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>
diff --git a/linux-user/aarch64/cpu_loop.c b/linux-user/aarch64/cpu_loop.c
index c97a646..65d815f 100644
--- a/linux-user/aarch64/cpu_loop.c
+++ b/linux-user/aarch64/cpu_loop.c
@@ -73,7 +73,7 @@
void cpu_loop(CPUARMState *env)
{
CPUState *cs = CPU(arm_env_get_cpu(env));
- int trapnr, sig;
+ int trapnr;
abi_long ret;
target_siginfo_t info;
@@ -121,13 +121,10 @@
break;
case EXCP_DEBUG:
case EXCP_BKPT:
- sig = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (sig) {
- info.si_signo = sig;
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
- }
+ 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_SEMIHOST:
env->xregs[0] = do_arm_semihosting(env);
diff --git a/linux-user/alpha/cpu_loop.c b/linux-user/alpha/cpu_loop.c
index c1a98c8..824b6d6 100644
--- a/linux-user/alpha/cpu_loop.c
+++ b/linux-user/alpha/cpu_loop.c
@@ -179,14 +179,10 @@
}
break;
case EXCP_DEBUG:
- info.si_signo = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (info.si_signo) {
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
- } else {
- arch_interrupt = false;
- }
+ 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. */
diff --git a/linux-user/arm/cpu_loop.c b/linux-user/arm/cpu_loop.c
index 26928fb..ee68aa6 100644
--- a/linux-user/arm/cpu_loop.c
+++ b/linux-user/arm/cpu_loop.c
@@ -397,18 +397,10 @@
break;
case EXCP_DEBUG:
excp_debug:
- {
- int sig;
-
- sig = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (sig)
- {
- info.si_signo = sig;
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
- }
- }
+ 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_KERNEL_TRAP:
if (do_kernel_trap(env))
diff --git a/linux-user/cris/cpu_loop.c b/linux-user/cris/cpu_loop.c
index 37bdcfa..dacf604 100644
--- a/linux-user/cris/cpu_loop.c
+++ b/linux-user/cris/cpu_loop.c
@@ -64,18 +64,10 @@
}
break;
case EXCP_DEBUG:
- {
- int sig;
-
- sig = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (sig)
- {
- info.si_signo = sig;
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
- }
- }
+ 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_ATOMIC:
cpu_exec_step_atomic(cs);
diff --git a/linux-user/hppa/cpu_loop.c b/linux-user/hppa/cpu_loop.c
index 0301c76..880955f 100644
--- a/linux-user/hppa/cpu_loop.c
+++ b/linux-user/hppa/cpu_loop.c
@@ -182,13 +182,10 @@
queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
break;
case EXCP_DEBUG:
- trapnr = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (trapnr) {
- info.si_signo = trapnr;
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, trapnr, QEMU_SI_FAULT, &info);
- }
+ 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 */
diff --git a/linux-user/i386/cpu_loop.c b/linux-user/i386/cpu_loop.c
index 2374abf..51cfa00 100644
--- a/linux-user/i386/cpu_loop.c
+++ b/linux-user/i386/cpu_loop.c
@@ -225,18 +225,10 @@
/* just indicate that signals should be handled asap */
break;
case EXCP_DEBUG:
- {
- int sig;
-
- sig = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (sig)
- {
- info.si_signo = sig;
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
- }
- }
+ 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_ATOMIC:
cpu_exec_step_atomic(cs);
diff --git a/linux-user/m68k/cpu_loop.c b/linux-user/m68k/cpu_loop.c
index 30c3332..bfb41bb 100644
--- a/linux-user/m68k/cpu_loop.c
+++ b/linux-user/m68k/cpu_loop.c
@@ -112,18 +112,10 @@
}
break;
case EXCP_DEBUG:
- {
- int sig;
-
- sig = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (sig)
- {
- info.si_signo = sig;
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
- }
- }
+ 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_ATOMIC:
cpu_exec_step_atomic(cs);
diff --git a/linux-user/microblaze/cpu_loop.c b/linux-user/microblaze/cpu_loop.c
index 2af93eb..c2190e1 100644
--- a/linux-user/microblaze/cpu_loop.c
+++ b/linux-user/microblaze/cpu_loop.c
@@ -113,18 +113,10 @@
}
break;
case EXCP_DEBUG:
- {
- int sig;
-
- sig = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (sig)
- {
- info.si_signo = sig;
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
