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

[Vedant Kumar via cfe-dev]

> On Aug 23, 2018, at 10:59 AM, David Greene <dag at cray.com> wrote:
> 
> 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.

Good point, that might be the issue here.


> 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.

+ 1.

vedant


> 
>                           -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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