Re: [scarthgap][PATCH] qemu: restore 64-bit file lock handling for 32-bit guests

[Babanpreet Singh <bbnpreetsingh@gmail.com>]

On Mon, 2026-08-31 at 09:12 +0200, Yoann Congal wrote:
> I don't understand how you can modify a 0002 by backporting 0001... Was
> Khem patch reverted? In that case, I think we better remove it and re-do
> the backport with non-reverted patches.

Fair, the trimmed 0002 is confusing. Nothing was reverted: Khem's patch
was never merged as such. What qemu took instead is two commits from
Michael Tokarev on 2024-08-29, both in 9.2.0:

  ac1bbe8ca46c linux-user/syscall.c: drop 64 suffix from flock64 &Co
  99174ce39e86 linux-user/syscall.c: eliminate other explicit LFS usages

The first covers the fcntl side without dropping the guest F_*LK64
cases the way the local patch does, which is the bug. The second is
line for line what was left of 0002 after my trim (truncate64, lseek64,
pread64, pwrite64). I only backported the first because it was enough
to fix the locks, and I agree that carrying half a local patch on top
of it is the wrong shape.

> Also, Khem's patch is merged now, can you fix the Upstream-status if we
> end up keeping it?

The Submitted link in 0002 points at a series that never landed, so I'd
rather not keep it. v2 follows in this thread: it drops 0002 and carries
both upstream commits as Backports. With both applied, syscall.c comes
out byte for byte the same as with the v1 stack, so the lock test
results from v1 still hold. qemu-native builds clean with it.

Thanks,
Baban