- }
- }
+ 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_ATOMIC:
cpu_exec_step_atomic(cs);
diff --git a/linux-user/mips/cpu_loop.c b/linux-user/mips/cpu_loop.c
index 97e4957..d0f62ec 100644
--- a/linux-user/mips/cpu_loop.c
+++ b/linux-user/mips/cpu_loop.c
@@ -592,18 +592,10 @@
/* just indicate that signals should be handled asap */
break;
case EXCP_DEBUG:
- {
- int sig;
-
- sig = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (sig)
- {
- info.si_signo = sig;
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
- }
- }
+ 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_SC:
if (do_store_exclusive(env)) {
diff --git a/linux-user/openrisc/cpu_loop.c b/linux-user/openrisc/cpu_loop.c
index 6c6ea87..f496e4b 100644
--- a/linux-user/openrisc/cpu_loop.c
+++ b/linux-user/openrisc/cpu_loop.c
@@ -85,13 +85,10 @@
/* We processed the pending cpu work above. */
break;
case EXCP_DEBUG:
- trapnr = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (trapnr) {
- info.si_signo = trapnr;
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
- }
+ 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_ATOMIC:
cpu_exec_step_atomic(cs);
diff --git a/linux-user/ppc/cpu_loop.c b/linux-user/ppc/cpu_loop.c
index 133a87f..801f5ac 100644
--- a/linux-user/ppc/cpu_loop.c
+++ b/linux-user/ppc/cpu_loop.c
@@ -69,7 +69,7 @@
{
CPUState *cs = CPU(ppc_env_get_cpu(env));
target_siginfo_t info;
- int trapnr, sig;
+ int trapnr;
target_ulong ret;
for(;;) {
@@ -449,15 +449,10 @@
env->gpr[3] = ret;
break;
case EXCP_DEBUG:
- sig = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (sig) {
- info.si_signo = sig;
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
- } else {
- arch_interrupt = false;
- }
+ 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 */
diff --git a/linux-user/riscv/cpu_loop.c b/linux-user/riscv/cpu_loop.c
index f137d39..4cf3e94 100644
--- a/linux-user/riscv/cpu_loop.c
+++ b/linux-user/riscv/cpu_loop.c
@@ -88,7 +88,7 @@
break;
case EXCP_DEBUG:
gdbstep:
- signum = gdb_handlesig(cs, TARGET_SIGTRAP);
+ signum = TARGET_SIGTRAP;
sigcode = TARGET_TRAP_BRKPT;
break;
default:
diff --git a/linux-user/s390x/cpu_loop.c b/linux-user/s390x/cpu_loop.c
index 99f5f15..51b5412 100644
--- a/linux-user/s390x/cpu_loop.c
+++ b/linux-user/s390x/cpu_loop.c
@@ -61,12 +61,9 @@
break;
case EXCP_DEBUG:
- sig = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (sig) {
- n = TARGET_TRAP_BRKPT;
- goto do_signal_pc;
- }
- break;
+ sig = TARGET_SIGTRAP;
+ n = TARGET_TRAP_BRKPT;
+ goto do_signal_pc;
case EXCP_PGM:
n = env->int_pgm_code;
switch (n) {
diff --git a/linux-user/sh4/cpu_loop.c b/linux-user/sh4/cpu_loop.c
index fdd3481..47e54b9 100644
--- a/linux-user/sh4/cpu_loop.c
+++ b/linux-user/sh4/cpu_loop.c
@@ -57,19 +57,10 @@
/* just indicate that signals should be handled asap */
break;
case EXCP_DEBUG:
- {
- int sig;
-
- sig = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (sig) {
- info.si_signo = sig;
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
- } else {
- arch_interrupt = false;
- }
- }
+ 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 0xa0:
case 0xc0:
diff --git a/linux-user/sparc/cpu_loop.c b/linux-user/sparc/cpu_loop.c
index 91f714a..7d5b337 100644
--- a/linux-user/sparc/cpu_loop.c
+++ b/linux-user/sparc/cpu_loop.c
@@ -268,18 +268,10 @@
}
break;
case EXCP_DEBUG:
- {
- int sig;
-
- sig = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (sig)
- {
- info.si_signo = sig;
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
- }
- }
+ 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_ATOMIC:
cpu_exec_step_atomic(cs);
diff --git a/linux-user/xtensa/cpu_loop.c b/linux-user/xtensa/cpu_loop.c
index d142988..bee78ed 100644
--- a/linux-user/xtensa/cpu_loop.c
+++ b/linux-user/xtensa/cpu_loop.c
@@ -239,13 +239,10 @@
}
break;
case EXCP_DEBUG:
- trapnr = gdb_handlesig(cs, TARGET_SIGTRAP);
- if (trapnr) {
- info.si_signo = trapnr;
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, trapnr, QEMU_SI_FAULT, &info);
- }
+ 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 EXC_DEBUG:
default:
