This change makes it easier to set a breakpoint on these calls.
This also addresses the issue that including <ldsodefs.h> without
<unistd.h> does not result usable _dl_*printf macros because of the
use of the STD*_FILENO macros there.
(The private symbol for _dl_fatal_printf will go away again
once the exception handling implementation is unified between
libc and ld.so.)
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Also add the private type union pthread_attr_transparent, to reduce
the amount of casting that is required.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
This is part of the libpthread removal project:
<https://sourceware.org/ml/libc-alpha/2019-10/msg00080.html>
Use __getline instead of __getdelim to avoid a localplt failure.
Likewise for __getrlimit/getrlimit.
The abilist updates were performed by:
git ls-files 'sysdeps/unix/sysv/linux/**/libc.abilist' \
| while read x ; do
echo "GLIBC_2.32 pthread_getattr_np F" >> $x
done
python3 scripts/move-symbol-to-libc.py --only-linux pthread_getattr_np
The private export of __pthread_getaffinity_np is no longer needed, but
the hidden alias still necessary so that the symbol can be exported with
versioned_symbol.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
This is part of the libpthread removal project:
<https://sourceware.org/ml/libc-alpha/2019-10/msg00080.html>
The abilist updates were performed by:
git ls-files 'sysdeps/unix/sysv/linux/**/libc.abilist' \
| while read x ; do
echo "GLIBC_2.32 pthread_getaffinity_np F" >> $x
done
python3 scripts/move-symbol-to-libc.py pthread_getaffinity_np
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
This is part of the libpthread removal project:
<https://sourceware.org/ml/libc-alpha/2019-10/msg00080.html>
The symbol did not previously exist in libc, so a new GLIBC_2.32
symbol is needed, to get correct dependency for binaries which
use the symbol but no longer link against libpthread.
The abilist updates were performed by:
git ls-files 'sysdeps/unix/sysv/linux/**/libc.abilist' \
| while read x ; do
echo "GLIBC_2.32 pthread_attr_setaffinity_np F" >> $x
done
python3 scripts/move-symbol-to-libc.py pthread_attr_setaffinity_np
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
The stubs for pthread_getaffinity_np, pthread_getname_np,
pthread_setaffinity_np, pthread_setname_np are replaced, and corresponding
tests are moved.
After the removal of the NaCl port, nptl is Linux-specific, and the stubs
are no longer needed. This effectively reverts commit
c76d1ff514 ("NPTL: Add stubs for Linux-only
extension functions.").
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This fixes a build error:
../sysdeps/unix/sysv/linux/ntp_gettime.c: In function ‘__ntp_gettime’:
../sysdeps/unix/sysv/linux/ntp_gettime.c:56:10: error: ‘ntv64.tai’ is used uninitialized in this function [-Werror=uninitialized]
56 | *ntv = valid_ntptimeval64_to_ntptimeval (ntv64);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The __clock_gettime internal function is not supporting 64 bit time on
architectures with __WORDSIZE == 32 and __TIMESIZE != 64 (like e.g. ARM 32
bit).
The __clock_gettime64 function shall be used instead in the glibc itself as
it supports 64 bit time on those systems.
This patch does not bring any changes to systems with __WORDSIZE == 64 as
for them the __clock_gettime64 is aliased to __clock_gettime (in
./include/time.h).
This patch provides new __ntp_gettimex64 explicit 64 bit function for getting
time parameters via NTP interface.
The call to __adjtimex in __ntp_gettime64 function has been replaced with
direct call to __clock_adjtime64 syscall, to simplify the code.
Moreover, a 32 bit version - __ntp_gettimex has been refactored to internally
use __ntp_gettimex64.
The __ntp_gettimex is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversions between struct
ntptimeval and 64 bit struct __ntptimeval64.
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Above tests were performed with Y2038 redirection applied as well as without to
test the proper usage of both __ntp_gettimex64 and __ntp_gettimex.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch provides new __ntp_gettime64 explicit 64 bit function for getting
time parameters via NTP interface.
Internally, the __clock_adjtime64 syscall is used instead of __adjtimex. This
patch is necessary for having architectures with __WORDSIZE == 32 Y2038 safe.
