Linkers are supposed to mark PIE binaries with DF_1_PIE, such binary
cannot be correctly and usefully loaded neither by dlopen(3) nor as a
dependency of other object. For instance, we cannot do anything
useful with COPY relocations, among other things.
Glibc already added similar restriction.
Requested and reviewed by: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D25086
It is wrong to relate on __FreeBSD_version, either from
include/param.h, kernel, or libc, to check for rtld features.
Rtld might be from newer world than the running userspace.
Add special private symbols exported by rtld itself, to indicate the
changes in runtime behavior, and features that cannot be otherwise
detected or deduced at runtime.
Note that the symbols are not exported from libc, so they intentionally
cannot be linked against, and exported from the private namespace from rtld.
Consumers are required to use dlsym(3). For instance, for
_rtld_version_laddr_offset, user should do
ptr = dlsym(RTLD_DEFAULT, "_rtld_version_laddr_offset")
or even
ptr = dlvsym(RTLD_DEFAULT, "_rtld_version_laddr_offset",
"FBSDprivate_1.0");
Non-null ptr means that the change is present.
Also add _rtld_version__FreeBSD_version indicator to report the
headers version used at time of the rtld build.
Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D24982
Keep link_map l_addr binary layout compatible, rename l_addr to l_base
where rtld returns map base. Provide relocbase in newly added l_addr.
This effectively reverts the patch to the initial version of D24918.
Reported by: antoine (portmgr)
Reviewed by: jhb, markj
Tested by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D24946
It previously returned the object map base address, while all other
ELF operating systems return load offset, i.e. the difference between
map base and the link base.
Explain the meaning of the field in the man page.
Stop filling the mips-only l_offs member, which is apparently unused.
PR: 246561
Requested by: Damjan Jovanovic <damjan.jov@gmail.com>
Reviewed by: emaste, jhb, cem (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D24918
Prior to this change, using lagg to aggregate wired and wireless networks
was broken in the (relatively common) case where wifi drivers + firmware
are loaded by devmatch, since the interface didn't exist at the time when
the lagg interface was being created.
Suggested by: imp
MFC after: 3 days
Assume gcc is at least 6.4, the oldest xtoolchain in the ports tree.
Assume clang is at least 6, which was in 11.2-RELEASE. Drop conditions
for older compilers.
Reviewed by: imp (earlier version), emaste, jhb
MFC after: 2 weeks
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D24802
Clang10 may use FPU instructions for optimizing operations with
memory blocks. But we don't want to do lengthy save/restore of all
FPU registers across each rtld_start() call.
MFC after: 3 week
For PIE binaries, ldd(1) performs dlopen(RTLD_TRACE) on the binary.
It is legal for binary to use initial exec TLS mode, but when such
binary (actually dso) is dlopened, we might not have enough free space
in the finalized static TLS segment. Make ldd operational by skipping
TLS space allocation, we are not going to execute any code from the
dso anyway.
Reported by: tobik
PR: 245677
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
instead of MK_KERBEROS. The reason for this change is some users
prefer to build FreeBSD WITHOUT_KERBEROS, wanting to retain the
Kerberos rc scripts to start/stop MIT Kerberos or Heimdal from ports.
PR: 197337
Reported by: Adam McDougall <ebay at looksharp.net>
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D24252
This is continuation of D21163/r359634, which handled the alignment
for global mode.
Non-x86 arches are not handled, maintainers are welcomed.
Tested by: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D24366
The sshd service is using ssh-keygen to generate missing SSH keys.
If ssh-keygen is missing, it prints the following message:
> /etc/rc.d/sshd: WARNING: /usr/bin/ssh-keygen does not exist.
It makes sense when the key is not generated yet and
cannot be created because ssh-keygen is missing.
The problem is that even if the key is present on the host,
the sshd service would still warn about missing ssh-keygen
(even though it does not need it).
