[PATCH 1/3] mips: Add __NR_syscalls macro in uapi/asm/unistd.h

From: Firoz Khan
Date: Fri Sep 14 2018 - 04:39:15 EST


NR_syscalls macro holds the number of system call exist in MIPS
architecture. This macro is currently not a part of uapi/asm/unistd.h
file. The purpose of this macro is We have to change the value of
NR_syscalls, 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 number of system call information. So we have two option to update
NR_syscalls value.

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

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

The 2nd option will be the recommended one. While __NR_syscalls
isn't strictly part of the uapi, having it as part of the generated
header to simplifies the implementation.

Signed-off-by: Firoz Khan <firoz.khan@xxxxxxxxxx>
---
arch/mips/include/uapi/asm/unistd.h | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/arch/mips/include/uapi/asm/unistd.h b/arch/mips/include/uapi/asm/unistd.h
index f25dd1d..f8bab34 100644
--- a/arch/mips/include/uapi/asm/unistd.h
+++ b/arch/mips/include/uapi/asm/unistd.h
@@ -390,17 +390,17 @@
#define __NR_statx (__NR_Linux + 366)
#define __NR_rseq (__NR_Linux + 367)
#define __NR_io_pgetevents (__NR_Linux + 368)
-
+#define __NR_syscalls 368

/*
* Offset of the last Linux o32 flavoured syscall
*/
-#define __NR_Linux_syscalls 368
+#define __NR_Linux_syscalls __NR_syscalls

#endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */

#define __NR_O32_Linux 4000
-#define __NR_O32_Linux_syscalls 368
+#define __NR_O32_Linux_syscalls __NR_syscalls

#if _MIPS_SIM == _MIPS_SIM_ABI64

@@ -737,16 +737,17 @@
#define __NR_statx (__NR_Linux + 326)
#define __NR_rseq (__NR_Linux + 327)
#define __NR_io_pgetevents (__NR_Linux + 328)
+#define __NR_syscalls 328

/*
* Offset of the last Linux 64-bit flavoured syscall
*/
-#define __NR_Linux_syscalls 328
+#define __NR_Linux_syscalls __NR_syscalls

#endif /* _MIPS_SIM == _MIPS_SIM_ABI64 */

#define __NR_64_Linux 5000
-#define __NR_64_Linux_syscalls 328
+#define __NR_64_Linux_syscalls __NR_syscalls

#if _MIPS_SIM == _MIPS_SIM_NABI32

@@ -1087,15 +1088,16 @@
#define __NR_statx (__NR_Linux + 330)
#define __NR_rseq (__NR_Linux + 331)
#define __NR_io_pgetevents (__NR_Linux + 332)
+#define __NR_syscalls 332

/*
* Offset of the last N32 flavoured syscall
*/
-#define __NR_Linux_syscalls 332
+#define __NR_Linux_syscalls __NR_syscalls

#endif /* _MIPS_SIM == _MIPS_SIM_NABI32 */

#define __NR_N32_Linux 6000
-#define __NR_N32_Linux_syscalls 332
+#define __NR_N32_Linux_syscalls __NR_syscalls

#endif /* _UAPI_ASM_UNISTD_H */
--
1.9.1