123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364 |
- /* -*- mode:c; c-file-style:"k&r"; c-basic-offset: 4; tab-width:4; indent-tabs-mode:nil; mode:auto-fill; fill-column:78; -*- */
- /* vim: set ts=4 sw=4 et tw=78 fo=cqt wm=0: */
- /* Copyright (C) 2014 Stony Brook University
- This file is part of Graphene Library OS.
- Graphene Library OS is free software: you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public License
- as published by the Free Software Foundation, either version 3 of the
- License, or (at your option) any later version.
- Graphene Library OS is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU Lesser General Public License for more details.
- You should have received a copy of the GNU Lesser General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- /*
- * db_signal.c
- *
- * This file contains APIs to set up handlers of exceptions issued by the
- * host, and the methods to pass the exceptions to the upcalls.
- */
- #include "pal_defs.h"
- #include "pal_linux_defs.h"
- #include "pal.h"
- #include "pal_internal.h"
- #include "pal_linux.h"
- #include "pal_error.h"
- #include "pal_security.h"
- #include "api.h"
- #include "ecall_types.h"
- #include <atomic.h>
- #include <sigset.h>
- #include <linux/signal.h>
- #include <ucontext.h>
- typedef struct exception_event {
- PAL_IDX event_num;
- PAL_CONTEXT * context;
- struct pal_frame * frame;
- } PAL_EVENT;
- #define SIGNAL_MASK_TIME 1000
- #define save_return_point(ptr) \
- asm volatile ("leaq 0(%%rip), %%rax\r\n" \
- "movq %%rax, %0\r\n" \
- : "=b"(ptr) :: "memory", "rax")
- void _DkGenericEventTrigger (PAL_IDX event_num, PAL_EVENT_HANDLER upcall,
- PAL_NUM arg, struct pal_frame * frame,
- PAL_CONTEXT * context)
- {
- struct exception_event event;
- event.event_num = event_num;
- event.context = context;
- event.frame = frame;
- (*upcall) ((PAL_PTR) &event, arg, context);
- }
- static bool
- _DkGenericSignalHandle (int event_num, PAL_NUM arg, struct pal_frame * frame,
- PAL_CONTEXT * context)
- {
- PAL_EVENT_HANDLER upcall = _DkGetExceptionHandler(event_num);
- if (upcall) {
- _DkGenericEventTrigger(event_num, upcall, arg, frame, context);
- return true;
- }
- return false;
- }
- #define ADDR_IN_PAL(addr) \
- ((void *) (addr) > TEXT_START && (void *) (addr) < TEXT_END)
- static struct pal_frame * get_frame (sgx_context_t * uc)
- {
- unsigned long rbp;
- if (uc) {
- unsigned long rip = uc->rip;
- rbp = uc->rbp;
- if (!ADDR_IN_PAL(rip))
- return NULL;
- } else {
- asm volatile ("movq %%rbp, %0" : "=r"(rbp) :: "memory");
- }
- while (ADDR_IN_PAL(((unsigned long *) rbp)[1]))
- rbp = *(unsigned long *) rbp;
- struct pal_frame * frame = (struct pal_frame *) rbp - 1;
- for (int i = 0 ; i < 8 ; i++) {
- if (frame->identifier == PAL_FRAME_IDENTIFIER)
- return frame;
