There's no differene between VM_FREELIST_ISADMA and VM_FREELIST_LOWMEM
except for the default boundary (16MB on x86 and 256MB on MIPS, but
they are otherwise the same). We don't need both for any system we
support (there were some really old ARC systems that did have ISA/EISA
bus, but we never ran on them and they are too old to ever grow
support for).
Differential Review: https://reviews.freebsd.org/D16290
Do not use vm_map_remove() to release KVA back to the system. Because
kernel map entries do not have an associated VM object, with r336030
the vm_map_remove() call will not update the kernel page tables. Avoid
relying on the vm_map layer and instead update the pmap and release KVA
to the kernel arena directly in kmem_bootstrap_free().
Because the pmap updates will generally result in superpage demotions,
modify pmap_init() to insert PTPs shadowed by superpage mappings into
the kernel pmap's radix tree.
While here, port r329171 to i386.
Reported by: alc
Reviewed by: alc, kib
X-MFC with: r336505
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D16426
code never sees FPU pcb flags not consistent with the hardware state.
This is uncovered by the eager FPU switch mode.
Analyzed, reviewed and tested by: gleb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
On i386 and amd64, add a vm_phys segment for physical memory used to
store the kernel binary and other preloaded data. This makes it
possible to free such memory back to the system once it is no longer
needed, e.g., when a preloaded kernel module is unloaded. Previously,
it would have remained unused.
Reviewed by: kib, royger
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D16330
Without this, the support for transparent superpage promotion on i386
was left disabled.
Reviewed by: alc, kib
Differential Revision: https://reviews.freebsd.org/D16279
add support for explicitly requesting that pmap_enter() create a 2 or 4 MB
page mapping. (Essentially, this feature allows the machine-independent
layer to create superpage mappings preemptively, and not wait for automatic
promotion to occur.)
Export pmap_ps_enabled() to the machine-independent layer.
Add a flag to pmap_pv_insert_pde() that specifies whether it should fail or
reclaim a PV entry when one is not available.
Refactor pmap_enter_pde() into two functions, one by the same name, that is
a general-purpose function for creating PDE PG_PS mappings, and another,
pmap_enter_4mpage(), that is used to prefault 2 or 4 MB read- and/or
execute-only mappings for execve(2), mmap(2), and shmat(2).
Reviewed by: kib
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D16246
For example, fully construct the new PTE before entering the critical
section. This change is a stepping stone to psind == 1 support on i386.
Reviewed by: kib, markj
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D16188
Doing so ensures that all threads sharing the pmap have a consistent
view of the mapping. This fixes the problem described in the commit
log messages for r329254 without the overhead of an extra fault in the
common case. Once other pmap_enter() implementations are similarly
modified, the workaround added in r329254 can be removed, reducing the
overhead of CoW faults.
See also r335784 for amd64. The i386 implementation of pmap_enter()
already reused the PV entry from the old mapping.
Reviewed by: kib, markj
Tested by: pho
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D16133
This restores counters(9) operation.
Revert r336024. Improve assert of pcpu size on x86.
Reviewed by: mmacy
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D16163
Due to the way rtld creates mappings for the shared objects, each dso
causes unmap of at least three guard map entries. For instance, in
the buildworld load, this change reduces the amount of pmap_remove()
calls by 1/5.
Profiled by: alc
Reviewed by: alc, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D16148
SMP systems by extending defined(SMP) to include defined(KLD_MODULE).
This is a regression issue after r335873 .
Discussed with: mmacy@
Sponsored by: Mellanox Technologies
- Change pcpu zone consumers to use a stride size of PAGE_SIZE.
(defined as UMA_PCPU_ALLOC_SIZE to make future identification easier)
- Allocate page from the correct domain for a given cpu.
- Don't initialize pc_domain to non-zero value if NUMA is not defined
There are some misconceptions surrounding this field. It is the
_VM_ NUMA domain and should only ever correspond to valid domain
values as understood by the VM.
The former slab size of sizeof(struct pcpu) was somewhat arbitrary.
The new value is PAGE_SIZE because that's the smallest granularity
which the VM can allocate a slab for a given domain. If you have
fewer than PAGE_SIZE/8 counters on your system there will be some
memory wasted, but this is obviously something where you want the
cache line to be coming from the correct domain.
Reviewed by: jeff
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D15933
It is possible that a fictitious unmanaged userspace mapping of
superpage is created on x86, e.g. by pmap_object_init_pt(), with the
physical address outside the vm_page_array[] coverage.
Noted and reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D16085
physical address, which is readily available after sucessfull
vm_page_pa_tryrelock().
Noted and reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D16085
physical address, which is readily available after sucessfull
vm_page_pa_tryrelock().
Noted and reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D16085
returning NULL.
vm_fault_quick_hold_pages() can be legitimately called on userspace
mappings backed by fictitious pages created by unmanaged device and sg
pagers.
Note that other architectures pmap_extract_and_hold() might need
similar fix, but I postponed the examination.
