Add retguard to amd64 syscalls.

Since we got rid of padded syscalls we have enough registers to do this.

ok deraadt@ ok kettenis@

Add ENTRY_NB() macro for doing an ASM function entry without setting
the binding to global (NB == "no binding"), as clang 13 is now
warning about changing the binding from global to weak.

This first

Add ENTRY_NB() macro for doing an ASM function entry without setting
the binding to global (NB == "no binding"), as clang 13 is now
warning about changing the binding from global to weak.

This first pass does amd64 and sparc64 and pulls DEFS.h out of the
per-arch directory to a common directory; others to follow

ok kettenis@

show more ...

Make brk() and sbrk() weak again as intended.

ok jca@

Don't need .text before ENTRY(), also minor spacing cleanups

Clang ignores a .weak directive before a function is actually defined. So
move it from before ENTRY() to after END(). Keeps brk(2) and sbrk(2) weak
when comping libc with clang.

ok guenther@

Use a Thread Information Block in both single and multi-threaded programs.
This stores errno, the cancelation flags, and related bits for each thread
and is allocated by ld.so or libc.a. This is an

Use a Thread Information Block in both single and multi-threaded programs.
This stores errno, the cancelation flags, and related bits for each thread
and is allocated by ld.so or libc.a. This is an ABI break from 5.9-stable!

Make libpthread dlopen'able by moving the cancelation wrappers into libc
and doing locking and fork/errno handling via callbacks that libpthread
registers when it first initializes. 'errno' *must* be declared via
<errno.h> now!

Clean up libpthread's symbol exports like libc.

On powerpc, offset the TIB/TCB/TLS data from the register per the ELF spec.

Testing by various, particularly sthen@ and patrick@
ok kettenis@

show more ...

Adds hidden _libc_FOO aliases for the system call stubs.
Stop generating _brk and _sbrk symbols: they've already been hidden.
Set the ELF symbol size on the syscall stubs.
Give the __{min,cur}brk sym

Adds hidden _libc_FOO aliases for the system call stubs.
Stop generating _brk and _sbrk symbols: they've already been hidden.
Set the ELF symbol size on the syscall stubs.
Give the __{min,cur}brk symbols a size and type, and hide more jump labels.

ok deraadt@

show more ...

Hide many (194!) symbols that nothing should be using.
Delete exect(2); it wasn't portable across archs and nothing used it.

ports test build by naddy@
ok deraadt@ kettenis@

Set FUNC symbol sizes of auto-generated and hand-written syscall wrappers.

Original diff from guenther@, adjusted by me.

OK guenther@

Convert cpp | as rules in bsd.lib.mk and lib/libc/sys/Makefile.inc to pure cc
invocations. This allows us to use the compiler builtin define __PIC__ to check
for PIC/PIEness rather than passing -DPI

Convert cpp | as rules in bsd.lib.mk and lib/libc/sys/Makefile.inc to pure cc
invocations. This allows us to use the compiler builtin define __PIC__ to check
for PIC/PIEness rather than passing -DPIC. Simplifies PIE work a lot.

ok matthew@, conceptually ok kurt@

show more ...

The int (32bit) argument must be sign extended on the 64 bit amd64 before
the add. ok miod@, toby@. olrite mickey@

CURBRK -> __curbrk changes from mickey, minbrk addition by me, ok mickey@

things for amd64; from art@