qemu/bsd-user/x86_64/target_arch_thread.h
Ilya Leoshkevich 1f31243a8c bsd-user/x86_64/target_arch_thread.h: Align stack
bsd-user qemu-x86_64 almost immediately dies with:

    qemu: 0x4002201a68: unhandled CPU exception 0xd - aborting

on FreeBSD 14.1-RELEASE. This is an instruction that requires
alignment:

    (gdb) x/i 0x4002201a68
       0x4002201a68:        movaps %xmm0,-0x40(%rbp)

and the argument is not aligned:

    (gdb) p/x env->regs[5]
    $1 = 0x822443b58

A quick experiment shows that the userspace entry point expects
misaligned rsp:

    (gdb) starti
    (gdb) p/x $rsp
    $1 = 0x7fffffffeaa8

Emulate this behavior in bsd-user.

[[ applied Richard's suggestion ]]

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Warner Losh <imp@bsdimp.com>
2024-11-04 20:26:40 -07:00

40 lines
1.3 KiB
C

/*
* x86_64 thread support
*
* Copyright (c) 2013 Stacey D. Son
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef TARGET_ARCH_THREAD_H
#define TARGET_ARCH_THREAD_H
/* Compare to vm_machdep.c cpu_set_upcall_kse() */
static inline void target_thread_set_upcall(CPUX86State *regs, abi_ulong entry,
abi_ulong arg, abi_ulong stack_base, abi_ulong stack_size)
{
/* XXX */
}
static inline void target_thread_init(struct target_pt_regs *regs,
struct image_info *infop)
{
regs->rax = 0;
regs->rsp = ((infop->start_stack - 8) & ~0xfUL) + 8;
regs->rip = infop->entry;
regs->rdi = infop->start_stack;
}
#endif /* TARGET_ARCH_THREAD_H */