diff options
Diffstat (limited to 'pkg/sentry/platform/safecopy/sighandler_amd64.s')
| -rw-r--r-- | pkg/sentry/platform/safecopy/sighandler_amd64.s | 133 |
1 files changed, 0 insertions, 133 deletions
diff --git a/pkg/sentry/platform/safecopy/sighandler_amd64.s b/pkg/sentry/platform/safecopy/sighandler_amd64.s deleted file mode 100644 index 475ae48e9..000000000 --- a/pkg/sentry/platform/safecopy/sighandler_amd64.s +++ /dev/null @@ -1,133 +0,0 @@ -// Copyright 2018 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -#include "textflag.h" - -// The signals handled by sigHandler. -#define SIGBUS 7 -#define SIGSEGV 11 - -// Offsets to the registers in context->uc_mcontext.gregs[]. -#define REG_RDI 0x68 -#define REG_RAX 0x90 -#define REG_IP 0xa8 - -// Offset to the si_addr field of siginfo. -#define SI_CODE 0x08 -#define SI_ADDR 0x10 - -// signalHandler is the signal handler for SIGSEGV and SIGBUS signals. It must -// not be set up as a handler to any other signals. -// -// If the instruction causing the signal is within a safecopy-protected -// function, the signal is handled such that execution resumes in the -// appropriate fault handling stub with AX containing the faulting address and -// DI containing the signal number. Otherwise control is transferred to the -// previously configured signal handler (savedSigSegvHandler or -// savedSigBusHandler). -// -// This function cannot be written in go because it runs whenever a signal is -// received by the thread (preempting whatever was running), which includes when -// garbage collector has stopped or isn't expecting any interactions (like -// barriers). -// -// The arguments are the following: -// DI - The signal number. -// SI - Pointer to siginfo_t structure. -// DX - Pointer to ucontext structure. -TEXT ·signalHandler(SB),NOSPLIT,$0 - // Check if the signal is from the kernel. - MOVQ $0x0, CX - CMPL CX, SI_CODE(SI) - JGE original_handler - - // Check if RIP is within the area we care about. - MOVQ REG_IP(DX), CX - CMPQ CX, ·memcpyBegin(SB) - JB not_memcpy - CMPQ CX, ·memcpyEnd(SB) - JAE not_memcpy - - // Modify the context such that execution will resume in the fault - // handler. - LEAQ handleMemcpyFault(SB), CX - JMP handle_fault - -not_memcpy: - CMPQ CX, ·memclrBegin(SB) - JB not_memclr - CMPQ CX, ·memclrEnd(SB) - JAE not_memclr - - LEAQ handleMemclrFault(SB), CX - JMP handle_fault - -not_memclr: - CMPQ CX, ·swapUint32Begin(SB) - JB not_swapuint32 - CMPQ CX, ·swapUint32End(SB) - JAE not_swapuint32 - - LEAQ handleSwapUint32Fault(SB), CX - JMP handle_fault - -not_swapuint32: - CMPQ CX, ·swapUint64Begin(SB) - JB not_swapuint64 - CMPQ CX, ·swapUint64End(SB) - JAE not_swapuint64 - - LEAQ handleSwapUint64Fault(SB), CX - JMP handle_fault - -not_swapuint64: - CMPQ CX, ·compareAndSwapUint32Begin(SB) - JB not_casuint32 - CMPQ CX, ·compareAndSwapUint32End(SB) - JAE not_casuint32 - - LEAQ handleCompareAndSwapUint32Fault(SB), CX - JMP handle_fault - -not_casuint32: - CMPQ CX, ·loadUint32Begin(SB) - JB not_loaduint32 - CMPQ CX, ·loadUint32End(SB) - JAE not_loaduint32 - - LEAQ handleLoadUint32Fault(SB), CX - JMP handle_fault - -not_loaduint32: -original_handler: - // Jump to the previous signal handler, which is likely the golang one. - XORQ CX, CX - MOVQ ·savedSigBusHandler(SB), AX - CMPL DI, $SIGSEGV - CMOVQEQ ·savedSigSegVHandler(SB), AX - JMP AX - -handle_fault: - // Entered with the address of the fault handler in RCX; store it in - // RIP. - MOVQ CX, REG_IP(DX) - - // Store the faulting address in RAX. - MOVQ SI_ADDR(SI), CX - MOVQ CX, REG_RAX(DX) - - // Store the signal number in EDI. - MOVL DI, REG_RDI(DX) - - RET |