Re: [GIT PULL -tip] fix 41 'make headers_check' warnings

From: Ingo Molnar
Date: Sun Jan 18 2009 - 06:02:52 EST



* Jaswinder Singh Rajput <jaswinder@xxxxxxxxxx> wrote:

> diff --git a/include/linux/acct.h b/include/linux/acct.h
> index 882dc72..a20c97c 100644
> --- a/include/linux/acct.h
> +++ b/include/linux/acct.h
> @@ -59,9 +59,13 @@ struct acct
> comp_t ac_majflt; /* Major Pagefaults */
> comp_t ac_swaps; /* Number of Swaps */
> /* m68k had no padding here. */
> -#if !defined(CONFIG_M68K) || !defined(__KERNEL__)
> +#ifdef __KERNEL__
> +#ifndef CONFIG_M68K
> __u16 ac_ahz; /* AHZ */
> -#endif
> +#endif /* CONFIG_M68K */
> +#else /* __KERNEL__ */
> + __u16 ac_ahz; /* AHZ */
> +#endif /* __KERNEL__ */

that looks rather ugly.

Why not just flip it around to:

#if !defined(__KERNEL__) || !defined(CONFIG_M68K)

? Does headers_check misinterpret that?

> * To make everything easier to port and manage cross platform
> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> index 343df9e..1202063 100644
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -528,6 +528,7 @@ struct sysinfo {
> /* Trap pasters of __FUNCTION__ at compile-time */
> #define __FUNCTION__ (__func__)
>
> +#ifdef __KERNEL__
> /* This helps us to avoid #ifdef CONFIG_NUMA */
> #ifdef CONFIG_NUMA
> #define NUMA_BUILD 1
> @@ -540,4 +541,8 @@ struct sysinfo {
> # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
> #endif
>
> +#else /* __KERNEL__ */
> +#define NUMA_BUILD 0
> +#endif /* __KERNEL__ */

Does NUMA_BUILD make any sense to user-space at all? Shouldnt we leave it
undefined?

> --- a/include/linux/pktcdvd.h
> +++ b/include/linux/pktcdvd.h
> @@ -33,11 +33,15 @@
> * able to sucessfully recover with this option (drive will return good
> * status as soon as the cdb is validated).
> */
> +#ifdef __KERNEL__
> #if defined(CONFIG_CDROM_PKTCDVD_WCACHE)
> #define USE_WCACHING 1
> #else
> #define USE_WCACHING 0
> #endif
> +#else /* __KERNEL__ */
> +#define USE_WCACHING 0
> +#endif /* __KERNEL__ */

does USE_WCACHING make any sense to user-space? Shouldnt we leave it
undefined?

> diff --git a/include/linux/raw.h b/include/linux/raw.h
> index 62d543e..3898e30 100644
> --- a/include/linux/raw.h
> +++ b/include/linux/raw.h
> @@ -13,6 +13,10 @@ struct raw_config_request
> __u64 block_minor;
> };
>
> +#ifdef __KERNEL__
> #define MAX_RAW_MINORS CONFIG_MAX_RAW_DEVS
> +#else /* __KERNEL__ */
> +#define MAX_RAW_MINORS 0
> +#endif /* __KERNEL__ */

ditto.

> #endif /* __LINUX_RAW_H */
> diff --git a/include/linux/socket.h b/include/linux/socket.h
> index f5771a2..d7daa52 100644
> --- a/include/linux/socket.h
> +++ b/include/linux/socket.h
> @@ -256,11 +256,15 @@ struct ucred {
> #define MSG_CMSG_CLOEXEC 0x40000000 /* Set close_on_exit for file
> descriptor received through
> SCM_RIGHTS */
> +#ifdef __KERNEL__
> #if defined(CONFIG_COMPAT)
> #define MSG_CMSG_COMPAT 0x80000000 /* This message needs 32 bit fixups */
> #else
> #define MSG_CMSG_COMPAT 0 /* We never have 32 bit fixups */
> #endif
> +#else /* __KERNEL__ */
> +#define MSG_CMSG_COMPAT 0 /* We never have 32 bit fixups */
> +#endif /* __KERNEL__ */

I suspect this flag should always be defined for user-space - the zero
value only makes sense in the kernel.

> --- a/include/linux/types.h
> +++ b/include/linux/types.h
> @@ -138,6 +138,7 @@ typedef __s64 int64_t;
> *
> * blkcnt_t is the type of the inode's block count.
> */
> +#ifdef __KERNEL__
> #ifdef CONFIG_LBD
> typedef u64 sector_t;
> typedef u64 blkcnt_t;
> @@ -145,6 +146,10 @@ typedef u64 blkcnt_t;
> typedef unsigned long sector_t;
> typedef unsigned long blkcnt_t;
> #endif
> +#else /* __KERNEL__ */
> +typedef unsigned long sector_t;
> +typedef unsigned long blkcnt_t;
> +#endif /* __KERNEL__ */

heh. types.h itself is not headers_check clean.

But this isnt particularly clean: we have now 3 blocks of typedefs while
there are just 2 variants. It would be cleaner to do something like:

#if !defined(__KERNEL__) || defined(CONFIG_LBD)

i.e. always provide the wider type to user-space.

ngo
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