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Chris Metcalf 2c7387ef99 asm-generic/stat.h: support 64-bit file time_t for stat() 
The existing asm-generic/stat.h specifies st_mtime, etc., as a 32-value,
and works well for 32-bit architectures (currently microblaze, score,
and 32-bit tile).  However, for 64-bit architectures it isn't sufficient
to return 32 bits of time_t; this isn't good insurance against the 2037
rollover.  (It also makes glibc support less convenient, since we can't
use glibc's handy STAT_IS_KERNEL_STAT mode.)

This change extends the two "timespec" fields for each of the three atime,
mtime, and ctime fields from "int" to "long".  As a result, on 32-bit
platforms nothing changes, and 64-bit platforms will now work as expected.

The only wrinkle is 32-bit userspace under 64-bit kernels taking advantage
of COMPAT mode.  For these, we leave the "struct stat64" definitions with
the "int" versions of the time_t and nsec fields, so that architectures
can implement compat_sys_stat64() and friends with sys_stat64(), etc.,
and get the expected 32-bit structure layout.  This requires a
field-by-field copy in the kernel, implemented by the code guarded
under __ARCH_WANT_STAT64.

This does mean that the shape of the "struct stat" and "struct stat64"
structures is different on a 64-bit kernel, but only one of the two
structures should ever be used by any given process: "struct stat"
is meant for 64-bit userspace only, and "struct stat64" for 32-bit
userspace only.  (On a 32-bit kernel the two structures continue to have
the same shape, since "long" is 32 bits.)

The alternative is keeping the two structures the same shape on 64-bit
kernels, which means a 64-bit time_t in "struct stat64" for 32-bit
processes.  This is a little unnatural since 32-bit userspace can't
do anything with 64 bits of time_t information, since time_t is just
"long", not "int64_t"; and in any case 32-bit userspace might expect
to be running under a 32-bit kernel, which can't provide the high 32
bits anyway.  In the case of a 32-bit kernel we'd then be extending the
kernel's 32-bit time_t to 64 bits, then truncating it back to 32 bits
again in userspace, for no particular reason.  And, as mentioned above,
if we have 64-bit time_t for 32-bit processes we can't easily use glibc's
STAT_IS_KERNEL_STAT, since glibc's stat structure requires an embedded
"struct timespec", which is a pair of "long" (32-bit) values in a 32-bit
userspace.  "Inventive" solutions are possible, but are pretty hacky.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
 		2010-11-01 15:31:29 -04:00
..
bitops bitops: remove duplicated extern declarations 2010-10-09 21:51:45 +02:00
4level-fixup.h mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
Kbuild include: replace unifdef-y with header-y 2010-08-14 22:26:51 +02:00
Kbuild.asm include: replace unifdef-y with header-y 2010-08-14 22:26:51 +02:00
atomic-long.h asm-generic: merge branch 'master' of torvalds/linux-2.6 2009-06-12 11:32:58 +02:00
atomic.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic 2010-10-22 11:17:06 -07:00
atomic64.h lib: Provide generic atomic64_t implementation 2009-06-15 13:27:38 +10:00
audit_change_attr.h audit: make link()/linkat() match "attribute change" predicate 2010-10-30 08:45:43 -04:00
audit_dir_write.h [PATCH] fix missing ifdefs in syscall classes hookup for generic targets 2006-09-22 17:48:56 -07:00
audit_read.h [PATCH] audit: more syscall classes added 2006-09-11 13:32:27 -04:00
audit_signal.h [PATCH] add SIGNAL syscall class (v3) 2007-05-11 05:38:25 -04:00
audit_write.h [PATCH] asm/generic: fix bug - kernel fails to build when enable some common audit code on Blackfin 2008-12-09 02:27:39 -05:00
auxvec.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
bitops.h asm-generic: make bitops.h usable 2009-06-11 21:02:31 +02:00
bitsperlong.h asm-generic: introduce asm/bitsperlong.h 2009-06-11 21:02:14 +02:00
bug.h panic: Allow warnings to set different taint flags 2010-05-19 08:36:48 +01:00
bugs.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
