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ASAN: Support coroutine context switching and stack tracing (#4153)

For coroutine, we should use `__sanitizer_start_switch_fiber` which
similar to`VALGRIND_STACK_REGISTER`, see
https://github.com/google/sanitizers/issues/189#issuecomment-1346243598
for details. If not fix this, asan will output warning:

```
==72269==WARNING: ASan is ignoring requested __asan_handle_no_return: stack type: default top: 0x00016f638000; bottom 0x000106bec000; size: 0x000068a4c000 (1755627520)
False positive error reports may follow
For details see https://github.com/google/sanitizers/issues/189
```

It will cause asan failed to get the stack, see
`research/st/asan-switch.cpp` for example:

```
==71611==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x000103600733 at pc 0x0001009d3d7c bp 0x000100b4bd40 sp 0x000100b4bd38
WRITE of size 1 at 0x000103600733 thread T0
    #0 0x1009d3d78 in foo(void*) asan-switch.cpp:13
```

After fix this issue, it should provide the full stack when crashing:

```
==73437==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x000103300733 at pc 0x000100693d7c bp 0x00016f76f550 sp 0x00016f76f548
WRITE of size 1 at 0x000103300733 thread T0
    #0 0x100693d78 in foo(void*) asan-switch.cpp:13
    #1 0x100693df4 in main asan-switch.cpp:23
    #2 0x195aa20dc  (<unknown module>)
```

For primordial coroutine, if not set the stack by
`st_set_primordial_stack`, then the stack is NULL and asan can't get the
stack tracing. Note that it's optional and only make it fail to display
the stack information, no other errors.

---

Co-authored-by: john <hondaxiao@tencent.com>
This commit is contained in:
Winlin 2024-08-22 17:12:39 +08:00 committed by GitHub
parent 55610cf689
commit 8f48a0e2d1
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
15 changed files with 236 additions and 15 deletions

View file

@ -195,6 +195,12 @@ endif
# or cache the stack and reuse it:
# make EXTRA_CFLAGS=-DMD_CACHE_STACK
#
# or enable support for valgrind:
# make EXTRA_CFLAGS="-DMD_VALGRIND"
#
# or enable support for asan:
# make EXTRA_CFLAGS="-DMD_ASAN -fsanitize=address -fno-omit-frame-pointer"
#
# or enable the coverage for utest:
# make UTEST_FLAGS="-fprofile-arcs -ftest-coverage"
#

