qemu/include/qemu/coroutine_int.h
Daniele Buono 58ebc2c313 coroutine: support SafeStack in ucontext backend
LLVM's SafeStack instrumentation does not yet support programs that make
use of the APIs in ucontext.h
With the current implementation of coroutine-ucontext, the resulting
binary is incorrect, with different coroutines sharing the same unsafe
stack and producing undefined behavior at runtime.
This fix allocates an additional unsafe stack area for each coroutine,
and sets the new unsafe stack pointer before calling swapcontext() in
qemu_coroutine_new.
This is the only place where the pointer needs to be manually updated,
since sigsetjmp/siglongjmp are already instrumented by LLVM to properly
support SafeStack.
The additional stack is then freed in qemu_coroutine_delete.

Signed-off-by: Daniele Buono <dbuono@linux.vnet.ibm.com>
Message-id: 20200529205122.714-2-dbuono@linux.vnet.ibm.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-06-23 15:46:05 +01:00

78 lines
2.5 KiB
C

/*
* Coroutine internals
*
* Copyright (c) 2011 Kevin Wolf <kwolf@redhat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef QEMU_COROUTINE_INT_H
#define QEMU_COROUTINE_INT_H
#include "qemu/queue.h"
#include "qemu/coroutine.h"
#ifdef CONFIG_SAFESTACK
/* Pointer to the unsafe stack, defined by the compiler */
extern __thread void *__safestack_unsafe_stack_ptr;
#endif
#define COROUTINE_STACK_SIZE (1 << 20)
typedef enum {
COROUTINE_YIELD = 1,
COROUTINE_TERMINATE = 2,
COROUTINE_ENTER = 3,
} CoroutineAction;
struct Coroutine {
CoroutineEntry *entry;
void *entry_arg;
Coroutine *caller;
/* Only used when the coroutine has terminated. */
QSLIST_ENTRY(Coroutine) pool_next;
size_t locks_held;
/* Only used when the coroutine has yielded. */
AioContext *ctx;
/* Used to catch and abort on illegal co-routine entry.
* Will contain the name of the function that had first
* scheduled the coroutine. */
const char *scheduled;
QSIMPLEQ_ENTRY(Coroutine) co_queue_next;
/* Coroutines that should be woken up when we yield or terminate.
* Only used when the coroutine is running.
*/
QSIMPLEQ_HEAD(, Coroutine) co_queue_wakeup;
QSLIST_ENTRY(Coroutine) co_scheduled_next;
};
Coroutine *qemu_coroutine_new(void);
void qemu_coroutine_delete(Coroutine *co);
CoroutineAction qemu_coroutine_switch(Coroutine *from, Coroutine *to,
CoroutineAction action);
#endif