[x86] Fix a really subtle miscompile due to a somewhat glaring bug in
EFLAGS copy lowering.
If you have a branch of LLVM, you may want to cherrypick this. It is
extremely unlikely to hit this case empirically, but it will likely
manifest as an "impossible" branch being taken somewhere, and will be
... very hard to debug.
Hitting this requires complex conditions living across complex
control flow combined with some interesting memory (non-stack)
initialized with the results of a comparison. Also, because you have
to arrange for an EFLAGS copy to be in *just* the right place, almost
anything you do to the code will hide the bug. I was unable to reduce
anything remotely resembling a "good" test case from the place where
I hit it, and so instead I have constructed synthetic MIR testing
that directly exercises the bug in question (as well as the good
behavior for completeness).
The issue is that we would mistakenly assume any SETcc with a valid
condition and an initial operand that was a register and a virtual
register at that to be a register *defining* SETcc...
It isn't though....
This would in turn cause us to test some other bizarre register,
typically the base pointer of some memory. Now, testing this register
and using that to branch on doesn't make any sense. It even fails the
machine verifier (if you are running it) due to the wrong register
class. But it will make it through LLVM, assemble, and it *looks*
fine... But wow do you get a very unsual and surprising branch taken
in your actual code.
The fix is to actually check what kind of SETcc instruction we're
dealing with. Because there are a bunch of them, I just test the
may-store bit in the instruction. I've also added an assert for
sanity that ensure we are, in fact, *defining* the register operand.
=D
Noticed by: kib
MFC after: 1 week
NT_GNU_PROPERTY_TYPE_0 in a .note.gnu.property section "contains a
program property note which describes special handling requirements
for linker and run-time loader." (from the System V Application Binary
Interface - Linux Extensions")
Intel CET uses two processor-specific program properties in
NT_GNU_PROPERTY_TYPE_0: GNU_PROPERTY_X86_FEATURE_1_IBT to indicate that
all executable sections are compatible with Indirect Branch Tracking,
and GNU_PROPERTY_X86_FEATURE_1_SHSTK to indicate that sections are
compatible with shadow stack.
A later change should add decoding of the individual properties.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
filter_create_ext() is documented to take a NULL terminated set of
arguments. 0 is promoted to an int so this would fail on 64-bit
systems if the value was not passed in a register. On all currently
supported 64-bit architectures it is.
Obtained from: CheriBSD
Sponsored by: DARPA, AFRL
These issues (PR 218860 and PR 218861) are still undergoing additional
discussion in the upstream context and there may be additional changes
to come.
PR: 218860
Submitted by: Eric McCorkle
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D10486
The Tag_ABI_VFP_args build attribute controls the procedure call
standard used for floating point parameters on ARM. The values are:
0 - Base AAPCS (FP Parameters passed in Core (Integer) registers
1 - VFP AAPCS (FP Parameters passed in FP registers)
2 - Toolchain specific (Neither Base or VFP)
3 - Compatible with all (No use of floating point parameters)
If the Tag_ABI_VFP_args build attribute is missing it has an implicit
value of 0.
We use the attribute in two ways:
* Detect a clash in calling convention between Base, VFP and Toolchain.
we follow ld.bfd's lead and do not error if there is a clash between an
implicit Base AAPCS caused by a missing attribute. Many projects
including the hard-float (VFP AAPCS) version of glibc contain assembler
files that do not use floating point but do not have Tag_ABI_VFP_args.
* Set the EF_ARM_ABI_FLOAT_SOFT or EF_ARM_ABI_FLOAT_HARD ELF header flag
for Base or VFP AAPCS respectively. This flag is used by some ELF
loaders.
References:
* Addenda to, and Errata in, the ABI for the ARM Architecture for
Tag_ABI_VFP_args
* Elf for the ARM Architecture for ELF header flags
Fixes LLVM PR36009
PR: 229050
Obtained from: llvm r338377 by Peter Smith
The LLD implementation of Tag_ABI_VFP_args needs to check the rarely
seen values of 3 (toolchain specific) and 4 compatible with both Base
and VFP. Add the missing enumeration values so that LLD can refer to
them without having to use the raw numbers.
Obtained from: llvm r338373 by Peter Smith
The ELF for the Arm architecture document defines, for EF_ARM_EABI_VER5
and above, the flags EF_ARM_ABI_FLOAT_HARD and EF_ARM_ABI_FLOAT_SOFT.
These have been defined to be compatible with the existing
EF_ARM_VFP_FLOAT and EF_ARM_SOFT_FLOAT used by gcc for
EF_ARM_EABI_UNKNOWN.
This patch adds the flags in addition to the existing ones so that any
code depending on the old names will still work.
Obtained from: llvm r338370 by Peter Smith
Update vendor/libarchive/dist to git 2c8c83b9731ff822fad6cc8c670ea5519c366a14
Important vendor changes:
PR #993: Chdir to -C directory for metalog processing
OSS-Fuzz #4969: Check size of the extended time field in zip archives
PR #973: Record informational compression level in gzip header
MFC after: 1 week
[ELF] Update addends in non-allocatable sections for REL targets when
creating a relocatable output.
LLVM PR: 37735
LLVM Differential Revision: https://reviews.llvm.org/D48929
PR: 225128
Obtained from: LLVM r336799 by Igor Kudrin
This code was originally written for NetBSD. r306031 tried to adapt it to
FreeBSD, but didn't correctly handle the case that tmpfs was available, but
not already loaded. Fix the logic to load the module if necessary. The
tmpfs tests shouldn't be skipped anymore.
