Commit Graph

24 Commits

Author SHA1 Message Date
Mark Johnston
9f9c9b22ec 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
2018-06-04 19:35:15 +00:00
Brooks Davis
87385baff6 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
2018-04-12 18:23:14 +00:00
Brooks Davis
97e5d68bb0 Remove architecture specific shmat.S files.
These files are identical to the generated system calls.
In the case of MIPS, the file was already disconnected from the build.

Submitted by:	Ali Mashtizadeh <ali@mashtizadeh.com>
Reviewed by:	kib
Differential Revision:	https://reviews.freebsd.org/D14976
2018-04-05 18:17:46 +00:00
Brooks Davis
aec2fba60f Reduce duplicate NOASM and PSEUDO definitions
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
2016-09-08 22:38:20 +00:00
Konstantin Belousov
afd3e268d2 Rewrite ptrace(2) wrappers in C.
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
2016-08-29 18:47:51 +00:00
George V. Neville-Neil
5cba398b0c Remove unusedd and obsolete openbsd_poll system call. (Phase 1)
Reported by:	brooks
Reviewed by:	brooks,jhb
Differential Revision:	https://reviews.freebsd.org/D7548
2016-08-18 10:50:40 +00:00
Brooks Davis
b60998c633 Replace use of the pipe(2) system call with pipe2(2) with a zero flags
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
2016-06-22 21:11:27 +00:00
Brooks Davis
0aa6527ff0 Removed unused special fork() implementations.
The arm version hasn't been used in ages.

The mips version uses a valid, but pointless check of v1 and has been
unhooked from the build since r276630.

Differential Revision:	https://reviews.freebsd.org/D2592
Reviewed by:	emaste
Sponsored by:	DARPA, AFRL
2015-05-29 19:42:55 +00:00
Konstantin Belousov
0538aafc41 The lseek(2), mmap(2), truncate(2), ftruncate(2), pread(2), and
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
2015-04-18 21:50:13 +00:00
Ed Maste
541236cf60 libc: Eliminate duplicate copies of __vdso_gettc.c
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D2152
2015-04-02 21:18:11 +00:00
Warner Losh
a5fc5b6223 Convert from WITHOUT_SYSCALL_COMPAT to MK_SYSCALL_COMPAT. 2014-04-05 17:54:43 +00:00
Konstantin Belousov
150facd256 Rework the __vdso_* symbols attributes to only make the symbols weak,
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
2013-01-30 12:48:16 +00:00
Jayachandran C.
60ddfa2837 use PTR_WORD for __curbrk and minbrk instead of .word, the new version
wil support all ABIs.

Approved by:	rrs (mentor)
2010-06-25 05:36:36 +00:00
Jayachandran C.
9279d32a64 Merge jmallett@'s n64 work into HEAD - changeset 2
Update libc Makefiles.
Add makecontext implementation.

Changes from http://svn.freebsd.org/base/user/jmallett/octeon

Approved by:	rrs(mentor), jmallett
2010-06-16 14:13:36 +00:00
Jayachandran C.
a7c139c0af Merge jmallett@'s n64 work into HEAD - changeset 1.
Update libc assembly code to use macros that work on both o32 and n64.
Merge string functions from NetBSD.

The changes are from http://svn.freebsd.org/base/user/jmallett/octeon

Approved by:	rrs (mentor), jmallett
2010-06-16 12:55:14 +00:00
Neel Natu
2f9f616df9 Reinstate the ptrace patch to restore the 'gp' register after calling
a function. I made a mistake in assuming that the .cprestore directive
will cause the assembler to automatically restore 'gp' after the 'jalr'.

The .cprestore directive does its magic only after 'jal' and 'bal'
instructions - not the 'jalr'.

Pointed out by: c.jayachandran@gmail.com
2010-02-04 05:49:59 +00:00
Randall Stewart
1df3671344 -White space cleanup (missing spaces in new line)
-Remove extra tab.
-Took out the duplicate code that cprestore does.
All suggested by Neel.
2010-02-03 20:54:04 +00:00
Randall Stewart
1de48bf3a3 This fixes a bug found and fixed by JC. Basically
no save was being done of the ra and gp pointers
before we call the __error function.

Obtained from:	JC (c.jayachandran@gmail.com)
2010-02-03 12:59:44 +00:00
Warner Losh
87e925fb53 Merge r197800 from projects/mips to head by hand:
r197800 | gonzo | 2009-10-06 00:35:52 -0600 (Tue, 06 Oct 2009) | 3 lines
- curbrk variable for sbrk and brk should be the same
- Add correct variable names to Symbol.map
2010-01-08 23:59:04 +00:00
Warner Losh
21fc9f2bcc These warnings are only relevant on NetBSD it seems. They don't seem
to be relevant to FreeBSD at all.
2009-02-19 19:53:58 +00:00
Ed Schouten
a1b5a8955e Mark uname(), getdomainname() and setdomainname() with COMPAT_FREEBSD4.
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
2008-11-09 10:45:13 +00:00
Warner Losh
4ce261061f Add mips support libc from the mips2-jnpr branch of perforce. 2008-04-26 12:08:02 +00:00
David E. O'Brien
d9c0a739c5 Remove these abortive MIPS bits. 2002-03-23 17:55:32 +00:00
Warner Losh
d7ee48f115 Bring in initial libc support for mips. These files were taken from
the OpenBSD tree and should be considered preliminary.  They are here
to facilitate building of the tree.
1999-03-03 07:06:17 +00:00