Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.
Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96
The initial value of NOASM is nearly the same in all cases and the
initial value of PSEUDO is the same in all cases so reduce duplication
(and hopefully, future merge conflicts) by machine independent defaults.
Also document the PSEUDO variable.
Reviewed by: jhb, kib
Obtained from: CheriBSD
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D7820
Besides removing hand-translation to assembler, this also adds missing
wrappers for arm64 and risc-v.
Reviewed by: emaste, jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D7694
In particular, preserve syscall arguments on stack, since callee is
not required to preserve arg-passing registers. Align stack.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Since ptrace(2) syscall can return -1 for non-error situations, libc
wrappers set errno to 0 before performing the syscall, as the service
to the caller. On both i386 and amd64, the errno symbol was directly
referenced, which only works correctly in single-threaded process.
Change assembler wrappers for ptrace(2) to get current thread errno
location by calling __error(). Allow __error interposing, as
currently allowed in cerror().
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Right now, userspace (fast) gettimeofday(2) on x86 only works for
RDTSC. For older machines, like Core2, where RDTSC is not C2/C3
invariant, and which fall to HPET hardware, this means that the call
has both the penalty of the syscall and of the uncached hw behind the
QPI or PCIe connection to the sought bridge. Nothing can me done
against the access latency, but the syscall overhead can be removed.
System already provides mappable /dev/hpetX devices, which gives
straight access to the HPET registers page.
Add yet another algorithm to the x86 'vdso' timehands. Libc is updated
to handle both RDTSC and HPET. For HPET, the index of the hpet device
to mmap is passed from kernel to userspace, index might be changed and
libc invalidates its mapping as needed.
Remove cpu_fill_vdso_timehands() KPI, instead require that
timecounters which can be used from userspace, to provide
tc_fill_vdso_timehands{,32}() methods. Merge i386 and amd64
libc/<arch>/sys/__vdso_gettc.c into one source file in the new
libc/x86/sys location. __vdso_gettc() internal interface is changed
to move timecounter algorithm detection into the MD code.
Measurements show that RDTSC even with the syscall overhead is faster
than userspace HPET access. But still, userspace HPET is three-four
times faster than syscall HPET on several Core2 and SandyBridge
machines.
Tested by: Howard Su <howard0su@gmail.com>
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D7473
value.
This eliminates the need for machine dependant assembly wrappers for
pipe(2).
It also make passing an invalid address to pipe(2) return EFAULT rather
than triggering a segfault. Document this behavior (which was already
true for pipe2(2), but undocumented).
Reviewed by: andrew
Approved by: re (gjb)
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D6815
Further to r240152 (i386) and r240178 (amd64), hide the .cerror symbol
so that it is not exported if symbol versioning is not in use. Without
this change WITHOUT_SYMVER libc contains .text relocations for .cerror,
as described in LLVM PR 26813 (http://llvm.org/pr26813).
This is a no-op for the regular build as the symbol version script
already controls .cerror visibility.
PR: 207712
Submitted by: Rafael Espíndola
Reviewed by: jilles, kib
Differential Revision: https://reviews.freebsd.org/D5571
of the timehands, from the kern_tc.c implementation to vdso. Add
comments giving hints where to look for the algorithm explanation.
To compensate the removal of rmb() in userspace binuptime(), add
explicit lfence instruction before rdtsc. On i386, add usual
complications to detect SSE2 presence; assume that old CPUs which do
not implement SSE2 also execute rdtsc almost in order.
Reviewed by: alc, bde (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
pwrite(2) syscalls are wrapped to provide compatibility with pre-7.x
kernels which required padding before the off_t parameter. The
fcntl(2) contains compatibility code to handle kernels before the
struct flock was changed during the 8.x CURRENT development. The
shims were reasonable to allow easier revert to the older kernel at
that time.
Now, two or three major releases later, shims do not serve any
purpose. Such old kernels cannot handle current libc, so revert the
compatibility code.
Make padded syscalls support conditional under the COMPAT6 config
option. For COMPAT32, the syscalls were under COMPAT6 already.
Remove WITHOUT_SYSCALL_COMPAT build option, which only purpose was to
(partially) disable the removed shims.
Reviewed by: jhb, imp (previous versions)
Discussed with: peter
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
The variable _logname_valid is not exported via the version script;
therefore, change C and i386/amd64 assembler code to remove indirection
(which allowed interposition). This makes the code slightly smaller and
faster.
Also, remove #define PIC_GOT from i386/amd64 in !PIC mode. Without PIC,
there is no place containing the address of each variable, so there is no
possible definition for PIC_GOT.
but use normal references instead of weak. This makes the statically
linked binaries to use fast gettimeofday(2) by forcing the linker to
resolve references and providing the neccessary functions.
