From: Marc-André Lureau <marcandre.lur...@redhat.com>
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 preferred, I didn't bother
checking the other coroutine implementations for now.
Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4...@amsat.org>
Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
Message-Id: <20180104160523.22995-16-marcandre.lur...@redhat.com>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
.travis.yml | 3 ++-
configure | 15 +++++++++++++++
include/qemu/compiler.h | 4 ++++
util/coroutine-ucontext.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 69 insertions(+), 1 deletion(-)
diff --git a/.travis.yml b/.travis.yml
index f583839..f2291e8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,12 +13,13 @@ addons:
- libattr1-dev
- libbrlapi-dev
- libcap-ng-dev
+ - libgcc-6-dev
- libgnutls-dev
- libgtk-3-dev
- libiscsi-dev
- liblttng-ust-dev
- - libnfs-dev
- libncurses5-dev
+ - libnfs-dev
- libnss3-dev
- libpixman-1-dev
- libpng12-dev
diff --git a/configure b/configure
index d033286..c785dab 100755
--- a/configure
+++ b/configure
@@ -5186,6 +5186,13 @@ if compile_prog "" "" ; then
fi
##########################################
+# check for asan header
+have_asan_iface_h=yes
+if ! check_include "sanitizer/asan_interface.h" ; then
+ have_asan_iface_h=no
+fi
+
+##########################################
# End of CC checks
# After here, no more $cc or $ld runs
@@ -5198,6 +5205,10 @@ elif test "$debug" = "yes"; then
write_c_skeleton;
if compile_prog "-fsanitize=address" ""; then
CFLAGS="-fsanitize=address $CFLAGS"
+ if test "$have_asan_iface_h" = "no" ; then
+ print_error "ASAN build enabled, but ASAN header missing." \
+ "Without code annotation, the report may be inferior."
+ fi
fi
if compile_prog "-fsanitize=undefined" ""; then
CFLAGS="-fsanitize=undefined $CFLAGS"
@@ -6320,6 +6331,10 @@ if test "$have_utmpx" = "yes" ; then
echo "HAVE_UTMPX=y" >> $config_host_mak
fi
+if test "$have_asan_iface_h" = "yes" ; then
+ echo "HAVE_ASAN_IFACE_H=y" >> $config_host_mak
+fi
+
if test "$ivshmem" = "yes" ; then
echo "CONFIG_IVSHMEM=y" >> $config_host_mak
fi
diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index 340e5fd..5fcc4f7 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 6621f3f..e53147f 100644
--- a/util/coroutine-ucontext.c
+++ b/util/coroutine-ucontext.c
@@ -31,6 +31,13 @@
#include <valgrind/valgrind.h>
#endif
+#if defined(__SANITIZE_ADDRESS__) || __has_feature(address_sanitizer)
+#ifdef HAVE_ASAN_IFACE_H
+#define CONFIG_ASAN 1
+#include <sanitizer/asan_interface.h>
+#endif
+#endif
+
typedef struct {
Coroutine base;
void *stack;
@@ -59,11 +66,37 @@ 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 +105,13 @@ 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 +124,7 @@ 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 +160,12 @@ 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 +211,19 @@ 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;
}
--
1.8.3.1
