[PATCH 27/28] linux: Add generic C syscall implementation

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

The hppa and riscv one are also removed.  The riscv specially is
abusing the internal interfaces by defining it with a different
signature.  If the idea is to provide an optimized version a better
alternative would be to provide an assembly one as other
architectures.

Checked on x86_64-linux-gnu and with build for the affected ABIs.
---
 sysdeps/unix/sysv/linux/hppa/syscall.c        | 65 -------------------
 sysdeps/unix/sysv/linux/{riscv => }/syscall.c | 33 ++++++----
 2 files changed, 20 insertions(+), 78 deletions(-)
 delete mode 100644 sysdeps/unix/sysv/linux/hppa/syscall.c
 rename sysdeps/unix/sysv/linux/{riscv => }/syscall.c (53%)

diff --git a/sysdeps/unix/sysv/linux/hppa/syscall.c b/sysdeps/unix/sysv/linux/hppa/syscall.c
deleted file mode 100644
index 7f6794b09f..0000000000
--- a/sysdeps/unix/sysv/linux/hppa/syscall.c
+++ /dev/null
@@ -1,65 +0,0 @@
-/* Copyright (C) 1997-2020 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library.  If not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <stdarg.h>
-#include <sysdep.h>
-#include <errno.h>
-
-/* HPPA implements syscall() in 'C'; the assembler version would
-   typically be in syscall.S. Also note that we have INLINE_SYSCALL,
-   INTERNAL_SYSCALL, and all the generated pure assembly syscall wrappers.
-   How often the function is used is unknown. */
-
-long int
-syscall (long int __sysno, ...)
-{
-  /* FIXME: Keep this matching INLINE_SYSCALL for hppa */
-  va_list args;
-  long int arg0, arg1, arg2, arg3, arg4, arg5;
-  long int __sys_res;
-
-  /* Load varargs */
-  va_start (args, __sysno);
-  arg0 = va_arg (args, long int);
-  arg1 = va_arg (args, long int);
-  arg2 = va_arg (args, long int);
-  arg3 = va_arg (args, long int);
-  arg4 = va_arg (args, long int);
-  arg5 = va_arg (args, long int);
-  va_end (args);
-
-  {
-    LOAD_ARGS_6 (arg0, arg1, arg2, arg3, arg4, arg5)
-    register unsigned long int __res asm("r28");
-    PIC_REG_DEF
-    LOAD_REGS_6
-    asm volatile (SAVE_ASM_PIC
-		  "	ble  0x100(%%sr2, %%r0)	\n"
-		  "	copy %1, %%r20		\n"
-		  LOAD_ASM_PIC
-		  : "=r" (__res)
-		  : "r" (__sysno) PIC_REG_USE ASM_ARGS_6
-		  : "memory", CALL_CLOB_REGS CLOB_ARGS_6);
-    __sys_res = __res;
-  }
-  if ((unsigned long int) __sys_res >= (unsigned long int) -4095)
-    {
-      __set_errno (-__sys_res);
-      __sys_res = -1;
-    }
-  return __sys_res;
-}
diff --git a/sysdeps/unix/sysv/linux/riscv/syscall.c b/sysdeps/unix/sysv/linux/syscall.c
similarity index 53%
rename from sysdeps/unix/sysv/linux/riscv/syscall.c
rename to sysdeps/unix/sysv/linux/syscall.c
index a99375c054..2e39ed9bc9 100644
--- a/sysdeps/unix/sysv/linux/riscv/syscall.c
+++ b/sysdeps/unix/sysv/linux/syscall.c
@@ -1,5 +1,5 @@
-/* system call interface.  Linux/RISC-V version.
-   Copyright (C) 2001-2020 Free Software Foundation, Inc.
+/* Indirect system call.  Linux version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -16,19 +16,26 @@
    License along with the GNU C Library.  If not, see
    <https://www.gnu.org/licenses/>.  */
 
+#include <stdarg.h>
 #include <sysdep.h>
 
 long int
-syscall (long int syscall_number, long int arg1, long int arg2, long int arg3,
-	 long int arg4, long int arg5, long int arg6, long int arg7)
+syscall (long int number, ...)
 {
-  long int ret;
-
-  ret = INTERNAL_SYSCALL_NCS (syscall_number, 7, arg1, arg2, arg3, arg4,
-			      arg5, arg6, arg7);
-
-  if (INTERNAL_SYSCALL_ERROR_P (ret))
-    return __syscall_error (ret);
-
-  return ret;
+  va_list args;
+
+  va_start (args, number);
+  long int arg0 = va_arg (args, long int);
+  long int arg1 = va_arg (args, long int);
+  long int arg2 = va_arg (args, long int);
+  long int arg3 = va_arg (args, long int);
+  long int arg4 = va_arg (args, long int);
+  long int arg5 = va_arg (args, long int);
+  va_end (args);
+
+  long int ret = INTERNAL_SYSCALL_NCS (number, 6, arg0, arg1, arg2,
+				       arg3, arg4, arg5);
+  return INTERNAL_SYSCALL_ERROR_P (ret)
+	 ? SYSCALL_ERROR_LABEL (INTERNAL_SYSCALL_ERRNO (ret))
+	 : ret;
 }
-- 
2.25.1