cache.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
cacheflush.h block: add helpers to run flush_dcache_page() against a bio and a request's pages 2009-11-26 09:16:19 +01:00
checksum.h add generic lib/checksum.c 2009-06-11 21:02:51 +02:00
cmpxchg-local.h Fix IRQ flag handling naming 2010-10-07 14:08:55 +01:00
cmpxchg.h Add cmpxchg_local to asm-generic for per cpu atomic operations 2008-02-07 08:42:30 -08:00
cputime.h taskstats: use real microsecond granularity for CPU times 2010-10-27 18:03:17 -07:00
current.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
delay.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
device.h Driver Core: Add platform device arch data V3 2009-07-22 00:28:38 +02:00
div64.h rename div64_64 to div64_u64 2008-05-01 08:03:58 -07:00
dma-coherent.h generic: per-device coherent dma allocator 2008-06-30 12:51:05 +02:00
dma-mapping-broken.h dma-mapping: remove dma_is_consistent API 2010-08-11 08:59:21 -07:00
dma-mapping-common.h dma-mapping: remove unnecessary sync_single_range_* in dma_map_ops 2010-05-27 09:12:52 -07:00
dma.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
emergency-restart.h [PATCH] Add emergency_restart() 2005-07-26 14:35:41 -07:00
errno-base.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
errno.h cfg80211: add rfkill support 2009-06-03 14:06:14 -04:00
fb.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
fcntl.h asm-generic: fcntl: make exported headers use strict posix types 2010-10-09 21:51:43 +02:00
futex.h remove __KERNEL__ tests of unexported headers under asm-generic/ 2008-04-30 08:29:54 -07:00
getorder.h asm-generic: rename page.h and uaccess.h 2009-06-11 21:02:17 +02:00
gpio.h gpiolib: fix HAVE_GPIO_LIB leftovers in asm-generic/gpio.h 2010-10-27 18:03:06 -07:00
hardirq.h Fix IRQ flag handling naming 2010-10-07 14:08:55 +01:00
hw_irq.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
ide_iops.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
int-l64.h asm-generic: introduce asm/bitsperlong.h 2009-06-11 21:02:14 +02:00
int-ll64.h asm-generic: introduce asm/bitsperlong.h 2009-06-11 21:02:14 +02:00
io.h asm-generic/io.h: allow people to override individual funcs 2010-10-18 09:20:46 +02:00
ioctl.h Make ioctl.h compatible with userland 2008-08-12 16:07:31 -07:00
ioctls.h ioctl: Use asm-generic/ioctls.h on cris (enables termiox) 2010-10-22 10:19:59 -07:00
iomap.h generic: add ioremap_wc() interface wrapper 2008-04-24 23:40:47 +02:00
ipcbuf.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
irq.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
irq_regs.h IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 2006-10-05 15:10:12 +01:00
irqflags.h Fix IRQ flag handling naming 2010-10-07 14:08:55 +01:00
kdebug.h asm-generic: kdebug.h: Checkpatch cleanup 2010-10-09 21:51:44 +02:00
kmap_types.h include/asm-generic/kmap_types.h: add helpful reminder 2010-05-25 08:07:03 -07:00
libata-portmap.h libata-portmap: Remove unused definitions 2007-10-12 14:55:37 -04:00
linkage.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
local.h local_t: Remove cpu_local_xx macros 2010-01-05 15:34:49 +09:00
local64.h arch: Implement local64_t 2010-06-09 11:12:36 +02:00
memory_model.h tree-wide: fix assorted typos all over the place 2009-12-04 15:39:55 +01:00
mm_hooks.h [PATCH] x86: PARAVIRT: add hooks to intercept mm creation and destruction 2007-05-02 19:27:14 +02:00
mman-common.h HWPOISON: Add a madvise() injector for soft page offlining 2009-12-16 12:20:00 +01:00
mman.h mm: add MAP_HUGETLB for mmaping pseudo-anonymous huge page regions 2009-09-22 07:17:41 -07:00
mmu.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
mmu_context.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
module.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
msgbuf.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
mutex-dec.h mutex: speed up generic mutex implementations 2008-10-23 09:18:20 -07:00
mutex-null.h fix file specification in comments 2006-10-03 23:01:26 +02:00
