[Bug nptl/22563] __cancel_jmp_buf in __pthread_unwind_buf_t is incompatible with setjmp/longmp

["cvs-commit at gcc dot gnu.org" <sourceware-bugzilla at sourceware dot org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=22563

--- Comment #10 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "GNU C Library master sources".

The branch, hjl/cet/setjmp has been created
        at  68b40b40591d177615be41c132f44c0e440a8d9d (commit)

- Log -----------------------------------------------------------------
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=68b40b40591d177615be41c132f44c0e440a8d9d

commit 68b40b40591d177615be41c132f44c0e440a8d9d
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Thu Dec 7 05:47:21 2017 -0800

    x86: Add feature_1 to tcbhead_t [BZ #22563]

    On x86, padding in struct __jmp_buf_tag is used for shadow stack pointer
    to support Shadow Stack in Intel Control-flow Enforcemen Technology.
    cancel_jmp_buf has been updated to include saved_mask so that it is as
    large as struct __jmp_buf_tag.  We must suport the old cancel_jmp_buf
    in existing binaries.  Since symbol versioning doesn't work on
    cancel_jmp_buf, feature_1 is added to tcbhead_t so that setjmp and
    longjmp can check if shadow stack is enabled.  NB: Shadow stack is
    enabled only if all modules are shadow stack enabled.

        [BZ #22563]
        * sysdeps/i386/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New.
        * sysdeps/i386/nptl/tls.h (tcbhead_t): Add feature_1.
        * sysdeps/x86_64/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New.
        * sysdeps/x86_64/nptl/tls.h (tcbhead_t): Rename __glibc_unused1
        to feature_1.

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=986d3051c30cf6a7bbd56e6704d0465682b542ef

commit 986d3051c30cf6a7bbd56e6704d0465682b542ef
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Wed Dec 6 15:00:46 2017 -0800

    Linux/x86: Update cancel_jmp_buf to match __jmp_buf_tag [BZ #22563]

    On x86, padding in struct __jmp_buf_tag is used for shadow stack pointer
    to support shadow stack in Intel Control-flow Enforcemen Technology.
    Since the cancel_jmp_buf array is passed to setjmp and longjmp by
    casting it to pointer to struct __jmp_buf_tag, it should be as large
    as struct __jmp_buf_tag.

    This patch adds bits/types/__cancel_jmp_buf_tag.h to define struct
    __cancel_jmp_buf_tag so that Linux/x86 can add saved_mask to
    cancel_jmp_buf.

        [BZ #22563]
        * bits/types/__cancel_jmp_buf_tag.h: New file.
        * sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h
        * sysdeps/unix/sysv/linux/x86/pthreaddef.h: Likewise.
        * sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h: Likewise.
        * nptl/Makefile (headers): Add
        bits/types/__cancel_jmp_buf_tag.h.
        * nptl/descr.h [NEED_SAVED_MASK_IN_CANCEL_JMP_BUF]
        (pthread_unwind_buf): Add saved_mask to cancel_jmp_buf.
        * sysdeps/nptl/pthread.h: Include
        <bits/types/__cancel_jmp_buf_tag.h>.
        (__pthread_unwind_buf_t): Use struct __cancel_jmp_buf_tag with
        __cancel_jmp_buf.

-----------------------------------------------------------------------

-- 
You are receiving this mail because:
You are on the CC list for the bug.