If multiple threads enter fortuna_pre_read contemporaneously, such as via
read(2) or getrandom(2), they could race to check how long it has been since
the last update due to a TOCTOU problem with 'now'.
Here is an example problematic execution:
Thread A: Thread B:
now_A = getsbinuptime();
now_B = getsbinuptime(); // now_B > now_A
RANDOM_RESEED_LOCK();
if (now - fs_lasttime > SBT_1S/10) {
fs_lasttime = now;
... // reseed
}
RANDOM_RESEED_UNLOCK();
RANDOM_RESEED_LOCK();
if (now_A - fs_lasttime > SBT_1S/10) // now_A - fs_lasttime underflows
fs_lasttime = now_A;
... // reseed again, despite less than 100ms elapsing
}
RANDOM_RESEED_UNLOCK();
To resolve the race, simply check the current time after we win the lock
race.
If getsbinuptime is perceived to be expensive, another option might be to
just accept the race and validate that fs_lasttime isn't "in the future."
(It should be within the last ~2^31 seconds out of ~2^32 seconds
representable duration.)
Reviewed by: delphij, markm
Approved by: secteam (delphij)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D16984
The convention for updating hc_destination[] is to index with a
random_entropy_source. Zero happens to match RANDOM_CACHED, which is
correct for this source (early random data). Spell the zero value as the
enum name instead of the magic constant.
No functional change.
Reviewed by: delphij, markm
Approved by: secteam (delphij)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D16983
When modifying an existing managed mapping, we should find a PV entry
for the old mapping. Verify this.
Before r335784 this would have been implicitly tested by the fact that
we always freed the PV entry for the old mapping.
Reviewed by: alc, kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D17626
it appropriately when building share/ctypedef and share/colldef.
This makes the resulting locale data in EL->EB (amd64->powerpc64) cross
build and in the native EB build match. Revert the changes done to libc
in r308170 as they are no longer needed.
PR: 231965
Reviewed by: bapt, emaste, sbruno, 0mp
Approved by: kib (mentor)
Differential Revision: https://reviews.freebsd.org/D17603
In various places, random represents the set of sources as a 32-bit word
bitmask. It assumes all sources fit within this, i.e., the maximum valid
source number is 31.
There was a comment specifying this limitation, but we can actually refuse
to compile if our assumption is violated instead. We still have a few spare
random source slots, but sooner or later someone may need to convert the
masks used from raw 32-bit words to bitset(9) APIs.
This prevents some kinds of developer foot-shooting when adding new random
sources. No functional change.
Reviewed by: delphij, markm
Approved by: secteam (delphij)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D16982
Currently, the 'thread' command (to switch the debugger to another thread)
only accepts decimal-encoded tids. Use the same parsing logic as 'show
thread <arg>' to accept hex-encoded thread pointers in addition to
decimal-encoded tids.
Document the 'thread' command in ddb.4 and expand the 'show thread'
documentation to cover the tid usage.
Reported by: bwidawsk
Reviewed by: bwidawsk (earlier version), kib (earlier version), markj
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D16962
Remove unnecessary use of function-local static variable. 32 bytes is
small enough to live on the stack.
Reviewed by: delphij, markm
Approved by: secteam (delphij)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D16937
FS&K GenerateBlocks function asserts C (counter) != 0. This should also
be true in our implementation.
Reviewed by: delphij, markm
Approved by: secteam (delphij)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D16936
When reseeding, only incorporate actual key material. Do not include e.g.
the derived key schedules or other AES context.
I don't think the extra material was harmful here, just not beneficial.
Reviewed by: delphij, markm
Approved by: secteam (delphij)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D16934
Like the companion API devvn_refthread, leave *ref uninitialized when a
reference was not acquired. Initializing to 1 provides a vaguely
correct-looking but bogus value for broken callers to (mistakenly) pass to
dev_relthread() when refthread fails.
Make it even more clear to consumers that dev_relthread is only valid when
dev_refthread succeeds.
Reviewed by: kib, markj
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D16885
We no longer build the drm/drm2 modules by default. See UPDATING for
which package to install instead. drm and drm2 have been completely
unsupported abandonware for a long time now. Please report issues with
the pkg modules to x11@freebsd.org.
Approved by: FreeBSD Graphics Team
Update messaging for which drm module to install. Add guidance on what
hardware is supported (which should be copied into the release
notes). Note: the in tree drivers are abandonware. There has been no
organized support for them for many years, and the plan is to still
remove them for all but arm once the transition to drm-*kmod is
complete. Also note that WITHOUT_MODULE_DRM and WITHOUT_MODULE_DRM2
should generally be added to src.conf for anybody using the drm-*kmod
ports. That will become default in 13 soon, however.
Approved by: FreeBSD Graphics Team
Relnotes: Yes
MFC After: 3 days
Differential Revision: https://reviews.freebsd.org/D17451
Although _libelf_is_mips64el is only called in contexts where we've
already checked that e_class is ELFCLASS64 but this may change in the
future. Add a safety belt so that we don't access an invalid e_ehdr64
union member if it does.
Reported by: jkoshy (in review D17380)
It is often useful for developers and administrators to determine a running
thread's stack for debugging purposes. With this feature, using ^T will
print that information
For now, the feature is disabled by default. Enable with sysctl
kern.tty_info_kstacks=1.
Discussed with: markj
Reviewed by: oshogbo
Relnotes: yes
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D17621
the 3WHS is completed, establish the backend connection. The trigger
for "3WHS completed" is the reception of the first ACK. However, we
should not proceed if that ACK also has RST or FIN set.
PR: 197484
Obtained from: OpenBSD
MFC after: 2 weeks
Currently, rc.inidiskless assumes that local system configuration
changes are kept in some mountable file system. For example,
nanobsd uses dedicated partition mounted as /cfg for this.
