diff mbox series

[2/2] linux-user: Clean up nios2 main loop signal handling

Message ID 20181019174958.26616-3-peter.maydell@linaro.org
State Accepted
Headers show
Series linux-user: Don't call gdb_handlesig unnecessarily | expand

Commit Message

Peter Maydell Oct. 19, 2018, 5:49 p.m. UTC
The nios2 main loop code's code does some odd
things with gdb_handlesig() that no other target
CPU does: it has some signals that are delivered
to gdb and only to gdb. Stop doing this, and instead
behave like all the other targets:
 * a trap instruction becomes a SIGTRAP
 * an unhandled exception type returned from cpu_exec()
   causes us to abort(), not to try to hand gdb a SIGILL

This fixes in passing Coverity issue CID 1390853,
which was a complaint that the old code failed to
check the return value from gdb_handlesig().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

---
Disclaimer: compile tested, and the change makes conceptual
sense, but I have no nios2 test environment.
---
 linux-user/nios2/cpu_loop.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

-- 
2.19.1

Comments

Laurent Vivier Nov. 12, 2018, 4:12 p.m. UTC | #1
On 19/10/2018 19:49, Peter Maydell wrote:
> The nios2 main loop code's code does some odd

> things with gdb_handlesig() that no other target

> CPU does: it has some signals that are delivered

> to gdb and only to gdb. Stop doing this, and instead

> behave like all the other targets:

>  * a trap instruction becomes a SIGTRAP

>  * an unhandled exception type returned from cpu_exec()

>    causes us to abort(), not to try to hand gdb a SIGILL

> 

> This fixes in passing Coverity issue CID 1390853,

> which was a complaint that the old code failed to

> check the return value from gdb_handlesig().

> 

> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

> ---

> Disclaimer: compile tested, and the change makes conceptual

> sense, but I have no nios2 test environment.


I'll push a slightly modified version of this patch: gdbsig is now
unused and my compiler complains about that.

Thanks,
Laurent

> ---

>  linux-user/nios2/cpu_loop.c | 14 +++++---------

>  1 file changed, 5 insertions(+), 9 deletions(-)

> 

> diff --git a/linux-user/nios2/cpu_loop.c b/linux-user/nios2/cpu_loop.c

> index dac7a061813..973dd54d791 100644

> --- a/linux-user/nios2/cpu_loop.c

> +++ b/linux-user/nios2/cpu_loop.c

> @@ -68,7 +68,10 @@ void cpu_loop(CPUNios2State *env)

>                  env->regs[R_EA] = env->regs[R_PC] + 4;

>                  env->regs[R_PC] = cpu->exception_addr;

>  

> -                gdbsig = TARGET_SIGTRAP;

> +                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 0xaa:

> @@ -106,14 +109,7 @@ kuser_fail:

>          default:

>              EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",

>                       trapnr);

> -            gdbsig = TARGET_SIGILL;

> -            break;

> -        }

> -        if (gdbsig) {

> -            gdb_handlesig(cs, gdbsig);

> -            if (gdbsig != TARGET_SIGTRAP) {

> -                exit(EXIT_FAILURE);

> -            }

> +            abort();

>          }

>  

>          process_pending_signals(env);

>
diff mbox series

Patch

diff --git a/linux-user/nios2/cpu_loop.c b/linux-user/nios2/cpu_loop.c
index dac7a061813..973dd54d791 100644
--- a/linux-user/nios2/cpu_loop.c
+++ b/linux-user/nios2/cpu_loop.c
@@ -68,7 +68,10 @@  void cpu_loop(CPUNios2State *env)
                 env->regs[R_EA] = env->regs[R_PC] + 4;
                 env->regs[R_PC] = cpu->exception_addr;
 
-                gdbsig = TARGET_SIGTRAP;
+                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 0xaa:
@@ -106,14 +109,7 @@  kuser_fail:
         default:
             EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
                      trapnr);
-            gdbsig = TARGET_SIGILL;
-            break;
-        }
-        if (gdbsig) {
-            gdb_handlesig(cs, gdbsig);
-            if (gdbsig != TARGET_SIGTRAP) {
-                exit(EXIT_FAILURE);
-            }
+            abort();
         }
 
         process_pending_signals(env);