Moreover, a 32 bit version - __ntp_gettime has been refactored to internally
use __ntp_gettime64.
The __ntp_gettime is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversions between struct
ntptimeval and 64 bit struct __ntptimeval64.
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Above tests were performed with Y2038 redirection applied as well as without to
test the proper usage of both __ntp_gettime64 and __ntp_gettime.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Those functions allow easy conversion between Y2038 safe, glibc internal
struct __ntptimeval64 and struct ntptimeval.
The reserved fields (i.e. __glibc_reserved{1234}) during conversion are
zeroed as well, to provide behavior similar to one in ntp_gettimex function
(where those are cleared before the struct ntptimeval is returned).
Those functions are put in Linux specific sys/timex.h file, as putting
them into glibc's local include/time.h would cause build break on HURD as
it doesn't support struct timex related syscalls.
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This type is a glibc's "internal" type to get time parameters data from
Linux kernel (NTP daemon interface). It stores time in struct __timeval64
rather than struct timeval, which makes it Y2038-proof.
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch provides new __adjtime64 explicit 64 bit function for adjusting
Linux kernel clock.
Internally, the __clock_adjtime64 syscall is used instead of __adjtimex. This
patch is necessary for having architectures with __WORDSIZE == 32 Y2038 safe.
Moreover, a 32 bit version - __adjtime has been refactored to internally use
__adjtime64.
The __adjtime is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversions between struct
timeval and 64 bit struct __timeval64.
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Above tests were performed with Y2038 redirection applied as well as without to
test the proper usage of both __adjtime64 and __adjtime.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch provides new ___adjtimex64 explicit 64 bit function for adjusting
Linux kernel clock.
Internally, the __clock_adjtime64 syscall is used. This patch is necessary
for having architectures with __WORDSIZE == 32 Y2038 safe.
Moreover, a 32 bit version - ___adjtimex has been refactored to internally
use ___adjtimex64.
The ___adjtimex is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversions between struct
timex and 64 bit struct __timex64.
Last but not least, in ___adjtimex64 function the __clock_adjtime syscall has
been replaced with __clock_adjtime64 to support 64 bit time on architectures
with __WORDSIZE == 32 and __TIMESIZE != 64.
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Above tests were performed with Y2038 redirection applied as well as without to
test the proper usage of both ___adjtimex64 and ___adjtimex.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch replaces auto generated wrapper (as described in
sysdeps/unix/sysv/linux/syscalls.list) for clock_adjtime with one which adds
extra support for reading 64 bit time values on machines with __TIMESIZE != 64.
To achieve this goal new __clock_adjtime64 explicit 64 bit function for
adjusting Linux clock has been added.
Moreover, a 32 bit version - __clock_adjtime has been refactored to internally
use __clock_adjtime64.
The __clock_adjtime is now supposed to be used on systems still supporting 32
bit time (__TIMESIZE != 64) - hence the necessary conversions between 64 bit
struct __timespec64 and struct timespec.
The new __clock_adjtime64 syscall available from Linux 5.1+ has been used, when
applicable.
Up till v5.4 in the Linux kernel there was a bug preventing this call from
obtaining correct struct's timex time.tv_sec time after time_t overflow
(i.e. not being Y2038 safe).
Build tests:
- ./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Linux kernel, headers and minimal kernel version for glibc build test matrix:
- Linux v5.1 (with clock_adjtime64) and glibc build with v5.1 as
minimal kernel version (--enable-kernel="5.1.0")
The __ASSUME_TIME64_SYSCALLS flag defined.
- Linux v5.1 and default minimal kernel version
The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports clock_adjtime64
syscall.
- Linux v4.19 (no clock_adjtime64 support) with default minimal kernel version
for contemporary glibc (3.2.0)
This kernel doesn't support clock_adjtime64 syscall, so the fallback to
clock_adjtime is tested.
Above tests were performed with Y2038 redirection applied as well as without
(so the __TIMESIZE != 64 execution path is checked as well).
