From 0e96f8065e7dc24aa5bc0a8cb14380c58ed6af13 Mon Sep 17 00:00:00 2001
From: lubinszARM <34124929+lubinszARM@users.noreply.github.com>
Date: Tue, 3 Nov 2020 09:32:22 -0800
Subject: arm64 kvm: inject sError to trigger sigbus

Use an sErr injection to trigger sigbus when we receive EFAULT from the
run ioctl.

After applying this patch, mmap_test_runsc_kvm will be passed on
Arm64.

Signed-off-by: Bin Lu <bin.lu@arm.com>
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/gvisor/pull/4542 from lubinszARM:pr_kvm_mmap_1 f81bd42466d1d60a581e5fb34de18b78878c68c1
PiperOrigin-RevId: 340461239
---
 pkg/sentry/platform/ring0/aarch64.go       | 67 +++++++++++++++++-------------
 pkg/sentry/platform/ring0/entry_arm64.s    | 31 +++++++++++++-
 pkg/sentry/platform/ring0/offsets_arm64.go | 45 +++++++++-----------
 3 files changed, 86 insertions(+), 57 deletions(-)

(limited to 'pkg/sentry/platform/ring0')

diff --git a/pkg/sentry/platform/ring0/aarch64.go b/pkg/sentry/platform/ring0/aarch64.go
index 87a573cc4..327d48465 100644
--- a/pkg/sentry/platform/ring0/aarch64.go
+++ b/pkg/sentry/platform/ring0/aarch64.go
@@ -58,46 +58,55 @@ type Vector uintptr
 
 // Exception vectors.
 const (
-	El1SyncInvalid = iota
-	El1IrqInvalid
-	El1FiqInvalid
-	El1ErrorInvalid
+	El1InvSync = iota
+	El1InvIrq
+	El1InvFiq
+	El1InvError
+
 	El1Sync
 	El1Irq
 	El1Fiq
-	El1Error
+	El1Err
+
 	El0Sync
 	El0Irq
 	El0Fiq
-	El0Error
-	El0Sync_invalid
-	El0Irq_invalid
-	El0Fiq_invalid
-	El0Error_invalid
-	El1Sync_da
-	El1Sync_ia
-	El1Sync_sp_pc
-	El1Sync_undef
-	El1Sync_dbg
-	El1Sync_inv
-	El0Sync_svc
-	El0Sync_da
-	El0Sync_ia
-	El0Sync_fpsimd_acc
-	El0Sync_sve_acc
-	El0Sync_sys
-	El0Sync_sp_pc
-	El0Sync_undef
-	El0Sync_dbg
-	El0Sync_inv
+	El0Err
+
+	El0InvSync
+	El0InvIrq
+	El0InvFiq
+	El0InvErr
+
+	El1SyncDa
+	El1SyncIa
+	El1SyncSpPc
+	El1SyncUndef
+	El1SyncDbg
+	El1SyncInv
+
+	El0SyncSVC
+	El0SyncDa
+	El0SyncIa
+	El0SyncFpsimdAcc
+	El0SyncSveAcc
+	El0SyncSys
+	El0SyncSpPc
+	El0SyncUndef
+	El0SyncDbg
+	El0SyncInv
+
+	El0ErrNMI
+	El0ErrBounce
+
 	_NR_INTERRUPTS
 )
 
 // System call vectors.
 const (
-	Syscall                 Vector = El0Sync_svc
-	PageFault               Vector = El0Sync_da
-	VirtualizationException Vector = El0Error
+	Syscall                 Vector = El0SyncSVC
+	PageFault               Vector = El0SyncDa
+	VirtualizationException Vector = El0ErrBounce
 )
 
 // VirtualAddressBits returns the number bits available for virtual addresses.
diff --git a/pkg/sentry/platform/ring0/entry_arm64.s b/pkg/sentry/platform/ring0/entry_arm64.s
index f9278b653..f489ad352 100644
--- a/pkg/sentry/platform/ring0/entry_arm64.s
+++ b/pkg/sentry/platform/ring0/entry_arm64.s
@@ -288,6 +288,10 @@
 #define ESR_ELx_WFx_ISS_WFE	(UL(1) << 0)
 #define ESR_ELx_xVC_IMM_MASK	((1UL << 16) - 1)
 
