lib{c,sys}: return wrapped syscall APIs to libc

These provide standard APIs, but are implemented using another system
call (e.g., pipe implemented in terms of pipe2) or are interposed by the
threadi

lib{c,sys}: return wrapped syscall APIs to libc

These provide standard APIs, but are implemented using another system
call (e.g., pipe implemented in terms of pipe2) or are interposed by the
threading library to support cancelation.

After discussion with kib (see D44111), I've concluded that it is
better to keep most public interfaces in libc with as little
as possible in libsys.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D44241

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libc/i386: don't attempt to export alloca

The assembly implementation was removed in 2006 (commit 3c03c7095e7e).

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D44242

libc: move MD sys related symbols to libsys

This is a mix genuine MD interfaces and compat symbols like _getlogin.

Reviewed by: kib, emaste, imp
Pull Request: https://github.com/freebsd/freebsd-src

libc: move MD sys related symbols to libsys

This is a mix genuine MD interfaces and compat symbols like _getlogin.

Reviewed by: kib, emaste, imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/908

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libc: centralize a few numeric symbols

fabs, __infinity, and __nan are universally implemented so declare them
in gen/Symbol.map.

We would also include __flt_rounds, but it's under FBSD_1.3 on arm

libc: centralize a few numeric symbols

fabs, __infinity, and __nan are universally implemented so declare them
in gen/Symbol.map.

We would also include __flt_rounds, but it's under FBSD_1.3 on arm so
until that's gone we're stuck with it. Likewise, everyone but i386
implements fp[gs]etmask.

Reviewed by: imp, kib, emaste
Differential Revision: https://reviews.freebsd.org/D42618

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libc: centralize makecontext symbols

Declare makecontext() and __makecontext() symbols centrally as they are
always implemented.

Reviewed by: imp, kib
Differential Revision: https://reviews.freebsd

libc: centralize makecontext symbols

Declare makecontext() and __makecontext() symbols centrally as they are
always implemented.

Reviewed by: imp, kib
Differential Revision: https://reviews.freebsd.org/D42617

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libc: centralize {_,sig,}{set,long}jmp symbols

These symbols are universally exposed and documented so declare them
centrally. Double- and triple-underscore versions exist on some
platforms, but le

libc: centralize {_,sig,}{set,long}jmp symbols

These symbols are universally exposed and documented so declare them
centrally. Double- and triple-underscore versions exist on some
platforms, but leave those alone for now.

Reviewed by: imp, kib
Differential Revision: https://reviews.freebsd.org/D42616

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libc: centralize ntoh symbols

These are implemented by net/ntoh.c via headers and compiler intrinsics
so declare them in net/Symbol.map.

Reviewed by: imp, kib, emaste
Differential Revision: https:/

libc: centralize ntoh symbols

These are implemented by net/ntoh.c via headers and compiler intrinsics
so declare them in net/Symbol.map.

Reviewed by: imp, kib, emaste
Differential Revision: https://reviews.freebsd.org/D42615

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libc: further centralize syscall symbols

All architectures necessarily implement _exit(2) and vfork(2) so
declare them in sys/Symbol.map.

Reviewed by: imp, kib, emaste
Differential Revision: https:

libc: further centralize syscall symbols

All architectures necessarily implement _exit(2) and vfork(2) so
declare them in sys/Symbol.map.

Reviewed by: imp, kib, emaste
Differential Revision: https://reviews.freebsd.org/D42614

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libc: Remove empty comments in Symbol.map

These were left over from $FreeBSD$ removal.

Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D42612

Remove $FreeBSD$: one-line .h pattern

Remove /^\s*\*+\s*\$FreeBSD\$.*$\n/

libc: Remove _get_tp() and _set_tp().

Their uses have been replaced by _tcb_get() and _tcb_set() from
<machine/tls.h>.

Reviewed by: kib, jrtc27
Sponsored by: The University of Cambridge, Google Inc

libc: Remove _get_tp() and _set_tp().