No regressions were observed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This version uses vector instructions and is up to 60% faster on medium
matches and up to 90% faster on long matches, compared to the POWER7
version. A few examples:
__rawmemchr_power9 __rawmemchr_power7
Length 32, alignment 0: 2.27566 3.77765
Length 64, alignment 2: 2.46231 3.51064
Length 1024, alignment 0: 17.3059 32.6678
When CET is enabled, it is an error to dlopen a non CET enabled shared
library in CET enabled application. It may be desirable to make CET
permissive, that is disable CET when dlopening a non CET enabled shared
library. With the new --enable-cet=permissive configure option, CET is
disabled when dlopening a non CET enabled shared library.
Add DEFAULT_DL_X86_CET_CONTROL to config.h.in:
/* The default value of x86 CET control. */
#define DEFAULT_DL_X86_CET_CONTROL cet_elf_property
which enables CET features based on ELF property note.
--enable-cet=permissive it to
/* The default value of x86 CET control. */
#define DEFAULT_DL_X86_CET_CONTROL cet_permissive
which enables CET features permissively.
Update tst-cet-legacy-5a, tst-cet-legacy-5b, tst-cet-legacy-6a and
tst-cet-legacy-6b to check --enable-cet and --enable-cet=permissive.
This was originally added to support binutils older than version
2.22:
<https://sourceware.org/ml/libc-alpha/2010-12/msg00051.html>
Since 2.22 is older than the minimum required binutils version
for building glibc, we no longer need this. (The changes do
not impact the statically linked startup code.)
Add stpcpy support to the POWER9 strcpy. This is up to 40% faster on
small strings and up to 90% faster on long relatively unaligned strings,
compared to the POWER8 version. A few examples:
__stpcpy_power9 __stpcpy_power8
Length 20, alignments in bytes 4/ 4: 2.58246 4.8788
Length 1024, alignments in bytes 1/ 6: 24.8186 47.8528
This version uses VSX store vector with length instructions and is
significantly faster on small strings and relatively unaligned large
strings, compared to the POWER8 version. A few examples:
__strcpy_power9 __strcpy_power8
Length 16, alignments in bytes 0/ 0: 2.52454 4.62695
Length 412, alignments in bytes 4/ 0: 11.6 22.9185
1. Include <dl-procruntime.c> to get architecture specific initializer in
rtld_global.
2. Change _dl_x86_feature_1[2] to _dl_x86_feature_1.
3. Add _dl_x86_feature_control after _dl_x86_feature_1, which is a
struct of 2 bitfields for IBT and SHSTK control
This fixes [BZ #25887].
The getcpu cache was removed from the kernel in Linux 2.6.24. glibc
support from the sched_getcpu implementation was removed in commit
dd26c44403 ("Consolidate sched_getcpu").
This patch fixes the optimized implementation of strcpy and strnlen
on a big-endian arm64 machine.
The optimized method uses neon, which can process 128bit with one
instruction. On a big-endian machine, the bit order should be reversed
for the whole 128-bits double word. But with instuction
rev64 datav.16b, datav.16b
it reverses 64bits in the two halves rather than reversing 128bits.
There is no such instruction as rev128 to reverse the 128bits, but we
can fix this by loading the data registers accordingly.
Fixes 0237b61526e7("aarch64: Optimized implementation of strcpy") and
2911cb68ed3d("aarch64: Optimized implementation of strnlen").
Signed-off-by: Lexi Shao <shaolexi@huawei.com>
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
After using "make update-syscall-lists" to update arch-syscall.h for
new kernel versions, sysd-syscalls will not be not be regenerated.
This will cause a compile error because the new data is not being
picked up.
Fixes commit a1bd5f8673
("Linux: Use system call tables during build").
Reviewed-by: Florian Weimer <fweimer@redhat.com>
When using outline atomics (-moutline-atomics, the default for ARMv8-A
starting with GCC 10), libgcc contains an ELF constructor which calls
__getauxval. This code is built outside of glibc, so none of its
internal PLT avoidance schemes can be applied to it. This change
suppresses the elf/check-localplt failure.
