[cfe-dev] [UBSan] Is static linking supported?

[David Greene via cfe-dev]

According to Reid Kleckner over on llvm-dev sanitizers will not work at
all with a statically-linked libc, as the interceptors use dlsym to set
up calls to sigaction and the like.  That matched my findings while
debugging the problem we're seeing.  If sanitizers are supposed to work
with static linking, then it seems like the dependence on dlsym needs to
be broken.

Otherwise, the sanitizers should catch a nullptr return value from dlsym
and report a friendly user error message.  I can write a patch to do
that if it seems like a good idea.  Even when linking dynamically, it
would be good to check the return value of dlsym and report the error to
the user.

                           -David

Vedant Kumar via cfe-dev <cfe-dev at lists.llvm.org> writes:

> On some platforms it's possible to statically link against the
> ASan/UBSan runtimes using the undocumented -static-libsan option. The
> default behavior on Darwin, Android, and Fuchsia is to link against a
> DSO.
>
>     On Aug 23, 2018, at 8:57 AM, Troy Johnson via cfe-dev
>     <cfe-dev at lists.llvm.org> wrote:
>
>     
>     
>     
>     The address sanitizer is documented as not supported with static
>     linking, but UBSan does not include the same disclaimer. UBSan
>     does not work for me with statically-linked executables. Instead,
>     the executables segfault immediately when attempting to install
>     signal handlers. Is this expected?
>
> No, that's not expected :). Could you share the options you used to
> compile and link it, and the backtrace you get?
>
> vedant
>
>     
>     
>     -Troy
>
>     
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