linux-user: Add cpu_loop_exit_sigsegv

This is a new interface to be provided by the os emulator for
raising SIGSEGV on fault.  Use the new record_sigsegv target hook.

Reviewed by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 22 insertions, 8 deletions

diff --git a/linux-user/signal.c b/linux-user/signal.c
index b816678..1359837 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -688,9 +688,27 @@ void force_sigsegv(int oldsig)
     }
     force_sig(TARGET_SIGSEGV);
 }
-
 #endif
 
+void cpu_loop_exit_sigsegv(CPUState *cpu, target_ulong addr,
+                           MMUAccessType access_type, bool maperr, uintptr_t ra)
+{
+    const struct TCGCPUOps *tcg_ops = CPU_GET_CLASS(cpu)->tcg_ops;
+
+    if (tcg_ops->record_sigsegv) {
+        tcg_ops->record_sigsegv(cpu, addr, access_type, maperr, ra);
+    } else if (tcg_ops->tlb_fill) {
+        tcg_ops->tlb_fill(cpu, addr, 0, access_type, MMU_USER_IDX, false, ra);
+        g_assert_not_reached();
+    }
+
+    force_sig_fault(TARGET_SIGSEGV,
+                    maperr ? TARGET_SEGV_MAPERR : TARGET_SEGV_ACCERR,
+                    addr);
+    cpu->exception_index = EXCP_INTERRUPT;
+    cpu_loop_exit_restore(cpu, ra);
+}
+
 /* abort execution with signal */
 static void QEMU_NORETURN dump_core_and_abort(int target_sig)
 {
@@ -806,7 +824,7 @@ static void host_signal_handler(int host_sig, siginfo_t *info, void *puc)
         access_type = adjust_signal_pc(&pc, is_write);
 
         if (host_sig == SIGSEGV) {
-            const struct TCGCPUOps *tcg_ops;
+            bool maperr = true;
 
             if (info->si_code == SEGV_ACCERR && h2g_valid(host_addr)) {
                 /* If this was a write to a TB protected page, restart. */
@@ -821,18 +839,14 @@ static void host_signal_handler(int host_sig, siginfo_t *info, void *puc)
                  * which means that we may get ACCERR when we want MAPERR.
                  */
                 if (page_get_flags(guest_addr) & PAGE_VALID) {
-                    /* maperr = false; */
+                    maperr = false;
                 } else {
                     info->si_code = SEGV_MAPERR;
                 }
             }
 
             sigprocmask(SIG_SETMASK, &uc->uc_sigmask, NULL);
-
-            tcg_ops = CPU_GET_CLASS(cpu)->tcg_ops;
-            tcg_ops->tlb_fill(cpu, guest_addr, 0, access_type,
-                              MMU_USER_IDX, false, pc);
-            g_assert_not_reached();
+            cpu_loop_exit_sigsegv(cpu, guest_addr, access_type, maperr, pc);
         } else {
             sigprocmask(SIG_SETMASK, &uc->uc_sigmask, NULL);
         }