glibc/sysdeps/unix/sysv/linux/x86
Adhemerval Zanella dba950e317 sysv: linux: Add 64-bit time_t variant for semctl
Different than others 64-bit time_t syscalls, the SysIPC interface
does not provide a new set of syscall for y2038 safeness.  Instead it
uses unused fields in semid_ds structure to return the high bits for
the timestamps.

To provide a y2038 safe interface a new symbol __semctl64 is added
and __semctl is change to call it instead (it adds some extra buffer
copying for the 32 bit time_t implementation).

Two new structures are added:

  1. kernel_semid64_ds: used internally only on 32-bit architectures
     to issue the syscall.  A handful of architectures (hppa, i386,
     mips, powerpc32, sparc32) require specific implementations due
     their kernel ABI.

  2. semid_ds64: this is only for __TIMESIZE != 64 to use along with
     the 64-bit semctl.  It is different than the kernel struct because
     the exported 64-bit time_t might require different alignment
     depending on the architecture ABI.

So the resulting implementation does:

  1. For 64-bit architectures it assumes semid_ds already contains
     64-bit time_t fields and will result in just the __semctl symbol
     using the __semctl64 code.  The semid_ds argument is passed as-is
     to the syscall.

  2. For 32-bit architectures with default 64-bit time_t (newer ABIs
     such riscv32 or arc), it will also result in only one exported
     symbol but with the required high/low handling.

     It might be possible to optimize it further to avoid the
     kernel_semid64_ds to semun transformation if the exported ABI
     for the architectures matches the expected kernel ABI, but the
     implementation is already complex enough and don't think this
     should be a hotspot in any case.

  3. Finally for 32-bit architecture with both 32-bit and 64-bit time_t
     support we follow the already set way to provide one symbol with
     64-bit time_t support and implement the 32-bit time_t support
     using the 64-bit one.

     The default 32-bit symbol will allocate and copy the semid_ds
     over multiple buffers, but this should be deprecated in favor
     of the __semctl64 anyway.

Checked on i686-linux-gnu and x86_64-linux-gnu.  I also did some sniff
tests on powerpc, powerpc64, mips, mips64, armhf, sparcv9, and
sparc64.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Tested-by: Alistair Francis <alistair.francis@wdc.com>
Tested-by: Vineet Gupta <vgupta@synopsys.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2020-07-09 12:05:35 -03:00
..
bits sysv: linux: Add 64-bit time_t variant for semctl 2020-07-09 12:05:35 -03:00
include/asm x86: Remove ARCH_CET_LEGACY_BITMAP [BZ #25397] 2020-03-18 04:35:54 -07:00
sys Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
arch-pkey.h Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
cpu-features.c x86: Move CET control to _dl_x86_feature_control [BZ #25887] 2020-05-18 06:15:02 -07:00
dl-cet.h x86: Remove ARCH_CET_LEGACY_BITMAP [BZ #25397] 2020-03-18 04:35:54 -07:00
dl-sysdep.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
elision-conf.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
elision-conf.h Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
elision-lock.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
elision-timed.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
elision-trylock.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
elision-unlock.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
force-elision.h Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
gettimeofday.c y2038: linux: Provide __gettimeofday64 implementation 2020-02-18 23:55:47 +01:00
hle.h
Implies
jmp_buf-ssp.sym
lowlevellock.h Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
Makefile x86: Add --enable-cet=permissive 2020-05-18 08:38:53 -07:00
pkey_get.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
pkey_set.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
pthread_mutex_cond_lock.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
pthread_mutex_lock.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
pthread_mutex_timedlock.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
pthread_mutex_trylock.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
setjmpP.h linux: Fix __NSIG_WORDS and add __NSIG_BYTES 2020-07-07 14:10:58 -03:00
sysconf.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
time.c linux: Consolidate time implementation 2020-01-03 11:22:04 -03:00
tst-cet-property-1.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
tst-cet-property-2.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
tst-cet-property-dep-2.S Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
tst-cet-setcontext-1.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
tst-saved_mask-1.c Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00