Currently RTLD is linked against libc_nossp_pic which means that any libc
symbol used in rtld can pull in a lot of depedencies. This was causing
symbol such as __libc_interposing and all the pthread stubs to be included
in RTLD even though they are not required. It turns out most of these
dependencies can easily be avoided by providing overrides inside of rtld.
This change is motivated by CHERI, where we have an experimental ABI that
requires additional relocation processing to allow the use of function
pointers inside of rtld. Instead of adding this self-relocation code to
RTLD I attempted to remove most function pointers from RTLD and discovered
that most of them came from the libc dependencies instead of being actually
used inside rtld.
A nice side-effect of this change is that rtld is now 22% smaller on amd64.
text data bss dec hex filename
0x21eb6 0xce0 0xe60 145910 239f6 /home/alr48/ld-elf-x86.before.so.1
0x1a6ed 0x728 0xdd8 113645 1bbed /home/alr48/ld-elf-x86.after.so.1
The number of R_X86_64_RELATIVE relocations that need to be processed on
startup has also gone down from 368 to 187 (almost 50% less).
Reviewed By: kib
Differential Revision: https://reviews.freebsd.org/D20663
Summary:
PowerPC has two PLT models: BSS-PLT and Secure-PLT. BSS-PLT uses runtime
code generation to generate the PLT stubs. Secure-PLT was introduced with
GCC 4.1 and Binutils 2.17 (base has GCC 4.2.1 and Binutils 2.17), and is a
more secure PLT format, using a read-only linkage table, with the dynamic
linker populating a non-executable index table.
This is the libc, rtld, and kernel support only. The toolchain and build
parts will be updated separately.
Reviewed By: nwhitehorn, bdragon, pfg
Differential Revision: https://reviews.freebsd.org/D20598
MFC after: 1 month
Use appropriate fsyncs to persist the rewritten /etc/motd file, when a
rewrite is performed.
Reported by: Jonathan Walton <jonathan AT isilon.com>
Reviewed by: allanjude, vangyzen
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20701
The logic I originally wrote to detect whether a driftfile option was in the
set of flags was based on the result of removing the pattern *flag* being an
empty string. That didn't handle the case where the string was empty to
begin with. Doh! So now it also specifically checks for an empty string.
The result of the bad check was that ntpd would run without a driftfile, but
it would do so only if it was running as root instead of the non-priveleged
ntpd user, which isn't a typical case. Ntpd runs fine without a driftfile,
although it does take it longer to stabilize the clock frequency at startup.
Reported by: avg@
Pointy hat: ian@
MFC after: some testing
Tag saved entropy files as "nodump," to signal that the files should not be
backed up by dump(8) or other automated backup software that honors the file
flag.
Do not produce an error if the target file resides on a filesystem that does
not support file flags (e.g., msdos /boot).
Reviewed by: delphij
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20358
- Remove an extra space after "usage:".
- Avoid lines exceeding 80 columns.
Based on notes from rgrimes.
MFC with: r348066
Event: Waterloo Hackathon 2019
There were several (apparently) copy-pasted NEED validation macros,
leading to the same error string for different issues. Change the
YP and NTP tags so they are distinct.
PR: 30863
Submitted by: Dan Lukes <dan@obluda.cz>
Reviewed by: markj
MFC after: 1 week
Event: Waterloo Hackathon 2019
ed(4) and ep(4) have been removed. fxp(4) remains popular in older
systems, but isn't as future proof as em(4).
Reviewed by: bz, jhb
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D20311
Use roundup2() and rounddown2() instead of inlining them.
Get rid of the fd local variable, use literal -1 for the mmap argument.
Use MAP_FAILED as mmap(2) failure indicator.
After that, apply some style.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
kern_execve() locks text vnode exclusive to be able to set and clear
VV_TEXT flag. VV_TEXT is mutually exclusive with the v_writecount > 0
condition.
The change removes VV_TEXT, replacing it with the condition
v_writecount <= -1, and puts v_writecount under the vnode interlock.
Each text reference decrements v_writecount. To clear the text
reference when the segment is unmapped, it is recorded in the
vm_map_entry backed by the text file as MAP_ENTRY_VN_TEXT flag, and
v_writecount is incremented on the map entry removal
The operations like VOP_ADD_WRITECOUNT() and VOP_SET_TEXT() check that
v_writecount does not contradict the desired change. vn_writecheck()
is now racy and its use was eliminated everywhere except access.