Their uses have been replaced by _tcb_get() and _tcb_set() from
<machine/tls.h>.

Reviewed by: kib, jrtc27
Sponsored by: The University of Cambridge, Google Inc.
Differential Revision: https://reviews.freebsd.org/D33354

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MFhead@r344527

Merge ^/head r344178 through r344512.

Add usermode helpers for for Intel userspace protection keys feature.

Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews

Add usermode helpers for for Intel userspace protection keys feature.

Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D18893

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Merge ^/head r340918 through r341763.

Remove MD __sys_* private symbols.

No references to any of these exist in the tree. The list was also
erratic with different architectures exporting different things
(arm64 and riscv exported none).

Remove MD __sys_* private symbols.

No references to any of these exist in the tree. The list was also
erratic with different architectures exporting different things
(arm64 and riscv exported none).

Reviewed by: kib
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D18425

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Reimplement brk() and sbrk() to avoid the use of _end.

Previously, libc.so would initialize its notion of the break address
using _end, a special symbol emitted by the static linker following
the bs

Reimplement brk() and sbrk() to avoid the use of _end.

Previously, libc.so would initialize its notion of the break address
using _end, a special symbol emitted by the static linker following
the bss section. Compatibility issues between lld and ld.bfd could
cause the wrong definition of _end (libc.so's definition rather than
that of the executable) to be used, breaking the brk()/sbrk()
interface.

Avoid this problem and future interoperability issues by simply not
relying on _end. Instead, modify the break() system call to return
the kernel's view of the current break address, and have libc
initialize its state using an extra syscall upon the first use of the
interface. As a side effect, this appears to fix brk()/sbrk() usage
in executables run with rtld direct exec, since the kernel and libc.so
no longer maintain separate views of the process' break address.

PR: 228574
Reviewed by: kib (previous version)
MFC after: 2 months
Differential Revision: https://reviews.freebsd.org/D15663

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Replace MD assembly exect() with a portable version.

Originally, on the VAX exect() enable tracing once the new executable
image was loaded. This was possible because tracing was controllable
throu

Replace MD assembly exect() with a portable version.

Originally, on the VAX exect() enable tracing once the new executable
image was loaded. This was possible because tracing was controllable
through user space code by setting the PSL_T flag. The following
instruction is a system call that activated tracing (as all
instructions do) by copying PSL_T to PSL_TP (trace pending). The
first instruction of the new executable image would trigger a trace
fault.

This is not portable to all platforms and the behavior was replaced with
ptrace(PT_TRACE_ME, ...) since FreeBSD forked off of the CSRG repository.
Platforms either incorrectly call execve(), trigger trace faults inside
the original executable, or do contain an implementation of this
function.

The exect() interfaces is deprecated or removed on NetBSD and OpenBSD.

Submitted by: Ali Mashtizadeh <ali@mashtizadeh.com>
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D14989

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MFH

Sponsored by: The FreeBSD Foundation

libc: stop exporting curbrk and minbrk in the private namespace

They are not used anywhere else in the base system and are an internal
implementation detail that does not need to be exposed.

Review

libc: stop exporting curbrk and minbrk in the private namespace

They are not used anywhere else in the base system and are an internal
implementation detail that does not need to be exposed.

Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5728

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Merge fresh head.

MFC @ r241285

IFC @ r242684

Sync from head

libc/i386: Do not export .cerror.

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 no

libc/i386: Do not export .cerror.

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.

Not exporting .cerror causes it to be jumped to directly instead of via the
PLT.

This change also takes advantage of .cerror's new status by not saving and
loading %ebx before jumping to it. (Therefore, .cerror now saves and loads
%ebx itself.) Where there was a conditional jump to a jump to .cerror, the
conditional jump has been changed to jump to .cerror directly (many modern
CPUs don't do static prediction and in any case it is not much of a benefit
anyway).

This change makes libc.so.7 a few kilobytes smaller.

Reviewed by: kib

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