Reported by: bde
Discussed with: alc
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D16085
- inline atomics in modules on i386 and amd64 (they were always
inline on other arches)
- allow modules to opt in to inlining locks by specifying
MODULE_TIED=1 in the makefile
Reviewed by: kib
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D16079
The Linux compatibility code was converting the version number (e.g.
2.6.32) in two different ways and then comparing the results.
The linux_map_osrel() function converted MAJOR.MINOR.PATCH similar to
what FreeBSD does natively. I.e. where major=v0, minor=v1, and patch=v2
v = v0 * 1000000 + v1 * 1000 + v2;
The LINUX_KERNVER() macro, on the other hand, converted the value with
bit shifts. I.e. where major=a, minor=b, and patch=c
v = (((a) << 16) + ((b) << 8) + (c))
The Linux kernel uses the later format via the KERNEL_VERSION() macro in
include/generated/uapi/linux/version.h
Fix is to use the LINUX_KERNVER() macro in linux_map_osrel() as well as
in the .trans_osrel functions.
PR: 229209
Reviewed by: emaste, cem, imp (mentor)
Approved by: imp (mentor)
Differential Revision: https://reviews.freebsd.org/D15952
Existing linuxulator platforms (i386, amd64) support legacy syscalls,
such as non-*at ones like open, but arm64 and other new platforms do
not.
Wrap these in #ifdef LINUX_LEGACY_SYSCALLS, #defined in the MD linux.h
files. We may need finer grained control in the future but this is
sufficient for now.
Reviewed by: andrew
Sponsored by: Turing Robotic Industries
Differential Revision: https://reviews.freebsd.org/D15237
The break() system call was renamed (several times) starting in v3
AT&T UNIX when C was invented and break was a language keyword. The
last vestage of a need for it to be called something else (eg obreak)
was removed in r225617 which consistantly prefixed all syscall
implementations.
Reviewed by: emaste, kib (older version)
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D15638
Give up and remove the almost useless informational message reporting
that device not available exception occured while our state tracking
indicates the current CPU has FPU context loaded for the current
thread.
It seems that this is recurring bug with some VM monitors.
Sponsored by: The FreeBSD Foundation
Most kernel memory that is allocated after boot does not need to be
executable. There are a few exceptions. For example, kernel modules
do need executable memory, but they don't use UMA or malloc(9). The
BPF JIT compiler also needs executable memory and did use malloc(9)
until r317072.
(Note that a side effect of r316767 was that the "small allocation"
path in UMA on amd64 already returned non-executable memory. This
meant that some calls to malloc(9) or the UMA zone(9) allocator could
return executable memory, while others could return non-executable
memory. This change makes the behavior consistent.)
This change makes malloc(9) return non-executable memory unless the new
M_EXEC flag is specified. After this change, the UMA zone(9) allocator
will always return non-executable memory, and a KASSERT will catch
attempts to use the M_EXEC flag to allocate executable memory using
uma_zalloc() or its variants.
Allocations that do need executable memory have various choices. They
may use the M_EXEC flag to malloc(9), or they may use a different VM
interfact to obtain executable pages.
Now that malloc(9) again allows executable allocations, this change also
reverts most of r317072.
PR: 228927
Reviewed by: alc, kib, markj, jhb (previous version)
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D15691
A call to npxsave() in the exception trampolines was not relocated.
This call to a garbage address usually paniced when made, but it is only
made when the thread has used an FPU recently, and this is not the usual
case.
PR: 228755
Reviewed by: kib
pmc_process_interrupt takes 5 arguments when only 3 are needed.
cpu is always available in curcpu and inuserspace can always be
derived from the passed trapframe.
While facially a reasonable cleanup this change was motivated
by the need to workaround a compiler bug.
core2_intr(cpu, tf) ->
pmc_process_interrupt(cpu, ring, pmc, tf, inuserspace) ->
pmc_add_sample(cpu, ring, pm, tf, inuserspace)
In the process of optimizing the tail call the tf pointer was getting
clobbered:
(kgdb) up
at /storage/mmacy/devel/freebsd/sys/dev/hwpmc/hwpmc_mod.c:4709
4709 pmc_save_kernel_callchain(ps->ps_pc,
(kgdb) up
1205 error = pmc_process_interrupt(cpu, PMC_HR, pm, tf,
resulting in a crash in pmc_save_kernel_callchain.
- increase pmc cpuid field from 8 to 12 bits
- add cpuid version string to initialize entry in the log
so that filter can identify which counter index an
event name maps to
- GC unused config flags
- make fixed counter assignment more robust as well as the
changes needed to be properly identified for filter
file in /sys/conf, so was unavailable in configurations that don't use
modules, and was not testable or notable in NOTES. Its normal
configuration (not using a module) is still silently deprecated in
aout(4) by not mentioning it there.
Update i386 NOTES for COMPAT_AOUT. It is not i386-only, or even very MD.
Sort its entry better.
