manages memory mappings and their contents.
+type MemoryManager interface {
+ //usermem.IO provides access to the contents of a virtual memory space.
+ usermem.IO
+ // MMap establishes a memory mapping.
+ MMap(ctx context.Context, opts memmap.MMapOpts) (usermem.Addr, error)
+ // AddressSpace returns the AddressSpace bound to mm.
+ AddressSpace() AddressSpace
+}
+
// Context represents the execution context for a single thread.
type Context interface {
// Switch resumes execution of the thread specified by the arch.Context
@@ -143,7 +155,30 @@ type Context interface {
// concurrent call to Switch().
//
// - ErrContextCPUPreempted: See the definition of that error for details.
- Switch(as AddressSpace, ac arch.Context, cpu int32) (*arch.SignalInfo, usermem.AccessType, error)
+ Switch(ctx context.Context, mm MemoryManager, ac arch.Context, cpu int32) (*arch.SignalInfo, usermem.AccessType, error)
+
+ // PullFullState() pulls a full state of the application thread.
+ //
+ // A platform can support lazy loading/restoring of a thread state
+ // which includes registers and a floating point state.
+ //
+ // For example, when the Sentry handles a system call, it may have only
+ // syscall arguments without other registers and a floating point
+ // state. And in this case, if the Sentry will need to construct a
+ // signal frame to call a signal handler, it will need to call
+ // PullFullState() to load all registers and FPU state.
+ //
+ // Preconditions: The caller must be running on the task goroutine.
+ PullFullState(as AddressSpace, ac arch.Context)
+
+ // FloatingPointStateChanged forces restoring a full state of the application thread.
+ //
+ // A platform can support lazy loading/restoring of a thread state.
+ // This means that if the Sentry has not changed a thread state,
+ // the platform may not restore it.
+ //
+ // Preconditions: The caller must be running on the task goroutine.
+ FloatingPointStateChanged()
// Interrupt interrupts a concurrent call to Switch(), causing it to return
// ErrContextInterrupt.
@@ -218,6 +253,13 @@ type AddressSpace interface {
// must be acquired via platform.NewAddressSpace().
Release()
+ // PreFork() is called before creating a copy of AddressSpace. This
+ // guarantees that this address space will be in a consistent state.
+ PreFork()
+
+ // PostFork() is called after creating a copy of AddressSpace.
+ PostFork()
+
// AddressSpaceIO methods are supported iff the associated platform's
// Platform.SupportsAddressSpaceIO() == true. AddressSpaces for which this
// does not hold may panic if AddressSpaceIO methods are invoked.
diff --git a/pkg/sentry/platform/ptrace/BUILD b/pkg/sentry/platform/ptrace/BUILD
index 29fd23cc3..e04165fbf 100644
--- a/pkg/sentry/platform/ptrace/BUILD
+++ b/pkg/sentry/platform/ptrace/BUILD
@@ -24,6 +24,7 @@ go_library(
visibility = ["//:sandbox"],
deps = [
"//pkg/abi/linux",
+ "//pkg/context",
"//pkg/log",
"//pkg/procid",
"//pkg/safecopy",
diff --git a/pkg/sentry/platform/ptrace/ptrace.go b/pkg/sentry/platform/ptrace/ptrace.go
index 08d055e05..45ff2bcc3 100644
--- a/pkg/sentry/platform/ptrace/ptrace.go
+++ b/pkg/sentry/platform/ptrace/ptrace.go
@@ -48,6 +48,7 @@ import (
"os"
"gvisor.dev/gvisor/pkg/abi/linux"
+ pkgcontext "gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/sentry/arch"
"gvisor.dev/gvisor/pkg/sentry/platform"
"gvisor.dev/gvisor/pkg/sentry/platform/interrupt"
@@ -95,7 +96,8 @@ type context struct {
}
// Switch runs the provided context in the given address space.
-func (c *context) Switch(as platform.AddressSpace, ac arch.Context, cpu int32) (*arch.SignalInfo, usermem.AccessType, error) {
+func (c *context) Switch(ctx pkgcontext.Context, mm platform.MemoryManager, ac arch.Context, cpu int32) (*arch.SignalInfo, usermem.AccessType, error) {
+ as := mm.AddressSpace()
s := as.(*subprocess)
isSyscall := s.switchToApp(c, ac)
@@ -180,6 +182,12 @@ func (c *context) Interrupt() {
// Release implements platform.Context.Release().
func (c *context) Release() {}
+// FloatingPointStateChanged implements platform.Context.FloatingPointStateChanged.
+func (c *context) FloatingPointStateChanged() {}
+
+// PullFullState implements platform.Context.PullFullState.
+func (c *context) PullFullState(as platform.AddressSpace, ac arch.Context) {}
+
// PTrace represents a collection of ptrace subprocesses.
type PTrace struct {
platform.MMapMinAddr
diff --git a/pkg/sentry/platform/ptrace/subprocess.go b/pkg/sentry/platform/ptrace/subprocess.go
index c990f3454..e1d54d8a2 100644
--- a/pkg/sentry/platform/ptrace/subprocess.go
+++ b/pkg/sentry/platform/ptrace/subprocess.go
@@ -662,3 +662,9 @@ func (s *subprocess) Unmap(addr usermem.Addr, length uint64) {
panic(fmt.Sprintf("munmap(%x, %x)) failed: %v", addr, length, err))
}
}
+
+// PreFork implements platform.AddressSpace.PreFork.
+func (s *subprocess) PreFork() {}
+
+// PostFork implements platform.AddressSpace.PostFork.
