ocassions, memory barriers semantic is not honoured by the hardware
itself. As a result, some random breakage can happen in uninvestigable
ways (for further explanation see at the content of the commit itself).
As long as just a specific familly is bugged of an entire architecture
is broken, a complete fix-up is impratical without harming to some
extents the other correct cases.
Considering that (and considering the frequency of the bug exposure)
just print out a warning message if the affected machine is identified.
Pointed out by: Samy Al Bahra <sbahra at repnop dot org>
Help on wordings by: jeff
MFC: 3 days
partially fixed on amd64 earlier. Rather than forcing linux_mmap_common()
to use a 32-bit offset, have it accept a 64-bit file offset. This offset
is then passed to the real mmap() call. Rather than inventing a structure
to hold the normal linux_mmap args that has a 64-bit offset, just pass
each of the arguments individually to linux_mmap_common() since that more
closes matches the existing style of various kern_foo() functions.
Submitted by: Christian Zander @ Nvidia
MFC after: 1 week
while in kernel mode, and later changing signal mask to block the
signal, was fixed for sigprocmask(2) and ptread_exit(3). The same race
exists for sigreturn(2), setcontext(2) and swapcontext(2) syscalls.
Use kern_sigprocmask() instead of direct manipulation of td_sigmask to
reschedule newly blocked signals, closing the race.
Reviewed by: davidxu
Tested by: pho
MFC after: 1 month
the memory or D-cache, depending on the semantics of the platform.
vm_sync_icache() is basically a wrapper around pmap_sync_icache(),
that translates the vm_map_t argumument to pmap_t.
o Introduce pmap_sync_icache() to all PMAP implementation. For powerpc
it replaces the pmap_page_executable() function, added to solve
the I-cache problem in uiomove_fromphys().
o In proc_rwmem() call vm_sync_icache() when writing to a page that
has execute permissions. This assures that when breakpoints are
written, the I-cache will be coherent and the process will actually
hit the breakpoint.
o This also fixes the Book-E PMAP implementation that was missing
necessary locking while trying to deal with the I-cache coherency
in pmap_enter() (read: mmu_booke_enter_locked).
The key property of this change is that the I-cache is made coherent
*after* writes have been done. Doing it in the PMAP layer when adding
or changing a mapping means that the I-cache is made coherent *before*
any writes happen. The difference is key when the I-cache prefetches.
handlers. This is primarily intended as a way to allow devices that use
multiple interrupts (e.g. MSI) to meaningfully distinguish the various
interrupt handlers.
- Add a new BUS_DESCRIBE_INTR() method to the bus interface to associate
a description with an active interrupt handler setup by BUS_SETUP_INTR.
It has a default method (bus_generic_describe_intr()) which simply passes
the request up to the parent device.
- Add a bus_describe_intr() wrapper around BUS_DESCRIBE_INTR() that supports
printf(9) style formatting using var args.
- Reserve MAXCOMLEN bytes in the intr_handler structure to hold the name of
an interrupt handler and copy the name passed to intr_event_add_handler()
into that buffer instead of just saving the pointer to the name.
- Add a new intr_event_describe_handler() which appends a description string
to an interrupt handler's name.
- Implement support for interrupt descriptions on amd64 and i386 by having
the nexus(4) driver supply a custom bus_describe_intr method that invokes
a new intr_describe() MD routine which in turn looks up the associated
interrupt event and invokes intr_event_describe_handler().
Requested by: many
Reviewed by: scottl
MFC after: 2 weeks
by looking at the bases used for non-relocatable executables by gnu ld(1),
and adjusting it slightly.
Discussed with: bz
Reviewed by: kan
Tested by: bz (i386, amd64), bsam (linux)
MFC after: some time
specify their own version of atomic_cmpset_* which could have been
different than the membar version.
Right now, however, FreeBSD is bound mostly to GCC-like compilers and
it is desired to add new support and compat shim mostly when there is
a real necessity, in order to avoid too much compatibility bloats.
In this optic, bring back atomic_cmpset_{acq, rel}_* to be the same as
atomic_cmpset_* and unwind the atomic_cmpset_barr_* introduction.