Finish gzip configuration (but not support) for amd64. gzip is really
gzipped aout. It is currently broken even for i386 (a call to vm fails).
amd64 has always attempted to configure and test it, but it depends on
COMPAT_AOUT (as noted). The bug that it depends on unconfigured files
was not detected since it is configured as a device. All other optional
image activators are configured properly using an option.
time, especially for SMP. If configured, it turns itself on at boot
time for calibration, so is fragile even if never otherwise used.
Both types of kernel profiling were supposed to use a global spinlock
in the SMP case. If hi-res profiling is configured (but not necessarily
used), this was supposed to be optimized by only using it when
necessary, and slightly more efficiently, in asm. But it was not done
at all for mcount entry where it is necessary. This caused crashes
in the SMP case when either type of profiling was enabled. For mcount
exit, it only caused wrong times. The times were wrongest with an
i8254 timer since using that requires exclusive access to the hardware.
The i8254 timer was too slow to use here 20 years ago and is much less
usable now, but it is the default for the SMP case since TSCs weren't
invariant when SMP was new. Do the locking in all hi-res SMP cases for
simplicity.
Calibration uses special asms, and the clobber lists in these were sort
of inverted. They contained the arg and return registers which are not
clobbered, but on amd64 they didn't contain the residue of the call-used
registers which may be clobbered (%r10 and %r11). This usually caused
hangs at boot time. This usually affected even the UP case.
kernel profiling remains broken).
memmove() was broken using ALTENTRY(). ALTENTRY() is only different from
ENTRY() in the profiling case, and its use in that case was sort of
backwards. The backwardness magically turned memmove() into memcpy()
instead of completely breaking it. Only the high resolution parts of
profiling itself were broken. Use ordinary ENTRY() for memmove().
Turn bcopy() into a tail call to memmove() to reduce complications.
This gives slightly different pessimizations and profiling lossage.
The pessimizations are minimized by not using a frame pointer() for
bcopy().
Calls to profiling functions from exception trampolines were not
relocated. This caused crashes on the first exception. Fix this using
function pointers.
Addresses of exception handlers in trampolines were not relocated. This
caused unknown offsets in the profiling data. Relocate by abusing
setidt_disp as for pmc although this is slower than necessary and
requires namespace pollution. pmc seems to be missing some relocations.
Stack traces and lots of other things in debuggers need similar relocations.
Most user addresses were misclassified as unknown kernel addresses and
then ignored. Treat all unknown addresses as user. Now only user
addresses in the kernel text range are significantly misclassified (as
known kernel addresses).
The ibrs functions didn't preserve enough registers. This is the only
recent breakage on amd64. Although these functions are written in
asm, in the profiling case they call profiling functions which are
mostly for the C ABI, so they only have to save call-used registers.
They also have to save arg and return registers in some cases and
actually save them in all cases to reduce complications. They end up
saving all registers except %ecx on i386 and %r10 and %r11 on amd64.
Saving these is only needed for 1 caller on each of amd64 and i386.
Save them there. This is slightly simpler.
Remove saving %ecx in handle_ibrs_exit on i386. Both handle_ibrs_entry
and handle_ibrs_exit use %ecx, but only the latter needed to or did
save it. But saving it there doesn't work for the profiling case.
amd64 has more automatic saving of the most common scratch registers
%rax, %rcx and %rdx (its complications for %r10 are from unusual use
of %r10 by SYSCALL). Thus profiling of handle_ibrs_exit_rs() was not
broken, and I didn't simplify the saving by moving the saving of these
registers from it to the caller.
Intel now provides comprehensive tables for all performance counters
and the various valid configuration permutations as text .json files.
Libpmc has been converted to use these and hwpmc_core has been greatly
simplified by moving to passthrough of the table values.
The one gotcha is that said tables don't support pentium pro and and pentium
IV. There's very few users of hwpmc on _amd64_ kernels on new hardware. It is
unlikely that anyone is doing low level optimization on 15 year old Intel
hardware. Nonetheless, if someone feels strongly enough to populate the
corresponding tables for p4 and ppro I will reinstate the files in to the
build.
Code for the K8 counters and !x86 architectures remains unchanged.
This is a follow-up to r321483, which disabled -Wmacro-redefined for
some lib/msun tests.
If an application included both fenv.h and ieeefp.h, several macros such
as __fldcw(), __fldenv() were defined in both headers, with slightly
different arguments, leading to conflicts.
Fix this by putting all the common macros in the machine-specific
versions of ieeefp.h. Where needed, update the arguments in places
where the macros are invoked.
This also slightly reduces the differences between the amd64 and i386
versions of ieeefp.h.
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D15633
pmap_is_prefaultable() and pmap_incore(), pushing the number of
shootdown IPIs back to the 3/1 kernel.
Benchmarked by: bde
Tested by: pho
Sponsored by: The FreeBSD Foundation
Create yet another temporal pte mapping routine pmap_pte_quick3(),
which is the copy of the pmap_pte_quick() and relies on the
pvh_global_lock to protect the frame. It accounts into the same
counters as pmap_pte_quick(). It is needed since pmap_copy() uses
pmap_pte_quick() already, and since a user pmap is no longer current
pmap.
pmap_copy() still provides the advantage for real-world workloads
involving lot of forks where processes do not exec immediately.
