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authorPeter Maydell <peter.maydell@linaro.org>2016-05-12 18:47:42 +0100
committerRiku Voipio <riku.voipio@linaro.org>2016-05-27 14:49:50 +0300
commita9175169cc55ecff23a158dfee7d9cbb0b75d185 (patch)
tree25dc5a2ef724bbe40d13e40688be183641c152ee /linux-user/main.c
parent6205086558955402983f1c2ff9e4c3ebe9f1c678 (diff)
downloadfocaccia-qemu-a9175169cc55ecff23a158dfee7d9cbb0b75d185.tar.gz
focaccia-qemu-a9175169cc55ecff23a158dfee7d9cbb0b75d185.zip
linux-user: Support for restarting system calls for tilegx targets
Update the tilegx main loop and sigreturn code:
 * on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn
 * return -TARGET_QEMU_ESIGRETURN from sigreturn rather than current R_RE
 * handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
   that the main loop should not touch any guest CPU state

Note that this fixes a bug where a sigreturn which happened to have
an errno value in TILEGX_R_RE would incorrectly cause TILEGX_R_ERR
to get set.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Diffstat (limited to 'linux-user/main.c')
-rw-r--r--linux-user/main.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/linux-user/main.c b/linux-user/main.c
index a532221ebc..4607e48278 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -3706,15 +3706,20 @@ void cpu_loop(CPUTLGState *env)
         cpu_exec_end(cs);
         switch (trapnr) {
         case TILEGX_EXCP_SYSCALL:
-            env->regs[TILEGX_R_RE] = do_syscall(env, env->regs[TILEGX_R_NR],
-                                                env->regs[0], env->regs[1],
-                                                env->regs[2], env->regs[3],
-                                                env->regs[4], env->regs[5],
-                                                env->regs[6], env->regs[7]);
-            env->regs[TILEGX_R_ERR] = TILEGX_IS_ERRNO(env->regs[TILEGX_R_RE])
-                                                      ? - env->regs[TILEGX_R_RE]
-                                                      : 0;
+        {
+            abi_ulong ret = do_syscall(env, env->regs[TILEGX_R_NR],
+                                       env->regs[0], env->regs[1],
+                                       env->regs[2], env->regs[3],
+                                       env->regs[4], env->regs[5],
+                                       env->regs[6], env->regs[7]);
+            if (ret == -TARGET_ERESTARTSYS) {
+                env->pc -= 8;
+            } else if (ret != -TARGET_QEMU_ESIGRETURN) {
+                env->regs[TILEGX_R_RE] = ret;
+                env->regs[TILEGX_R_ERR] = TILEGX_IS_ERRNO(ret) ? -ret : 0;
+            }
             break;
+        }
         case TILEGX_EXCP_OPCODE_EXCH:
             do_exch(env, true, false);
             break;