Reviewed by: emaste
Approved by: emaste (src)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D23911
This is mostly two problems spread out far and wide:
- ypldap_process should be declared properly
- debug is defined differently in many programs
For the latter, just extern it and define it everywhere that actually needs
it. This mostly works out nicely for ^/libexec/ypxfr, which can remove the
assignment at the beginning of main in favor of defining it properly.
-fno-common will become the default in GCC10/LLVM11.
MFC after: 3 days
See https://sourceware.org/bugzilla/show_bug.cgi?id=24606 for the test case.
See https://reviews.llvm.org/D64930 for the background and more discussion.
Also this fixes another bug in malloc_aligned() where total size of
the allocated memory might be not enough to fit the aligned requested
block after the initial pointer is incremented by the pointer size.
Reviewed by: bdragon
Tested by: antoine (exp-run PR 244866), bdragon, emaste
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D21163
The bootstrap flua should not be used for REPL-like activities; exclude it
to save the dependency on libedit and not waste time with it.
X-MFC-With: r359453
rc scripts arent configuration files so use FILES instead of CONFS.
While here put rc scripts into related package (sendmail in the FreeBSD-sendmail
package, wpa_supplicant in the FreeBSD-wpa etc ...)
Reviewed by: bapt, emaste
Differential Revision: https://reviews.freebsd.org/D24177
On UFS with SU+J, sometimes fsck's default recovery from journal marks the
filesystem as clean but some errors remain.
With SU only, default fsck in preen mode sometimes thinks all errors have
been fixed but some still remain.
To address the issues above, this change adds a new config option:
fsck_flags. By default it's set to -p, but the user may change it to -y
or -f -y, for instance, to force a full fsck after a system crash.
Submitted by: jhibbits@ (original version)
Reviewed by: mckusick
Differential Revision: https://reviews.freebsd.org/D24087
nsswitch.conf for backward compatibility. This file was used
over 19 years ago, before introducing nsdispatch() in the
name-service lookup APIs.
MFC after: 3 days
The new liblua will be used in a forthcoming import of kyua.
Reviewed by: kevans
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D24090
Lua does not provide a native way to change the permission of a file.
Submitted by: Yang Wang <2333@outlook.jp>
Reviewed by: kevans
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D24036
autofs was introduced with FreeBSD 10.1 and is the supported method for
automounting filesystems. As of r296194 the amd man page claimed that it
is deprecated. Remove it from base now; the sysutils/am-utils port is
still available if necessary.
Discussed with: cy
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
r358556 added alignas() use to the functional tests, which isn't defined
until C11. Raise the -std to C11 to fix the build under freebsd-gcc{6,9}.
Reported by: mhorne, Jenkins/CI
The windowsize option permits multiple blocks to be transmitted
before the receiver sends an ACK improving throughput for larger
files.
Reviewed by: asomers
MFC after: 2 weeks
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D23836
realpath(3) is used a lot e.g., by clang and is a major source of getcwd
and fstatat calls. This can be done more efficiently in the kernel.
This works by performing a regular lookup while saving the name and found
parent directory. If the terminal vnode is a directory we can resolve it using
usual means. Otherwise we can use the name saved by lookup and resolve the
parent.
See the review for sample syscall counts.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D23574
lld 10.0 seems to generate this relocation for rdtsc_mb() ifunc in our libc.
Reported, reviewed, and tested by: dim (amd64, previous version)
Discussed with: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23652
This allows for rtld to not issue two sigprocmask(2) syscalls for each
symbol binding operation in single-threaded processes. Rtld needs to
block signals as part of locking to ensure signal safety of the bind
process, because signal handlers might need to lazily resolve symbol
references.
As result, number of syscalls issued on startup by simple programs not
using libthr, is typically reduced 2x. For instance, for hello world,
I see:
non-sigfastblock
# (truss ./hello > /dev/null) |& wc -l
63
sigfastblock
# (truss ./hello > /dev/null) |& wc -l
37
Tested by: pho
Disscussed with: cem, emaste, jilles
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D12773
It's faster and more reliable to wait_for_pids than to sleep 1.
cem@ suggested just to remove auditd_stop() and use the rc.subr default
stop action (SIGTERM instead of audit -t), which has a built-in
wait_for_pids. That may be a better solution.