Also, fix a comment that was dislocated by r306031.
Reported by: Jenkins
MFC after: 2 weeks
Code analysis and runtime analysis using truss(8) indicate that the only
privileged operations performed by ntpd are adjusting system time, and
(re-)binding to privileged UDP port 123. These changes add a new mac(4)
policy module, mac_ntpd(4), which grants just those privileges to any
process running with uid 123.
This also adds a new user and group, ntpd:ntpd, (uid:gid 123:123), and makes
them the owner of the /var/db/ntp directory, so that it can be used as a
location where the non-privileged daemon can write files such as the
driftfile, and any optional logfile or stats files.
Because there are so many ways to configure ntpd, the question of how to
configure it to run without root privs can be a bit complex, so that will be
addressed in a separate commit. These changes are just what's required to
grant the limited subset of privs to ntpd, and the small change to ntpd to
prevent it from exiting with an error if running as non-root.
Differential Revision: https://reviews.freebsd.org/D16281
Prevent installation of an all-zero TK.
This is also upline git commit 53bb18cc8b7a4da72e47e4b3752d0d2135cffb23.
Obtained from: https://w1.fi/security/2017-1/\
rebased-v2.6-0004-Prevent-installation-\
of-an-all-zero-TK.patch
X-MFC-with: r336203
libibverbs example utilities.
This allows connecting to both IPv4 and IPv6 and reverts
some FreeBSD only patches.
MFC after: 1 week
Sponsored by: Mellanox Technologies
Add the ability to to parse sysfs paths to sysctl nodes by replacing '/' with '.'
Submitted by: slavash@
MFC after: 1 week
Sponsored by: Mellanox Technologies
Request init/fini array on FreeBSD 12 and later
Summary:
It seems a bad idea to change the default in the middle of a release
branch due to possible changes in global ctor / dtor ordering between
.ctors and .init_array. With FreeBSD 11.0's release imminent lets
change the default now for FreeBSD 12 (the current development
stream) and later.
FreeBSD rtld has supported .init_array / .fini_array for many years.
As of Jan 1 2017 all supported FreeBSD releases and branches will
have support.
Reviewers: dim, brooks, arichardson
Reviewed By: dim, brooks, arichardson
Subscribers: bsdjhb, krytarowski, emaste, cfe-commits
Differential Revision: https://reviews.llvm.org/D24867
Requested by: jhb
MFC after: 3 days
auditd_wait_for_events() relies on read(2) being interrupted by signals,
but it registers signal handlers with signal(3), which sets SA_RESTART.
That breaks asynchronous signal handling. It means that signals don't
actually get handled until after an audit(8) trigger is received.
Symptoms include:
* Sending SIGTERM to auditd doesn't kill it right away; you must send
SIGTERM and then send a trigger with auditon(2).
* Same with SIGHUP
* Zombie child processes don't get reaped until auditd receives a trigger
sent by auditon. This includes children created by expiring audit trails
at auditd startup.
Fix by using sigaction(2) instead of signal(3).
Cherry pick https://github.com/openbsm/openbsm/commit/d060887
PR: 229381
Reviewed by: cem
Obtained from: OpenBSM
MFC after: 2 weeks
Differential Revision: https://github.com/openbsm/openbsm/pull/36
The issue was caused by header pollution brought by GCC 8.1.
We now have to remove include-fixed headers in the GCC installation
directory.
Sponsored by: DARPA, AFRL
Pointed out by: jhb
o Also move printf.h to go after it since it does require declaration
of va_list.
This fixes build with latest RISC-V GNU Toolchain with GCC 8.1
Sponsored by: DARPA, AFRL
For developers gensnmptree can now generate functions for enums to convert
between enums and strings and to check the validity of a value.
The sources in FreeBSD are now in sync with the upstream which allows to
bring in IPv6 modifications.
- Change the C++ directory entries to honor --sysroot if it is set.
- Don't define CROSS_INCLUDE_DIR for the cross compiler. Instead, set
TARGET_SYSTEM_ROOT to point to WORLDTMP and always define
STANDARD_INCLUDE_DIR.
- Change STANDARD_INCLUDE_DIR and the C++ include directories to just
start with "/usr" always. The compiler will prepend the sysroot when
doing cross-builds. GCC_INCLUDE_DIR (which contains headers that ship
with the compiler such as intrinsincs rather than OS-supplied headers)
remains hardcoded to look in TOOLS_PREFIX.
Reviewed by: bdrewery (older version)
Sponsored by: DARPA / AFRL
Differential Revision: https://reviews.freebsd.org/D15127
Magic file for dump(8) had this dump and previous dump dates reversed.
Fix order for all three flavours of the dump(8) format.
This fix was committed to upstream repo as magic/Magdir/dump,v 1.17
and will be merged during next vendor import.
PR: 223155
MFC after: 2 weeks
The local hostname was blindly copied into the to the nn_name array.
When the hostname exceeded 16 bytes, it would overflow. Truncate the
hostname to 15 bytes plus a 0 terminator which is the "workstation name"
suffix.
Use defensive strlcpy() when filling nn_name in all cases.
PR: 228354
Reported by: donald.buchholz@intel.com
Reviewed by: jpaetzel, ian (prior version)
Discussed with: Security Officer (gtetlow)
MFC after: 3 days
Security: Stack overflow with the hostname.
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D15936
o Restore floating-point registers in jumpto()
These are required to native cross build GCC and GDB
(both do require libc++ and libunwind).
These are not tested.
Sponsored by: DARPA, AFRL
When running mckey, errors may happen in the init/connect stage.
When leaving multicast groups, we override this value.
