Qjs errors with on darwin asan

[satk0]

Hi all,

While working on r2, @trufae has found an issue with asan while running qjs on Mac. Namely:

The patch that makes it work is the following:

diff --git a/quickjs.c b/quickjs.c
index 3108855..4656d96 100644
--- a/quickjs.c
+++ b/quickjs.c
@@ -1773,9 +1773,13 @@ static inline uintptr_t js_get_stack_pointer(void)

 static inline bool js_check_stack_overflow(JSRuntime *rt, size_t alloca_size)
 {
+#if __has_feature(address_sanitizer)
+    return false;
+#else
     uintptr_t sp;
     sp = js_get_stack_pointer() - alloca_size;
     return unlikely(sp < rt->stack_limit);
+#endif
 }

 JSRuntime *JS_NewRuntime2(const JSMallocFunctions *mf, void *opaque)

But idk if that's an elegant solution to this problem.

[saghul]

It's probably because due to how much ASN bloats the stack size the check doesn't pass.

Rather than doing that you can override it at the app layer by setting the stack size to 0 when compiling under ASAN.

qjs itself it able to run under ASAN no problem, I suppose because the extra JS code it runs is minimal.

[satk0]

Oh nice, thanks for the answer, so setting STACK_SIZE=0 in Makefile should help?

[trufae]

Or by calling the api in the constructor at runtime. Thanks

[saghul]

Yep, you can do this:

#if __has_feature(address_sanitizer)
    JS_SetMaxStackSize(rt, 0);
#endif

Or you can play with it until you find the right value. It's 1MB by default.

[satk0]

Nicee, thanks! Will let you know how it goes ;)

[trufae]

Solved here radareorg/radare2#23911 Thanks for clarifying