Benchmarked by: bde
Sponsored by: The FreeBSD Foundation
While at it add missing _acq_ and _rel_ variants for 64-bit atomic
operations under i386.
Reviewed by: kib @
MFC after: 1 week
Sponsored by: Mellanox Technologies
In particular, stop using pmap_pte() to read non-promoted pte while
walking the page table. pmap_pte() needs to shoot down the kernel
mapping globally which causes IPI broadcast. Since
pmap_extract_and_hold() is used for slow copyin(9), it is very
significant hit for the 4/4 kernels.
Instead, create single purpose per-processor page frame and use it to
locally map page table page inside the critical section, to avoid
reuse of the frame by other thread if context switched.
Measurement demostrated very significant improvements in any load that
utilizes copyin/copyout.
Found and benchmarked by: bde
Sponsored by: The FreeBSD Foundation
The TSC-s are checked and synchronized only if they were good
originally. That is, invariant, synchronized, etc.
This is necessary on an AMD-based system where after a wakeup from STR I
see that BSP clock differs from AP clocks by a count that roughly
corresponds to one second. The APs are in sync with each other. Not
sure if this is a hardware quirk or a firmware bug.
This is what I see after a resume with this change:
SMP: passed TSC synchronization test after adjustment
acpi_timer0: restoring timecounter, ACPI-fast -> TSC-low
Reviewed by: kib
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D15551
Make memmove the primary interface, but have bcopy be an alternative
entry point that jumps into memmove. This will slightly pessimize
bcopy calls, but those are about to get much rarer. Return dst always,
but it will be ignored by bcopy callers. We can remove just the alt
entry point if we ever remove bcopy entirely.
Differential Revision: https://reviews.freebsd.org/D15374
Instead, construct an auxargs array and copy it out all at once.
Use an array of Elf_Auxinfo rather than pairs of Elf_Addr * to represent
the array. This is the correct type where pairs of words just happend
to work. To reduce the size of the diff, AUXARGS_ENTRY is altered to act
on this array rather than introducing a new macro.
Return errors on copyout() and suword() failures and handle them in the
caller.
Incidentally fixes AT_RANDOM and AT_EXECFN in 32-bit linux on amd64
which incorrectly used AUXARG_ENTRY instead of AUXARGS_ENTRY_32
(now removed due to the use of proper types).
Reviewed by: kib
Comments from: emaste, jhb
Obtained from: CheriBSD
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D15485
We certainly should clear PSL_T when calling the SIGTRAP signal
handler, which is already done by all x86 sendsig(9) ABI code. On the
other hand, there is no obvious reason why PSL_T needs to be cleared
when returning from the signal handler. For instance, Linux allows
userspace to set PSL_T and keep tracing enabled for the desired
period. There are userspace programs which would use PSL_T if we make
it possible, for instance sbcl.
Remember if PSL_T was set by PT_STEP or PT_SETSTEP by mean of TDB_STEP
flag, and only clear it when the flag is set.
Discussed with: Ali Mashtizadeh
Reviewed by: jhb (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D15054
r334005: add pc_ibpb_set as it is now referenced by common code
(although presumably not needed on i386 since it has been there
since the first spectre mitigation work on amd64)
r334009: there is no amd64 rflags -> i386 eflags
- Add constants for fields in DR6 and the reserved fields in DR7. Use
these constants instead of magic numbers in most places that use DR6
and DR7.
- Refer to T_TRCTRAP as "debug exception" rather than a "trace trap"
as it is not just for trace exceptions.
- Always read DR6 for debug exceptions and only clear TF in the flags
register for user exceptions where DR6.BS is set.
- Clear DR6 before returning from a debug exception handler as
recommended by the SDM dating all the way back to the 386. This
allows debuggers to determine the cause of each exception. For
kernel traps, clear DR6 in the T_TRCTRAP case and pass DR6 by value
to other parts of the handler (namely, user_dbreg_trap()). For user
traps, wait until after trapsignal to clear DR6 so that userland
debuggers can read DR6 via PT_GETDBREGS while the thread is stopped
in trapsignal().
Reviewed by: kib, rgrimes
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D15189
This turns on support for kernel dump encryption and compression, and
netdump. arm and mips platforms are omitted for now, since they are more
constrained and don't benefit as much from these features.
Reviewed by: cem, manu, rgrimes
Tested by: manu (arm64)
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D15465
is executed on the right stack already. No copy from the entry stack
to the kstack must be performed for vm86 bios call code to function.
To access the pcb flags on kernel entry, unconditionally switch to
kernel address space if vm86 mode is detected.
This fixes very early vm86 bios calls, typically done when boot is
performed by boot2 without loader, and kernel falls back to BIOS calls
to get SMAP.
Reported by: bde
Sponsored by: The FreeBSD Foundation
PCB_VM86CALL pcb flag not set should be treated same as return to
userspace.
Most important, the address space must be switched. This fixes
usermode vm86 operations after the 4/4 split.
Sponsored by: The FreeBSD Foundation
exception code is copied to the trampoline.