Discussed with: cem
Reviewed by: asomers
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D23223
They were introduced to take care of ifunc, but right now no architecture
provides ifunc'ed variants. Since rtld uses memset extensively this results in
a pessmization. Should someone want to use ifunc here they should provide a
mandatory symbol (e.g., rtld_memset).
See the review for profiling data.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D23176
Move all MD statements into $MACHINE_ARCH/Makefile.inc.
Unconditionally apply version script to rtld, the interpreter is not
functional without it for long time.
Reviewed by: brooks, emaste
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D23083
The path is already absolute.
Noted and reviewed by: rstone
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23121
instead of killing the process. The same behaviour of terminating
image activation if the $ORIGIN cannot be resolved for the main
object, is kept.
Reported by: Greg V <greg@unrelenting.technology>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23053
We know the binary relative name and can reliably calculate cwd path.
Because realpath(3) was already linked into ld-elf.so.1, reuse it
there to resolve dots and dotdots making the path more canonical.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23014
People use rc.conf inside vnet jails to configure networking setups.
Presumably because some sysctl were not virtualised up until r356527 the
script was not run for vnet jails leaving the rc.conf options without
effect for non-obvious reasons. Run the netoptions startup script also
for VNET jails now to make the rc.conf options work.
PR: 243193
MFC after: 2 weeks
binpath local was changed from char array to a char pointer, update
strlcpy/strlcat uses.
Reported by: Coverity through vangyzen
CID: 1412239 and 1412240
Reviewed by: emaste, imp, vangyzen
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23090
When rtld is directly executed with arguments, it has to move the
program arguments, environment and elf aux data up a few slots to
remove its own arguments before the process being executed sees
them. When copying the environment, rtld was incorrectly testing
whether the location about to be written to currently contained
NULL, when was supposed to check whether it had just copied the
NULL terminator of the environment string. This had the result
that the ELF aux data was mostly treated as environment variables,
and rtld would quickly crash when it tried to access required
ELF aux data that it didn't think was present.
Differential Revision: https://reviews.freebsd.org/D23008
Reviewed by: kib
MFC after: 1 month
When activated in direct exec mode, kernel-provided AT_EXECPATH points
to the interpreter. We need to recalculate auxv to point to the
string with the path to the executable which is actually executed.
The somewhat problematic case is when the executable path is relative
and either $PATH use is not enabled or it contains '/' so $PATH search
is not performed. In this case resulting AT_EXECPATH is relative, I
might fix this later.
Reported and reviewed by: rstone
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D22894
Summary:
As a transition aide, implement an alternative elfN_freebsd_fixup which
is called for old powerpc binaries. Similarly, add a translation to rtld to
convert old values to new ones (as expected by a new rtld).
Translation of old<->new values is incomplete, but sufficient to allow an
installworld of a new userspace from an old one when a new kernel is running.
Test Plan:
Someone needs to see how a new kernel/rtld/libc works with an old
binary. If if works we can probalby ship this. If not we probalby need
some more compat bits.
Submitted by: brooks
Reviewed by: jhibbits
Differential Revision: https://reviews.freebsd.org/D20799
As PowerPC is moving to clang, we can finally start taking advantage of
IFUNC.
Implement the MD parts of IFUNC handling for rtld.
Currently, it is necessary to look for R_PPC_IRELATIVE in the PLT in
addition to RELA. This is an ABI violation, but LLD9 has some .iplt bugs
that require this as a workaround.
Reviewed by: jhibbits
Differential Revision: https://reviews.freebsd.org/D22855
As PowerPC is moving to clang, we can finally start taking advantage of
IFUNC.
Implement the MD parts of IFUNC handling for rtld.
