[src/trunk]: src/sys/arch/aarch64/aarch64 Fix __syscall(2) for COMPAT_NETBSD3...

[rin <rin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1c580a513871
branches:  trunk
changeset: 1021187:1c580a513871
user:      rin <rin%NetBSD.org@localhost>
date:      Sat May 15 11:38:26 2021 +0000

description:
Fix __syscall(2) for COMPAT_NETBSD32 on aarch64{,eb}.

The 1st argument for __syscall(2) is quad_t, which is stored in r0 and r1.

Now, tests/lib/libc/t_syscall:mmap___syscall passes for COMPAT_NETBSD32.

diffstat:

 sys/arch/aarch64/aarch64/aarch32_syscall.c |  25 ++++++++++++++++++++-----
 1 files changed, 20 insertions(+), 5 deletions(-)

diffs (46 lines):

diff -r f854298ba784 -r 1c580a513871 sys/arch/aarch64/aarch64/aarch32_syscall.c
--- a/sys/arch/aarch64/aarch64/aarch32_syscall.c        Sat May 15 11:06:07 2021 +0000
+++ b/sys/arch/aarch64/aarch64/aarch32_syscall.c        Sat May 15 11:38:26 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: aarch32_syscall.c,v 1.3 2019/04/12 09:29:26 ryo Exp $  */
+/*     $NetBSD: aarch32_syscall.c,v 1.4 2021/05/15 11:38:26 rin Exp $  */
 
 /*
  * Copyright (c) 2018 Ryo Shimizu <ryo%nerv.org@localhost>
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: aarch32_syscall.c,v 1.3 2019/04/12 09:29:26 ryo Exp $");
+__KERNEL_RCSID(0, "$NetBSD: aarch32_syscall.c,v 1.4 2021/05/15 11:38:26 rin Exp $");
 
 #include <sys/param.h>
 #include <sys/ktrace.h>
@@ -91,9 +91,24 @@
        code %= EMULNAMEU(SYS_NSYSENT);
        callp = p->p_emul->e_sysent + code;
        if (__predict_false(callp->sy_flags & SYCALL_INDIRECT)) {
-               nargs_reg -= 1;
-               regstart = 1;   /* args start from r1 */
-               code = tf->tf_reg[0] % EMULNAMEU(SYS_NSYSENT);
+               int off = 1;
+#ifdef NETBSD32_SYS_netbsd32____syscall /* XXX ugly: apply only for NETBSD32 */
+               /*
+                * For __syscall(2), 1st argument is quad_t, which is
+                * stored in r0 and r1.
+                */
+               if (code == NETBSD32_SYS_netbsd32____syscall)
+                       off = 2;
+#endif
+               nargs_reg -= off;
+               regstart = off; /* args start from r1 or r2 */
+#ifdef __AARCH64EB__
+               if (off == 2)
+                       code = tf->tf_reg[1];
+               else
+#endif
+                       code = tf->tf_reg[0];
+               code %= EMULNAMEU(SYS_NSYSENT);
                callp = p->p_emul->e_sysent + code;
 
                /* don't allow nested syscall */