qemu-patch-raspberry4/linux-user/hppa/cpu_loop.c
Peter Maydell b10089a14c linux-user: Don't call gdb_handlesig() before queue_signal()
The CPU main-loop routines for linux-user generally
call gdb_handlesig() when they're about to queue a
SIGTRAP signal. This is wrong, because queue_signal()
will cause us to pend a signal, and process_pending_signals()
will then call gdb_handlesig() itself. So the effect is that
we notify gdb of the SIGTRAP, and then if gdb says "OK,
continue with signal X" we will incorrectly notify
gdb of the signal X as well. We don't do this double-notify
for anything else, only SIGTRAP.

Remove this unnecessary and incorrect code from all
the targets except for nios2 (whose main loop is
doing something different and broken, and will be handled
in a separate patch).

This bug only manifests if the user responds to the reported
SIGTRAP using "signal SIGFOO" rather than "continue"; since
the latter is the overwhelmingly common thing to do after a
breakpoint most people won't have hit this.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20181019174958.26616-2-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-11-12 15:48:00 +01:00

209 lines
6.5 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 "cpu_loop-common.h"
static abi_ulong hppa_lws(CPUHPPAState *env)
{
uint32_t which = env->gr[20];
abi_ulong addr = env->gr[26];
abi_ulong old = env->gr[25];
abi_ulong new = env->gr[24];
abi_ulong size, ret;
switch (which) {
default:
return -TARGET_ENOSYS;
case 0: /* elf32 atomic 32bit cmpxchg */
if ((addr & 3) || !access_ok(VERIFY_WRITE, addr, 4)) {
return -TARGET_EFAULT;
}
old = tswap32(old);
new = tswap32(new);
ret = atomic_cmpxchg((uint32_t *)g2h(addr), old, new);
ret = tswap32(ret);
break;
case 2: /* elf32 atomic "new" cmpxchg */
size = env->gr[23];
if (size >= 4) {
return -TARGET_ENOSYS;
}
if (((addr | old | new) & ((1 << size) - 1))
|| !access_ok(VERIFY_WRITE, addr, 1 << size)
|| !access_ok(VERIFY_READ, old, 1 << size)
|| !access_ok(VERIFY_READ, new, 1 << size)) {
return -TARGET_EFAULT;
}
/* Note that below we use host-endian loads so that the cmpxchg
can be host-endian as well. */
switch (size) {
case 0:
old = *(uint8_t *)g2h(old);
new = *(uint8_t *)g2h(new);
ret = atomic_cmpxchg((uint8_t *)g2h(addr), old, new);
ret = ret != old;
break;
case 1:
old = *(uint16_t *)g2h(old);
new = *(uint16_t *)g2h(new);
ret = atomic_cmpxchg((uint16_t *)g2h(addr), old, new);
ret = ret != old;
break;
case 2:
old = *(uint32_t *)g2h(old);
new = *(uint32_t *)g2h(new);
ret = atomic_cmpxchg((uint32_t *)g2h(addr), old, new);
ret = ret != old;
break;
case 3:
{
uint64_t o64, n64, r64;
o64 = *(uint64_t *)g2h(old);
n64 = *(uint64_t *)g2h(new);
#ifdef CONFIG_ATOMIC64
r64 = atomic_cmpxchg__nocheck((uint64_t *)g2h(addr), o64, n64);
ret = r64 != o64;
#else
start_exclusive();
r64 = *(uint64_t *)g2h(addr);
ret = 1;
if (r64 == o64) {
*(uint64_t *)g2h(addr) = n64;
ret = 0;
}
end_exclusive();
#endif
}
break;
}
break;
}
env->gr[28] = ret;
return 0;
}
void cpu_loop(CPUHPPAState *env)
{
CPUState *cs = CPU(hppa_env_get_cpu(env));
target_siginfo_t info;
abi_ulong ret;
int trapnr;
while (1) {
cpu_exec_start(cs);
trapnr = cpu_exec(cs);
cpu_exec_end(cs);
process_queued_cpu_work(cs);
switch (trapnr) {
case EXCP_SYSCALL:
ret = do_syscall(env, env->gr[20],
env->gr[26], env->gr[25],
env->gr[24], env->gr[23],
env->gr[22], env->gr[21], 0, 0);
switch (ret) {
default:
env->gr[28] = ret;
/* We arrived here by faking the gateway page. Return. */
env->iaoq_f = env->gr[31];
env->iaoq_b = env->gr[31] + 4;
break;
case -TARGET_ERESTARTSYS:
case -TARGET_QEMU_ESIGRETURN:
break;
}
break;
case EXCP_SYSCALL_LWS:
env->gr[21] = hppa_lws(env);
/* We arrived here by faking the gateway page. Return. */
env->iaoq_f = env->gr[31];
env->iaoq_b = env->gr[31] + 4;
break;
case EXCP_ITLB_MISS:
case EXCP_DTLB_MISS:
case EXCP_NA_ITLB_MISS:
case EXCP_NA_DTLB_MISS:
case EXCP_IMP:
case EXCP_DMP:
case EXCP_DMB:
case EXCP_PAGE_REF:
case EXCP_DMAR:
case EXCP_DMPI:
info.si_signo = TARGET_SIGSEGV;
info.si_errno = 0;
info.si_code = TARGET_SEGV_ACCERR;
info._sifields._sigfault._addr = env->cr[CR_IOR];
queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
break;
case EXCP_UNALIGN:
info.si_signo = TARGET_SIGBUS;
info.si_errno = 0;
info.si_code = 0;
info._sifields._sigfault._addr = env->cr[CR_IOR];
queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
break;
case EXCP_ILL:
case EXCP_PRIV_OPR:
case EXCP_PRIV_REG:
info.si_signo = TARGET_SIGILL;
info.si_errno = 0;
info.si_code = TARGET_ILL_ILLOPN;
info._sifields._sigfault._addr = env->iaoq_f;
queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
break;
case EXCP_OVERFLOW:
case EXCP_COND:
case EXCP_ASSIST:
info.si_signo = TARGET_SIGFPE;
info.si_errno = 0;
info.si_code = 0;
info._sifields._sigfault._addr = env->iaoq_f;
queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
break;
case EXCP_DEBUG:
info.si_signo = TARGET_SIGTRAP;
info.si_errno = 0;
info.si_code = TARGET_TRAP_BRKPT;
queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
break;
case EXCP_INTERRUPT:
/* just indicate that signals should be handled asap */
break;
default:
g_assert_not_reached();
}
process_pending_signals(env);
}
}
void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
{
int i;
for (i = 1; i < 32; i++) {
env->gr[i] = regs->gr[i];
}
env->iaoq_f = regs->iaoq[0];
env->iaoq_b = regs->iaoq[1];
}