From a0577d2aa9bd42d5d584fa03649a166ba45c2f3d Mon Sep 17 00:00:00 2001
From: Richard Henderson <rth@twiddle.net>
Date: Sun, 27 Sep 2015 14:26:04 -0700
Subject: [PATCH] target-tilegx: Use TILEGX_EXCP_SIGNAL instead of
 TILEGX_EXCP_SEGV

Consolidate signal handling under a single exception.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 linux-user/main.c   | 41 +++++++++++++++++++++++------------------
 target-tilegx/cpu.c |  7 ++++++-
 target-tilegx/cpu.h |  3 +--
 3 files changed, 30 insertions(+), 21 deletions(-)

diff --git a/linux-user/main.c b/linux-user/main.c
index 9e8b92b..1f60ff2 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -3414,17 +3414,6 @@ void cpu_loop(CPUS390XState *env)
 
 #ifdef TARGET_TILEGX
 
-static void gen_sigsegv_maperr(CPUTLGState *env, target_ulong addr)
-{
-    target_siginfo_t info;
-
-    info.si_signo = TARGET_SIGSEGV;
-    info.si_errno = 0;
-    info.si_code = TARGET_SEGV_MAPERR;
-    info._sifields._sigfault._addr = addr;
-    queue_signal(env, info.si_signo, &info);
-}
-
 static void gen_sigill_reg(CPUTLGState *env)
 {
     target_siginfo_t info;
@@ -3436,17 +3425,36 @@ static void gen_sigill_reg(CPUTLGState *env)
     queue_signal(env, info.si_signo, &info);
 }
 
-static void do_signal(CPUTLGState *env)
+static void do_signal(CPUTLGState *env, int signo, int sigcode)
 {
     target_siginfo_t info;
 
-    info.si_signo = env->signo;
+    info.si_signo = signo;
     info.si_errno = 0;
-    info.si_code = env->sigcode;
     info._sifields._sigfault._addr = env->pc;
+
+    if (signo == TARGET_SIGSEGV) {
+        /* The passed in sigcode is a dummy; check for a page mapping
+           and pass either MAPERR or ACCERR.  */
+        target_ulong addr = env->excaddr;
+        info._sifields._sigfault._addr = addr;
+        if (page_check_range(addr, 1, PAGE_VALID) < 0) {
+            sigcode = TARGET_SEGV_MAPERR;
+        } else {
+            sigcode = TARGET_SEGV_ACCERR;
+        }
+    }
+    info.si_code = sigcode;
+
     queue_signal(env, info.si_signo, &info);
 }
 
+static void gen_sigsegv_maperr(CPUTLGState *env, target_ulong addr)
+{
+    env->excaddr = addr;
+    do_signal(env, TARGET_SIGSEGV, 0);
+}
+
 static void set_regval(CPUTLGState *env, uint8_t reg, uint64_t val)
 {
     if (unlikely(reg >= TILEGX_R_COUNT)) {
@@ -3634,15 +3642,12 @@ void cpu_loop(CPUTLGState *env)
             do_fetch(env, trapnr, false);
             break;
         case TILEGX_EXCP_SIGNAL:
-            do_signal(env);
+            do_signal(env, env->signo, env->sigcode);
             break;
         case TILEGX_EXCP_REG_IDN_ACCESS:
         case TILEGX_EXCP_REG_UDN_ACCESS:
             gen_sigill_reg(env);
             break;
-        case TILEGX_EXCP_SEGV:
-            gen_sigsegv_maperr(env, env->excaddr);
-            break;
         default:
             fprintf(stderr, "trapnr is %d[0x%x].\n", trapnr, trapnr);
             g_assert_not_reached();
diff --git a/target-tilegx/cpu.c b/target-tilegx/cpu.c
index 78b73e4..3c5481d 100644
--- a/target-tilegx/cpu.c
+++ b/target-tilegx/cpu.c
@@ -22,6 +22,7 @@
 #include "qemu-common.h"
 #include "hw/qdev-properties.h"
 #include "migration/vmstate.h"
+#include "linux-user/syscall_defs.h"
 
 static void tilegx_cpu_dump_state(CPUState *cs, FILE *f,
                                   fprintf_function cpu_fprintf, int flags)
@@ -121,8 +122,12 @@ static int tilegx_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int rw,
 {
     TileGXCPU *cpu = TILEGX_CPU(cs);
 
-    cs->exception_index = TILEGX_EXCP_SEGV;
+    /* The sigcode field will be filled in by do_signal in main.c.  */
+    cs->exception_index = TILEGX_EXCP_SIGNAL;
     cpu->env.excaddr = address;
+    cpu->env.signo = TARGET_SIGSEGV;
+    cpu->env.sigcode = 0;
+
     return 1;
 }
 
diff --git a/target-tilegx/cpu.h b/target-tilegx/cpu.h
index 023ccd4..6f04fe7 100644
--- a/target-tilegx/cpu.h
+++ b/target-tilegx/cpu.h
@@ -60,8 +60,7 @@ enum {
 typedef enum {
     TILEGX_EXCP_NONE = 0,
     TILEGX_EXCP_SYSCALL = 1,
-    TILEGX_EXCP_SEGV = 2,
-    TILEGX_EXCP_SIGNAL = 3,
+    TILEGX_EXCP_SIGNAL = 2,
     TILEGX_EXCP_OPCODE_UNKNOWN = 0x101,
     TILEGX_EXCP_OPCODE_UNIMPLEMENTED = 0x102,
     TILEGX_EXCP_OPCODE_CMPEXCH = 0x103,
-- 
2.7.4