Eric Lee / linux-smarc-t335x-v3.2

01 Aug, 2006

1 commit

  • 0b0bf7a3c   [PATCH] vDSO hash-style fix ... Browse Code »

    The latest toolchains can produce a new ELF section in DSOs and
    dynamically-linked executables. The new section ".gnu.hash" replaces
    ".hash", and allows for more efficient runtime symbol lookups by the
    dynamic linker. The new ld option --hash-style={sysv|gnu|both} controls
    whether to produce the old ".hash", the new ".gnu.hash", or both. In some
    new systems such as Fedora Core 6, gcc by default passes --hash-style=gnu
    to the linker, so that a standard invocation of "gcc -shared" results in
    producing a DSO with only ".gnu.hash". The new ".gnu.hash" sections need
    to be dealt with the same way as ".hash" sections in all respects; only the
    dynamic linker cares about their contents. To work with older dynamic
    linkers (i.e. preexisting releases of glibc), a binary must have the old
    ".hash" section. The --hash-style=both option produces binaries that a new
    dynamic linker can use more efficiently, but an old dynamic linker can
    still handle.

    The new section runs afoul of the custom linker scripts used to build vDSO
    images for the kernel. On ia64, the failure mode for this is a boot-time
    panic because the vDSO's PT_IA_64_UNWIND segment winds up ill-formed.

    This patch addresses the problem in two ways.

    First, it mentions ".gnu.hash" in all the linker scripts alongside ".hash".
    This produces correct vDSO images with --hash-style=sysv (or old tools),
    with --hash-style=gnu, or with --hash-style=both.

    Second, it passes the --hash-style=sysv option when building the vDSO
    images, so that ".gnu.hash" is not actually produced. This is the most
    conservative choice for compatibility with any old userland. There is some
    concern that some ancient glibc builds (though not any known old production
    system) might choke on --hash-style=both binaries. The optimizations
    provided by the new style of hash section do not really matter for a DSO
    with a tiny number of symbols, as the vDSO has. If someone wants to use
    =gnu or =both for their vDSO builds and worry less about that
    compatibility, just change the option and the linker script changes will
    make any choice work fine.

    Signed-off-by: Roland McGrath
    Cc: "Luck, Tony"
    Cc: Kyle McMartin
    Cc: Paul Mackerras
    Cc: Benjamin Herrenschmidt
    Cc: Jeff Dike
    Cc: Andi Kleen
    Cc: Sam Ravnborg
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Roland McGrath
     

01 Jul, 2006

1 commit

22 Apr, 2006

1 commit

  • 2fd830381   [PARISC] Further work for multiple page sizes ... Browse Code »

    More work towards supporing multiple page sizes on 64-bit. Convert
    some assumptions that 64bit uses 3 level page tables into testing
    PT_NLEVELS. Also some BUG() to BUG_ON() conversions and some cleanups
    to assembler.

    Signed-off-by: Helge Deller
    Signed-off-by: Kyle McMartin

    Helge Deller
     

11 Jan, 2006

2 commits

17 Apr, 2005

1 commit

  • 1da177e4c   Linux-2.6.12-rc2 ... Browse Code »

    Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds