This is the mail archive of the mailing list for the glibc project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH] hppa: avoid NULL dereference of sym_map in elf_machine_rela()

> While glibc has to work around it for the time being (either by not
> using __builtin_trap, or by providing abort here), I think it would be
> nice to press for fixing this on the compiler side. There's no good
> reason for the compiler to generate a call to abort when every ISA
> I've ever seen has HCF-type instructions that can be used directly
> with no dependency on a function call. Aside from the ldso issues,
> __builtin_trap or similar compiler-generated traps might be used in
> places where the call is impossible, like handling a fatal condition
> where the GOT is corrupt, where the TCB is corrupt (in which case
> abort can't properly raise signals for the calling thread), or where
> the function pointer used to make syscalls (via vdso on x86, for
> instance) is corrupt. In the worst case, this corruption was caused by
> an attacker who has happily put the address of shellcode at one of the
> above places.

It's very straightforward to define it for any machine that lacks it.  I
haven't actually done a survey of existing GCC backends.  You might want to
do that and report bugs to individual backends.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]