Reported by: bde
Tested by: marius (sparc64)
MFC after: 2 weeks
For some reason, libc exports the symbol .cerror (HIDENAME(cerror)), albeit
in the FBSDprivate_1.0 version. It looks like there is no reason for this
since it is not used from other libraries. Given that it cannot be accessed
from C and its strange calling convention, it is rather unlikely that other
things rely on it. Perhaps it is from a time when symbols could not be
hidden.
Most of the amd64 assembler code jumps to .cerror using the GOT. It can jump
to it directly now, as in non-PIC mode.
There are also some minor size optimizations to instructions but they yield
virtually no benefit in the size of libc.so.7 due to padding.
Reviewed by: kib
clock_gettime(2) functions if supported. The speedup seen in
microbenchmarks is in range 4x-7x depending on the hardware.
Only amd64 and i386 architectures are supported. Libc uses rdtsc and
kernel data to calculate current time, if enabled by kernel.
Hopefully, this code is going to migrate into vdso in some future.
Discussed with: bde
Reviewed by: jhb
Tested by: flo
MFC after: 1 month
Looking at our source code history, it seems the uname(),
getdomainname() and setdomainname() system calls got deprecated
somewhere after FreeBSD 1.1, but they have never been phased out
properly. Because we don't have a COMPAT_FREEBSD1, just use
COMPAT_FREEBSD4.
Also fix the Linuxolator to build without the setdomainname() routine by
just making it call userland_sysctl on kern.domainname. Also replace the
setdomainname()'s implementation to use this approach, because we're
duplicating code with sysctl_domainname().
I wasn't able to keep these three routines working in our
COMPAT_FREEBSD32, because that would require yet another keyword for
syscalls.master (COMPAT4+NOPROTO). Because this routine is probably
unused already, this won't be a problem in practice. If it turns out to
be a problem, we'll just restore this functionality.
Reviewed by: rdivacky, kib
is used to set the ELF size attribute for functions. It isn't normally
critical but some things can make use of it (gdb for stack traces).
Valgrind needs it so I'm adding it in. The problem is present on all
branches and on both i386 and amd64.
syscalls, unless WITHOUT_SYSCALL_COMPAT is defined. The default case
will have the .c wrappers still. If you define WITHOUT_SYSCALL_COMPAT,
the .c wrappers will go away and libc will make direct syscalls.
After 7-stable starts, the direct syscall method will be default.
Approved by: re (kensmith)
at it, use the ANSI C generic pointer type for the second argument,
thus matching the documentation.
Remove the now extraneous (and now conflicting) function declarations
in various libc sources. Remove now unnecessary casts.
Reviewed by: bde
value for getcontext() in a preserved register rather than on the stack.
The second time around, the stack value would likely have changed so we
can't depend on it for the return value.
- All those diffs to syscalls.master for each architecture *are*
necessary. This needed clarification; the stub code generation for
mlockall() was disabled, which would prevent applications from
linking to this API (suggested by mux)
- Giant has been quoshed. It is no longer held by the code, as
the required locking has been pushed down within vm_map.c.
- Callers must specify VM_MAP_WIRE_HOLESOK or VM_MAP_WIRE_NOHOLES
to express their intention explicitly.
- Inspected at the vmstat, top and vm pager sysctl stats level.
Paging-in activity is occurring correctly, using a test harness.
- The RES size for a process may appear to be greater than its SIZE.
This is believed to be due to mappings of the same shared library
page being wired twice. Further exploration is needed.
- Believed to back out of allocations and locks correctly
(tested with WITNESS, MUTEX_PROFILING, INVARIANTS and DIAGNOSTIC).
PR: kern/43426, standards/54223
Reviewed by: jake, alc
Approved by: jake (mentor)
MFC after: 2 weeks
- strip out the nasty PIC_PROLOGUE/EPILOGUE stuff, since we dont have
to lose a register in PIC mode anymore (we use %rip-relative addressing).
- update for C register argument passing conventions.
- convert 32 bit to 64 bit register sizes etc.
variables. Both symbols are set to the same value by the linker,
and _end symbol has less chances to clash with application defined
global symbols.
alpha, ia64 and sparc64 ports already use _end, i386 is now
consistent with them.
Reviewed by: bde
Approved by: obrien
Reported by: pirzyk
- Renumber labels since the previous revision removed one.
- Remove useless and wrong comment.
- Repeating the function name is just redundant.
- The previous revision made the comment about %edx useless.
- The comment about %eax was wrong (but did explain why %eax used to be
fixed up).
Submitted by: bde
and treating (almost) all system calls the same way:
__sys_foo - actual syscall
foo, _foo - weak definitions to __sys_foo
Change PSEUDO syscalls (currently only _exit and _getlogin) to
be __sys_foo (T) and _foo (W).
Add $FreeBSD$ to a few files to satisfy commitprep.
Suggested by: bde
