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Date: Tue, 7 Jun 2022 12:31:20 +0200
From: "Gerd Hoffmann" <kraxel@redhat.com>
To: devel@edk2.groups.io, jirislaby@kernel.org
Subject: Re: [edk2-devel] ovmf miscompiles with gcc-12
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  Hi,

> The reason is TemporaryRamMigration() overwrites rbp unconditionally -- it
> adds an offset to rbp even if rbp is NOT used as a frame pointer

> Now, what is the right way to fix this? Do the SetJump/LongJump in assembly
> and wrap it into push rbp/pop rbp?

push/pop rbp will break in case frame pointers are used, no?

I think essentially the code needs to know whenever frame pointers are
used or not and then update (or not) rbp depending on that.  Update
compiler flags to explicitly set -f(no-)omit-frame-pointer, also add
-D OMIT_FRAME_POINTER=1, the compile conditionally on OMIT_FRAME_POINTER?

take care,
  Gerd