On 3/20/26 22:23, Peter Maydell wrote:
On Fri, 20 Mar 2026 at 01:15, Richard Henderson
<[email protected]> wrote:
On 3/19/26 22:27, Peter Maydell wrote:
I also note that for the data structure I am fixing, we never do
an xsave/xrestore on it -- it is purely junk unused padding.
The real xsave/xrestore info is elsewhere, in the dynamic part
of the signal frame.
That is an excellent point. The structure you're fixing is never really used.
It's only use at present is to be included in the ia32 sigframe structure, and
is only
used for padding. As an unintended side effect, the alignment of
X86LegacyXSaveArea is
inherited by sigframe.
Perhaps we should simply have
- struct target_fpstate_32 fpstate_unused;
+ char fpstate_unused[sizeof(struct target_fregs_state) +
+ sizeof(X86LegacyXSaveArea)];
I did consider something like that; from the commit message:
# Replace the use of X86LegacyXSaveArea with a set of fields that match
# the kernel _fpstate_32 struct, and assert that the length is correct.
# We could equally have used
# uint8_t legacy_area[512];
# but following the kernel is probably less confusing overall.
Either way works, so I guess I don't care very strongly.
Ok then,
Reviewed-by: Richard Henderson <[email protected]>
r~
