Commit Graph

7 Commits

Author SHA1 Message Date
Arnd Bergmann
48166e6ea4 y2038: add 64-bit time_t syscalls to all 32-bit architectures
This adds 21 new system calls on each ABI that has 32-bit time_t
today. All of these have the exact same semantics as their existing
counterparts, and the new ones all have macro names that end in 'time64'
for clarification.

This gets us to the point of being able to safely use a C library
that has 64-bit time_t in user space. There are still a couple of
loose ends to tie up in various areas of the code, but this is the
big one, and should be entirely uncontroversial at this point.

In particular, there are four system calls (getitimer, setitimer,
waitid, and getrusage) that don't have a 64-bit counterpart yet,
but these can all be safely implemented in the C library by wrapping
around the existing system calls because the 32-bit time_t they
pass only counts elapsed time, not time since the epoch. They
will be dealt with later.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2019-02-07 00:13:28 +01:00
Arnd Bergmann
d33c577ccc y2038: rename old time and utime syscalls
The time, stime, utime, utimes, and futimesat system calls are only
used on older architectures, and we do not provide y2038 safe variants
of them, as they are replaced by clock_gettime64, clock_settime64,
and utimensat_time64.

However, for consistency it seems better to have the 32-bit architectures
that still use them call the "time32" entry points (leaving the
traditional handlers for the 64-bit architectures), like we do for system
calls that now require two versions.

Note: We used to always define __ARCH_WANT_SYS_TIME and
__ARCH_WANT_SYS_UTIME and only set __ARCH_WANT_COMPAT_SYS_TIME and
__ARCH_WANT_SYS_UTIME32 for compat mode on 64-bit kernels. Now this is
reversed: only 64-bit architectures set __ARCH_WANT_SYS_TIME/UTIME, while
we need __ARCH_WANT_SYS_TIME32/UTIME32 for 32-bit architectures and compat
mode. The resulting asm/unistd.h changes look a bit counterintuitive.

This is only a cleanup patch and it should not change any behavior.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2019-02-07 00:13:28 +01:00
Arnd Bergmann
00bf25d693 y2038: use time32 syscall names on 32-bit
This is the big flip, where all 32-bit architectures set COMPAT_32BIT_TIME
and use the _time32 system calls from the former compat layer instead
of the system calls that take __kernel_timespec and similar arguments.

The temporary redirects for __kernel_timespec, __kernel_itimerspec
and __kernel_timex can get removed with this.

It would be easy to split this commit by architecture, but with the new
generated system call tables, it's easy enough to do it all at once,
which makes it a little easier to check that the changes are the same
in each table.

Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-02-07 00:13:28 +01:00
Arnd Bergmann
8dabe7245b y2038: syscalls: rename y2038 compat syscalls
A lot of system calls that pass a time_t somewhere have an implementation
using a COMPAT_SYSCALL_DEFINEx() on 64-bit architectures, and have
been reworked so that this implementation can now be used on 32-bit
architectures as well.

The missing step is to redefine them using the regular SYSCALL_DEFINEx()
to get them out of the compat namespace and make it possible to build them
on 32-bit architectures.

Any system call that ends in 'time' gets a '32' suffix on its name for
that version, while the others get a '_time32' suffix, to distinguish
them from the normal version, which takes a 64-bit time argument in the
future.

In this step, only 64-bit architectures are changed, doing this rename
first lets us avoid touching the 32-bit architectures twice.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-02-07 00:13:27 +01:00
Arnd Bergmann
0d6040d468 arch: add split IPC system calls where needed
The IPC system call handling is highly inconsistent across architectures,
some use sys_ipc, some use separate calls, and some use both.  We also
have some architectures that require passing IPC_64 in the flags, and
others that set it implicitly.

For the addition of a y2038 safe semtimedop() system call, I chose to only
support the separate entry points, but that requires first supporting
the regular ones with their own syscall numbers.

The IPC_64 is now implied by the new semctl/shmctl/msgctl system
calls even on the architectures that require passing it with the ipc()
multiplexer.

I'm not adding the new semtimedop() or semop() on 32-bit architectures,
those will get implemented using the new semtimedop_time64() version
that gets added along with the other time64 calls.
Three 64-bit architectures (powerpc, s390 and sparc) get semtimedop().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2019-01-25 17:22:50 +01:00
Arnd Bergmann
275f22148e ipc: rename old-style shmctl/semctl/msgctl syscalls
The behavior of these system calls is slightly different between
architectures, as determined by the CONFIG_ARCH_WANT_IPC_PARSE_VERSION
symbol. Most architectures that implement the split IPC syscalls don't set
that symbol and only get the modern version, but alpha, arm, microblaze,
mips-n32, mips-n64 and xtensa expect the caller to pass the IPC_64 flag.

For the architectures that so far only implement sys_ipc(), i.e. m68k,
mips-o32, powerpc, s390, sh, sparc, and x86-32, we want the new behavior
when adding the split syscalls, so we need to distinguish between the
two groups of architectures.

The method I picked for this distinction is to have a separate system call
entry point: sys_old_*ctl() now uses ipc_parse_version, while sys_*ctl()
does not. The system call tables of the five architectures are changed
accordingly.

As an additional benefit, we no longer need the configuration specific
definition for ipc_parse_version(), it always does the same thing now,
but simply won't get called on architectures with the modern interface.

A small downside is that on architectures that do set
ARCH_WANT_IPC_PARSE_VERSION, we now have an extra set of entry points
that are never called. They only add a few bytes of bloat, so it seems
better to keep them compared to adding yet another Kconfig symbol.
I considered adding new syscall numbers for the IPC_64 variants for
consistency, but decided against that for now.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-01-25 17:22:50 +01:00
Firoz Khan
9bcbf97c62
mips: add system call table generation support
The system call tables are in different format in all
architecture and it will be difficult to manually add,
modify or delete the syscall table entries in the res-
pective files. To make it easy by keeping a script and
which will generate the uapi header and syscall table
file. This change will also help to unify the implemen-
tation across all architectures.

The system call table generation script is added in
kernel/syscalls directory which contain the scripts to
generate both uapi header file and system call table
files. The syscall.tbl will be input for the scripts.

syscall.tbl contains the list of available system calls
along with system call number and corresponding entry
point. Add a new system call in this architecture will
be possible by adding new entry in the syscall.tbl file.

Adding a new table entry consisting of:
  	- System call number.
	- ABI.
	- System call name.
	- Entry point name.
	- Compat entry name, if required.

syscallhdr.sh, syscallnr.sh and syscalltbl.sh will gene-
rate uapi header unistd_n64/n32/o32.h, unistd_nr_n64/n32/-
o32.h and syscall_table_32_o32/64_n64/64-n32/64-o32.h files
respectively. All *.sh files will parse the content sys-
call.tbl to generate the header and table files. unistd-
_n64/n32/o32.h and unistd_nr_n64/n32/o32.h will be included
by uapi/asm/unistd.h and syscall_table_32_o32/64_n64/64-n32-
/64-o32.h is included by kernel/syscall_table32_o32/64-
_n64/64-n32/64-o32.S - the real system call table.

ARM, s390 and x86 architecuture does have similar support.
I leverage their implementation to come up with a generic
solution.

Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
[paul.burton@mips.com:
 - Change sysnr_pfx_unistd_nr_n64 to 64.]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: y2038@lists.linaro.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: arnd@arndb.de
Cc: deepa.kernel@gmail.com
Cc: marcin.juszkiewicz@linaro.org
2018-12-14 11:19:01 -08:00