x86/syscalls: Use __NR_syscalls instead of __NR_syscall_max

__NR_syscall_max is only used by x86 and UML. In contrast, __NR_syscalls is
widely used by all the architectures.

Convert __NR_syscall_max to __NR_syscalls and adjust the usage sites.

This prepares x86 to switch to the generic syscallhdr.sh script.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210517073815.97426-6-masahiroy@kernel.org

Author: masahir0y

arch/um/kernel/skas/syscall.c

@@ -41,7 +41,7 @@ void handle_syscall(struct uml_pt_regs *r)
 		goto out;
 
 	syscall = UPT_SYSCALL_NR(r);
-	if (syscall >= 0 && syscall <= __NR_syscall_max)
+	if (syscall >= 0 && syscall < __NR_syscalls)
 		PT_REGS_SET_SYSCALL_RETURN(regs,
 				EXECUTE_SYSCALL(syscall, regs));
 

arch/x86/entry/syscalls/syscallhdr.sh

@@ -28,7 +28,7 @@ grep -E "^[0-9A-Fa-fXx]+[[:space:]]+${my_abis}" "$in" | sort -n | (
 
     echo ""
     echo "#ifdef __KERNEL__"
-    echo "#define __NR_${prefix}syscall_max $max"
+    echo "#define __NR_${prefix}syscalls $(($max + 1))"
     echo "#endif"
     echo ""
     echo "#endif /* ${fileguard} */"

arch/x86/include/asm/unistd.h

@@ -13,7 +13,7 @@
 #  define __ARCH_WANT_SYS_OLD_MMAP
 #  define __ARCH_WANT_SYS_OLD_SELECT
 
-#  define __NR_ia32_syscall_max __NR_syscall_max
+#  define IA32_NR_syscalls (__NR_syscalls)
 
 # else
 
@@ -26,12 +26,12 @@
 #  define __ARCH_WANT_COMPAT_SYS_PWRITEV64
 #  define __ARCH_WANT_COMPAT_SYS_PREADV64V2
 #  define __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
-#  define X32_NR_syscalls (__NR_x32_syscall_max + 1)
+#  define X32_NR_syscalls (__NR_x32_syscalls)
+#  define IA32_NR_syscalls (__NR_ia32_syscalls)
 
 # endif
 
-# define NR_syscalls (__NR_syscall_max + 1)
-# define IA32_NR_syscalls (__NR_ia32_syscall_max + 1)
+# define NR_syscalls (__NR_syscalls)
 
 # define __ARCH_WANT_NEW_STAT
 # define __ARCH_WANT_OLD_READDIR