Re: [PATCH v5 0/2] fix p_align on PT_LOAD segment in DSO isn't honored

["H.J. Lu" <hjl.tools@gmail.com>]

On Fri, Dec 10, 2021 at 4:39 AM Rongwei Wang
<rongwei.wang@linux.alibaba.com> wrote:
>
> Hi
>
> This patch mainly to fix a reported bug:
>
> "p_align on PT_LOAD segment in DSO isn't honored"
> https://sourceware.org/bugzilla/show_bug.cgi?id=28676
>
> A testcase had been builded by H.J.Lu:
> https://sourceware.org/bugzilla/attachment.cgi?id=13838
>
> And in Patch 1/1, I also show a simple testcase which
> modified from H.J.Lu.
>
> And a similar bug in ELF binary was also reported:
> https://bugzilla.kernel.org/show_bug.cgi?id=215275

I submitted a kernel patch:

https://lore.kernel.org/lkml/20211209174052.370537-1-hjl.tools@gmail.com/T/

Hopefully, it will be landed soon.

> A related fix patch could been found:
> https://lore.kernel.org/linux-mm/20211009092658.59665-4-rongwei.wang@linux.alibaba.com/
> Originally, we send this patch for introducing .text
> hugepages, was not aware of it's bug. And now, I am
> not sure whether kernel maintainer will regards it as
> a bug. But it deserved try again.
>
> Thanks.
>
> Changelog:
>
> v4 -> v5
> - Patch "Add a testcase to check alignment of PT_LOAD segment"
> add new testcase for PT_LOAD segment
> - Patch "elf: Properly align PT_LOAD segments"
> fix map_start to use map_start_aligned when second mmap failed
>
> v3 -> v4
> - Patch "elf: Properly align PT_LOAD segments"
> Call unmap when the second mmap fails.
>
> v2 -> v3
> - Patch "elf: Properly align PT_LOAD segments"
> move mapalign into 'struct loadcmd'
> fix some coding style
>
> RFC/v1 -> v2
>
> - Patch "elf: align the mapping address of LOAD segments with p_align"
> fix coding format and add testcase in commit.
>
> RFC link:
> https://patchwork.sourceware.org/project/glibc/patch/20211204045848.71105-2-rongwei.wang@linux.alibaba.com/
>
> H.J. Lu (1):
>   Add a testcase to check alignment of PT_LOAD segment
>
> Rongwei Wang (1):
>   elf: Properly align PT_LOAD segments
>
>  elf/Makefile          | 14 +++++++++++--
>  elf/dl-load.c         |  1 +
>  elf/dl-load.h         |  2 +-
>  elf/dl-map-segments.h | 49 +++++++++++++++++++++++++++++++++++++++----
>  elf/tst-align3.c      | 37 ++++++++++++++++++++++++++++++++
>  elf/tst-alignmod3.c   | 31 +++++++++++++++++++++++++++
>  6 files changed, 127 insertions(+), 7 deletions(-)
>  create mode 100644 elf/tst-align3.c
>  create mode 100644 elf/tst-alignmod3.c
>
> --
> 2.27.0
>

LGTM.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>

Can you check it in?

Thanks.

--
H.J.