Currently, it is necessary to look for R_PPC_IRELATIVE in the PLT in
addition to RELA. This is an ABI violation, but LLD9 has some .iplt bugs
that require this as a workaround.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D22789
When a PT_LOAD segment has a zero p_filesz, skip the data mmap, as mmapping
zero bytes from a file is an error.
A PT_LOAD with zero p_filesz is legal (but somewhat uncommon due to segment
merging in modern linkers, as it is more efficient to merge .data and .bss
by just extending p_memsz in the previous segment, assuming compatible
page protection.)
This was seen on ports/graphics/glew on a powerpc64 ELFv2 experimental
build.
Submitted by: Alfredo Dal'Ava Junior <alfredo.junior@eldorado.org.br>
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D22634
Update a bunch of Makefile.depend files as
a result of adding Makefile.depend.options files
Reviewed by: bdrewery
MFC after: 1 week
Sponsored by: Juniper Networks
Differential Revision: https://reviews.freebsd.org/D22494
Leaf directories that have dependencies impacted
by options need a Makefile.depend.options file
to avoid churn in Makefile.depend
DIRDEPS for cases such as OPENSSL, TCP_WRAPPERS etc
can be set in local.dirdeps-options.mk
which can add to those set in Makefile.depend.options
See share/mk/dirdeps-options.mk
Reviewed by: bdrewery
MFC after: 1 week
Sponsored by: Juniper Networks
Differential Revision: https://reviews.freebsd.org/D22469
TP points to the start of the TLS block after the tcb, but
Obj_Entry.tlsoffset includes the tcb, so subtract the size of the tcb
to compute the offset relative to TP.
This is identical to the same fixes for powerpc in r339072 and r342671.
Reviewed by: James Clarke
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D22661
o Remove All Rights Reserved from my notices
o imp@FreeBSD.org everywhere
o regularize punctiation, eliminate date ranges
o Make sure that it's clear that I don't claim All Rights reserved by listing
All Rights Reserved on same line as other copyright holders (but not
me). Other such holders are also listed last where it's clear.
Before this commit, the save-entropy script rotates entropy files
like logs. This involves creating a new file that holds the entropy
and renaming of all existing entropy files. However, the entropy
data do not really need to be kept in a particular order, and
replacing the oldest file is sufficient.
This commit replaces the rotation with a scan in the
[1..entropy_save_num] space that finds the first empty slot, or
the slot of the oldest file, and writes entropy into that slot.
This also fixes an issue that prevents save-entropy from saving
any entropy when there is one non-regular file in any slot as a
side effect.
Based on an earlier patch from peterj@.
PR: 134225
Reported by: peterj
Reviewed by: csprng (cem, markm)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D22612
When a system has no internet connection, or when it is configured to obtain
ntpd leapfiles from some source other than the internet, or even when the
sysadmin has decided for some reason to customize ntp.conf to eliminate use
of the leapfile, the rc.d/ntpd script emits various error messages related
to the file.
This change allows setting the rc var ntp_db_leapfile to NONE to disable all
automatic processing related to that file in rc.d/ntpd.
Differential Revision: https://reviews.freebsd.org/D22461
Four bytes of padding are needed in the regular powerpc case to bring the
stack frame size up to a multiple of 16 bytes to meet ABI requirements.
Fixes odd hangs I was encountering during testing.
Summary:
We need to save off the full 64-bit register, not just the low 32 bits,
of all registers getting saved off in _rtld_bind_start. Additionally,
we need to save off the other SPE registers (SPEFSCR and accumulator),
so that their program state is not affected by the PLT resolver.
Reviewed by: bdragon
Differential Revision: https://reviews.freebsd.org/D22520
Each boot, regenerate /var/run/os-release based on the currently running
system. Create a /etc/os-release symlink pointing to this file (so that this
doesn't create a new reason /etc can not be mounted read-only).