- frame = (struct pal_frame *) ((void *) frame - 8);
- }
- return NULL;
- }
- asm (".type arch_exception_return_asm, @function;"
- "arch_exception_return_asm:"
- " pop %rax;"
- " pop %rbx;"
- " pop %rcx;"
- " pop %rdx;"
- " pop %rsi;"
- " pop %rdi;"
- " pop %r8;"
- " pop %r9;"
- " pop %r10;"
- " pop %r11;"
- " pop %r12;"
- " pop %r13;"
- " pop %r14;"
- " pop %r15;"
- " retq;");
- extern void arch_exception_return (void) asm ("arch_exception_return_asm");
- void _DkExceptionRealHandler (int event, PAL_NUM arg, struct pal_frame * frame,
- PAL_CONTEXT * context)
- {
- if (frame) {
- frame = __alloca(sizeof(struct pal_frame));
- frame->identifier = PAL_FRAME_IDENTIFIER;
- frame->func = &_DkExceptionRealHandler;
- frame->funcname = "_DkExceptionRealHandler";
- store_register(rsp, frame->arch.rsp);
- store_register(rbp, frame->arch.rbp);
- unsigned long * last_frame = ((unsigned long *) frame->arch.rbp) + 1;
- last_frame[0] = (unsigned long) arch_exception_return;
- last_frame[1] = context->rax;
- last_frame[2] = context->rbx;
- last_frame[3] = context->rcx;
- last_frame[4] = context->rdx;
- last_frame[5] = context->rsi;
- last_frame[6] = context->rdi;
- last_frame[7] = context->r8;
- last_frame[8] = context->r9;
- last_frame[9] = context->r10;
- last_frame[10] = context->r11;
- last_frame[11] = context->r12;
- last_frame[12] = context->r13;
- last_frame[13] = context->r14;
- last_frame[14] = context->r15;
- last_frame[15] = context->rip;
- }
- _DkGenericSignalHandle(event, arg, frame, context);
- }
- void restore_sgx_context (sgx_context_t * uc)
- {
- /* prepare the return address */
- uc->rsp -= 8;
- *(uint64_t *) uc->rsp = uc->rip;
- /* now pop the stack */
- asm volatile ("mov %0, %%rsp\n"
- "pop %%rax\n"
- "pop %%rcx\n"
- "pop %%rdx\n"
- "pop %%rbx\n"
- "add $8, %%rsp\n" /* don't pop RSP yet */
- "pop %%rbp\n"
- "pop %%rsi\n"
- "pop %%rdi\n"
- "pop %%r8\n"
- "pop %%r9\n"
- "pop %%r10\n"
- "pop %%r11\n"
- "pop %%r12\n"
- "pop %%r13\n"
- "pop %%r14\n"
- "pop %%r15\n"
- "popfq\n"
- "mov -104(%%rsp), %%rsp\n"
- "ret\n"
- :: "r"(uc) : "memory");
- }
- void _DkExceptionHandler (unsigned int exit_info, sgx_context_t * uc)
- {
- #if SGX_HAS_FSGSBASE == 0
- /* set the FS first if necessary */
- uint64_t fsbase = (uint64_t) GET_ENCLAVE_TLS(fsbase);
- if (fsbase)
- wrfsbase(fsbase);
- #endif
- union {
- sgx_arch_exitinfo_t info;
- int intval;
- } ei = { .intval = exit_info };
- int event_num;
- PAL_CONTEXT * ctx;
- if (!ei.info.valid) {
- event_num = exit_info;
- goto handle_event;
- }
- if (ei.info.vector == SGX_EXCEPTION_VECTOR_UD) {
- unsigned char * instr = (unsigned char *) uc->rip;
- if (instr[0] == 0xcc) { /* skip int 3 */
- uc->rip++;
- restore_sgx_context(uc);
- return;
- }
- if (instr[0] == 0x0f && instr[1] == 0xa2) {
- unsigned int values[4];