The correct value is then copied to trampoline automatically, so
tramp_idleptd_reloced can be eliminated.
This will allow to use the same exception entry code to handle traps
from vm86 bios calls on early boot stage, as after the trampoline is
configured.
Sponsored by: The FreeBSD Foundation
Record common_tssd, the descriptor to be written in GDT to point to
the common TSS, before LTR is executed. The LTR instruction sets the
loaded descriptor type to 386 TSS busy, which traps on reloads.
Sponsored by: The FreeBSD Foundation
Since pop %ss/mov %ss instructions defer all interrupts and exceptions
for the next instruction, it is possible that the userspace watchpoint
trap executes on the first instruction of the kernel entry for
syscall/bpt.
In this case, DB# should be treated similarly to NMI: on amd64 we must
always load GSBASE even if the trap comes from kernel mode, and load
the kernel page table root into %cr3. Moreover, the trap must
use the dedicated stack, because we are still on the user stack when
trapped on syscall entry.
For i386, we must reload %cr3. The syscall instruction is not configured,
so there is no issue with executing on user stack when trapping.
Due to some CPU erratas it is not always possible to detect that the
userspace watchpoint triggered by inspecting %dr6. In trap(), compare the
trap %rip with the known unsafe entry points and if matched pretend that
the watchpoint did not fire at all.
Thank you to the MSRC Incident Response Team, and in particular Greg
Lenti and Nate Warfield, for coordinating the response to this issue
across multiple vendors.
Thanks to Computer Recycling at The Working Center of Kitchener for
making hardware available to allow us to test the patch on additional
CPU families.
Reviewed by: jhb
Discussed with: Matthew Dillon
Tested by: emaste
Sponsored by: The FreeBSD Foundation
Security: CVE-2018-8897
Security: FreeBSD-SA-18:06.debugreg
Required MD bits are only provided for x86.
Reviewed by: jhb (previous version, as part of the larger patch)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D13838
This driver was for an early and uncommon legacy PCI 10GbE for a single
ASIC, Intel 82597EX. Intel quickly shifted to the long lived ixgbe family.
Submitted by: kbowling
Reviewed by: brooks imp jeffrey.e.pieper@intel.com
Relnotes: yes
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D15234
Dumpers may wish to print messages from an initialization hook; this
change ensures that such messages aren't mixed with output from the
generic dump code.
MFC after: 1 week
Use proper method to access userspace. For now, only the slow copyout
path is implemented.
Reported and tested by: tijl (previous version)
Sponsored by: The FreeBSD Foundation
Remove auxarg_size as it was only used once right after a confusing
assignment in each of the variants of exec_copyout_strings().
Reviewed by: emaste
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D15123
This will allow to hook a ddb script to "kdb.enter.trap" event.
Previously there was no specific name for this event, so it could only
be handled by either "kdb.enter.unknown" or "kdb.enter.default" hooks.
Both are very unspecific.
Having a specific event is useful because the fatal trap condition is
very similar to panic but it has an additional property that the current
stack frame is the frame where the trap occurred. So, both a register
dump and a stack bottom dump have additional information that can help
analyze the problem.
I have added the event only on architectures that have trap_fatal()
function defined. I haven't looked at other architectures. Their
maintainers can add support for the event later.
Sample script:
kdb.enter.trap=bt; show reg; x/aS $rsp,20; x/agx $rsp,20
Reviewed by: kib, jhb, markj
MFC after: 11 days
Sponsored by: Panzura
Differential Revision: https://reviews.freebsd.org/D15093
Half of implementations always failed (returned (-1)) and they were
previously used in only one place.
Reviewed by: kib, andrew
Obtained from: CheriBSD
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D15102
'bool' is preferred to 'boolean_t'. We only get the boolean_t
definition by header pollution (though the same is true for
bool). Since we use both, switch entirely to bool.
Note: We still have TRUE/FALSE instead of true/false in heavy use in
the rest of the file. These are with ints of various flavors, so
that's appropriate, even though we should eventually migrate to bool
and true/false (though the tables they are in are nicely packed with
short and wouldn't be so nicely packed with bool, another reason
to leave it alone for now).
The change makes the user and kernel address spaces on i386
independent, giving each almost the full 4G of usable virtual addresses
except for one PDE at top used for trampoline and per-CPU trampoline
stacks, and system structures that must be always mapped, namely IDT,
GDT, common TSS and LDT, and process-private TSS and LDT if allocated.
By using 1:1 mapping for the kernel text and data, it appeared
possible to eliminate assembler part of the locore.S which bootstraps
initial page table and KPTmap. The code is rewritten in C and moved
into the pmap_cold(). The comment in vmparam.h explains the KVA
layout.