Fix that by saving the return value from rdma_leave_multicast to different
parameter, and only in case of failure in rdma_leave_multicast override it.
MFC after: 1 week
Approved by: hselasky (mentor), kib (mentor)
Sponsored by: Mellanox Technologies
Aligns the build with the FreeBSD traditional approach to not build in
contrib/, and to track inter-dependencies between libraries.
With help from: bdrewery
Reviewed by: bdrewery, hselasky
Sponsored by: Mellanox Technologies
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D15648
- Restore local change to include <net/bpf.h> inside pcap.h.
This fixes ports build problems.
- Update local copy of dlt.h with new DLT types.
- Revert no longer needed <net/bpf.h> includes which were added
as part of r334277.
Suggested by: antoine@, delphij@, np@
MFC after: 3 weeks
Sponsored by: Mellanox Technologies
Upstream change ed47534 consciously added some redundant functional
declarations, and I'm not sure why. AFAICT they were never required. On
FreeBSD, they break the build with GCC (but not Clang) for any program
including libbsm.h with WARNS=6.
Fix by cherry-picking upstream change
https://github.com/openbsm/openbsm/commit/0553c27
Reported by: emaste
Reviewed by: cem
Obtained from: OpenBSM
MFC after: 2 weeks
Pull Request: https://github.com/openbsm/openbsm/pull/31
Vendor import two upstream commits:
c1bb8784abd3ca978e376b0d10e324db0491237b
9c4af7213cc2543a1f5586d8f2c19f86aa0cbe72
When using tcpdump -I -i wlanN and wlanN is not a monitor mode VAP,
tcpdump will print an error message saying rfmon is not supported.
Give a concise explanation as to how one might solve this problem by
creating a monitor mode VAP.
MFC after: 1 month
Approved by: hselasky (mentor), kib (mentor)
Sponsored by: Mellanox Technologies
- Add xo_format_is_numeric() with improved logic to decide if format
strings are numeric, so json output quotes them
- Convert docs to sphinx/rst
- update tests
Includes fix for PR 221676:
27d3021cc3 (diff-5a0d468963477f7daedb8308c219dd80)
PR: 221676
MFC after: 5 days
Merge the latest file(1) in.
Relevent Changelog:
- extend the support for ${x?:} expansions for magic descriptions
- add support for ${x?:} in mime types to handle pie binaries.
- add support for negative offsets (offsets from the end of file)
- close the file on error when writing magic
Relnotes: yes
We've been maintaining top(1) for a long time, and the upstream
hasn't existed/been used in similarly as long. Make it clear that we own
top(1)
Tested with 'make universe'. Everything passed except MIPS which failed
for unrelated reasons. Install also tested for amd64.
Reviewed by: sbruno
No objections: imp, mmacy
Differential Revision: https://reviews.freebsd.org/D15387
PeepholeOpt cleanup/refactor; NFC
- Less unnecessary use of `auto`
- Add early `using RegSubRegPair(AndIdx) =` to avoid countless
`TargetInstrInfo::` qualifications.
- Use references instead of pointers where possible.
- Remove unused parameters.
- Rewrite the CopyRewriter class hierarchy:
- Pull out uncoalescable copy rewriting functionality into
PeepholeOptimizer class.
- Use an abstract base class to make it clear that rewriters are
independent.
- Remove unnecessary \brief in doxygen comments.
- Remove unused constructor and method from ValueTracker.
- Replace UseAdvancedTracking of ValueTracker with DisableAdvCopyOpt
use.
Even though upstream marked this as "No Functional Change", it does
contain some functional changes, and these fix a compiler hang for one
particular source file in the devel/godot port.
PR: 228261
MFC after: 3 days
I've been holding back on this because 1.7.0 requires OpenSSL 1.1.0 or
newer for full DANE support. But we can't wait forever, and nothing in
base uses DANE anyway, so here we go.
Read locking is over used in the kernel to guarantee liveness. This API makes
it easy to provide livenes guarantees without atomics.
Includes epoch_test kernel module to stress test the API.
Documentation will follow initial use case.
Test case and improvements to preemption handling in response to discussion
with mjg@
Reviewed by: imp@, shurd@
Approved by: sbruno@
A non-alloc note section should not have a PT_NOTE program header.
Found while linking ghc (Haskell compiler) with lld on FreeBSD. Haskell
emits a .debug-ghc-link-info note section (as the name suggests, it
contains link info) as a SHT_NOTE section without SHF_ALLOC set.
For this case ld.bfd does not emit a PT_NOTE segment for
.debug-ghc-link-info. lld previously emitted a PT_NOTE with p_vaddr = 0
and FreeBSD's rtld segfaulted when trying to parse a note at address 0.
LLVM PR: https://llvm.org/pr37361
LLVM review: https://reviews.llvm.org/D46623
PR: 226872
Reviewed by: dim
Sponsored by: The FreeBSD Foundation
This can cause ibpanic in ibstat when width is not set properly
as can occur when Ethernet port is connected to InfiniBand fabric.
ibpanic: [8167] main: stat of IB device 'mlx5_0' failed: m
With this change, Rate is displayed as 0 with ibstat for
this scenario.
MFC after: 3 days
Approved by: hselasky (mentor), kib (mentor)
Sponsored by: Mellanox Technologies
The target is not necessarily a FreeBSD binary - for example, it may be
a Linux binary running under the linuxulator. Basic ptrace (live)
debugging already worked in this case, except for the assertion.
Sponsored by: Turing Robotic Industries Inc.
[X86] In X86FlagsCopyLowering, when rewriting a memory setcc we need
to emit an explicit MOV8mr instruction.
