[x86] Kernel v5.14 series panic on Celeron Mendocino CPU

[Ser Olmy]

Booting any 5.14 kernel on certain Celeron-based 32-bit machines results in a panic:

[   22.546247] Run /init as init process
[   22.610556] init[1] bad frame in sigreturn frame:(ptrval) ip:b7d46be6 sp:bff3af30 orax:ffffffff in libc-2.33.so[b7c94000+156000]
[   22.749531] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
[   22.750240] CPU: 0 PID: 1 Comm: init Not tainted 5.14.9 #1
[   22.750240] Hardware name: Hewlett-Packard HP PC/HP Board, BIOS  JD.00.06 12/06/2001
[   22.750240] Call Trace:
[   22.750240]  ? dump_stack_lvl+0x32/0x41
[   22.750240]  ? dump_stack+0xa/0xc
[   22.750240]  ? panic+0xa2/0x23f
[   22.750240]  ? do_exit.cold+0x94/0x94
[   22.750240]  ? do_group_exit+0x2a/0x80
[   22.750240]  ? get_signal+0x142/0x7a0
[   22.750240]  ? arch_do_signal_or_restart+0xb1/0x570
[   22.750240]  ? force_sig_info_to_task+0x65/0xf0
[   22.750240]  ? vprintk_emit+0x150/0x190
[   22.750240]  ? exit_to_user_mode_prepare+0x145/0x1e0
[   22.750240]  ? syscall_exit_to_user_mode+0x18/0x40
[   22.750240]  ? do_int80_syscall_32+0x3d/0x80
[   22.750240]  ? entry_INT80_32+0xf0/0xf0

I've bisected it to this commit:

6f9866a166cd1ad3ebb2dcdb3874aa8fee8dea2f [x86/fpu/signal: Let xrstor handle the features to init]

Reverting it results in a working system.

Regards,

Olmy