There is no PCID mechanism available in protected mode, so each
kernel/user switch forth and back completely flushes the TLB, except
for the trampoline PTD region. The TLB invalidations for userspace
becomes trivial, because IPI handlers switch page tables. On the other
hand, context switches no longer need to reload %cr3.
copyout(9) was rewritten to use vm_fault_quick_hold(). An issue for
new copyout(9) is compatibility with wiring user buffers around sysctl
handlers. This explains two kind of locks for copyout ptes and
accounting of the vslock() calls. The vm_fault_quick_hold() AKA slow
path, is only tried after the 'fast path' failed, which temporary
changes mapping to the userspace and copies the data to/from small
per-cpu buffer in the trampoline. If a page fault occurs during the
copy, it is short-circuit by exception.s to not even reach C code.
The change was motivated by the need to implement the Meltdown
mitigation, but instead of KPTI the full split is done. The i386
architecture already shows the sizing problems, in particular, it is
impossible to link clang and lld with debugging. I expect that the
issues due to the virtual address space limits would only exaggerate
and the split gives more liveness to the platform.
Tested by: pho
Discussed with: bde
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D14633
The miscellaneous x86 sysent->sv_setregs() implementations tried to
migrate PSL_T from the previous program to the new executed one, but
they evaluated regs->tf_eflags after the whole regs structure was
bzeroed. Make this functional by saving PSL_T value before zeroing.
Note that if the debugger is not attached, executing the first
instruction in the new program with PSL_T set results in SIGTRAP, and
since all intercepted signals are reset to default dispostion on
exec(2), this means that non-debugged process gets killed immediately
if PSL_T is inherited. In particular, since suid images drop
P_TRACED, attempt to set PSL_T for execution of such program would
kill the process.
Another issue with userspace PSL_T handling is that it is reset by
trap(). It is reasonable to clear PSL_T when entering SIGTRAP
handler, to allow the signal to be handled without recursion or
delivery of blocked fault. But it is not reasonable to return back to
the normal flow with PSL_T cleared. This is too late to change, I
think.
Discussed with: bde, Ali Mashtizadeh
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
Differential revision: https://reviews.freebsd.org/D14995
Previously linuxulator had three identical copies of
linux_exec_imgact_try. Deduplicate before adding another arch to
linuxulator.
Sponsored by: Turing Robotic Industries Inc
Differential Revision: https://reviews.freebsd.org/D14856
opt_compat.h is mentioned in nearly 180 files. In-progress network
driver compabibility improvements may add over 100 more so this is
closer to "just about everywhere" than "only some files" per the
guidance in sys/conf/options.
Keep COMPAT_LINUX32 in opt_compat.h as it is confined to a subset of
sys/compat/linux/*.c. A fake _COMPAT_LINUX option ensure opt_compat.h
is created on all architectures.
Move COMPAT_LINUXKPI to opt_dontuse.h as it is only used to control the
set of compiled files.
Reviewed by: kib, cem, jhb, jtl
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D14941
So that it doesn't rely on physmap[1] containing an address below
1MiB. Instead scan the full physmap and search for a suitable address
to place the trampoline code (below 1MiB) and the initial memory pages
(below 4GiB).
Sponsored by: Citrix Systems R&D
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D14878
x86/cpu_machdep.c now needs to include elan_mmcr.h when CPU_ELAN is set.
While here, also remove the now unneeded inclusion of isareg.h in i386
and amd64 vm_machdep.c.
Reported by: lwhsu
MFC after: 14 days
X-MFC with: r331878
Because I didn't see any reason not too.
I've been making some changes to the code and couldn't help but notice
that the i386 and am64 code was nearly identical.
MFC after: 17 days
If cpu_reset() is called on an AP and if it somehow fails to wake the
BSP, then it's better to attempt the reset on the AP than just sit there
spinning on an unusable and undebuggable system.
MFC after: 16 days
The processor is "parked" in a spin-loop already and that's sufficient
for the reset. There is nothing that stop_cpus() would add here, only
extra complexity and fragility.
The original processor does not need to enable interrupts now, in fact,
it must not do that.
MFC after: 2 weeks
platforms. Original commit message as follows:
Only use CPUs in the domain the device is attached to for default
assignment. Device drivers are able to override the default assignment
if they bind directly. There are severe performance penalties for
handling interrupts on remote CPUs and this should only be done in
very controlled circumstances.
Reviewed by: jhb, kib
Tested by: pho
Sponsored by: Netflix, Dell/EMC Isilon
Differential Revision: https://reviews.freebsd.org/D14838
These have been supplanted by the MI signal information codes in
<sys/signal.h> since 7.0. The FPE_*_TRAP ones were deprecated even
earlier in 1999.
PR: 226579 (exp-run)
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D14637
assignment. Device drivers are able to override the default assignment
if they bind directly. There are severe performance penalties for
handling interrupts on remote CPUs and this should only be done in
very controlled circumstances.
Reviewed by: jhb, kib
Tested by: pho (earlier version)
Sponsored by: Netflix, Dell/EMC Isilon
Differential Revision: https://reviews.freebsd.org/D14838
Bring #includes closer to style(9) and reduce differences between the
(three) MD versions of linux_machdep.c and linux_sysvec.c.
Sponsored by: Turing Robotic Industries Inc.
i386 was changed to only require critical section around the thread
FPU state manipulations, and vm86_bioscall callers already enter
critical section for other reasons.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
ibcs2_getdents() copies a dirent structure to userland. The ibcs2
dirent structure contains a 2 byte pad element. This element is never
initialized, but copied to userland none-the-less.
