Strange location of kernel-features.h

[Peter Kjellerstedt]

Can anyone explain to me why kernel-features.h is placed in
libpthread/linuxthreads/sysdeps/pthread? As far as I can tell
there is nothing pthread related in that file.

This placement will prevent the changes made below by Carmelo in
libc/sysdeps/linux/common/getdents.c from taking effect for no
apparent reason at all if one uses libpthread/linuxthreads.old.
Moreover, if __ASSUME_GETDENTS32_D_TYPE actually happens to be
defined while compiling getdents.c when using
libpthread/linuxthreads I would say that is more of an accident
than anything else since there are no indications in the list of
included files that one is expecting kernel-features.h to be
included...

//Peter

> -----Original Message-----
> From: uclibc-cvs-bounces at uclibc.org [mailto:uclibc-cvs-
> bounces at uclibc.org] On Behalf Of carmelo at uclibc.org
> Sent: den 9 september 2008 14:02
> To: uclibc-cvs at uclibc.org
> Subject: svn commit: trunk/uClibc: libc/sysdeps/linux/common libpthread/lin etc...
>
> Author: carmelo
> Date: 2008-09-09 05:01:37 -0700 (Tue, 09 Sep 2008)
> New Revision: 23363
>
> Log:
> Use getdents syscall if kernel provide supports for this
> instead of relying upon getdents64.
>
> Signed-off-by: Filippo Arcidiacono <filippo.arcidiacono at st.com>
> Signed-off-by: Carmelo Amoroso <carmelo.amoroso at st.com>
>
>
> Modified:
>    trunk/uClibc/libc/sysdeps/linux/common/getdents.c
>    trunk/uClibc/libpthread/linuxthreads/sysdeps/pthread/kernel-features.h
>
>
> Changeset:
> Modified: trunk/uClibc/libc/sysdeps/linux/common/getdents.c
> ===================================================================
> --- trunk/uClibc/libc/sysdeps/linux/common/getdents.c   2008-09-09
> 08:50:18 UTC (rev 23362)
> +++ trunk/uClibc/libc/sysdeps/linux/common/getdents.c   2008-09-09
> 12:01:37 UTC (rev 23363)
> @@ -18,8 +18,7 @@
>  #include <bits/kernel_types.h>
>
>  /* With newer versions of linux, the getdents syscall returns d_type
> - * information after the name field.  Someday, we should add support for
> - * that instead of always calling getdents64 ...
> + * information after the name field.
>   *
>   * See __ASSUME_GETDENTS32_D_TYPE in glibc's kernel-features.h for specific
>   * version / arch details.
> @@ -39,14 +38,42 @@
>
>  ssize_t __getdents (int fd, char *buf, size_t nbytes) attribute_hidden;
>
> -#if ! defined __UCLIBC_HAS_LFS__ || ! defined __NR_getdents64
> +#define __NR___syscall_getdents __NR_getdents
> +static inline _syscall3(int, __syscall_getdents, int, fd, unsigned char *, kdirp, size_t, count);
>
> +#ifdef __ASSUME_GETDENTS32_D_TYPE
> +ssize_t __getdents (int fd, char *buf, size_t nbytes)
> +{
> +       ssize_t retval;
> +
> +       retval = __syscall_getdents(fd, (unsigned char *)buf, nbytes);
> +
> +       /* The kernel added the d_type value after the name.  Change
> +       this now.  */
> +       if (retval != -1) {
> +               union {
> +                       struct kernel_dirent k;
> +                       struct dirent u;
> +               } *kbuf = (void *) buf;
> +
> +               while ((char *) kbuf < buf + retval) {
> +                       char d_type = *((char *) kbuf + kbuf->k.d_reclen - 1);
> +                       memmove (kbuf->u.d_name, kbuf->k.d_name,
> +                       strlen (kbuf->k.d_name) + 1);
> +                       kbuf->u.d_type = d_type;
> +
> +                       kbuf = (void *) ((char *) kbuf + kbuf->k.d_reclen);
> +               }
> +       }
> +
> +       return retval;
> +}
> +
> +#elif ! defined __UCLIBC_HAS_LFS__ || ! defined __NR_getdents64
> +
>  /* Experimentally off - libc_hidden_proto(memcpy) */
>  libc_hidden_proto(lseek)
>
> -#define __NR___syscall_getdents __NR_getdents
> -static __inline__ _syscall3(int, __syscall_getdents, int, fd, unsigned char *, kdirp, size_t, count);
> -
>  ssize_t __getdents (int fd, char *buf, size_t nbytes)
>  {
>      struct dirent *dp;
>
> Modified: trunk/uClibc/libpthread/linuxthreads/sysdeps/pthread/kernel-
> features.h
> ===================================================================
> --- trunk/uClibc/libpthread/linuxthreads/sysdeps/pthread/kernel-features.h      2008-09-09 08:50:18 UTC (rev 23362)
> +++ trunk/uClibc/libpthread/linuxthreads/sysdeps/pthread/kernel-features.h      2008-09-09 12:01:37 UTC (rev 23363)
> @@ -62,6 +62,14 @@
>  # define __ASSUME_VFORK_SYSCALL                1
>  #endif
>
> +/* Starting with version 2.6.4-rc1 the getdents syscall returns d_type
> + *    information as well and in between 2.6.5 and 2.6.8 most compat wrappers
> + *       were fixed too.  Except s390{,x} which was fixed in 2.6.11.
> */
> +#if (__LINUX_KERNEL_VERSION >= 0x020608 && !defined __s390__) \
> +    || (__LINUX_KERNEL_VERSION >= 0x02060b && defined __s390__)
> +# define __ASSUME_GETDENTS32_D_TYPE 1
> +#endif
> +
>  /* These features were surely available with 2.4.12.  */
>  #if __LINUX_KERNEL_VERSION >= 132108 && defined __mc68000__
>  # define __ASSUME_MMAP2_SYSCALL                1
>
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