Previously the code only knew how to handle setcc to a register.
This should fix a crash in the chromium build.
This fixes various assertion failures while building ports targeting
i386:
* www/firefox: isReg() && "This is not a register operand!"
* www/iridium, www/qt5-webengine: (I.atEnd() || std::next(I) ==
def_instr_end()) && "getVRegDef assumes a single definition or no
definition"
* devel/powerpc64-gcc: FromReg != ToReg && "Cannot replace a reg with
itself"
Reported by: jbeich
PR: 225330, 227686, 227698, 227699
MFC after: 1 week
X-MFC-With: r332833
EFLAGS copy that lives out of a basic block!" errors on i386.
Pull in r325446 from upstream clang trunk (by me):
[X86] Add 'sahf' CPU feature to frontend
Summary:
Make clang accept `-msahf` (and `-mno-sahf`) flags to activate the
`+sahf` feature for the backend, for bug 36028 (Incorrect use of
pushf/popf enables/disables interrupts on amd64 kernels). This was
originally submitted in bug 36037 by Jonathan Looney
<jonlooney@gmail.com>.
As described there, GCC also uses `-msahf` for this feature, and the
backend already recognizes the `+sahf` feature. All that is needed is
to teach clang to pass this on to the backend.
The mapping of feature support onto CPUs may not be complete; rather,
it was chosen to match LLVM's idea of which CPUs support this feature
(see lib/Target/X86/X86.td).
I also updated the affected test case (CodeGen/attr-target-x86.c) to
match the emitted output.
Reviewers: craig.topper, coby, efriedma, rsmith
Reviewed By: craig.topper
Subscribers: emaste, cfe-commits
Differential Revision: https://reviews.llvm.org/D43394
Pull in r328944 from upstream llvm trunk (by Chandler Carruth):
[x86] Expose more of the condition conversion routines in the public
API for X86's instruction information. I've now got a second patch
under review that needs these same APIs. This bit is nicely
orthogonal and obvious, so landing it. NFC.
Pull in r329414 from upstream llvm trunk (by Craig Topper):
[X86] Merge itineraries for CLC, CMC, and STC.
These are very simple flag setting instructions that appear to only
be a single uop. They're unlikely to need this separation.
Pull in r329657 from upstream llvm trunk (by Chandler Carruth):
[x86] Introduce a pass to begin more systematically fixing PR36028
and similar issues.
The key idea is to lower COPY nodes populating EFLAGS by scanning the
uses of EFLAGS and introducing dedicated code to preserve the
necessary state in a GPR. In the vast majority of cases, these uses
are cmovCC and jCC instructions. For such cases, we can very easily
save and restore the necessary information by simply inserting a
setCC into a GPR where the original flags are live, and then testing
that GPR directly to feed the cmov or conditional branch.
However, things are a bit more tricky if arithmetic is using the
flags. This patch handles the vast majority of cases that seem to
come up in practice: adc, adcx, adox, rcl, and rcr; all without
taking advantage of partially preserved EFLAGS as LLVM doesn't
currently model that at all.
There are a large number of operations that techinaclly observe
EFLAGS currently but shouldn't in this case -- they typically are
using DF. Currently, they will not be handled by this approach.
However, I have never seen this issue come up in practice. It is
already pretty rare to have these patterns come up in practical code
with LLVM. I had to resort to writing MIR tests to cover most of the
logic in this pass already. I suspect even with its current amount
of coverage of arithmetic users of EFLAGS it will be a significant
improvement over the current use of pushf/popf. It will also produce
substantially faster code in most of the common patterns.
This patch also removes all of the old lowering for EFLAGS copies,
and the hack that forced us to use a frame pointer when EFLAGS copies
were found anywhere in a function so that the dynamic stack
adjustment wasn't a problem. None of this is needed as we now lower
all of these copies directly in MI and without require stack
adjustments.
Lots of thanks to Reid who came up with several aspects of this
approach, and Craig who helped me work out a couple of things
tripping me up while working on this.
Differential Revision: https://reviews.llvm.org/D45146
Pull in r329673 from upstream llvm trunk (by Chandler Carruth):
[x86] Model the direction flag (DF) separately from the rest of
EFLAGS.
This cleans up a number of operations that only claimed te use EFLAGS
due to using DF. But no instructions which we think of us setting
EFLAGS actually modify DF (other than things like popf) and so this
needlessly creates uses of EFLAGS that aren't really there.
In fact, DF is so restrictive it is pretty easy to model. Only STD,
CLD, and the whole-flags writes (WRFLAGS and POPF) need to model
this.
I've also somewhat cleaned up some of the flag management instruction
definitions to be in the correct .td file.
Adding this extra register also uncovered a failure to use the
correct datatype to hold X86 registers, and I've corrected that as
necessary here.
Differential Revision: https://reviews.llvm.org/D45154
Pull in r330264 from upstream llvm trunk (by Chandler Carruth):
[x86] Fix PR37100 by teaching the EFLAGS copy lowering to rewrite
uses across basic blocks in the limited cases where it is very
straight forward to do so.
This will also be useful for other places where we do some limited
EFLAGS propagation across CFG edges and need to handle copy rewrites
afterward. I think this is rapidly approaching the maximum we can and
should be doing here. Everything else begins to require either heroic
analysis to prove how to do PHI insertion manually, or somehow
managing arbitrary PHI-ing of EFLAGS with general PHI insertion.
Neither of these seem at all promising so if those cases come up,
we'll almost certainly need to rewrite the parts of LLVM that produce
those patterns.
