Re: [PATCH 0/9] Enable orphan section warning

[Sedat Dilek]

On Fri, Feb 28, 2020 at 1:22 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
> Hi!
>
> A recent bug was solved for builds linked with ld.lld, and tracking
> it down took way longer than it needed to (a year). Ultimately, it
> boiled down to differences between ld.bfd and ld.lld's handling of
> orphan sections. Similarly, the recent FGKASLR series brough up orphan
> section handling too[2]. In both cases, it would have been nice if the
> linker was running with --orphan-handling=warn so that surprise sections
> wouldn't silently get mapped into the kernel image at locations up to
> the whim of the linker's orphan handling logic. Instead, all desired
> sections should be explicitly identified in the linker script (to be
> either kept or discarded) with any orphans throwing a warning. The
> powerpc architecture actually already does this, so this series seeks
> to extend this coverage to x86, arm64, and arm.
>
> This series depends on tip/x86/boot (where recent .eh_frame fixes[3]
> landed), and has a minor conflict[4] with the ARM tree (related to
> the earlier mentioned bug). As it uses refactorings in the asm-generic
> linker script, and makes changes to kbuild, I think the cleanest place
> for this series to land would also be through -tip. Once again (like
> my READ_IMPLIES_EXEC series), I'm looking to get maintainer Acks so
> this can go all together with the least disruption. Splitting it up by
> architecture seems needlessly difficult.
>
> Thanks!
>

Hi Kees,

what is the status of this patchset?
Looks like it is not in tip or linux-next Git.

Thanks.

Regards,
- Sedat -

> -Kees
>
> [1] https://github.com/ClangBuiltLinux/linux/issues/282
> [2] https://lore.kernel.org/lkml/202002242122.AA4D1B8@keescook/
> [3] https://lore.kernel.org/lkml/158264960194.28353.10560165361470246192.tip-bot2@tip-bot2/
> [4] https://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8959/1
>
> H.J. Lu (1):
>   Add RUNTIME_DISCARD_EXIT to generic DISCARDS
>
> Kees Cook (8):
>   scripts/link-vmlinux.sh: Delay orphan handling warnings until final
>     link
>   vmlinux.lds.h: Add .gnu.version* to DISCARDS
>   x86/build: Warn on orphan section placement
>   x86/boot: Warn on orphan section placement
>   arm64/build: Use common DISCARDS in linker script
>   arm64/build: Warn on orphan section placement
>   arm/build: Warn on orphan section placement
>   arm/boot: Warn on orphan section placement
>
>  arch/arm/Makefile                             |  4 ++++
>  arch/arm/boot/compressed/Makefile             |  2 ++
>  arch/arm/boot/compressed/vmlinux.lds.S        | 17 ++++++--------
>  .../arm/{kernel => include/asm}/vmlinux.lds.h | 22 ++++++++++++++-----
>  arch/arm/kernel/vmlinux-xip.lds.S             |  5 ++---
>  arch/arm/kernel/vmlinux.lds.S                 |  5 ++---
>  arch/arm64/Makefile                           |  4 ++++
>  arch/arm64/kernel/vmlinux.lds.S               | 13 +++++------
>  arch/x86/Makefile                             |  4 ++++
>  arch/x86/boot/compressed/Makefile             |  3 ++-
>  arch/x86/boot/compressed/vmlinux.lds.S        | 13 +++++++++++
>  arch/x86/kernel/vmlinux.lds.S                 |  7 ++++++
>  include/asm-generic/vmlinux.lds.h             | 11 ++++++++--
>  scripts/link-vmlinux.sh                       |  6 +++++
>  14 files changed, 85 insertions(+), 31 deletions(-)
>  rename arch/arm/{kernel => include/asm}/vmlinux.lds.h (92%)
>
> --
> 2.20.1
>
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