+/* ISS field definitions for system error */
+#define ESR_ELx_SERR_MASK	(0x1)
+#define ESR_ELx_SERR_NMI	(0x1)
+
 // LOAD_KERNEL_ADDRESS loads a kernel address.
 #define LOAD_KERNEL_ADDRESS(from, to) \
 	MOVD from, to; \
@@ -691,7 +695,7 @@ el0_sp_pc:
 	B ·Shutdown(SB)
 
 el0_undef:
-	EXCEPTION_WITH_ERROR(1, El0Sync_undef)
+	EXCEPTION_WITH_ERROR(1, El0SyncUndef)
 
 el0_dbg:
 	B ·Shutdown(SB)
@@ -707,6 +711,29 @@ TEXT ·El0_fiq(SB),NOSPLIT,$0
 
 TEXT ·El0_error(SB),NOSPLIT,$0
 	KERNEL_ENTRY_FROM_EL0
+	WORD $0xd5385219        // MRS ESR_EL1, R25
+	AND $ESR_ELx_SERR_MASK, R25, R24
+	CMP $ESR_ELx_SERR_NMI, R24
+	BEQ el0_nmi
+	B el0_bounce
+el0_nmi:
+        WORD $0xd538d092     //MRS   TPIDR_EL1, R18
+        WORD $0xd538601a     //MRS   FAR_EL1, R26
+
+        MOVD R26, CPU_FAULT_ADDR(RSV_REG)
+
+        MOVD $1, R3
+        MOVD R3, CPU_ERROR_TYPE(RSV_REG) // Set error type to user.
+
+        MOVD $El0ErrNMI, R3
+        MOVD R3, CPU_VECTOR_CODE(RSV_REG)
+
+        MRS ESR_EL1, R3
+        MOVD R3, CPU_ERROR_CODE(RSV_REG)
+
+        B ·kernelExitToEl1(SB)
+
+el0_bounce:
 	WORD $0xd538d092     //MRS   TPIDR_EL1, R18
 	WORD $0xd538601a     //MRS   FAR_EL1, R26
 
@@ -718,7 +745,7 @@ TEXT ·El0_error(SB),NOSPLIT,$0
 	MOVD $VirtualizationException, R3
 	MOVD R3, CPU_VECTOR_CODE(RSV_REG)
 
-	B ·HaltAndResume(SB)
+	B ·kernelExitToEl1(SB)
 
 TEXT ·El0_sync_invalid(SB),NOSPLIT,$0
 	B ·Shutdown(SB)
diff --git a/pkg/sentry/platform/ring0/offsets_arm64.go b/pkg/sentry/platform/ring0/offsets_arm64.go
index 45eba960d..53bc3353c 100644
--- a/pkg/sentry/platform/ring0/offsets_arm64.go
+++ b/pkg/sentry/platform/ring0/offsets_arm64.go
@@ -47,43 +47,36 @@ func Emit(w io.Writer) {
 	fmt.Fprintf(w, "#define _KERNEL_FLAGS        0x%02x\n", KernelFlagsSet)
 
 	fmt.Fprintf(w, "\n// Vectors.\n")
-	fmt.Fprintf(w, "#define El1SyncInvalid  0x%02x\n", El1SyncInvalid)
-	fmt.Fprintf(w, "#define El1IrqInvalid 0x%02x\n", El1IrqInvalid)
-	fmt.Fprintf(w, "#define El1FiqInvalid 0x%02x\n", El1FiqInvalid)
-	fmt.Fprintf(w, "#define El1ErrorInvalid 0x%02x\n", El1ErrorInvalid)
 
 	fmt.Fprintf(w, "#define El1Sync 0x%02x\n", El1Sync)
 	fmt.Fprintf(w, "#define El1Irq 0x%02x\n", El1Irq)
 	fmt.Fprintf(w, "#define El1Fiq 0x%02x\n", El1Fiq)
-	fmt.Fprintf(w, "#define El1Error 0x%02x\n", El1Error)
+	fmt.Fprintf(w, "#define El1Err 0x%02x\n", El1Err)
 
 	fmt.Fprintf(w, "#define El0Sync 0x%02x\n", El0Sync)
 	fmt.Fprintf(w, "#define El0Irq 0x%02x\n", El0Irq)
 	fmt.Fprintf(w, "#define El0Fiq 0x%02x\n", El0Fiq)
-	fmt.Fprintf(w, "#define El0Error 0x%02x\n", El0Error)
+	fmt.Fprintf(w, "#define El0Err 0x%02x\n", El0Err)
 
