diff options
Diffstat (limited to 'libc/sysdeps/linux/common')
| -rw-r--r-- | libc/sysdeps/linux/common/xstatconv.c | 72 |
1 files changed, 69 insertions, 3 deletions
diff --git a/libc/sysdeps/linux/common/xstatconv.c b/libc/sysdeps/linux/common/xstatconv.c index 60ec25bd5..325b70550 100644 --- a/libc/sysdeps/linux/common/xstatconv.c +++ b/libc/sysdeps/linux/common/xstatconv.c @@ -55,26 +55,92 @@ void __xstat_conv(struct kernel_stat *kbuf, struct stat *buf) #endif } - #if defined(__UCLIBC_HAS_LFS__) +#if defined(__UCLIBC_HAS_LFS__) + +/* OK, this is ugly, but not much we can do about it. + * + * The issue at hand is that the kernel introduced an ABI change between + * 2.4 and 2.6 for big endian machines on some architectures in stat64 with + * st_dev and st_rdev fields. Older kernels used 'short' but newer kernels + * use a 'long'. As if that wasn't fun enough, the location of st_blocks and + * its padding have swapped. So, when applicable, we need to detect and shift + * bits around and hope for the best. The kernel at least helps us out a bit + * because it will be sure to zero out all padding fields. + * + * Unimportant Note About Mis-detections: + * - if user is running a 2.4 system with the old ABI and they stat a file on + * a system which major 0 / minor 0. We can ignore this though because the + * kernel has major 0 reserved for non mountable devices (wh00t!) + * - if user is running a 2.6 system with the new ABI and they stat a file on + * a device whose st_dev fills up the lower 6 bytes into the upper 2 bytes + * which overlap. Again we should be able to safely ignore this because + * that means it'd be a pretty big ass (read: uncommon) major/minor combo :). + + Old [2.4]: +struct stat64 { + unsigned short st_dev; + unsigned char __pad0[10]; + ... + unsigned long st_blocks; + unsigned long __pad4; + ... + New [2.6]: +struct stat64 { + unsigned long long st_dev; + unsigned char __pad0[4]; + ... + unsigned long __pad4; + unsigned long st_blocks; + ... + + * sizeof(unsigned short) = 2 + * sizeof(unsigned long long) = 8 + */ +#include <endian.h> +#include <sys/utsname.h> +#if BYTE_ORDER == BIG_ENDIAN && \ + (defined(__ARMEB__)) /* || defined(__sh__) || defined(__sparc__))*/ +# define NEED_ABI_CHECK 1 +#else +# define NEED_ABI_CHECK 0 +#endif + void __xstat64_conv(struct kernel_stat64 *kbuf, struct stat64 *buf) { /* Convert to current kernel version of `struct stat64'. */ + +#if NEED_ABI_CHECK + if (!kbuf->st_dev.old_abi) { + /* new 2.6 ABI */ + buf->st_dev = kbuf->st_dev.new_abi; + buf->st_rdev = kbuf->st_rdev.new_abi; + buf->st_blocks = kbuf->st_blocks; + } else { + /* old 2.4 ABI */ + buf->st_dev = kbuf->st_dev.old_abi; + buf->st_rdev = kbuf->st_dev.old_abi; + buf->st_blocks = kbuf->__pad_st_blocks; + } +#else buf->st_dev = kbuf->st_dev; buf->st_ino = kbuf->st_ino; + buf->st_rdev = kbuf->st_rdev; +#endif + #ifdef _HAVE_STAT64___ST_INO buf->__st_ino = kbuf->__st_ino; #endif + buf->st_mode = kbuf->st_mode; buf->st_nlink = kbuf->st_nlink; buf->st_uid = kbuf->st_uid; buf->st_gid = kbuf->st_gid; - buf->st_rdev = kbuf->st_rdev; buf->st_size = kbuf->st_size; buf->st_blksize = kbuf->st_blksize; - buf->st_blocks = kbuf->st_blocks; buf->st_atime = kbuf->st_atime; buf->st_mtime = kbuf->st_mtime; buf->st_ctime = kbuf->st_ctime; + #ifdef STAT_HAVE_NSEC buf->st_atime_nsec = kbuf->st_atime_nsec; buf->st_mtime_nsec = kbuf->st_mtime_nsec; |