[FFmpeg-devel] [PATCH] Add assembly support for -fsanitize=hwaddress tagged globals.

[Peter Collingbourne]

On Thu, Aug 15, 2019 at 11:00 AM Peter Collingbourne <pcc at google.com> wrote:
>
> As of LLVM r368102, Clang will set a pointer tag in bits 56-63 of the
> address of a global when compiling with -fsanitize=hwaddress. This requires
> an adjustment to assembly code that takes the address of such globals: the
> code cannot use the regular R_AARCH64_ADR_PREL_PG_HI21 relocation to refer
> to the global, since the tag would take the address out of range. Instead,
> the code must use the non-checking (_NC) variant of the relocation (the
> link-time check is substituted by a runtime check).
>
> This change makes the necessary adjustment in the movrel macro, where it is
> needed when compiling with -fsanitize=hwaddress.

It came to my attention that this patch was sent without a
Signed-off-by line. Will send a v2 with the Signed-off-by.

Peter