-	fmt.Fprintf(w, "#define El0Sync_invalid 0x%02x\n", El0Sync_invalid)
-	fmt.Fprintf(w, "#define El0Irq_invalid 0x%02x\n", El0Irq_invalid)
-	fmt.Fprintf(w, "#define El0Fiq_invalid 0x%02x\n", El0Fiq_invalid)
-	fmt.Fprintf(w, "#define El0Error_invalid 0x%02x\n", El0Error_invalid)
+	fmt.Fprintf(w, "#define El1SyncDa 0x%02x\n", El1SyncDa)
+	fmt.Fprintf(w, "#define El1SyncIa 0x%02x\n", El1SyncIa)
+	fmt.Fprintf(w, "#define El1SyncSpPc 0x%02x\n", El1SyncSpPc)
+	fmt.Fprintf(w, "#define El1SyncUndef 0x%02x\n", El1SyncUndef)
+	fmt.Fprintf(w, "#define El1SyncDbg 0x%02x\n", El1SyncDbg)
+	fmt.Fprintf(w, "#define El1SyncInv 0x%02x\n", El1SyncInv)
 
-	fmt.Fprintf(w, "#define El1Sync_da 0x%02x\n", El1Sync_da)
-	fmt.Fprintf(w, "#define El1Sync_ia 0x%02x\n", El1Sync_ia)
-	fmt.Fprintf(w, "#define El1Sync_sp_pc 0x%02x\n", El1Sync_sp_pc)
-	fmt.Fprintf(w, "#define El1Sync_undef 0x%02x\n", El1Sync_undef)
-	fmt.Fprintf(w, "#define El1Sync_dbg 0x%02x\n", El1Sync_dbg)
-	fmt.Fprintf(w, "#define El1Sync_inv 0x%02x\n", El1Sync_inv)
+	fmt.Fprintf(w, "#define El0SyncSVC 0x%02x\n", El0SyncSVC)
+	fmt.Fprintf(w, "#define El0SyncDa 0x%02x\n", El0SyncDa)
+	fmt.Fprintf(w, "#define El0SyncIa 0x%02x\n", El0SyncIa)
+	fmt.Fprintf(w, "#define El0SyncFpsimdAcc 0x%02x\n", El0SyncFpsimdAcc)
+	fmt.Fprintf(w, "#define El0SyncSveAcc 0x%02x\n", El0SyncSveAcc)
+	fmt.Fprintf(w, "#define El0SyncSys 0x%02x\n", El0SyncSys)
+	fmt.Fprintf(w, "#define El0SyncSpPc 0x%02x\n", El0SyncSpPc)
+	fmt.Fprintf(w, "#define El0SyncUndef 0x%02x\n", El0SyncUndef)
+	fmt.Fprintf(w, "#define El0SyncDbg 0x%02x\n", El0SyncDbg)
+	fmt.Fprintf(w, "#define El0SyncInv 0x%02x\n", El0SyncInv)
 
-	fmt.Fprintf(w, "#define El0Sync_svc 0x%02x\n", El0Sync_svc)
-	fmt.Fprintf(w, "#define El0Sync_da 0x%02x\n", El0Sync_da)
-	fmt.Fprintf(w, "#define El0Sync_ia 0x%02x\n", El0Sync_ia)
-	fmt.Fprintf(w, "#define El0Sync_fpsimd_acc 0x%02x\n", El0Sync_fpsimd_acc)
-	fmt.Fprintf(w, "#define El0Sync_sve_acc 0x%02x\n", El0Sync_sve_acc)
-	fmt.Fprintf(w, "#define El0Sync_sys 0x%02x\n", El0Sync_sys)
-	fmt.Fprintf(w, "#define El0Sync_sp_pc 0x%02x\n", El0Sync_sp_pc)
-	fmt.Fprintf(w, "#define El0Sync_undef 0x%02x\n", El0Sync_undef)
-	fmt.Fprintf(w, "#define El0Sync_dbg 0x%02x\n", El0Sync_dbg)
-	fmt.Fprintf(w, "#define El0Sync_inv 0x%02x\n", El0Sync_inv)
+	fmt.Fprintf(w, "#define El0ErrNMI 0x%02x\n", El0ErrNMI)
 
 	fmt.Fprintf(w, "#define PageFault 0x%02x\n", PageFault)
 	fmt.Fprintf(w, "#define Syscall 0x%02x\n", Syscall)
-- 
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