We do now require dominator trees in order to reliably diagnose
patterns that would require PHI nodes. This is a bit unfortunate but
it seems better than the completely mysterious crash we would get
otherwise.
Differential Revision: https://reviews.llvm.org/D45673
Together, these should ensure clang does not use pushf/popf sequences to
save and restore flags, avoiding problems with unrelated flags (such as
the interrupt flag) being restored unexpectedly.
Requested by: jtl
PR: 225330
MFC after: 1 week
Add includes for <curses.h> and <termcap.h> where necessary, and
rename a few internal functions to have a "top_" prefix to avoid
clashes with standard names from curses.h/termcap.h headers.
Top now compiles without warnings on both gcc and clang.
Reviewed by: emaste, imp, jhb
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D15115
[X86] Add 'sahf' CPU feature to frontend
Summary:
Make clang accept `-msahf` (and `-mno-sahf`) flags to activate the
`+sahf` feature for the backend, for bug 36028 (Incorrect use of
pushf/popf enables/disables interrupts on amd64 kernels). This was
originally submitted in bug 36037 by Jonathan Looney
<jonlooney@gmail.com>.
As described there, GCC also uses `-msahf` for this feature, and the
backend already recognizes the `+sahf` feature. All that is needed is
to teach clang to pass this on to the backend.
The mapping of feature support onto CPUs may not be complete; rather,
it was chosen to match LLVM's idea of which CPUs support this feature
(see lib/Target/X86/X86.td).
I also updated the affected test case (CodeGen/attr-target-x86.c) to
match the emitted output.
Reviewers: craig.topper, coby, efriedma, rsmith
Reviewed By: craig.topper
Subscribers: emaste, cfe-commits
Differential Revision: https://reviews.llvm.org/D43394
Pull in r328944 from upstream llvm trunk (by Chandler Carruth):
[x86] Expose more of the condition conversion routines in the public
API for X86's instruction information. I've now got a second patch
under review that needs these same APIs. This bit is nicely
orthogonal and obvious, so landing it. NFC.
Pull in r329414 from upstream llvm trunk (by Craig Topper):
[X86] Merge itineraries for CLC, CMC, and STC.
These are very simple flag setting instructions that appear to only
be a single uop. They're unlikely to need this separation.
Pull in r329657 from upstream llvm trunk (by Chandler Carruth):
[x86] Introduce a pass to begin more systematically fixing PR36028
and similar issues.
The key idea is to lower COPY nodes populating EFLAGS by scanning the
uses of EFLAGS and introducing dedicated code to preserve the
necessary state in a GPR. In the vast majority of cases, these uses
are cmovCC and jCC instructions. For such cases, we can very easily
save and restore the necessary information by simply inserting a
setCC into a GPR where the original flags are live, and then testing
that GPR directly to feed the cmov or conditional branch.
However, things are a bit more tricky if arithmetic is using the
flags. This patch handles the vast majority of cases that seem to
come up in practice: adc, adcx, adox, rcl, and rcr; all without
taking advantage of partially preserved EFLAGS as LLVM doesn't
currently model that at all.
There are a large number of operations that techinaclly observe
EFLAGS currently but shouldn't in this case -- they typically are
using DF. Currently, they will not be handled by this approach.
However, I have never seen this issue come up in practice. It is
already pretty rare to have these patterns come up in practical code
with LLVM. I had to resort to writing MIR tests to cover most of the
logic in this pass already. I suspect even with its current amount
of coverage of arithmetic users of EFLAGS it will be a significant
improvement over the current use of pushf/popf. It will also produce
substantially faster code in most of the common patterns.
This patch also removes all of the old lowering for EFLAGS copies,
and the hack that forced us to use a frame pointer when EFLAGS copies
were found anywhere in a function so that the dynamic stack
adjustment wasn't a problem. None of this is needed as we now lower
all of these copies directly in MI and without require stack
adjustments.
Lots of thanks to Reid who came up with several aspects of this
approach, and Craig who helped me work out a couple of things
tripping me up while working on this.
Differential Revision: https://reviews.llvm.org/D45146
Pull in r329673 from upstream llvm trunk (by Chandler Carruth):
[x86] Model the direction flag (DF) separately from the rest of
EFLAGS.
This cleans up a number of operations that only claimed te use EFLAGS
due to using DF. But no instructions which we think of us setting
EFLAGS actually modify DF (other than things like popf) and so this
needlessly creates uses of EFLAGS that aren't really there.
In fact, DF is so restrictive it is pretty easy to model. Only STD,
CLD, and the whole-flags writes (WRFLAGS and POPF) need to model
this.
I've also somewhat cleaned up some of the flag management instruction
definitions to be in the correct .td file.
Adding this extra register also uncovered a failure to use the
correct datatype to hold X86 registers, and I've corrected that as
necessary here.
Differential Revision: https://reviews.llvm.org/D45154
Together, these should ensure clang does not use pushf/popf sequences to
save and restore flags, avoiding problems with unrelated flags (such as
the interrupt flag) being restored unexpectedly.
Requested by: jtl
PR: 225330
MFC after: 1 week
While Arcnet has some continued deployment in industrial controls, the
lack of drivers for any of the PCI, USB, or PCIe NICs on the market
suggests such users aren't running FreeBSD.
Evidence in the PR database suggests that the cm(4) driver (our sole
Arcnet NIC) was broken in 5.0 and has not worked since.
PR: 182297
Reviewed by: jhibbits, vangyzen
Relnotes: yes
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D15057
Strip @VER suffices from the LTO output.
This fixes pr36623.