- if (!_DkCpuIdRetrieve(uc->rax & 0xffffffff,
- uc->rcx & 0xffffffff, values)) {
- uc->rip += 2;
- uc->rax = values[0];
- uc->rbx = values[1];
- uc->rcx = values[2];
- uc->rdx = values[3];
- restore_sgx_context(uc);
- return;
- }
- }
- if (instr[0] == 0x0f && instr[1] == 0x31) {
- uc->rip += 2;
- uc->rdx = 0;
- uc->rax = 0;
- restore_sgx_context(uc);
- return;
- }
- }
- switch (ei.info.vector) {
- case SGX_EXCEPTION_VECTOR_DE:
- event_num = PAL_EVENT_DIVZERO;
- break;
- case SGX_EXCEPTION_VECTOR_AC:
- event_num = PAL_EVENT_MEMFAULT;
- break;
- default:
- restore_sgx_context(uc);
- return;
- }
- handle_event:
- ctx = __alloca(sizeof(PAL_CONTEXT));
- memset(ctx, 0, sizeof(PAL_CONTEXT));
- ctx->rax = uc->rax;
- ctx->rbx = uc->rbx;
- ctx->rcx = uc->rcx;
- ctx->rdx = uc->rdx;
- ctx->rsp = uc->rsp;
- ctx->rbp = uc->rbp;
- ctx->rsi = uc->rsi;
- ctx->rdi = uc->rdi;
- ctx->r8 = uc->r8;
- ctx->r9 = uc->r9;
- ctx->r10 = uc->r10;
- ctx->r11 = uc->r11;
- ctx->r12 = uc->r12;
- ctx->r13 = uc->r13;
- ctx->r14 = uc->r14;
- ctx->r15 = uc->r15;
- ctx->efl = uc->rflags;
- ctx->rip = uc->rip;
- struct pal_frame * frame = get_frame(uc);
- PAL_NUM arg = 0;
- _DkExceptionRealHandler(event_num, arg, frame, ctx);
- restore_sgx_context(uc);
- }
- void _DkRaiseFailure (int error)
- {
- PAL_EVENT_HANDLER upcall = _DkGetExceptionHandler(PAL_EVENT_FAILURE);
- if (!upcall)
- return;
- PAL_EVENT event;
- event.event_num = PAL_EVENT_FAILURE;
- event.context = NULL;
- event.frame = NULL;
- (*upcall) ((PAL_PTR) &event, error, NULL);
- }
- void _DkExceptionReturn (void * event)
- {
- PAL_EVENT * e = event;
- sgx_context_t uc;
- PAL_CONTEXT * ctx = e->context;
- if (!ctx) {
- struct pal_frame * frame = e->frame;
- if (!frame)
- return;
- __clear_frame(frame);
- arch_restore_frame(&frame->arch);
- asm volatile ("xor %%rax, %%rax\r\n"
- "leaveq\r\n"
- "retq\r\n" ::: "memory");
- }
- uc.rax = ctx->rax;
- uc.rbx = ctx->rbx;
- uc.rcx = ctx->rcx;
- uc.rdx = ctx->rdx;
- uc.rsp = ctx->rsp;
- uc.rbp = ctx->rbp;
- uc.rsi = ctx->rsi;
- uc.rdi = ctx->rdi;
- uc.r8 = ctx->r8;
- uc.r9 = ctx->r9;
- uc.r10 = ctx->r10;
- uc.r11 = ctx->r11;
- uc.r12 = ctx->r12;
- uc.r13 = ctx->r13;
- uc.r14 = ctx->r14;
- uc.r15 = ctx->r15;
- uc.rflags = ctx->efl;
- uc.rip = ctx->rip;
- restore_sgx_context(&uc);
- }
- void _DkHandleExternelEvent (PAL_NUM event, sgx_context_t * uc)
- {
- struct pal_frame * frame = get_frame(uc);
- if (event == PAL_EVENT_RESUME &&
- frame && frame->func == DkObjectsWaitAny)
- return;
- if (!frame) {
- frame = __alloca(sizeof(struct pal_frame));
- frame->identifier = PAL_FRAME_IDENTIFIER;
- frame->func = &_DkHandleExternelEvent;
- frame->funcname = "_DkHandleExternelEvent";
- arch_store_frame(&frame->arch);
- }
- if (!_DkGenericSignalHandle(event, 0, frame, NULL)
- && event != PAL_EVENT_RESUME)
- _DkThreadExit();
- }
|