The script can now be called to query the definition status of
system call numbers across all architectures, like this:
$ python3 sysdeps/unix/sysv/linux/glibcsyscalls.py query-syscall sync_file_range sync_file_range2
sync_file_range:
defined: aarch64 alpha csky hppa i386 ia64 m68k microblaze mips/mips32 mips/mips64/n32 mips/mips64/n64 nios2 riscv/rv64 s390/s390-32 s390/s390-64 sh sparc/sparc32 sparc/sparc64 x86_64/64 x86_64/x32
undefined: arm powerpc/powerpc32 powerpc/powerpc64
sync_file_range2:
defined: arm powerpc/powerpc32 powerpc/powerpc64
undefined: aarch64 alpha csky hppa i386 ia64 m68k microblaze mips/mips32 mips/mips64/n32 mips/mips64/n64 nios2 riscv/rv64 s390/s390-32 s390/s390-64 sh sparc/sparc32 sparc/sparc64 x86_64/64 x86_64/x32
This command lists the headers containing the system call numbers:
$ python3 sysdeps/unix/sysv/linux/glibcsyscalls.py list-headers
The argument parser code is based on a suggestion from Adhemerval Zanella.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Since __x86_shared_non_temporal_threshold is defined as
long int __x86_shared_non_temporal_threshold;
and long int is 4 bytes for x32, use RDX_LP to compare against
__x86_shared_non_temporal_threshold in assembly code.
Only alpha and ia64 do not support __NR_umount2 (defined as
__NR_umount), but recent kernel fixes (74cd2184833f for ia64, and
12b57c5c70f39 for alpha) add the required alias.
Checked with a build against all affected ABIs.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
This consolidates the copy-pasted arch specific semaphore header into
single version (based on s390) which suffices 32-bit and and 64-bit
arch/ABI based on the canonical WORDSIZE.
For now I've left out arches which use alternate defines to choose for
32 vs 64-bit builds (aarch64, mips) which in theory can also use the same
header.
Passes build-many for
aarch64-linux-gnu arm-linux-gnueabi arm-linux-gnueabihf
riscv64-linux-gnu-rv64imac-lp64 riscv64-linux-gnu-rv64imafdc-lp64
x86_64-linux-gnu microblaze-linux-gnu nios2-linux-gnu
Suggested-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Those functions allow easy conversion between Y2038 safe, glibc internal
struct __timex64 and struct timex.
Those functions are put in Linux specific sys/timex.h file, as putting
them into glibc's local include/time.h would cause build break on HURD as
it doesn't support struct timex related syscalls.
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The introduced glibc's 'internal' struct __timex64 is a copy of Linux kernel's
struct __kernel_timex (v5.6) introduced for properly handling data for
clock_adjtime64 syscall.
As the struct's __kernel_timex size is the same as for archs with
__WORDSIZE == 64, proper padding and data types conversion (i.e. long to long
long) had to be added for architectures with __WORDSIZE == 32 &&
__TIMESIZE != 64.
Moreover, it stores time in struct __timeval64 rather than struct
timeval, which makes it Y2038-proof.
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
For Linux glibc ports the __TIMESIZE == 64 ensures proper aliasing for
__clock_gettime64 (to __clock_gettime).
When __TIMESIZE != 64 (like ARM32, PPC) the glibc expects separate definition
of the __clock_gettime64.
The HURD port only provides __clock_gettime, so this patch adds
__clock_gettime64 as a tiny wrapper on it.
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
strcmp is used while resolving PLT references. Vector registers
should not be used during this. The P9 strcmp makes heavy use of
vector registers, so it should be avoided in rtld.
This prevents quiet vector register corruption when glibc is configured
with --disable-multi-arch and --with-cpu=power9. This can be seen with
test-float64x-compat_totalordermag during the first call into
totalordermagf64x@GLIBC_2.27.
Add a guard to fallback to the power8 implementation when building
power9 strcmp for libraries other than libc.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The minimum GCC version has been raised to 6.2 for building
glibc. Therefore, follow the advice inside the implementation
and remove the GCC < 6 codepath.
Likewise, remove the hidden_proto as all internal usages should
inline now.