The problem is that we have to parse versions out of names before LTO
so that LTO can use that information.
When we get the LTO produced .o files, we replace the previous symbols
with the LTO produced ones, but they still have @ in their names.
We could just trim the name directly, but calling parseSymbolVersion
to do it is simpler.
This is a follow-up to r331366, since we discovered that lld could
append version strings to symbols twice, when using Link Time
Optimization.
MFC after: 3 months
X-MFC-With: r327952
Don't treat .symver as a regular alias definition.
This patch starts simplifying the handling of .symver.
For now it just moves the responsibility for creating an alias down to
the streamer. With that the asm streamer can pass a .symver unchanged,
which is nice since gas cannot parse "foo@bar = zed".
In a followup I hope to move the handling down to the writer so that
we don't need special hacks for avoiding breaking names with @@@ on
windows.
Pull in r327160 from upstream llvm trunk (by Rafael Espindola):
Delay creating an alias for @@@.
With this we only create an alias for @@@ once we know if it should
use @ or @@. This avoids last minutes renames and hacks to handle MS
names.
This only handles the ELF writer. LTO still has issues with @@@
aliases.
Pull in r327928 from upstream llvm trunk (by Vitaly Buka):
Object: Move attribute calculation into RecordStreamer. NFC
Summary: Preparation for D44274
Reviewers: pcc, espindola
Subscribers: hiraditya
Differential Revision: https://reviews.llvm.org/D44276
Pull in r327930 from upstream llvm trunk (by Vitaly Buka):
Object: Fix handling of @@@ in .symver directive
Summary:
name@@@nodename is going to be replaced with name@@nodename if symbols is
defined in the assembled file, or name@nodename if undefined.
https://sourceware.org/binutils/docs/as/Symver.html
Fixes PR36623
Reviewers: pcc, espindola
Subscribers: mehdi_amini, hiraditya
Differential Revision: https://reviews.llvm.org/D44274
Together, these changes fix handling of @@@ in .symver directives when
doing Link Time Optimization.
Reported by: Shawn Webb <shawn.webb@hardenedbsd.org>
MFC after: 3 months
X-MFC-With: r327952
This is originally based on a patch from David Chisnall for soft-float
N64 but has since been updated to support O32, N32, and hard-float ABIs.
The soft-float O32, N32, and N64 support has been committed upstream.
The hard-float changes are still in review upstream.
Enable LLVM_LIBUNWIND on mips when building with a suitable (C+11-capable)
toolchain. This has been tested with external GCC for all ABIs and
O32 and N64 with clang.
Reviewed by: emaste
Obtained from: CheriBSD (original N64 patch)
Sponsored by: DARPA / AFRL
Differential Revision: https://reviews.freebsd.org/D14701
Ordinarily, the continue clause of the for-loop would free 'line.' In this
case we instead return early, missing the free. Add an explicit free to
avoid the leak.
Reported by: Coverity
Sponsored by: Dell EMC Isilon
In out of memory scenarios (where one of these allocations failed but
other(s) did not), nm(1) could reference the uninitialized value of these
allocations (undefined behavior).
Always initialize any successful allocations as the most expedient
resolution of the issue. However, I would encourage upstream elftoolchain
contributors to clean up the error path to just abort immediately, rather
than proceeding sloppily when one allocation fails.
Reported by: Coverity
Sponsored by: Dell EMC Isilon
[CodeGen] Fix TBAA info for accesses to members of base classes
Resolves:
Bug 35724 - regression (r315984): fatal error: error in backend:
Broken function found (Did not see access type in access path!)
https://bugs.llvm.org/show_bug.cgi?id=35724
Differential Revision: https://reviews.llvm.org/D41547
This fixes "Did not see access type in access path" fatal errors when
building the devel/gdb port (version 8.1).
Reported by: jbeich
PR: 226658
MFC after: 3 months
X-MFC-With: r327952
[ConstantFolding, InstSimplify] Handle more vector GEPs
This patch addresses some additional cases where the compiler crashes
upon encountering vector GEPs. This should fix PR36116.
Differential Revision: https://reviews.llvm.org/D44219
Reference: https://bugs.llvm.org/show_bug.cgi?id=36116
This fixes an assertion when building the emulators/snes9x port.
Reported by: jbeich
PR: 225471
MFC after: 3 months
X-MFC-With: r327952
[ARM] Fix for PR36577
Don't PerformSHLSimplify if the given node is used by a node that
also uses a constant because we may get stuck in an infinite combine
loop.
bugzilla: https://bugs.llvm.org/show_bug.cgi?id=36577
Patch by Sam Parker.
Differential Revision: https://reviews.llvm.org/D44097
This fixes a hang when compiling one particular file in java/openjdk8
for armv6 and armv7.
Reported by: swills
PR: 226388
POSIX explicitly states that the application must declare union semun.
This makes no sense, but it is what it is. This brings us into line
with Linux, MacOS/Darwin, and NetBSD.
In a ports exp-run a moderate number of ports fail due to a lack of
approprate autotools-like discovery mechanisms or local patches. A
commit to address them will follow shortly.
PR: 224300, 224443 (exp-run)
Reviewed by: emaste, jhb, kib
Exp-run by: antoine
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D14492
We don't support float in the boot loaders, so don't include
interfaces for float or double in systems headers. In addition, take
the unusual step of spiking double and float to prevent any more
accidental seepage.
or double so ifdef that code out when the numbers aren't float at all.
There's still references in the lmathlib.c, but we don't compile that
for the loader yet.
