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[Qemu-devel] [PATCH 12/12] WIP ucontext: annotate coroutine stack for AS
From: |
Marc-André Lureau |
Subject: |
[Qemu-devel] [PATCH 12/12] WIP ucontext: annotate coroutine stack for ASAN |
Date: |
Fri, 8 Dec 2017 01:58:25 +0100 |
Not strictly necessary, but it may help ASAN and remove some false
positives.
Sadly, this annotation produces an ASAN error:
$ tests/test-coroutine -p /basic/lifecycle
/basic/lifecycle: ==27655==WARNING: ASan doesn't fully support
makecontext/swapcontext functions and may produce false positives in some cases!
==27655==AddressSanitizer CHECK failed:
/builddir/build/BUILD/compiler-rt-4.0.1.src/lib/asan/asan_poisoning.cc:38
"((AddrIsAlignedByGranularity(addr + size))) != (0)" (0x0, 0x0)
#0 0x55d1e4e8a695 in __asan::AsanCheckFailed(char const*, int, char const*,
unsigned long long, unsigned long long)
(/home/elmarco/src/qq/build/tests/test-coroutine+0x1c0695)
#1 0x55d1e4ea6235 in __sanitizer::CheckFailed(char const*, int, char
const*, unsigned long long, unsigned long long)
(/home/elmarco/src/qq/build/tests/test-coroutine+0x1dc235)
#2 0x55d1e4e82ea4 in __asan::PoisonShadow(unsigned long, unsigned long,
unsigned char) (/home/elmarco/src/qq/build/tests/test-coroutine+0x1b8ea4)
#3 0x55d1e4dde1e7 in __asan::FakeStack::Destroy(int)
(/home/elmarco/src/qq/build/tests/test-coroutine+0x1141e7)
#4 0x55d1e528b775 in qemu_coroutine_switch
/home/elmarco/src/qq/util/coroutine-ucontext.c:219:9
#5 0x55d1e528b18d in coroutine_trampoline
/home/elmarco/src/qq/util/coroutine-ucontext.c:114:9
#6 0x7fb3e0087bef (/lib64/libc.so.6+0x50bef)
Signed-off-by: Marc-André Lureau <address@hidden>
---
util/coroutine-ucontext.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/util/coroutine-ucontext.c b/util/coroutine-ucontext.c
index 6621f3f692..d200498c38 100644
--- a/util/coroutine-ucontext.c
+++ b/util/coroutine-ucontext.c
@@ -31,6 +31,25 @@
#include <valgrind/valgrind.h>
#endif
+#if (defined(__has_feature) && __has_feature(address_sanitizer)) || \
+ __SANITIZE_ADDRESS__
+#include <sanitizer/asan_interface.h>
+#else
+/* stub to check correct arguments */
+static inline void
+__sanitizer_start_switch_fiber(void **fake_stack_save,
+ const void *bottom, size_t size)
+{
+}
+
+static inline void
+__sanitizer_finish_switch_fiber(void *fake_stack_save,
+ const void **bottom_old,
+ size_t *size_old)
+{
+}
+#endif
+
typedef struct {
Coroutine base;
void *stack;
@@ -64,6 +83,15 @@ static void coroutine_trampoline(int i0, int i1)
union cc_arg arg;
CoroutineUContext *self;
Coroutine *co;
+ const void *bottom_old;
+ size_t size_old;
+ void *fake_stack_save;
+
+ __sanitizer_finish_switch_fiber(NULL, &bottom_old, &size_old);
+ if (!leader.stack) {
+ leader.stack = (void *)bottom_old;
+ leader.stack_size = size_old;
+ }
arg.i[0] = i0;
arg.i[1] = i1;
@@ -72,9 +100,14 @@ static void coroutine_trampoline(int i0, int i1)
/* Initialize longjmp environment and switch back the caller */
if (!sigsetjmp(self->env, 0)) {
+ __sanitizer_start_switch_fiber(&fake_stack_save,
+ bottom_old, size_old);
siglongjmp(*(sigjmp_buf *)co->entry_arg, 1);
}
+ __sanitizer_finish_switch_fiber(&fake_stack_save,
+ NULL, NULL);
+
while (true) {
co->entry(co->entry_arg);
qemu_coroutine_switch(co, co->caller, COROUTINE_TERMINATE);
@@ -87,6 +120,7 @@ Coroutine *qemu_coroutine_new(void)
ucontext_t old_uc, uc;
sigjmp_buf old_env;
union cc_arg arg = {0};
+ void *fake_stack_save;
/* The ucontext functions preserve signal masks which incurs a
* system call overhead. sigsetjmp(buf, 0)/siglongjmp() does not
@@ -122,8 +156,13 @@ Coroutine *qemu_coroutine_new(void)
/* swapcontext() in, siglongjmp() back out */
if (!sigsetjmp(old_env, 0)) {
+ __sanitizer_start_switch_fiber(&fake_stack_save,
+ co->stack, co->stack_size);
swapcontext(&old_uc, &uc);
}
+
+ __sanitizer_finish_switch_fiber(&fake_stack_save, NULL, NULL);
+
return &co->base;
}
@@ -169,13 +208,21 @@ 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;
current = to_;
ret = sigsetjmp(from->env, 0);
if (ret == 0) {
+
+ __sanitizer_start_switch_fiber(action == COROUTINE_TERMINATE ?
+ NULL : &fake_stack_save,
+ to->stack, to->stack_size);
siglongjmp(to->env, action);
}
+
+ __sanitizer_finish_switch_fiber(&fake_stack_save, NULL, NULL);
+
return ret;
}
--
2.15.1.355.g36791d7216
- [Qemu-devel] [PATCH 07/12] readline: add a free function, (continued)
- [Qemu-devel] [PATCH 07/12] readline: add a free function, Marc-André Lureau, 2017/12/07
- [Qemu-devel] [PATCH 06/12] vl: fix direct firmware directories leak, Marc-André Lureau, 2017/12/07
- [Qemu-devel] [PATCH 08/12] tests: fix migration-test leak, Marc-André Lureau, 2017/12/07
- [Qemu-devel] [PATCH 09/12] crypto: fix stack-buffer-overflow error, Marc-André Lureau, 2017/12/07
- [Qemu-devel] [PATCH 11/12] tests: fix qmp-test leak, Marc-André Lureau, 2017/12/07
- [Qemu-devel] [PATCH 10/12] qemu-config: fix leak in query-command-line-options, Marc-André Lureau, 2017/12/07
- [Qemu-devel] [PATCH 12/12] WIP ucontext: annotate coroutine stack for ASAN,
Marc-André Lureau <=
- Re: [Qemu-devel] [PATCH 00/12] Various build-sys and ASAN related fixes, no-reply, 2017/12/11
- Re: [Qemu-devel] [PATCH 00/12] Various build-sys and ASAN related fixes, no-reply, 2017/12/11
- Re: [Qemu-devel] [PATCH 00/12] Various build-sys and ASAN related fixes, no-reply, 2017/12/11