However, small embedded devices like MIPS routers may have no enough flash
space to keep full-blown file system but have only one or couple
small flash blocks to keep persistent local configuration overrides.
This change extends rc.initdiskless and introduces ability to run auxiliary
command /conf/T/M/extract that is supposed to extract configuration overrides
from such local storage.
For example, the command /conf/default/etc/extract may contain something like:
cd "$1" && bsdcpio --quiet -idu < /dev/map/cfg
bsdcpio command extracts compressed archive from the storage to /etc
assuming the storage is exposed by the kernel as /dev/map/cfg to userland.
PR: 204215
MFC after: 1 month
When we set the ifname we have to copy the string, rather than just keep
the pointer.
PR: 231323
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D17507
Some best-effort consumers may find trylock behavior for stack(9) symbol
resolution acceptable. Expose that behavior to such consumers.
This API is ugly. If in the future the modules and linker file list locking
is cleaned up such that the linker_files list can be iterated safely without
acquiring a sleepable lock, this API should be removed. However, most of
the time nothing will be holding the linker files lock exclusive and the
acquisition can proceed.
Reviewed by: markj
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D17620
and make previously working configuration like this work again:
gif_interfaces="gif0"
gifconfig_gif0="1.1.1.1 2.2.2.2"
ifconfig_gif0="inet 192.168.1.1 192.168.1.2 netmask 255.255.255.252"
PR: 204700
MFC after: 1 month
We would fail to clear DNS search list configuration if a router
stopped specifying the DNSSL RA option. I suspect that the bug
was mostly harmless, as the RDNSS and DNSSL options are typically used
together and omitting the RDNSS option would have the same effect.
CID: 1006219
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Pre-defined policies are useful when integrating the domainset(9)
policy machinery into various kernel memory allocators.
The refactoring will make it easier to add NUMA support for other
architectures.
No functional change intended.
Reviewed by: alc, gallatin, jeff, kib
Tested by: pho (part of a larger patch)
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17416
In r339350 filter_reloc() was removed, to fix the case of stripping
statically linked binaries with relocations (which may come from ifunc
use, for example). As a side effect this changed the behaviour when
stripping object files - the output was broken both before and after
r339350, in different ways. Unfortunately GCC's build process relies
on the previous behaviour, so:
- Revert r339350, restoring filter_reloc().
- Fix an unitialized variable use (commited as r3638 in ELF Tool Chain).
- Change filter_reloc() to omit relocations referencing removed
symbols, while retaining relocations with no symbol reference.
- Retain the entire relocation section if it references the dynamic
symbol table (fix from kaiw in D17596).
PR: 232176
Reported by: antoine
Reviewed by: kaiw
MFC with: r339350
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17596
This makes the compiler less likely to reload the content from %gs.
The 'P' modifier drops all synteax prefixes and 'n' constraint treats
input as a known at compilation time immediate integer.
Example reloading victim was spinlock_enter.
Stolen from: OpenBSD
Reported by: jtl
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17615
Apparently AMD machines cannot tolerate this. This was uncovered by
r339386, where cache flush started really flushing the requested range.
Introduce pmap_mapdev_pciecfg(), which simply does not flush cache
comparing with pmap_mapdev(). It assumes that the MCFG region was
never accessed through the cacheable mapping, which is most likely
true for machine to boot at all.
Note that i386 does not need the change, since the architecture
handles access per-page due to the KVA shortage, and page remapping
already does not flush the cache.
Reported and tested by: mjg, Mike Tancsa <mike@sentex.net>
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
Approved by: re (gjb)
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D17612
returns the section start and stop locations as well as a count if the
caller asks for them.
There was only one out-of-file consumer of count which did not actually
use it and hence was eliminated in r339407.
In r194784 parse_dpcpu(), and in r195699 parse_vnet() (a copy of the
former) started to use the link_elf_lookup_set() interface internally
also asking for the count.
count is computed as the difference of the void **stop - void **start
locations and as such, if the absoulte numbers
(stop - start) % sizeof(void *) != 0
a round-down happens, e.g., **stop 0x1003 - **start 0x1000 => count 0.
To get the section size instead of "count is the number of pointer
elements in the section", the parse_*() functions do a
count *= sizeof(void *).
They use the result to allocate memory and copy the section data
into the "master" and per-instance memory regions with a size of
count.
As a result of count possibly round-down this can miss the last
bytes of the section. The good news is that we do not touch
out of bounds memory during these operations (we may at a later stage
if the last bytes would overflow the master sections).
Given relocation in elf_relocaddr() works based on the absolute
numbers of start and stop, this means that we can possibly try to
access relocated data which was never copied and hence we get
random garbage or at best zeroed memory.
Stop the two (last) consumers of count (the parse_*() functions)
from using count as well, and calculate the section size based on
the absolute numbers of stop and start and use the proper size for
the memory allocation and data copies. This will make the symbols
in the last bytes of the pcpu or vnet sections be presented as
expected.
PR: 232289
Approved by: re (gjb)
MFC after: 2 weeks
code paths. Both are not consistent and the one on the syn cache code
does not conform to the relevant specifications (Page 69 of RFC 793
and Section 4.2 of RFC 5961).
This patch fixes this:
* The sequence numbers checks are fixed as specified on
page Page 69 RFC 793.
* The sysctl variable net.inet.tcp.insecure_rst is now honoured
and the behaviour as specified in Section 4.2 of RFC 5961.
Approved by: re (gjb@)
Reviewed by: bz@, glebius@, rrs@,
Differential Revision: https://reviews.freebsd.org/D17595
Sponsored by: Netflix, Inc.
