| Message ID | 1542262461-29024-2-git-send-email-firoz.khan@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | mips: system call table generation support | expand |
On Thu, Nov 15, 2018 at 7:14 AM Firoz Khan <firoz.khan@linaro.org> wrote: > > The 2nd option will be the recommended one. For that, I > added the __NR_syscalls macro in uapi/asm/unistd.h along > with __NR_Linux_syscalls. The macro __NR_syscalls 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. I fear this doesn't work the way you hoped: > --- a/arch/mips/include/uapi/asm/unistd.h > +++ b/arch/mips/include/uapi/asm/unistd.h > @@ -391,16 +391,19 @@ > #define __NR_rseq (__NR_Linux + 367) > #define __NR_io_pgetevents (__NR_Linux + 368) > > +#ifdef __KERNEL__ > +#define __NR_syscalls 368 > +#endif We now have three different definitions of __NR_syscalls, one for each ABI. User space previously saw the correct one (now it doesn't see any, but that's ok). > /* > * Offset of the last Linux o32 flavoured syscall > */ > -#define __NR_Linux_syscalls 368 > +#define __NR_Linux_syscalls __NR_syscalls so this part part again is ok. > #endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */ > > #define __NR_O32_Linux 4000 > -#define __NR_O32_Linux_syscalls 368 > +#define __NR_O32_Linux_syscalls __NR_syscalls but this part is not: Now __NR_O32_Linux_syscalls is defined to __NR_syscalls, which may be one of the three values. Any usage of __NR_O32_Linux_syscalls in a 64-bit kernel is then clearly wrong. > #endif /* _MIPS_SIM == _MIPS_SIM_NABI32 */ > > #define __NR_N32_Linux 6000 > -#define __NR_N32_Linux_syscalls 332 > +#define __NR_N32_Linux_syscalls __NR_syscalls Same for this one. Arnd
Hi Arnd, On Mon, 19 Nov 2018 at 21:22, Arnd Bergmann <arnd@arndb.de> wrote: > > On Thu, Nov 15, 2018 at 7:14 AM Firoz Khan <firoz.khan@linaro.org> wrote: > > > > The 2nd option will be the recommended one. For that, I > > added the __NR_syscalls macro in uapi/asm/unistd.h along > > with __NR_Linux_syscalls. The macro __NR_syscalls 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. > > I fear this doesn't work the way you hoped: > > > --- a/arch/mips/include/uapi/asm/unistd.h > > +++ b/arch/mips/include/uapi/asm/unistd.h > > @@ -391,16 +391,19 @@ > > #define __NR_rseq (__NR_Linux + 367) > > #define __NR_io_pgetevents (__NR_Linux + 368) > > > > +#ifdef __KERNEL__ > > +#define __NR_syscalls 368 > > +#endif > > We now have three different definitions of __NR_syscalls, > one for each ABI. User space previously saw the correct > one (now it doesn't see any, but that's ok). > > > /* > > * Offset of the last Linux o32 flavoured syscall > > */ > > -#define __NR_Linux_syscalls 368 > > +#define __NR_Linux_syscalls __NR_syscalls > > so this part part again is ok. > > > #endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */ > > > > #define __NR_O32_Linux 4000 > > -#define __NR_O32_Linux_syscalls 368 > > +#define __NR_O32_Linux_syscalls __NR_syscalls > > but this part is not: Now __NR_O32_Linux_syscalls is defined > to __NR_syscalls, which may be one of the three values. > Any usage of __NR_O32_Linux_syscalls in a 64-bit kernel > is then clearly wrong. > > > #endif /* _MIPS_SIM == _MIPS_SIM_NABI32 */ > > > > #define __NR_N32_Linux 6000 > > -#define __NR_N32_Linux_syscalls 332 > > +#define __NR_N32_Linux_syscalls __NR_syscalls > > Same for this one. Thanks for the feedback. Will address all the comments. Firoz > > Arnd
diff --git a/arch/mips/include/uapi/asm/unistd.h b/arch/mips/include/uapi/asm/unistd.h index f25dd1d..0ccf954 100644 --- a/arch/mips/include/uapi/asm/unistd.h +++ b/arch/mips/include/uapi/asm/unistd.h @@ -391,16 +391,19 @@ #define __NR_rseq (__NR_Linux + 367) #define __NR_io_pgetevents (__NR_Linux + 368) +#ifdef __KERNEL__ +#define __NR_syscalls 368 +#endif /* * 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 @@ -738,15 +741,19 @@ #define __NR_rseq (__NR_Linux + 327) #define __NR_io_pgetevents (__NR_Linux + 328) +#ifdef __KERNEL__ +#define __NR_syscalls 328 +#endif + /* * 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 @@ -1088,14 +1095,18 @@ #define __NR_rseq (__NR_Linux + 331) #define __NR_io_pgetevents (__NR_Linux + 332) +#ifdef __KERNEL__ +#define __NR_syscalls 332 +#endif + /* * 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 */
__NR_Linux_syscalls macro holds the number of system call exist in mips architecture. We have to change the value of __NR_Linux_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 total number of system calls information. So we have two option to update __NR- _Linux_syscalls value. 1. Update __NR_Linux_syscalls in asm/unistd.h manually by counting the no.of system calls. No need to update __NR_Linux_syscalls 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_Linux_syscalls 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_Linux_syscalls. The macro __NR_syscalls 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@linaro.org> --- arch/mips/include/uapi/asm/unistd.h | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) -- 1.9.1