qemu/target/i386/tcg/user/excp_helper.c
Richard Henderson f74bd157c6 target/i386: Implement x86_cpu_record_sigsegv
Record cr2, error_code, and exception_index.  That last means
that we must exit to cpu_loop ourselves, instead of letting
exception_index being overwritten.

Use the maperr parameter to properly set PG_ERROR_P_MASK.

Reviewed by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-11-02 07:00:52 -04:00

51 lines
1.8 KiB
C

/*
* x86 exception helpers - user-mode specific code
*
* Copyright (c) 2003 Fabrice Bellard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "exec/exec-all.h"
#include "tcg/helper-tcg.h"
void x86_cpu_record_sigsegv(CPUState *cs, vaddr addr,
MMUAccessType access_type,
bool maperr, uintptr_t ra)
{
X86CPU *cpu = X86_CPU(cs);
CPUX86State *env = &cpu->env;
/*
* The error_code that hw reports as part of the exception frame
* is copied to linux sigcontext.err. The exception_index is
* copied to linux sigcontext.trapno. Short of inventing a new
* place to store the trapno, we cannot let our caller raise the
* signal and set exception_index to EXCP_INTERRUPT.
*/
env->cr[2] = addr;
env->error_code = ((access_type == MMU_DATA_STORE) << PG_ERROR_W_BIT)
| (maperr ? 0 : PG_ERROR_P_MASK)
| PG_ERROR_U_MASK;
cs->exception_index = EXCP0E_PAGE;
/* Disable do_interrupt_user. */
env->exception_is_int = 0;
env->exception_next_eip = -1;
cpu_loop_exit_restore(cs, ra);
}