x86, um: Use the same style generated syscall tables as native

Now when the native kernel uses a single style of generated system
call table, follow suite for UML and implement the same style, all in
C.  This requires __NR_syscall_max and NR_syscalls to be generated; on
native this is done in asm-headers.h but that file is common to all
UML architectures; therefore put it in user-headers.h instead which
already have accommodations for architecture-specific values.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 12 insertions, 19 deletions

diff --git a/arch/x86/um/sys_call_table_64.c b/arch/x86/um/sys_call_table_64.c
index 99522f78b162..797a639bcca5 100644
--- a/arch/x86/um/sys_call_table_64.c
+++ b/arch/x86/um/sys_call_table_64.c
@@ -1,11 +1,12 @@
 /*
- * System call table for UML/x86-64, copied from arch/x86_64/kernel/syscall.c
+ * System call table for UML/x86-64, copied from arch/x86/kernel/syscall_*.c
  * with some changes for UML.
  */
 
 #include <linux/linkage.h>
 #include <linux/sys.h>
 #include <linux/cache.h>
+#include <generated/user_constants.h>
 
 #define __NO_STUBS
 
@@ -34,31 +35,23 @@
 #define stub_sigaltstack sys_sigaltstack
 #define stub_rt_sigreturn sys_rt_sigreturn
 
-#define __SYSCALL(nr, sym) extern asmlinkage void sym(void) ;
-#undef _ASM_X86_UNISTD_64_H
-#include "../../x86/include/asm/unistd_64.h"
+#define __SYSCALL_64(nr, sym, compat) extern asmlinkage void sym(void) ;
+#include <asm/syscalls_64.h>
 
-#undef __SYSCALL
-#define __SYSCALL(nr, sym) [ nr ] = sym,
-#undef _ASM_X86_UNISTD_64_H
+#undef __SYSCALL_64
+#define __SYSCALL_64(nr, sym, compat) [ nr ] = sym,
 
 typedef void (*sys_call_ptr_t)(void);
 
 extern void sys_ni_syscall(void);
 
-/*
- * We used to have a trick here which made sure that holes in the
- * x86_64 table were filled in with sys_ni_syscall, but a comment in
- * unistd_64.h says that holes aren't allowed, so the trick was
- * removed.
- * The trick looked like this
- *	[0 ... UM_NR_syscall_max] = &sys_ni_syscall
- * before including unistd_64.h - the later initializations overwrote
- * the sys_ni_syscall filler.
- */
-
 sys_call_ptr_t sys_call_table[] __cacheline_aligned = {
-#include <asm/unistd_64.h>
+	/*
+	 * Smells like a compiler bug -- it doesn't work
+	 * when the & below is removed.
+	 */
+	[0 ... __NR_syscall_max] = &sys_ni_syscall,
+#include <asm/syscalls_64.h>
 };
 
 int syscall_table_size = sizeof(sys_call_table);