+func (s *subprocess) PostFork() {}
diff --git a/pkg/sentry/platform/ring0/kernel_arm64.go b/pkg/sentry/platform/ring0/kernel_arm64.go
index fca3a5478..d483ff03c 100644
--- a/pkg/sentry/platform/ring0/kernel_arm64.go
+++ b/pkg/sentry/platform/ring0/kernel_arm64.go
@@ -59,11 +59,13 @@ func (c *CPU) SwitchToUser(switchOpts SwitchOpts) (vector Vector) {
regs.Pstate &= ^uint64(UserFlagsClear)
regs.Pstate |= UserFlagsSet
+ LoadFloatingPoint(switchOpts.FloatingPointState)
SetTLS(regs.TPIDR_EL0)
kernelExitToEl0()
regs.TPIDR_EL0 = GetTLS()
+ SaveFloatingPoint(switchOpts.FloatingPointState)
vector = c.vecCode
diff --git a/pkg/sentry/platform/ring0/lib_arm64.go b/pkg/sentry/platform/ring0/lib_arm64.go
index a6345010d..00e52c8af 100644
--- a/pkg/sentry/platform/ring0/lib_arm64.go
+++ b/pkg/sentry/platform/ring0/lib_arm64.go
@@ -38,6 +38,12 @@ func SaveVRegs(*byte)
// LoadVRegs loads V0-V31 registers.
func LoadVRegs(*byte)
+// LoadFloatingPoint loads floating point state.
+func LoadFloatingPoint(*byte)
+
+// SaveFloatingPoint saves floating point state.
+func SaveFloatingPoint(*byte)
+
// GetTLS returns the value of TPIDR_EL0 register.
func GetTLS() (value uint64)
diff --git a/pkg/sentry/platform/ring0/lib_arm64.s b/pkg/sentry/platform/ring0/lib_arm64.s
index b63e14b41..86bfbe46f 100644
--- a/pkg/sentry/platform/ring0/lib_arm64.s
+++ b/pkg/sentry/platform/ring0/lib_arm64.s
@@ -129,3 +129,89 @@ TEXT ·LoadVRegs(SB),NOSPLIT,$0-8
ISB $15
RET
+
+TEXT ·LoadFloatingPoint(SB),NOSPLIT,$0-8
+ MOVD addr+0(FP), R0
+
+ MOVD 0(R0), R1
+ MOVD R1, FPSR
+ MOVD 8(R0), R1
+ MOVD R1, NZCV
+
+ FMOVD 16*1(R0), F0
+ FMOVD 16*2(R0), F1
+ FMOVD 16*3(R0), F2
+ FMOVD 16*4(R0), F3
+ FMOVD 16*5(R0), F4
+ FMOVD 16*6(R0), F5
+ FMOVD 16*7(R0), F6
+ FMOVD 16*8(R0), F7
+ FMOVD 16*9(R0), F8
+ FMOVD 16*10(R0), F9
+ FMOVD 16*11(R0), F10
+ FMOVD 16*12(R0), F11
+ FMOVD 16*13(R0), F12
+ FMOVD 16*14(R0), F13
+ FMOVD 16*15(R0), F14
+ FMOVD 16*16(R0), F15
+ FMOVD 16*17(R0), F16
+ FMOVD 16*18(R0), F17
+ FMOVD 16*19(R0), F18
+ FMOVD 16*20(R0), F19
+ FMOVD 16*21(R0), F20
+ FMOVD 16*22(R0), F21
+ FMOVD 16*23(R0), F22
+ FMOVD 16*24(R0), F23
+ FMOVD 16*25(R0), F24
+ FMOVD 16*26(R0), F25
+ FMOVD 16*27(R0), F26
+ FMOVD 16*28(R0), F27
+ FMOVD 16*29(R0), F28
+ FMOVD 16*30(R0), F29
+ FMOVD 16*31(R0), F30
+ FMOVD 16*32(R0), F31
+
+ RET
+
+TEXT ·SaveFloatingPoint(SB),NOSPLIT,$0-8
+ MOVD addr+0(FP), R0
+
+ MOVD FPSR, R1
+ MOVD R1, 0(R0)
+ MOVD NZCV, R1
+ MOVD R1, 8(R0)
+
+ FMOVD F0, 16*1(R0)
+ FMOVD F1, 16*2(R0)
+ FMOVD F2, 16*3(R0)
+ FMOVD F3, 16*4(R0)
+ FMOVD F4, 16*5(R0)
+ FMOVD F5, 16*6(R0)
+ FMOVD F6, 16*7(R0)
+ FMOVD F7, 16*8(R0)
+ FMOVD F8, 16*9(R0)
+ FMOVD F9, 16*10(R0)
+ FMOVD F10, 16*11(R0)
+ FMOVD F11, 16*12(R0)
+ FMOVD F12, 16*13(R0)
+ FMOVD F13, 16*14(R0)
+ FMOVD F14, 16*15(R0)
+ FMOVD F15, 16*16(R0)
+ FMOVD F16, 16*17(R0)
+ FMOVD F17, 16*18(R0)
+ FMOVD F18, 16*19(R0)
+ FMOVD F19, 16*20(R0)
+ FMOVD F20, 16*21(R0)
+ FMOVD F21, 16*22(R0)
+ FMOVD F22, 16*23(R0)
+ FMOVD F23, 16*24(R0)
+ FMOVD F24, 16*25(R0)
+ FMOVD F25, 16*26(R0)
+ FMOVD F26, 16*27(R0)
+ FMOVD F27, 16*28(R0)
+ FMOVD F28, 16*29(R0)
+ FMOVD F29, 16*30(R0)
+ FMOVD F30, 16*31(R0)
+ FMOVD F31, 16*32(R0)
+
+ RET
generated by cgit v1.2.3 (git 2.39.1) at 2025-03-09 12:24:09 +0000