Differential Revision: https://reviews.freebsd.org/D14472
sbt is the time in the future that the tsleep_sbt() is expected to be completed
at. sbtt is the current time. Depending on the precision with sysctl
kern.timecounter.alloweddeviation the start time may be incremented by
tc_tick_sbt. The same increment is needed for the current time of sbtt before
calculating the difference. The impact of missing this increment is that rmtp
may increase by one tc_tick_sbt on every early [EINTR] return. If the same
struct is passed in for rqtp as rmtp this can result in rqtp effectively
incrementing by tc_tick_sbt and sleeping longer than originally intended.
This problem was introduced in r247797.
Reviewed by: kib, markj, vangyzen (all on an older version of the test)
MFC after: 2 weeks
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D14362
PR36157: When injecting an implicit function declaration in C89, find
the right DeclContext rather than injecting it wherever we happen to
be.
This avoids creating functions whose DeclContext is a struct or
similar.
This fixes assertion failures when parsing certain not-completely-valid
struct declarations.
Reported by: ae
PR: 225862
MFC after: 3 months
X-MFC-With: r327952
Fix for #31362 - ms_abi is implemented incorrectly for values >=16
bytes.
Summary:
This patch is a fix for following issue:
https://bugs.llvm.org/show_bug.cgi?id=31362 The problem was caused by
front end lowering C calling conventions without taking into account
calling conventions enforced by attribute. In this case win64cc was
no correctly lowered on targets other than Windows.
Reviewed By: rnk (Reid Kleckner)
Differential Revision: https://reviews.llvm.org/D43016
Author: belickim <mateusz.belicki@intel.com>
This fixes clang 6.0.0 assertions when building the emulators/wine and
emulators/wine-devel ports, and should also make it use the correct
Windows calling conventions. Bump __FreeBSD_version to make the fix
easy to detect.
PR: 224863
MFC after: 3 months
X-MFC-With: r327952
The MIPS assembly parser treats forward-declared local symbols as global
symbols. This results in CALL16 relocations being used against local
(private) symbols which then fail to resolve when linking binaries.
Add .local to force the init and fini functions to be treated as local as
a workaround.
Submitted by: sbruno
Sponsored by: DARPA / AFRL
has been switched to libedit long ago, libreadline was built as an
internallib for a while and kept only for gdbtui which was broken using
libreadline.
Since gdb has been mostly deorbitted in all arches, gdbtui was only installed
on arm and sparc64, given it has been removed, gdb has been switched to use
libedit, no consumers are left for libreadline. Thus this removal
Don't declare some types that FreeBSD incorrectly declares.
Fix an incorrect call to open() (missing mode).
ANSIfy prototypes.
Enable SysV message queue, semaphore, and shared memory tests.
With exception of the workaround for union semun, these fixes have been
committed to NetBSD.
Reviewed by: asomers
Approved by: CheriBSD
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D13471
Use 'pfctl -k' when blocking a site to kill active tcp connections
from the blocked address.
Fix 'purge' operation for pf, which must dynamically determine which
filters have been created, so the filters can be flushed by name.
MFC after: 2 weeks
6.0.0 (branches/release_60 r324090).
This introduces retpoline support, with the -mretpoline flag. The
upstream initial commit message (r323155 by Chandler Carruth) contains
quite a bit of explanation. Quoting:
Introduce the "retpoline" x86 mitigation technique for variant #2 of
the speculative execution vulnerabilities disclosed today,
specifically identified by CVE-2017-5715, "Branch Target Injection",
and is one of the two halves to Spectre.
Summary:
First, we need to explain the core of the vulnerability. Note that
this is a very incomplete description, please see the Project Zero
blog post for details:
https://googleprojectzero.blogspot.com/2018/01/reading-privileged-memory-with-side.html
The basis for branch target injection is to direct speculative
execution of the processor to some "gadget" of executable code by
poisoning the prediction of indirect branches with the address of
that gadget. The gadget in turn contains an operation that provides a
side channel for reading data. Most commonly, this will look like a
load of secret data followed by a branch on the loaded value and then
a load of some predictable cache line. The attacker then uses timing
of the processors cache to determine which direction the branch took
*in the speculative execution*, and in turn what one bit of the
loaded value was. Due to the nature of these timing side channels and
the branch predictor on Intel processors, this allows an attacker to
leak data only accessible to a privileged domain (like the kernel)
back into an unprivileged domain.
The goal is simple: avoid generating code which contains an indirect
branch that could have its prediction poisoned by an attacker. In
many cases, the compiler can simply use directed conditional branches
and a small search tree. LLVM already has support for lowering
switches in this way and the first step of this patch is to disable
jump-table lowering of switches and introduce a pass to rewrite
explicit indirectbr sequences into a switch over integers.
However, there is no fully general alternative to indirect calls. We
introduce a new construct we call a "retpoline" to implement indirect
calls in a non-speculatable way. It can be thought of loosely as a
trampoline for indirect calls which uses the RET instruction on x86.
Further, we arrange for a specific call->ret sequence which ensures
the processor predicts the return to go to a controlled, known
location. The retpoline then "smashes" the return address pushed onto
the stack by the call with the desired target of the original
indirect call. The result is a predicted return to the next
instruction after a call (which can be used to trap speculative
execution within an infinite loop) and an actual indirect branch to
an arbitrary address.
On 64-bit x86 ABIs, this is especially easily done in the compiler by
using a guaranteed scratch register to pass the target into this
device. For 32-bit ABIs there isn't a guaranteed scratch register
and so several different retpoline variants are introduced to use a
scratch register if one is available in the calling convention and to
otherwise use direct stack push/pop sequences to pass the target
address.