View file

@ -51,6 +51,12 @@ Linux with valgrind and epoll:
make linux-debug EXTRA_CFLAGS="-DMD_HAVE_EPOLL -DMD_VALGRIND"
```
Linux with ASAN(Google Address Sanitizer):
```bash
make linux-debug EXTRA_CFLAGS="-DMD_ASAN"
```
## Mac: Usage
Get code:

View file

@ -3,3 +3,12 @@
#include "common.h"
void *_st_primordial_stack_bottom = NULL;
size_t _st_primordial_stack_size = 0;
void st_set_primordial_stack(void *top, void *bottom)
{
_st_primordial_stack_bottom = bottom;
_st_primordial_stack_size = (char *)top - (char *)bottom;
}

View file

@ -162,6 +162,10 @@ struct _st_thread {
_st_clist_t tlink; /* For putting on thread queue */
#endif
#ifdef MD_ASAN
void *fake_stack; /* Fake stack for ASAN */
#endif
st_utime_t due; /* Wakeup time when thread is sleeping */
_st_thread_t *left; /* For putting in timeout heap */
_st_thread_t *right; /* -- see docs/timeout_heap.txt for details */
@ -314,7 +318,7 @@ extern __thread _st_eventsys_t *_st_eventsys;
* Forward declarations
*/
void _st_vp_schedule(void);
void _st_vp_schedule(_st_thread_t *from);
void _st_vp_check_clock(void);
void *_st_idle_thread_start(void *arg);
void _st_thread_main(void);
@ -365,6 +369,64 @@ _st_thread_t *st_thread_create(void *(*start)(void *arg), void *arg, int joinabl
#define ST_SWITCH_IN_CB(_thread)
#endif
#ifdef MD_ASAN
/*
* Fiber annotation interface.
*
* Before switching to a different stack, one must call
* __sanitizer_start_switch_fiber with a pointer to the bottom of the
* destination stack and its size. When code starts running on the new stack,
* it must call __sanitizer_finish_switch_fiber to finalize the switch.
* The start_switch function takes a void** to store the current fake stack if
* there is one (it is needed when detect_stack_use_after_return is enabled).
* When restoring a stack, this pointer must be given to the finish_switch
* function. In most cases, this void* can be stored on the stack just before
* switching. When leaving a fiber definitely, null must be passed as first
* argument to the start_switch function so that the fake stack is destroyed.
* If you do not want support for stack use-after-return detection, you can
* always pass null to these two functions.
* Note that the fake stack mechanism is disabled during fiber switch, so if a
* signal callback runs during the switch, it will not benefit from the stack
* use-after-return detection.
*
* See https://github.com/google/sanitizers/issues/189#issuecomment-1346243598
*/
extern void __sanitizer_start_switch_fiber(void **fake_stack_save,
const void *bottom, size_t size);
extern void __sanitizer_finish_switch_fiber(void *fake_stack_save,
const void **bottom_old,
size_t *size_old);
/* The stack for primoridal thread. */
extern void *_st_primordial_stack_bottom;
extern size_t _st_primordial_stack_size;
static inline void _st_asan_start_switch(_st_thread_t *from, _st_thread_t *thread)
{
/* For primordial thread, the stack is NULL, so asan can not capture it. */
const void *stk_bottom = thread->stack ? thread->stack->stk_bottom : NULL;
size_t stk_size = thread->stack ? thread->stack->stk_size : 0;
/* For primordial thread, user should setup the stack information. */
if (!stk_bottom && (thread->flags & _ST_FL_PRIMORDIAL)) {
stk_bottom = _st_primordial_stack_bottom;
stk_size = _st_primordial_stack_size;
}
/*
* Save the current stack to fake_stack of from, tell asan the target stack
* we are targeting to switch to.
*/
__sanitizer_start_switch_fiber(&from->fake_stack, stk_bottom, stk_size);
}
static inline void _st_asan_finish_switch(_st_thread_t *thread)
{
__sanitizer_finish_switch_fiber(thread->fake_stack, NULL, NULL);
}
#endif
/*
* Switch away from the current thread context by saving its state and
* calling the thread scheduler
@ -374,9 +436,14 @@ static inline void _st_switch_context(_st_thread_t *thread)
ST_SWITCH_OUT_CB(thread);
if (!_st_md_cxt_save(thread->context)) {
_st_vp_schedule();
_st_vp_schedule(thread);
}
#ifdef MD_ASAN
/* Switch from other thread to this running thread. */
_st_asan_finish_switch(thread);
#endif
ST_DEBUG_ITERATE_THREADS();
ST_SWITCH_IN_CB(thread);
}
@ -385,8 +452,11 @@ static inline void _st_switch_context(_st_thread_t *thread)
* Restore a thread context that was saved by _st_switch_context or
* initialized by _ST_INIT_CONTEXT
*/
static inline void _st_restore_context(_st_thread_t *thread)
static inline void _st_restore_context(_st_thread_t *from, _st_thread_t *thread)
{
#ifdef MD_ASAN
_st_asan_start_switch(from, thread);
#endif
_st_this_thread = thread;
_st_md_cxt_restore(thread->context, 1);
}

View file

@ -159,6 +159,8 @@ extern st_netfd_t st_open(const char *path, int oflags, mode_t mode);
extern void st_destroy(void);
extern int st_thread_setspecific2(st_thread_t thread, int key, void *value);
extern void st_set_primordial_stack(void *top, void *bottom);
#ifdef DEBUG
extern void _st_show_thread_stack(st_thread_t thread, const char *messg);
extern void _st_iterate_threads(void);

View file

@ -135,7 +135,7 @@ int st_poll(struct pollfd *pds, int npds, st_utime_t timeout)
}
void _st_vp_schedule(void)
void _st_vp_schedule(_st_thread_t *from)
{
_st_thread_t *thread;
@ -159,7 +159,7 @@ void _st_vp_schedule(void)
/* Resume the thread */
thread->state = _ST_ST_RUNNING;
_st_restore_context(thread);
_st_restore_context(from, thread);
}
@ -368,6 +368,11 @@ int st_thread_join(_st_thread_t *thread, void **retvalp)
void _st_thread_main(void)
{
_st_thread_t *thread = _st_this_thread;
#ifdef MD_ASAN
/* Switch from other thread to this new created thread. */
_st_asan_finish_switch(thread);
#endif
/*
* Cap the stack by zeroing out the saved return address register
@ -572,7 +577,7 @@ void _st_vp_check_clock(void)
/* Make thread runnable */
ST_ASSERT(!(thread->flags & _ST_FL_IDLE_THREAD));
thread->state = _ST_ST_RUNNABLE;
// Insert at the head of RunQ, to execute timer first.
/* Insert at the head of RunQ, to execute timer first. */
st_clist_insert_after(&thread->links, &_st_this_vp.run_q);
}
}
@ -589,7 +594,7 @@ void st_thread_yield()
/* Check sleep queue for expired threads */
_st_vp_check_clock();
// If not thread in RunQ to yield to, ignore and continue to run.
/* If not thread in RunQ to yield to, ignore and continue to run. */
if (_st_this_vp.run_q.next == &_st_this_vp.run_q) {
return;
}
@ -598,11 +603,11 @@ void st_thread_yield()
++_st_stat_thread_yield2;
#endif
// Append thread to the tail of RunQ, we will back after all threads executed.
/* Append thread to the tail of RunQ, we will back after all threads executed. */
me->state = _ST_ST_RUNNABLE;
st_clist_insert_before(&me->links, &_st_this_vp.run_q);
// Yield to other threads in the RunQ.
/* Yield to other threads in the RunQ. */
_st_switch_context(me);
}
@ -664,8 +669,9 @@ _st_thread_t *st_thread_create(void *(*start)(void *arg), void *arg, int joinabl
thread->arg = arg;
/* Note that we must directly call rather than call any functions. */
if (_st_md_cxt_save(thread->context))
if (_st_md_cxt_save(thread->context)) {
_st_thread_main();
}
MD_GET_SP(thread) = (long)(stack->sp);
/* If thread is joinable, allocate a termination condition variable */