Atomic check for writeability and increment of v_writecount is
performed by the VOP. vn_truncate() now increments v_writecount
around VOP_SETATTR() call, lack of which is arguably a bug on its own.
nullfs bypasses v_writecount to the lower vnode always, so nullfs
vnode has its own v_writecount correct, and lower vnode gets all
references, since object->handle is always lower vnode.
On the text vnode' vm object dealloc, the v_writecount value is reset
to zero, and deadfs vop_unset_text short-circuit the operation.
Reclamation of lowervp always reclaims all nullfs vnodes referencing
lowervp first, so no stray references are left.
Reviewed by: markj, trasz
Tested by: mjg, pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D19923
- Remove dead and most likely rotten MALLOC_DEBUG, MSTAT, and RCHECK options.
- Remove unused headers.
- Remove one case of undefined behavior where left shift could overflow.
It is impossible on practice for rtld and libthr consumer.
PR: 237577
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Since inits for the main binary are run from rtld (for some time), the
rtld_exit atexit(3) handler, which is passed from rtld to the program
entry and installed by csu, is installed after any atexit(3) handlers
installed by main binary constructors. This means that rtld_exit() is
fired before main binary handlers.
Typical C++ static constructors are executed from init (either binary
or libs) but use atexit(3) to ensure that destructors are called in
the right order, independent of the linking order. Also, C++
libraries finalizers call __cxa_finalize(3) to flush library'
atexit(3) entries. Since atexit(3) entry is cleared after being run,
this would be mostly innocent, except that, atexit(rtld_exit) done
after main binary constructors, makes destructors from libraries
executed before destructors for main.
Fix by reordering atexit(rtld_exit) before inits for main binary, same
as it happened when inits were called by csu. Do it using new private
libc symbol with pre-defined ABI.
Reported. tested, and reviewed by: kan
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
This causes some increase of the dynamic linker size, but benefits of
avoiding compiling private copy or the linker when debugging is
required. definitely worth it.
The dbg() calls can be compiled out by defining LD_NO_DEBUG symbol.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Since r233109, kldload has the -n option, which silently ignores options
that are already loaded.
https://lists.freebsd.org/pipermail/freebsd-rc/2018-December/003899.html
Note that this script no longer reports if the module is already loaded,
but it could be argued this wasn't particularly useful information.
PR: docs/234248
Reviewed by: bcr (docs), kib, rgrimes (visual)
Approved by: jilles
Differential Revision: https://reviews.freebsd.org/D18670
ifconfig(8) syntax allows to specify only single address_family,
so we need additional invocation of ifconfig to support configuration
of cloned gif interface that may use different address families
for its internal and external addresses.
Also, ifconfig(8) does not allow to omit "inet6" keyword for address family
specifying IPv6 addresses as outer addresses of the interface.
Also, address_family is not "parameter" and it has to go before parameters
including "tunnel" keyword, so "ifconfig gif0 tunnel inet6 $oip1 $oip2" would be
wrong syntax and only "ifconfig gif0 inet6 tunnel $oip1 $oip2" is right.
With this change, the following works:
gifconfig_gif0="inet6 2a00::1 2a01::1"
ifconfig_gif0="inet 10.0.0.1 10.0.0.2 netmask 255.255.255.252"
MFC after: 2 weeks
The goal of saving entropy in Fortuna is two-fold: (1) to provide early
availability of the random device (unblocking) on next boot; and (2), to
have known, high-quality entropy available for that initial seed. We know
it is high quality because it's output taken from Fortuna.
The FS&K paper makes it clear that Fortuna unblocks when enough bits have
been input that the output //may// be safely seeded. But they emphasize
that the quality of various entropy sources is unknown, and a saved entropy
file is essential for both availability and ensuring initial
unpredictability.
In FreeBSD we persist entropy using two mechanisms:
1. The /etc/rc.d/random shutdown() function, which is used for ordinary
shutdowns and reboots; and,
2. A cron job that runs every dozen minutes or so to persist new entropy, in
case the system suffers from power loss or a crash (bypassing the
ordinary shutdown path).
