[PATCH v1 2/4] xtensa: add __NR_syscalls along with __NR_syscall_count

From: Firoz Khan
Date: Thu Nov 01 2018 - 09:57:04 EST


__NR_syscall_count macro holds the number of system call
exist in xtensa architecture. We have to change the value
of __NR_syscall_count, if we add or delete a system call.

One of the patch in this patch series has a script which
will generate a uapi header based on syscall.tbl file.
The syscall.tbl file contains the total number of system
calls information. So we have two option to update __NR-
_syscall_count value.

1. Update __NR_syscall_count in asm/unistd.h manually by
counting the no.of system calls. No need to update __NR-
_syscall_count until we either add a new system call or
delete existing system call.

2. We can keep this feature it above mentioned script,
that will count the number of syscalls and keep it in
a generated file. In this case we don't need to expli-
citly update __NR_syscall_count in asm/unistd.h file.

The 2nd option will be the recommended one. For that, I
added the __NR_syscalls macro in uapi/asm/unistd.h along
with __NR_syscall_count asm/unistd.h. The macro __NR_sys-
calls also added for making the name convention same across
all architecture. While __NR_syscalls isn't strictly part
of the uapi, having it as part of the generated header to
simplifies the implementation. We also need to enclose
this macro with #ifdef __KERNEL__ to avoid side effects.

Signed-off-by: Firoz Khan <firoz.khan@xxxxxxxxxx>
---
arch/xtensa/include/asm/unistd.h | 2 ++
arch/xtensa/include/uapi/asm/unistd.h | 4 +++-
2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/xtensa/include/asm/unistd.h b/arch/xtensa/include/asm/unistd.h
index c73eca83..b844081 100644
--- a/arch/xtensa/include/asm/unistd.h
+++ b/arch/xtensa/include/asm/unistd.h
@@ -5,6 +5,8 @@
#define __ARCH_WANT_SYS_CLONE
#include <uapi/asm/unistd.h>

+#define __NR_syscall_count __NR_syscalls
+
#define __ARCH_WANT_STAT64
#define __ARCH_WANT_SYS_UTIME
#define __ARCH_WANT_SYS_LLSEEK
diff --git a/arch/xtensa/include/uapi/asm/unistd.h b/arch/xtensa/include/uapi/asm/unistd.h
index c8ac79a..fa26aa2 100644
--- a/arch/xtensa/include/uapi/asm/unistd.h
+++ b/arch/xtensa/include/uapi/asm/unistd.h
@@ -778,7 +778,9 @@
#define __NR_statx 351
__SYSCALL(351, sys_statx, 5)

-#define __NR_syscall_count 352
+#ifdef __KERNEL__
+#define __NR_syscalls 352
+#endif

#undef __SYSCALL

--
1.9.1