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[Qemu-devel] [PATCH v2 12/13] ucontext: annotate coroutine stack for ASA
From: |
Marc-André Lureau |
Subject: |
[Qemu-devel] [PATCH v2 12/13] ucontext: annotate coroutine stack for ASAN |
Date: |
Fri, 15 Dec 2017 16:06:58 +0100 |
It helps ASAN to detect more leaks on coroutine stacks, as found in
the following patch.
A similar work would need to be done for sigaltstack & windows fibers
to have similar coverage. Since ucontext is prefered, I didn't bother
checking the other coroutine implementations for now.
Signed-off-by: Marc-André Lureau <address@hidden>
---
include/qemu/compiler.h | 4 ++++
util/coroutine-ucontext.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 50 insertions(+)
diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index 340e5fdc09..5fcc4f7ec7 100644
--- a/include/qemu/compiler.h
+++ b/include/qemu/compiler.h
@@ -111,4 +111,8 @@
#define GCC_FMT_ATTR(n, m)
#endif
+#ifndef __has_feature
+#define __has_feature(x) 0 /* compatibility with non-clang compilers */
+#endif
+
#endif /* COMPILER_H */
diff --git a/util/coroutine-ucontext.c b/util/coroutine-ucontext.c
index 6621f3f692..e78eae8766 100644
--- a/util/coroutine-ucontext.c
+++ b/util/coroutine-ucontext.c
@@ -31,6 +31,11 @@
#include <valgrind/valgrind.h>
#endif
+#if defined(__SANITIZE_ADDRESS__) || __has_feature(address_sanitizer)
+#define CONFIG_ASAN 1
+#include <sanitizer/asan_interface.h>
+#endif
+
typedef struct {
Coroutine base;
void *stack;
@@ -59,11 +64,37 @@ union cc_arg {
int i[2];
};
+static void finish_switch_fiber(void *fake_stack_save)
+{
+#ifdef CONFIG_ASAN
+ const void *bottom_old;
+ size_t size_old;
+
+ __sanitizer_finish_switch_fiber(fake_stack_save, &bottom_old, &size_old);
+
+ if (!leader.stack) {
+ leader.stack = (void *)bottom_old;
+ leader.stack_size = size_old;
+ }
+#endif
+}
+
+static void start_switch_fiber(void **fake_stack_save,
+ const void *bottom, size_t size)
+{
+#ifdef CONFIG_ASAN
+ __sanitizer_start_switch_fiber(fake_stack_save, bottom, size);
+#endif
+}
+
static void coroutine_trampoline(int i0, int i1)
{
union cc_arg arg;
CoroutineUContext *self;
Coroutine *co;
+ void *fake_stack_save = NULL;
+
+ finish_switch_fiber(NULL);
arg.i[0] = i0;
arg.i[1] = i1;
@@ -72,9 +103,13 @@ static void coroutine_trampoline(int i0, int i1)
/* Initialize longjmp environment and switch back the caller */
if (!sigsetjmp(self->env, 0)) {
+ start_switch_fiber(&fake_stack_save,
+ leader.stack, leader.stack_size);
siglongjmp(*(sigjmp_buf *)co->entry_arg, 1);
}
+ finish_switch_fiber(fake_stack_save);
+
while (true) {
co->entry(co->entry_arg);
qemu_coroutine_switch(co, co->caller, COROUTINE_TERMINATE);
@@ -87,6 +122,7 @@ Coroutine *qemu_coroutine_new(void)
ucontext_t old_uc, uc;
sigjmp_buf old_env;
union cc_arg arg = {0};
+ void *fake_stack_save = NULL;
/* The ucontext functions preserve signal masks which incurs a
* system call overhead. sigsetjmp(buf, 0)/siglongjmp() does not
@@ -122,8 +158,12 @@ Coroutine *qemu_coroutine_new(void)
/* swapcontext() in, siglongjmp() back out */
if (!sigsetjmp(old_env, 0)) {
+ start_switch_fiber(&fake_stack_save, co->stack, co->stack_size);
swapcontext(&old_uc, &uc);
}
+
+ finish_switch_fiber(fake_stack_save);
+
return &co->base;
}
@@ -169,13 +209,19 @@ qemu_coroutine_switch(Coroutine *from_, Coroutine *to_,
CoroutineUContext *from = DO_UPCAST(CoroutineUContext, base, from_);
CoroutineUContext *to = DO_UPCAST(CoroutineUContext, base, to_);
int ret;
+ void *fake_stack_save = NULL;
current = to_;
ret = sigsetjmp(from->env, 0);
if (ret == 0) {
+ start_switch_fiber(action == COROUTINE_TERMINATE ?
+ NULL : &fake_stack_save, to->stack, to->stack_size);
siglongjmp(to->env, action);
}
+
+ finish_switch_fiber(fake_stack_save);
+
return ret;
}
--
2.15.1.355.g36791d7216
- Re: [Qemu-devel] [PATCH v2 05/13] tests: fix check-qobject leak:, (continued)
- [Qemu-devel] [PATCH v2 09/13] crypto: fix stack-buffer-overflow error, Marc-André Lureau, 2017/12/15
- [Qemu-devel] [PATCH v2 07/13] readline: add a free function, Marc-André Lureau, 2017/12/15
- [Qemu-devel] [PATCH v2 08/13] tests: fix migration-test leak, Marc-André Lureau, 2017/12/15
- [Qemu-devel] [PATCH v2 11/13] tests: fix qmp-test leak, Marc-André Lureau, 2017/12/15
- [Qemu-devel] [PATCH v2 10/13] qemu-config: fix leak in query-command-line-options, Marc-André Lureau, 2017/12/15
- [Qemu-devel] [PATCH v2 12/13] ucontext: annotate coroutine stack for ASAN,
Marc-André Lureau <=
- [Qemu-devel] [PATCH v2 13/13] tests: fix coroutine leak in /basic/entered, Marc-André Lureau, 2017/12/15
- Re: [Qemu-devel] [PATCH v2 00/13] Various build-sys and ASAN related fixes, Marc-André Lureau, 2017/12/15