Note that ibcs2 has not built on HEAD since r302095.
Submitted by: Domagoj Stolfa <ds815@cam.ac.uk>
Reported by: Ilja Van Sprundel <ivansprundel@ioactive.com>
MFC after: 3 days
Security: Kernel memory disclosure (803)
assym is only to be included by other .s files, and should never
actually be assembled by itself.
Reviewed by: imp, bdrewery (earlier)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D14180
It's preferable to have a consistent prefix. This also reduces
differences between the three linux*_sysvec.c files.
Sponsored by: Turing Robotic Industries Inc.
There's a fair amount of duplication between MD linuxulator files.
Make indentation and comments consistent between the three versions of
linux_sysvec.c to reduce diffs when comparing them.
Sponsored by: Turing Robotic Industries Inc.
Three copies of the linuxulator linux_sysvec.c contained identical
BSD to Linux errno translation tables, and future work to support other
architectures will also use the same table. Move the table to a common
file to be used by all. Make it 'const int' to place it in .rodata.
(Some existing Linux architectures use MD errno values, but x86 and Arm
share the generic set.)
This change should introduce no functional change; a followup will add
missing errno values.
MFC after: 3 weeks
Sponsored by: Turing Robotic Industries Inc.
Differential Revision: https://reviews.freebsd.org/D14665
Migrate to modern types before creating MD Linuxolator bits for new
architectures.
Reviewed by: cem
Sponsored by: Turing Robotic Industries Inc.
Differential Revision: https://reviews.freebsd.org/D14676
Nothing uses the #define's values or the types. (Some NTP code does use
an audio_info_t, but it is in #ifdef'd support for Solaris and is not
this audio_info_t).
Sponsored by: DARPA, AFRL
While there is no immediate leak, if the structure changes underneath
us, there might be in the future.
Submitted by: Domagoj Stolfa <domagoj.stolfa@gmail.com>
MFC After: 1 month
Sponsored by: DARPA/AFRL
correctly for the data contained on each memory page.
There are several components to this change:
* Add a variable to indicate the start of the R/W portion of the
initial memory.
* Stop detecting NX bit support for each AP. Instead, use the value
from the BSP and, if supported, activate the feature on the other
APs just before loading the correct page table. (Functionally, we
already assume that the BSP and all APs had the same support or
lack of support for the NX bit.)
* Set the RW and NX bits correctly for the kernel text, data, and
BSS (subject to some caveats below).
* Ensure DDB can write to memory when necessary (such as to set a
breakpoint).
* Ensure GDB can write to memory when necessary (such as to set a
breakpoint). For this purpose, add new MD functions gdb_begin_write()
and gdb_end_write() which the GDB support code can call before and
after writing to memory.
This change is not comprehensive:
* It doesn't do anything to protect modules.
* It doesn't do anything for kernel memory allocated after the kernel
starts running.
* In order to avoid excessive memory inefficiency, it may let multiple
types of data share a 2M page, and assigns the most permissions
needed for data on that page.
Reviewed by: jhb, kib
Discussed with: emaste
MFC after: 2 weeks
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D14282
imcsmb(4) provides smbus(4) support for the SMBus controller functionality
in the integrated Memory Controllers (iMCs) embedded in Intel Sandybridge-
Xeon, Ivybridge-Xeon, Haswell-Xeon, and Broadwell-Xeon CPUs. Each CPU
implements one or more iMCs, depending on the number of cores; each iMC
implements two SMBus controllers (iMC-SMBs).
*** IMPORTANT NOTE ***
Because motherboard firmware or the BMC might try to use the iMC-SMBs for
monitoring DIMM temperatures and/or managing an NVDIMM, the driver might
need to temporarily disable those functions, or take a hardware interlock,
before using the iMC-SMBs. Details on how to do this may vary from board to
board, and the procedure may be proprietary. It is strongly suggested that
anyone wishing to use this driver contact their motherboard vendor, and
modify the driver as described in the manual page and in the driver itself.
(For what it's worth, the driver as-is has been tested on various SuperMicro
motherboards.)
Reviewed by: avg, jhb
MFC after: 1 week
Relnotes: yes
Sponsored by: Panasas
Differential Revision: https://reviews.freebsd.org/D14447
Discussed with: avg, ian, jhb
Tested by: allanjude (previous version), Panasas
This deliberately breaks the API in preperation for future syscall
revisions which will remove these nonstandard members.
In an exp-run a single port (devel/qemu-user-static) was found to
use them which it did becuase it emulates system calls. This has
been fixed in the ports tree.
PR: 224443 (exp-run)
Reviewed by: kib, jhb (previous version)
Exp-run by: antoine
Sponsored by: DARPA, AFRP
Differential Revision: https://reviews.freebsd.org/D14490
No implementation of fpu_kern_enter() can fail, and it was causing needless
error checking boilerplate and confusion. Change the return code to void to
match reality.
