V2 [PATCH] Check multiple NT_GNU_PROPERTY_TYPE_0 notes [BZ #23509]

[H.J. Lu]

On Tue, Aug 14, 2018 at 10:32 AM, H.J. Lu <hongjiu.lu@intel.com> wrote:
> The older linker treats .note.gnu.property section as a generic note
> section and just concatenates all .note.gnu.property sections from the
> inputs to the output.  When the older linker is used to created the
> program on CET-enabled OS, the generated output has .note.gnu.property
> section with multiple NT_GNU_PROPERTY_TYPE_0 notes whose IBT and SHSTK
> enable bits are set even if the program isn't CET enabled.  Such program
> will crash on CET-enabled machines.  This patch updates the note parser:
>
> 1. Skip note parsing if a NT_GNU_PROPERTY_TYPE_0 note has been processed.
> 2. Check multiple NT_GNU_PROPERTY_TYPE_0 notes.
>
> OK for master?
>
> H.J.
> ---
>         [BZ #23509]
>         * sysdeps/x86/dl-prop.h (_dl_process_cet_property_note): Skip
>         note parsing if a NT_GNU_PROPERTY_TYPE_0 note has been processed.
>         Update the l_cet field when processing NT_GNU_PROPERTY_TYPE_0 note.
>         Check multiple NT_GNU_PROPERTY_TYPE_0 notes.
>         * sysdeps/x86/link_map.h (l_cet): Expand to 3 bits,  Add
>         lc_unknown.

Here is the updated patch which passed CET smoke test:

https://github.com/hjl-tools/cet-smoke-test

-- 
H.J.
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