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authorgVisor bot <gvisor-bot@google.com>2020-01-08 11:48:34 -0800
committergVisor bot <gvisor-bot@google.com>2020-01-08 11:48:34 -0800
commitbb96f525769b0929bdcce7f933ead70af1b85e6d (patch)
treecb84b3c3d31423b40c0b55b96d1046a84a5d6bc8
parentdb376e13924be59182ed4df95762328febf26298 (diff)
parente710f654015d2d35d8a8df07ef54ddbc442cbc9d (diff)
Merge pull request #1273 from lubinszARM:pr_ring_3
PiperOrigin-RevId: 288743614
-rw-r--r--pkg/sentry/platform/ring0/entry_arm64.s67
1 files changed, 67 insertions, 0 deletions
diff --git a/pkg/sentry/platform/ring0/entry_arm64.s b/pkg/sentry/platform/ring0/entry_arm64.s
index 813ef9822..64e9c0845 100644
--- a/pkg/sentry/platform/ring0/entry_arm64.s
+++ b/pkg/sentry/platform/ring0/entry_arm64.s
@@ -357,6 +357,73 @@ TEXT ·Current(SB),NOSPLIT,$0-8
#define STACK_FRAME_SIZE 16
TEXT ·kernelExitToEl0(SB),NOSPLIT,$0
+ // Step1, save sentry context into memory.
+ REGISTERS_SAVE(RSV_REG, CPU_REGISTERS)
+ MOVD RSV_REG_APP, CPU_REGISTERS+PTRACE_R9(RSV_REG)
+
+ WORD $0xd5384003 // MRS SPSR_EL1, R3
+ MOVD R3, CPU_REGISTERS+PTRACE_PSTATE(RSV_REG)
+ MOVD R30, CPU_REGISTERS+PTRACE_PC(RSV_REG)
+ MOVD RSP, R3
+ MOVD R3, CPU_REGISTERS+PTRACE_SP(RSV_REG)
+
+ MOVD CPU_REGISTERS+PTRACE_R3(RSV_REG), R3
+
+ // Step2, save SP_EL1, PSTATE into kernel temporary stack.
+ // switch to temporary stack.
+ LOAD_KERNEL_STACK(RSV_REG)
+ WORD $0xd538d092 //MRS TPIDR_EL1, R18
+
+ SUB $STACK_FRAME_SIZE, RSP, RSP
+ MOVD CPU_REGISTERS+PTRACE_SP(RSV_REG), R11
+ MOVD CPU_REGISTERS+PTRACE_PSTATE(RSV_REG), R12
+ STP (R11, R12), 16*0(RSP)
+
+ MOVD CPU_REGISTERS+PTRACE_R11(RSV_REG), R11
+ MOVD CPU_REGISTERS+PTRACE_R12(RSV_REG), R12
+
+ // Step3, test user pagetable.
+ // If user pagetable is empty, trapped in el1_ia.
+ WORD $0xd538d092 //MRS TPIDR_EL1, R18
+ SWITCH_TO_APP_PAGETABLE(RSV_REG)
+ WORD $0xd538d092 //MRS TPIDR_EL1, R18
+ SWITCH_TO_KVM_PAGETABLE(RSV_REG)
+ WORD $0xd538d092 //MRS TPIDR_EL1, R18
+
+ // If pagetable is not empty, recovery kernel temporary stack.
+ ADD $STACK_FRAME_SIZE, RSP, RSP
+
+ // Step4, load app context pointer.
+ MOVD CPU_APP_ADDR(RSV_REG), RSV_REG_APP
+
+ // Step5, prepare the environment for container application.
+ // set sp_el0.
+ MOVD PTRACE_SP(RSV_REG_APP), R1
+ WORD $0xd5184101 //MSR R1, SP_EL0
+ // set pc.
+ MOVD PTRACE_PC(RSV_REG_APP), R1
+ MSR R1, ELR_EL1
+ // set pstate.
+ MOVD PTRACE_PSTATE(RSV_REG_APP), R1
+ WORD $0xd5184001 //MSR R1, SPSR_EL1
+
+ // RSV_REG & RSV_REG_APP will be loaded at the end.
+ REGISTERS_LOAD(RSV_REG_APP, 0)
+
+ // switch to user pagetable.
+ MOVD PTRACE_R18(RSV_REG_APP), RSV_REG
+ MOVD PTRACE_R9(RSV_REG_APP), RSV_REG_APP
+
+ SUB $STACK_FRAME_SIZE, RSP, RSP
+ STP (RSV_REG, RSV_REG_APP), 16*0(RSP)
+
+ WORD $0xd538d092 //MRS TPIDR_EL1, R18
+
+ SWITCH_TO_APP_PAGETABLE(RSV_REG)
+
+ LDP 16*0(RSP), (RSV_REG, RSV_REG_APP)
+ ADD $STACK_FRAME_SIZE, RSP, RSP
+
ERET()
TEXT ·kernelExitToEl1(SB),NOSPLIT,$0