(This trivial change took nine days to land because of the commit hook on
sys/dev/random. Please consider removing the hook or otherwise lowering the
bar -- secteam never seems to have free time to review patches.)
Reported by: Lachlan McIlroy <Lachlan.McIlroy AT isilon.com>
Reviewed by: delphij
Approved by: secteam (delphij)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D14380
Make vm_wait() take the vm_object argument which specifies the domain
set to wait for the min condition pass. If there is no object
associated with the wait, use curthread' policy domainset. The
mechanics of the wait in vm_wait() and vm_wait_domain() is supplied by
the new helper vm_wait_doms(), which directly takes the bitmask of the
domains to wait for passing min condition.
Eliminate pagedaemon_wait(). vm_domain_clear() handles the same
operations.
Eliminate VM_WAIT and VM_WAITPFAULT macros, the direct functions calls
are enough.
Eliminate several control state variables from vm_domain, unneeded
after the vm_wait() conversion.
Scetched and reviewed by: jeff
Tested by: pho
Sponsored by: The FreeBSD Foundation, Mellanox Technologies
Differential revision: https://reviews.freebsd.org/D14384
Many licenses on Linuxolator files contained small variations from the
standard FreeBSD license text. To avoid license proliferation switch to
the standard 2-clause FreeBSD license for those files where I have
permission from each of the listed copyright holders. Additional files
waiting on permission from others are listed in review D14210.
Approved by: kan, marcel, sos, rdivacky
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
The idea is, the pmap_qenter() API is now defined to not produce executable
mappings. If you need executable mappings, use another API.
Add pg_nx flag in pmap_qenter on x86 to make kernel pages non-executable.
Other architectures that support execute-specific permissons on page table
entries should subsequently be updated to match.
Submitted by: Darrick Lew <darrick.freebsd AT gmail.com>
Reviewed by: markj
Discussed with: alc, jhb, kib
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D14062
compilation under FreeBSD. The mthca driver was temporarily removed as
part of the Linux 4.9 RoCE/infinband upgrade.
Top commit in Linux source tree:
69973b830859bc6529a7a0468ba0d80ee5117826
Sponsored by: Mellanox Technologies
significant source of cache line contention from vm_page_alloc(). Use
accessors and vm_page_unwire_noq() so that the mechanism can be easily
changed in the future.
Reviewed by: markj
Discussed with: kib, glebius
Tested by: pho (earlier version)
Sponsored by: Netflix, Dell/EMC Isilon
Differential Revision: https://reviews.freebsd.org/D14273
global to per-domain state. Protect reservations with the free lock
from the domain that they belong to. Refactor to make vm domains more
of a first class object.
Reviewed by: markj, kib, gallatin
Tested by: pho
Sponsored by: Netflix, Dell/EMC Isilon
Differential Revision: https://reviews.freebsd.org/D14000
A version of each of the MD files by necessity exists for each CPU
architecture supported by the Linuxolator. Clean these up so that new
architectures do not inherit whitespace issues.
Clean up shared Linuxolator files while here.
Sponsored by: Turing Robotic Industries Inc.
It is coded according to the Intel document 336996-001, reading of the
patches posted on lkml, and some additional consultations with Intel.
For existing processors, you need a microcode update which adds IBRS
CPU features, and to manually enable it by setting the tunable/sysctl
hw.ibrs_disable to 0. Current status can be checked in sysctl
hw.ibrs_active. The mitigation might be inactive if the CPU feature
is not patched in, or if CPU reports that IBRS use is not required, by
IA32_ARCH_CAP_IBRS_ALL bit.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D14029
Use PCID to avoid complete TLB shootdown when switching between user
and kernel mode with PTI enabled.
I use the model close to what I read about KAISER, user-mode PCID has
1:1 correspondence to the kernel-mode PCID, by setting bit 11 in PCID.
Full kernel-mode TLB shootdown is performed on context switches, since
KVA TLB invalidation only works in the current pmap. User-mode part of
TLB is flushed on the pmap activations as well.
Similarly, IPI TLB shootdowns must handle both kernel and user address
spaces for each address. Note that machines which implement PCID but
do not have INVPCID instructions, cause the usual complications in the
IPI handlers, due to the need to switch to the target PCID temporary.
This is racy, but because for PCID/no-INVPCID we disable the
interrupts in pmap_activate_sw(), IPI handler cannot see inconsistent
state of CPU PCID vs PCPU pmap/kcr3/ucr3 pointers.
On the other hand, on kernel/user switches, CR3_PCID_SAVE bit is set
and we do not clear TLB.
I can imagine alternative use of PCID, where there is only one PCID
allocated for the kernel pmap. Then, there is no need to shootdown
kernel TLB entries on context switch. But copyout(3) would need to
either use method similar to proc_rwmem() to access the userspace
data, or (in reverse) provide a temporal mapping for the kernel buffer
into user mode PCID and use trampoline for copy.
Reviewed by: markj (previous version)
Tested by: pho
Discussed with: alc (some aspects)
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
Differential revision: https://reviews.freebsd.org/D13985
