mii/qemu
1
0
Fork 0
mirror of https://github.com/mii443/qemu.git synced 2025-12-03 19:18:23 +00:00
Code Issues Packages Projects Releases Wiki Activity

coroutine: support SafeStack in ucontext backend

Browse Source 
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>
This commit is contained in:
Daniele Buono
2020-05-29 16:51:19 -04:00
committed by Stefan Hajnoczi
parent ddd633e525
commit 58ebc2c313
2 changed files with 33 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
include/qemu/coroutine_int.h
View File

@@ -28,6 +28,11 @@
#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 {