Glibc 2.12 issue

Michael Hope michael.hope at linaro.org
Wed Sep 1 22:10:55 BST 2010


On Thu, Sep 2, 2010 at 1:41 AM,  <Alexander.Kanevskiy at nokia.com> wrote:
> On 01/09/2010 15:24, "ext Loïc Minier" <loic.minier at linaro.org> wrote:
>> On Tue, Aug 31, 2010, Michael Hope wrote:
>>> The solution is to add -fno-stack-protector to the libgcc build
>>> options and rebuild the compiler.  I've heard (but can't track down
>>> the link) that the ARM libgcc unwind functions must be built this way
>>> in any case.
>>>
>>> See
>>>
>>> http://svn.debian.org/wsvn/gcccvs/branches/sid/gcc-4.5/debian/patches/gcc-def
>>> ault-ssp.diff
>>> for how Debian does this.
>>
>>  How can we fix this in the upstream sources?  Should glibc or libgcc
>>  detect this erroneous state?
> Probably glibc, as this error appeared in 2.12, and not reproducible with
> the same gcc and flags with glibc 2.11.

There's a few questions here:

 1. What in libanl has caused the new call to gnu_Unwind_Backtrace?
Fixing this will remove the immediate problem
 2. Does the backtrace work with -fstack-protector?
 3. Should libgcc be built without -fstack-protector?

(3) is interesting as libgcc is such a fundamental library that it
really shouldn't have dependencies on anything else.

What's the opinion of people on the list?

-- Michael



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