qemu/linux-user/nios2/cpu_loop.c
Richard Henderson 3747727aad linux-user/nios2: Handle various SIGILL exceptions
We missed out on a couple of exception types that may
legitimately be raised by a userland program.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220421151735.31996-59-richard.henderson@linaro.org>
2022-04-26 08:17:05 -07:00

157 lines
5.2 KiB
C

/*
* qemu user cpu loop
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* 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/>.
*/
#include "qemu/osdep.h"
#include "qemu.h"
#include "user-internals.h"
#include "cpu_loop-common.h"
#include "signal-common.h"
void cpu_loop(CPUNios2State *env)
{
CPUState *cs = env_cpu(env);
int trapnr, ret;
for (;;) {
cpu_exec_start(cs);
trapnr = cpu_exec(cs);
cpu_exec_end(cs);
switch (trapnr) {
case EXCP_INTERRUPT:
/* just indicate that signals should be handled asap */
break;
case EXCP_DIV:
/* Match kernel's handle_diverror_c(). */
env->pc -= 4;
force_sig_fault(TARGET_SIGFPE, TARGET_FPE_INTDIV, env->pc);
break;
case EXCP_UNALIGN:
case EXCP_UNALIGND:
force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN,
env->ctrl[CR_BADADDR]);
break;
case EXCP_ILLEGAL:
case EXCP_UNIMPL:
/* Match kernel's handle_illegal_c(). */
env->pc -= 4;
force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC, env->pc);
break;
case EXCP_SUPERI:
/* Match kernel's handle_supervisor_instr(). */
env->pc -= 4;
force_sig_fault(TARGET_SIGILL, TARGET_ILL_PRVOPC, env->pc);
break;
case EXCP_TRAP:
switch (env->error_code) {
case 0:
qemu_log_mask(CPU_LOG_INT, "\nSyscall\n");
ret = do_syscall(env, env->regs[2],
env->regs[4], env->regs[5], env->regs[6],
env->regs[7], env->regs[8], env->regs[9],
0, 0);
if (ret == -QEMU_ESIGRETURN) {
/* rt_sigreturn has set all state. */
break;
}
if (ret == -QEMU_ERESTARTSYS) {
env->pc -= 4;
break;
}
/*
* See the code after translate_rc_and_ret: all negative
* values are errors (aided by userspace restricted to 2G),
* errno is returned positive in r2, and error indication
* is a boolean in r7.
*/
env->regs[2] = abs(ret);
env->regs[7] = ret < 0;
break;
case 1:
qemu_log_mask(CPU_LOG_INT, "\nTrap 1\n");
force_sig_fault(TARGET_SIGUSR1, 0, env->pc);
break;
case 2:
qemu_log_mask(CPU_LOG_INT, "\nTrap 2\n");
force_sig_fault(TARGET_SIGUSR2, 0, env->pc);
break;
case 31:
qemu_log_mask(CPU_LOG_INT, "\nTrap 31\n");
/* Match kernel's breakpoint_c(). */
env->pc -= 4;
force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
break;
default:
qemu_log_mask(CPU_LOG_INT, "\nTrap %d\n", env->error_code);
force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLTRP, env->pc);
break;
case 16: /* QEMU specific, for __kuser_cmpxchg */
{
abi_ptr g = env->regs[4];
uint32_t *h, n, o;
if (g & 0x3) {
force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN, g);
break;
}
ret = page_get_flags(g);
if (!(ret & PAGE_VALID)) {
force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_MAPERR, g);
break;
}
if (!(ret & PAGE_READ) || !(ret & PAGE_WRITE)) {
force_sig_fault(TARGET_SIGSEGV, TARGET_SEGV_ACCERR, g);
break;
}
h = g2h(cs, g);
o = env->regs[5];
n = env->regs[6];
env->regs[2] = qatomic_cmpxchg(h, o, n) - o;
}
break;
}
break;
case EXCP_DEBUG:
force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
break;
default:
EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
trapnr);
abort();
}
process_pending_signals(env);
}
}
void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
{
env->regs[R_SP] = regs->sp;
env->pc = regs->ea;
}