commit 5457dc9e37fe0a29989bd64306c63941074864ce
author Laurent Vivier <laurent@vivier.eu> Fri Jul 08 01:17:27 2016 +0200
committer Riku Voipio <riku.voipio@linaro.org> Thu Sep 22 07:24:21 2016 +0300
tree 500f40acbc2b3e2e4401a037447d93904856c522
parent 45eafb4d32ced9ff1dcb3800c89f8beaf47b61cc

linux-user: fix TARGET_NR_select

TARGET_NR_select can have three different implementations:

  1- to always return -ENOSYS

     microblaze, ppc, ppc64

     -> TARGET_WANT_NI_OLD_SELECT

  2- to take parameters from a structure pointed by arg1
    (kernel sys_old_select)

     i386, arm, m68k

     -> TARGET_WANT_OLD_SYS_SELECT

  3- to take parameters from arg[1-5]
     (kernel sys_select)

     x86_64, alpha, s390x,
     cris, sparc, sparc64

Some (new) architectures don't define NR_select,

  4- but only NR__newselect with sys_select:

      mips, mips64, sh

  5- don't define NR__newselect, and use pselect6 syscall:

      aarch64, openrisc, tilegx, unicore32

Reported-by: Timothy Pearson <tpearson@raptorengineering.com>
Reported-by: Allan Wirth <awirth@akamai.com>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

linux-user/syscall.c

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index d7e4d9f..7aa2c1d 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -1444,6 +1444,29 @@
 
     return ret;
 }
+
+#if defined(TARGET_WANT_OLD_SYS_SELECT)
+static abi_long do_old_select(abi_ulong arg1)
+{
+    struct target_sel_arg_struct *sel;
+    abi_ulong inp, outp, exp, tvp;
+    long nsel;
+
+    if (!lock_user_struct(VERIFY_READ, sel, arg1, 1)) {
+        return -TARGET_EFAULT;
+    }
+
+    nsel = tswapal(sel->n);
+    inp = tswapal(sel->inp);
+    outp = tswapal(sel->outp);
+    exp = tswapal(sel->exp);
+    tvp = tswapal(sel->tvp);
+
+    unlock_user_struct(sel, arg1, 0);
+
+    return do_select(nsel, inp, outp, exp, tvp);
+}
+#endif
 #endif
 
 static abi_long do_pipe2(int host_pipe[], int flags)
@@ -8668,24 +8691,15 @@
         break;
 #if defined(TARGET_NR_select)
     case TARGET_NR_select:
-#if defined(TARGET_S390X) || defined(TARGET_ALPHA)
-        ret = do_select(arg1, arg2, arg3, arg4, arg5);
+#if defined(TARGET_WANT_NI_OLD_SELECT)
+        /* some architectures used to have old_select here
+         * but now ENOSYS it.
+         */
+        ret = -TARGET_ENOSYS;
+#elif defined(TARGET_WANT_OLD_SYS_SELECT)
+        ret = do_old_select(arg1);
 #else
-        {
-            struct target_sel_arg_struct *sel;
-            abi_ulong inp, outp, exp, tvp;
-            long nsel;
-
-            if (!lock_user_struct(VERIFY_READ, sel, arg1, 1))
-                goto efault;
-            nsel = tswapal(sel->n);
-            inp = tswapal(sel->inp);
-            outp = tswapal(sel->outp);
-            exp = tswapal(sel->exp);
-            tvp = tswapal(sel->tvp);
-            unlock_user_struct(sel, arg1, 0);
-            ret = do_select(nsel, inp, outp, exp, tvp);
-        }
+        ret = do_select(arg1, arg2, arg3, arg4, arg5);
 #endif
         break;
 #endif