[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <alpine.LNX.2.20.13.1708030154550.12138@monopod.intra.ispras.ru>
Date: Thu, 3 Aug 2017 02:00:03 +0300 (MSK)
From: Alexander Monakov <amonakov@...ras.ru>
To: musl@...ts.openwall.com
Subject: Re: possible bug in setjmp implementation for ppc64
On Tue, 1 Aug 2017, David Edelsohn wrote:
> "If glibc is built as a static library, the contents of r2 are saved
> in the jmp_buf; but if glibc is built as a dynamic library, the
> contents of the TOC save slot is saved in the jmp_buf. Similarly, if
> glibc is built as a dynamic library, longjmp *updates* the TOC save
> slot with the r2 value from the jmp_buf before returning."
>
> GLIBC setjmp/longjmp code explicitly differs for shared and static
> versions of the library. Musl libc needs equivalent functionality in
> its implementation.
Note that since Glibc also supports static dlopen, it is possible to arrive
at a situation where libc.a longjmp is used for returning to a call site
of libc.so setjmp, in which case TOC save slot is not restored as it
ought to be, and the caller of setjmp segfaults. A testcase is available at
https://sourceware.org/bugzilla/show_bug.cgi?id=21895
Thanks.
Alexander
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