This is compatible with what other systems do and is what the sysutil/os-release
port attempted to do, but in an incomplete way. Linux, Solaris and DragonFly all
implement this natively as well. The complete standard can be found at
https://www.freedesktop.org/software/systemd/man/os-release.html
Moving this to the base solves both the non-standard location problem with the
port, as well as the lack of update of this file on system update.
Bump __FreeBSD_version to 1300060
PR: 238953
Differential Revision: https://reviews.freebsd.org/D22271
FreeBSDlua ("flua") is a FreeBSD-private lua, flavored with whatever
extensions we need for base system operations. We currently support a subset
of lfs and lposix that are used in the rewrite of makesyscall.sh into lua,
added in r354786.
flua is intentionally written such that one can install standard lua and
some set of lua modules from ports and achieve the same effect.
linit_flua is a copy of linit.c from contrib/lua with lfs and lposix added
in. This is similar to what we do in stand/. linit.c has been renamed to
make it clear that this has flua-specific bits.
luaconf has been slightly obfuscated to make extensions more difficult. Part
of the problem is that flua is already hard enough to use as a bootstrap
tool because it's not in PATH- attempting to do extension loading would
require a special bootstrap version of flua with paths changed to protect
the innocent.
src.lua.mk has been added to make it easy for in-tree stuff to find flua,
whether it's bootstrap-flua or relying on PATH frobbing by Makefile.inc1.
Reviewed by: brooks, emaste (both earlier version), imp
Differential Revision: https://reviews.freebsd.org/D21893
to disable mounting Linux-specific filesystems under /compat/linux
when 'linux_enable' is set to YES.
Reviewed by: netchild, ian (earlier version)
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D22320
Alter bsd.compat.mk to set MACHINE and MACHINE_ARCH when included
directly so MD paths in Makefiles work. In the process centralize
setting them in LIBCOMPATWMAKEENV.
Alter .PATH and CFLAGS settings in work when the Makefile is included.
While here only support LIB32 on supported platforms rather than always
enabling it and requiring users of MK_LIB32 to filter based
TARGET/MACHINE_ARCH.
The net effect of this change is to make Makefile.libcompat only build
compatability libraries.
Changes relative to r354449:
Correct detection of the compiler type when bsd.compat.mk is used
outside Makefile.libcompat. Previously it always matched the clang
case.
Set LDFLAGS including the linker emulation for mips where -m32 seems to
be insufficent.
Reviewed by: imp, kib (origional version in r354449)
Obtained from: CheriBSD (conceptually)
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D22251
Alter bsd.compat.mk to set MACHINE and MACHINE_ARCH when included
directly so MD paths in Makefiles work. In the process centralize
setting them in LIBCOMPATWMAKEENV.
Alter .PATH and CFLAGS settings in work when the Makefile is included.
While here only support LIB32 on supported platforms rather than always
enabling it and requiring users of MK_LIB32 to filter based
TARGET/MACHINE_ARCH.
The net effect of this change is to make Makefile.libcompat only build
compatability libraries.
Reviewed by: imp, kib
Obtained from: CheriBSD (conceptually)
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D22251
Previously the watchdog timeout message was appended to the last entry
in the "Waiting for PIDS" list, resulting in a message like
Waiting for PIDS: 31299 31296 90201 9020090 second watchdog timeout
expired. Shutdown terminated.
Print a newline to separate the watchdog timeout message. Also perform
the kill before logging or echoing the message.
PR: 241072
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
This change allows to specify a watchdog(9) timeout for a system
shutdown. The timeout is activated when the watchdogd daemon is
stopped. The idea is to a prevent any indefinite hang during late
stages of the shutdown. The feature is implemented in rc.d/watchdogd,
it builds upon watchdogd -x option.
Note that the shutdown timeout is not actiavted when the watchdogd
service is individually stopped by an operator. It is also not
activated for the 'shutdown' to the single-user mode. In those cases it
is assumed that the operator knows what they are doing and they have
means to recover the system should it hang.