This "retpoline" mitigation is fully described in the following blog
post: https://support.google.com/faqs/answer/7625886
We also support a target feature that disables emission of the
retpoline thunk by the compiler to allow for custom thunks if users
want them. These are particularly useful in environments like
kernels that routinely do hot-patching on boot and want to hot-patch
their thunk to different code sequences. They can write this custom
thunk and use `-mretpoline-external-thunk` *in addition* to
`-mretpoline`. In this case, on x86-64 thu thunk names must be:
```
__llvm_external_retpoline_r11
```
or on 32-bit:
```
__llvm_external_retpoline_eax
__llvm_external_retpoline_ecx
__llvm_external_retpoline_edx
__llvm_external_retpoline_push
```
And the target of the retpoline is passed in the named register, or in
the case of the `push` suffix on the top of the stack via a `pushl`
instruction.
There is one other important source of indirect branches in x86 ELF
binaries: the PLT. These patches also include support for LLD to
generate PLT entries that perform a retpoline-style indirection.
The only other indirect branches remaining that we are aware of are
from precompiled runtimes (such as crt0.o and similar). The ones we
have found are not really attackable, and so we have not focused on
them here, but eventually these runtimes should also be replicated for
retpoline-ed configurations for completeness.
For kernels or other freestanding or fully static executables, the
compiler switch `-mretpoline` is sufficient to fully mitigate this
particular attack. For dynamic executables, you must compile *all*
libraries with `-mretpoline` and additionally link the dynamic
executable and all shared libraries with LLD and pass `-z
retpolineplt` (or use similar functionality from some other linker).
We strongly recommend also using `-z now` as non-lazy binding allows
the retpoline-mitigated PLT to be substantially smaller.
When manually apply similar transformations to `-mretpoline` to the
Linux kernel we observed very small performance hits to applications
running typic al workloads, and relatively minor hits (approximately
2%) even for extremely syscall-heavy applications. This is largely
due to the small number of indirect branches that occur in
performance sensitive paths of the kernel.
When using these patches on statically linked applications,
especially C++ applications, you should expect to see a much more
dramatic performance hit. For microbenchmarks that are switch,
indirect-, or virtual-call heavy we have seen overheads ranging from
10% to 50%.
However, real-world workloads exhibit substantially lower performance
impact. Notably, techniques such as PGO and ThinLTO dramatically
reduce the impact of hot indirect calls (by speculatively promoting
them to direct calls) and allow optimized search trees to be used to
lower switches. If you need to deploy these techniques in C++
applications, we *strongly* recommend that you ensure all hot call
targets are statically linked (avoiding PLT indirection) and use both
PGO and ThinLTO. Well tuned servers using all of these techniques saw
5% - 10% overhead from the use of retpoline.
We will add detailed documentation covering these components in
subsequent patches, but wanted to make the core functionality
available as soon as possible. Happy for more code review, but we'd
really like to get these patches landed and backported ASAP for
obvious reasons. We're planning to backport this to both 6.0 and 5.0
release streams and get a 5.0 release with just this cherry picked
ASAP for distros and vendors.
This patch is the work of a number of people over the past month:
Eric, Reid, Rui, and myself. I'm mailing it out as a single commit
due to the time sensitive nature of landing this and the need to
backport it. Huge thanks to everyone who helped out here, and
everyone at Intel who helped out in discussions about how to craft
this. Also, credit goes to Paul Turner (at Google, but not an LLVM
contributor) for much of the underlying retpoline design.
Reviewers: echristo, rnk, ruiu, craig.topper, DavidKreitzer
Subscribers: sanjoy, emaste, mcrosier, mgorny, mehdi_amini, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D41723
MFC after: 3 months
X-MFC-With: r327952
PR: 224669
sparc64 and riscv do not support 10 arguments, but MIPS now does.
While here, combine clauses for architectures that support the same
number of arguments to reduce duplication.
Sponsored by: DARPA / AFRL
The test was marked as an expected failure in r320414 after r319971's import
of a newer jemalloc removed an essential feature (opt.redzone) for
reproducing the behavior it was testing. Since then, no way has been found
or demonstrated to reliably test the behavior, so remove the test.
PR: 220309
The root problem is that we were creating a PT_LOAD just for the header.
That was technically valid, but inconvenient: we should not be making
the ELF discontinuous.
The solution is to allow a section with LMAExpr to be added to a PT_LOAD
if that PT_LOAD doesn't already have a LMAExpr.
LLVM PR: 36017
Obtained from: LLVM r323625 by Rafael Espindola
If two sections are in the same PT_LOAD, their relatives offsets,
virtual address and physical addresses are all the same.
[Rafael] initially wanted to have a single global LMAOffset, on the
assumption that every ELF file was in practiced loaded contiguously in
both physical and virtual memory.
Unfortunately that is not the case. The linux kernel has:
LOAD 0x200000 0xffffffff81000000 0x0000000001000000 0xced000 0xced000 R E 0x200000
LOAD 0x1000000 0xffffffff81e00000 0x0000000001e00000 0x15f000 0x15f000 RW 0x200000
LOAD 0x1200000 0x0000000000000000 0x0000000001f5f000 0x01b198 0x01b198 RW 0x200000
LOAD 0x137b000 0xffffffff81f7b000 0x0000000001f7b000 0x116000 0x1ec000 RWE 0x200000
The delta for all but the third PT_LOAD is the same:
0xffffffff80000000. [Rafael] thinks the 3rd one is a hack for implementing
per cpu data, but we can't break that.
Obtained from: LLVM r323456 by Rafael Espindola
