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author | Arnd Bergmann <arnd@arndb.de> | 2015-05-05 23:13:15 +0200 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2018-04-20 15:57:50 +0200 |
commit | f991f01571281b82e5e6ca74445f5d3f42d72212 (patch) | |
tree | 8fac76e5a5d6fdc776fb8b6c4eb8a74b49118a26 /include/uapi/asm-generic/shmbuf.h | |
parent | time: Change nanosleep to safe __kernel_* types (diff) | |
download | linux-f991f01571281b82e5e6ca74445f5d3f42d72212.tar.xz linux-f991f01571281b82e5e6ca74445f5d3f42d72212.zip |
y2038: asm-generic: Extend sysvipc data structures
Most architectures now use the asm-generic copy of the sysvipc data
structures (msqid64_ds, semid64_ds, shmid64_ds), which use 32-bit
__kernel_time_t on 32-bit architectures but have padding behind them to
allow extending the type to 64-bit.
Unfortunately, that fails on all big-endian architectures, which have the
padding on the wrong side. As so many of them get it wrong, we decided to
not bother even trying to fix it up when we introduced the asm-generic
copy. Instead we always use the padding word now to provide the upper
32 bits of the seconds value, regardless of the endianess.
A libc implementation on a typical big-endian system can deal with
this by providing its own copy of the structure definition to user
space, and swapping the two 32-bit words before returning from the
semctl/shmctl/msgctl system calls.
Note that msqid64_ds and shmid64_ds were broken on x32 since commit
f4b4aae18288 ("x86/headers/uapi: Fix __BITS_PER_LONG value for x32
builds"). I have sent a separate fix for that, but as we no longer
have to worry about x32 here, I no longer worry about x32 here and
use 'unsigned long' instead of __kernel_ulong_t.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to '')
-rw-r--r-- | include/uapi/asm-generic/shmbuf.h | 41 |
1 files changed, 20 insertions, 21 deletions
diff --git a/include/uapi/asm-generic/shmbuf.h b/include/uapi/asm-generic/shmbuf.h index 2b6c3bb97f97..e504422fc501 100644 --- a/include/uapi/asm-generic/shmbuf.h +++ b/include/uapi/asm-generic/shmbuf.h @@ -19,42 +19,41 @@ * * * Pad space is left for: - * - 64-bit time_t to solve y2038 problem * - 2 miscellaneous 32-bit values */ struct shmid64_ds { struct ipc64_perm shm_perm; /* operation perms */ size_t shm_segsz; /* size of segment (bytes) */ +#if __BITS_PER_LONG == 64 __kernel_time_t shm_atime; /* last attach time */ -#if __BITS_PER_LONG != 64 - unsigned long __unused1; -#endif __kernel_time_t shm_dtime; /* last detach time */ -#if __BITS_PER_LONG != 64 - unsigned long __unused2; -#endif __kernel_time_t shm_ctime; /* last change time */ -#if __BITS_PER_LONG != 64 - unsigned long __unused3; +#else + unsigned long shm_atime; /* last attach time */ + unsigned long shm_atime_high; + unsigned long shm_dtime; /* last detach time */ + unsigned long shm_dtime_high; + unsigned long shm_ctime; /* last change time */ + unsigned long shm_ctime_high; #endif __kernel_pid_t shm_cpid; /* pid of creator */ __kernel_pid_t shm_lpid; /* pid of last operator */ - __kernel_ulong_t shm_nattch; /* no. of current attaches */ - __kernel_ulong_t __unused4; - __kernel_ulong_t __unused5; + unsigned long shm_nattch; /* no. of current attaches */ + unsigned long __unused4; + unsigned long __unused5; }; struct shminfo64 { - __kernel_ulong_t shmmax; - __kernel_ulong_t shmmin; - __kernel_ulong_t shmmni; - __kernel_ulong_t shmseg; - __kernel_ulong_t shmall; - __kernel_ulong_t __unused1; - __kernel_ulong_t __unused2; - __kernel_ulong_t __unused3; - __kernel_ulong_t __unused4; + unsigned long shmmax; + unsigned long shmmin; + unsigned long shmmni; + unsigned long shmseg; + unsigned long shmall; + unsigned long __unused1; + unsigned long __unused2; + unsigned long __unused3; + unsigned long __unused4; }; #endif /* __ASM_GENERIC_SHMBUF_H */ |