On 9.8.2018 07:27, Firoz Khan wrote: > __NR_syscalls macro holds the number of system call exist in this > architecture. This macro is currently the part of asm/unistd.h file. > We have 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 asm/unistd.h manually by counting the > no.of system calls. No need to update __NR_syscalls untill > 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. For that, I moved the > NR_syscalls macro from asm/unistd.h to uapi/asm/unistd.h. The macro > name also changed form NR_syscalls to __NR_syscalls 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. This macro was in unistd.h in past but it was moved out because it was causing problem with strace. commit 40c2702a02b755e0183b702778331b351f3be20c Author: Michal Simek <michal.simek@xxxxxxxxxx> AuthorDate: Mon Jul 8 09:50:24 2013 +0200 Commit: Michal Simek <michal.simek@xxxxxxxxxx> CommitDate: Wed Jul 10 07:32:09 2013 +0200 microblaze: Move __NR_syscalls from uapi That's why I don't think this is the right thing to do. I have grepped strace and glibc and none is using this macro that's why I think it shouldn't be exported via uapi. Thanks, Michal