Filesystems are free to cache dirty data indefinitely, with arbitrary flush
policy. Fsync must be used to ensure the data is persisted, especially for
the cron job save-entropy, whose entire goal is power loss and crash safe
entropy persistence.
Ordinary shutdown may not need the fsync because unmount should flush out
the dirty entropy file shortly afterwards. But it is always possible power
loss or crash occurs during the short window after rc.d/random shutdown runs
and before the filesystem is unmounted, so the additional fsync there seems
harmless.
PR: 230876
Reviewed by: delphij, markj, markm
Approved by: secteam (delphij)
Differential Revision: https://reviews.freebsd.org/D19742
If dso uses initial exec TLS mode, rtld tries to allocate TLS in
static space. If there is no space left, the dlopen(3) fails. If space
if allocated, initial content from PT_TLS segment is distributed to
all threads' pcbs, which was missed and caused un-initialized TLS
segment for such dso after dlopen(3).
The mode is auto-detected either due to the relocation used, or if the
DF_STATIC_TLS dynamic flag is set. In the later case, the TLS segment
is tried to allocate earlier, which increases chance of the dlopen(3)
to succeed. LLD was recently fixed to properly emit the flag, ld.bdf
did it always.
Initial test by: dumbbell
Tested by: emaste (amd64), ian (arm)
Tested by: Gerald Aryeetey <aryeeteygerald_rogers.com> (arm64)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D19072
allocate_tls_offset returns true on success. The same issue existed
on arm and was fixed in r345693.
PR: 236880
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
allocate_tls_offset returns true on success. This still needs more
testing and review, but this change is consistent with other archs.
PR: 236880
Reported by: Andrew Gierth <andrew@tao11.riddles.org.uk>
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
r345620 by kib@ fixed the rtld issue that caused a crash at startup
during resolution of libc's ifuncs with BIND_NOW.
PR: 233333
Sponsored by: The FreeBSD Foundation
modules by declaring corresponding variables in rc.conf. Also document
them in rc.conf(5).
Submitted by: Dries Michiels
Differential Revision: https://reviews.freebsd.org/D19673
It seems my subconcious plan in r345088 to not only prefer IPv6 autoconf
but to also slowly deteriorate legacy IP auto-configuration was uncovered
way too early.
In case IPv6 is a thing yet ipv6_autoconfif was not true, we would not
bring up the interface yet tell the follow-up DHCPv4 configuration in
ifconfig_up() that we did. So unless you were doing SYNCDHCP or IPv6
you would not get legacy-IP DHCPv4 configuration.
I see multiple problems here: (a) people not yet using IPv6 (obviously a
problem), and (b) the dhclient startup script not running dhclient in
that case despite configured to do so (needs to be investigated seperately).
Reported by: Pawel Biernacki (pawel.biernacki gmail.com)
Tested by: Pawel Biernacki
Differential Revision: https://reviews.freebsd.org/D19488
Pointyhat to: bz (not sure if it is for breaking or
for letting them notice it so easily)
Before this change we would only run rtsol on an interface which was
set to accept_rtadv and did not have rtsold enabled. This change
removes the latter condition and always runs rtsol (rather than the
deferred rtsold) to reduce the delay until we send the first RS.
This change will also handle the accept_rtadv before dhcp hence
starting IPv6 auto-configuration before IPV4 DHCP.
This change is intended for FreeBSD 13 and later only and will not be MFCed.
Reviewed by: hrs
Differential Revision: https://reviews.freebsd.org/D19488
FreeBSD removed the default /etc/pf.conf file in previous releases, but
the documentation kept mentioning it like any other file present in the
system. Change pf.conf(5) to mention in the description of the default
ruleset location that this file needs to be created manually. Also, the
default rc.conf file had it's comment extended a bit to let people know
that this file does not exist by default.
PR: 231977
Submitted by: koobs@
Reviewed by: kp@, 0mp@
Approved by: kp@
MFC after: 10 days
Differential Revision: https://reviews.freebsd.org/D19530
is specified.
When WITHOUT_IPFILTER is specified, delete-old-files fails to delete
the optional rc.d files from above. Fix this.
WITHOUT_IPFILTER fails to delete the ipfilter.5 optional file during
delete-old-files. Fix this.
Reported by: Dmitry Luhtionov <dmitryluhtionov@gmail.com>
MFC after: 1 week