Significant subchanges and implementation details:
- the argument to rc.shutdown, completely unused before, is assigned to
rc_shutdown variable that can be inspected by rc scripts
- init(8) passes "single" or "reboot" as the argument, this is not
changed
- the argument is not mandatory and if it is not set then rc_shutdown is
set to "unspecified"
- however, the default jail management scripts and jail configuration
examples have been updated to pass "jail" to rc.shutdown, just in case
- the new timeout can be set via watchdogd_shutdown_timeout rc option
- for consistency, the regular timeout can now be set via
watchdogd_timeout rc option
- watchdogd_shutdown_timeout and watchdogd_timeout override timeout
specifications in watchdogd_flags
- existing configurations, where the new rc options are not set, should
keep working as before
I am not particularly wed to any of the implementation specifics.
I am open to changing or removing any of them as long as the provided
functionality is the same (or very close) to the proposed one.
For example, I think it can be implemented without using watchdogd -x,
by means of watchdog(1) alone. In that case there would be a small
window between stopping watchdogd and running watchdog, but I think that
that is acceptable.
Reviewed by: bcr (man page changes)
MFC after: 5 weeks
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D21221
'sysvipc' - it has nothing to do with ABIs, and I'd like to later
rename 'abi' to 'linux', which better describes its purpose and also
matches the rcvar name.
Reviewed by: emaste
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21615
has become very trigger-happy with libc++ 9.0.0.
It does not help that gcc's implementation of this warning is even more
trigger-happy, in the sense that it already warns on the declaration
itself, not when you are using it. This is very annoying with our use
of -Wsystem-headers. That should really be disabled for gcc.
After the aux vector is moved, it is necessary to re-digest aux_info so the
pointers are updated to the new locations.
This was causing thread creation to fail on powerpc64 when using direct
execution due to a nonsense value being read for aux_info[AT_STACKPROT].
Approved by: jhibbits (mentor)
Differential Revision: https://reviews.freebsd.org/D21656
std::auto_ptr in a whole bunch of individual Makefiles, make the warning
globally non-fatal instead. This is similar to what was done to many
more non-fatal warnings from newer gcc versions.
A user may set ${name}_env variable in rc.conf(5) in order to set additional
environment variables for a service command. Unfortunately, at the moment
this variable is only honored when the command is specified via the command
variable. Those additional environment variables coming from ${name}_env
are never set if the service is started via the ${rc_arg}_cmd variable (for
example start_cmd).
PR: 239692
Reviewed by: bcr, jilles
Approved by: src (jilles)
Differential Revision: https://reviews.freebsd.org/D21228
It doesn't need to be in runtime and might help people who want to
experiment with other rc system or don't use one (like in small
embedded mfsroot).
Reviewed by: bapt, gjb
Differential Revision: https://reviews.freebsd.org/D21499
In the past, this allocator seems to have allocated things larger than
a page seperately. Much of this code was removed at some point (perhaps
along with sbrk() used) so remove the rest. Instead, keep allocating in
power-of-two bins up to FIRST_BUCKET_SIZE << (NBUCKETS - 1). If we want
something more efficent, we should use a fancier allocator.
While here, remove some vestages of sbrk() use. Most importantly, don't
try to page align the pagepool since it's always page aligned by mmap().
Reviewed by: kib
Obtained from: CheriBSD
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D21453
In Seventh Edition UNIX, the last pointer passed to free() was
guaranteed to not actually have been freed allowing memory to be
"compacted" via the following pattern:
free(foo);
foo = realloc(foo, newsize);
Further, Andrew Koenig reports in "C Traps and Pitfalls" that the
original realloc() implementation required this pattern.
The C standard is clear that this is Undefined Behavior. Modern
allocators don't support it and no portable code could rely on it so
remove this support.
Note: the removed implementation contains an off-by-one error and if
an item isn't found on the freelist, then twice as much memory as the
largest possible allocation will be copied.
Reviewed by: kib, imp
Obtained from: CheriBSD
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D21296