mutex-xchg.h mutex: speed up generic mutex implementations 2008-10-23 09:18:20 -07:00
mutex.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
page.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
param.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
parport.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
pci-dma-compat.h dma-mapping: pci: move pci_set_dma_mask and pci_set_consistent_dma_mask to pci-dma-compat.h 2010-03-12 15:52:42 -08:00
pci.h PCI: remove pcibios_scan_all_fns() 2009-09-09 13:29:18 -07:00
percpu.h percpu: Optimize __get_cpu_var() 2010-09-10 10:56:51 +02:00
pgalloc.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
pgtable-nopmd.h mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
pgtable-nopud.h mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
pgtable.h [S390] add support for nonquiescing sske 2010-10-25 16:10:15 +02:00
poll.h Consolidate asm/poll.h 2007-05-11 08:29:34 -07:00
posix_types.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
resource.h sched: SCHED_FIFO/SCHED_RR watchdog timer 2008-01-25 21:08:27 +01:00
rtc.h asm-generic: make get_rtc_time overridable 2009-06-11 21:02:18 +02:00
scatterlist.h asm-generic: remove ARCH_HAS_SG_CHAIN in scatterlist.h 2010-05-27 09:12:54 -07:00
sections.h asm/sections: add text/data checking functions for arches to override 2009-09-23 07:39:30 -07:00
segment.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
sembuf.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
serial.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
setup.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
shmbuf.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
shmparam.h asm-generic: add generic sysv ipc headers 2009-06-11 21:02:15 +02:00
siginfo.h HWPOISON: Add new SIGBUS error codes for hardware poison signals 2009-09-16 11:50:06 +02:00
signal-defs.h asm-generic: rename termios.h, signal.h and mman.h 2009-06-11 21:01:52 +02:00
signal.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
socket.h net: Generalize socket rx gap / receive queue overflow cmsg 2009-10-12 13:26:31 -07:00
sockios.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
spinlock.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
stat.h asm-generic/stat.h: support 64-bit file time_t for stat() 2010-11-01 15:31:29 -04:00
statfs.h add f_flags to struct statfs(64) 2010-08-09 16:48:44 -04:00
string.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
swab.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
syscall.h asm-generic: syscall_get_nr returns int 2009-09-22 19:56:50 -07:00
syscalls.h Fix the declaration of sys_execve() in asm-generic/syscalls.h 2010-08-18 12:12:38 -07:00
system.h asm-generic: cmpxchg does not handle non-long arguments 2010-10-09 21:51:27 +02:00
termbits.h tty: Add EXTPROC support for LINEMODE 2010-08-10 13:47:39 -07:00
termios-base.h asm-generic: rename termios.h, signal.h and mman.h 2009-06-11 21:01:52 +02:00
termios.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
timex.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
tlb.h mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
tlbflush.h asm-generic: add generic NOMMU versions of some headers 2009-06-11 21:02:50 +02:00
topology.h topology: alternate fix for ia64 tiger_defconfig build breakage 2010-08-09 20:44:57 -07:00
types.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
uaccess-unaligned.h asm-generic: rename page.h and uaccess.h 2009-06-11 21:02:17 +02:00
uaccess.h asm-generic: uaccess: fix up local access_ok() usage 2009-06-19 14:58:08 +02:00
ucontext.h asm-generic: add generic ABI headers 2009-06-11 21:02:15 +02:00
unaligned.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
unistd.h Add fanotify syscalls to <asm-generic/unistd.h>. 2010-08-13 08:08:37 -04:00
user.h asm-generic: add generic versions of common headers 2009-06-11 21:02:37 +02:00
vga.h asm-generic: add legacy I/O header files 2009-06-11 21:02:42 +02:00
vmlinux.lds.h Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 15:13:55 -07:00
xor.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00