Commit a98dc92dd1 ("x86: Add cache
information support for Zhaoxin processors") introduced an unused
variable warning in the default i686-linux-gnu build:
In file included from ../sysdeps/i386/cacheinfo.c:3:
../sysdeps/x86/cacheinfo.c: In function 'init_cacheinfo':
../sysdeps/x86/cacheinfo.c:762:16: error: unused variable 'eax' [-Werror=unused-variable]
762 | unsigned int eax;
| ^~~
Add a C wrapper to pass arguments in
/* Control process execution. */
extern int prctl (int __option, ...) __THROW;
to prctl syscall:
extern int prctl (int, unsigned long int, unsigned long int,
unsigned long int, unsigned long int);
On platforms where long double may have two different formats, i.e.: the
same format as double (64-bits) or something else (128-bits), building
with -mlong-double-128 is the default and function calls in the user
program match the name of the function in Glibc. When building with
-mlong-double-64, Glibc installed headers redirect such calls to the
appropriate function.
Likewise, the internals of glibc are now built against IEEE long double.
However, the only (minimally) notable usage of long double is difftime.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
GCC 7.5.0 (PR94200) will refuse to compile if both -mabi=% and
-mlong-double-128 are passed on the command line. Surprisingly,
it will work happily if the latter is not. For the sake of
maintaining status quo, test for and blacklist such compilers.
Tested with a GCC 8.3.1 and GCC 7.5.0 compiler for ppc64le.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
This is a small step up from 2.25 which brings in support for
rewriting the .gnu.attributes section of libc/libm.so.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Add compiler feature tests to ensure we can build ieee128 long double.
These test for -mabi=ieeelongdouble, -mno-gnu-attribute, and -Wno-psabi.
Likewise, verify some compiler bugs have been addressed. These aren't
helpful for building glibc, but may cause test failures when testing
the new long double. See notes below from Raji.
On powerpc64le, some older compiler versions give error for the function
signbit() for 128-bit floating point types. This is fixed by PR83862
in gcc 8.0 and backported to gcc6 and gcc7. This patch adds a test
to check compiler version to avoid compiler errors during make check.
Likewise, test for -mno-gnu-attribute support which was
On powerpc64le, a few files are built on IEEE long double mode
(-mabi=ieeelongdouble), whereas most are built on IBM long double mode
(-mabi=ibmlongdouble, the default for -mlong-double-128). Since binutils
2.31, linking object files with different long double modes causes
errors similar to:
ld: libc_pic.a(s_isinfl.os) uses IBM long double,
libc_pic.a(ieee128-qefgcvt.os) uses IEEE long double.
collect2: error: ld returned 1 exit status
make[2]: *** [../Makerules:649: libc_pic.os] Error 1
The warnings are fair and correct, but in order for glibc to have
support for both long double modes on powerpc64le, they have to be
ignored. This can be accomplished with the use of -mno-gnu-attribute
option when building the few files that require IEEE long double mode.
However, -mno-gnu-attribute is not available in GCC 6, the minimum
version required to build glibc, so this patch adds a test for this
feature in powerpc64le builds, and fails early if it's not available.
Co-Authored-By: Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
Co-Authored-By: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Improve the commentary to aid future developers who will stumble
upon this novel, yet not always perfect, mechanism to support
alternative formats for long double.
Likewise, rename __LONG_DOUBLE_USES_FLOAT128 to
__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI now that development work
has settled down. The command used was
git grep -l __LONG_DOUBLE_USES_FLOAT128 ':!./ChangeLog*' | \
xargs sed -i 's/__LONG_DOUBLE_USES_FLOAT128/__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI/g'
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
To obtain Zhaoxin CPU cache information, add a new function
handle_zhaoxin().
Add a new function get_common_cache_info() that extracts the code
in init_cacheinfo() to get the value of the variable shared, threads.
Add Zhaoxin branch in init_cacheinfo() for initializing variables,
such as __x86_shared_cache_size.
Since the the U marker can only be applied to 2 unsigned long arguments
in syscalls.list files, add a C wrapper for process_vm_readv and
process_vm_writev syscals which have more than 2 unsigned long arguments.