Requested by: jhb
Reviewed by: jhb
Tested by: Giovanni Trematerra <giovanni dot trematerra at
gmail dot com>
- Allocate memory for wakeup code after ACPI bus is attached. The early
memory allocation hack was inherited from i386 but amd64 does not need it.
- Exclude real mode IVT and BDA explicitly. Improve comments about memory
allocation and reason for the exclusions. It is a no-op in reality, though.
- Remove an unnecessary CLD from wakeup code and re-align.
not defined through macros or similar) in order to be later compiled in
the kernel and offer this way the support for modules (and
compatibility among the UP case and SMP case).
Fix this for the newly introduced atomic_cmpset_barr_* cases by defining
and specifying a template. Note that the new DEFINE_CMPSET_GEN()
template save more typing on amd64 than the current code. [1]
- Fix the style for memory barriers on amd64.
[1] Reported by: Paul B. Mahol <onemda at gmail dot com>
memory barriers should also ensure that the compiler doesn't reorder paths
where they are used. GCC, however, does that aggressively, even in
presence of volatile operands. The most reliable way GCC offers for avoid
instructions reordering is clobbering "memory" even if that is
theoretically an heavy-weight operation, flushing the content of all
the registers and forcing reload of them (We could rely, however, on
gcc DTRT by just understanding the purpose as this is a well-known
pattern for many modern operating-systems).
Not all our memory barriers, right now, clobber memory for GCC-like
compilers. The most notable cases are IA32 and amd64 where the memory
barrier are treacted the same as normal atomic instructions.
Fix this by offering the possibility to implement atomic instructions
with memory barriers separately from the normal version and implement
the GCC-like specific one using memory clobbering.
Thanks to Chris Lattner (@apple) for his discussion on llvm specifics.
Reported by: jhb
Reviewed by: jhb
Tested by: rdivacky, Giovanni Trematerra
<giovanni dot trematerra at gmail dot com>
first and the native ia32 compat as middle (before other things).
o(ld)brandinfo as well as third party like linux, kfreebsd, etc.
stays on SI_ORDER_ANY coming last.
The reason for this is only to make sure that even in case we would
overflow the MAX_BRANDS sized array, the native FreeBSD brandinfo
would still be there and the system would be operational.
Reviewed by: kib
MFC after: 1 month
pmap_invalidate_cache_range() when self-snoop is apparently not reported
in cpu features. We get a reserved trap when clflushing APIC registers
window.
XEN in full system virtualization mode removes self-snoop from CPU
features, making this a problem.
Tested by: csjp
Reviewed by: alc
MFC after: 3 days
are currently two problems with the use of 1GB page mappings by the direct
map. First, at least one device driver uses pmap_extract() rather than
DMAP_TO_PHYS() to translate a direct map address to a physical address.
Unfortunately, neither pmap_extract() nor pmap_kextract() yet support 1GB
page mappings. Second, pmap_bootstrap() needs to interrogate the MTRRs to
ensure that a 1GB page mapping doesn't span two MTRRs of different types.
Reported and tested by: Daniel O'Connor
MFC after: 3 days
devices that we also support, just not by default (thus only LINT or
module builds by default).
While currently there is only "/dev/full" [2], we are planning to see more
in the future. We may decide to change the module/dependency logic in the
future should the list grow too long.
This is not part of linux.ko as also non-linux binaries like kFreeBSD
userland or ports can make use of this as well.
Suggested by: rwatson [1] (name)
Submitted by: ed [2]
Discussed with: markm, ed, rwatson, kib (weeks ago)
Reviewed by: rwatson, brueffer (prev. version)
PR: kern/68961
MFC after: 6 weeks
o introduce PCIE_REGMAX and use it instead of ad-hoc constant
o where 'reg' parameter/variable is not already unsigned, cast it to
unsigned before comparison with maximum value to cut off negative
values
o use PCI_SLOTMAX in several places where 31 or 32 were explicitly used
o drop redundant check of 'bytes' in i386 pciereg_cfgread() - valid
values are already checked in the subsequent switch
Reviewed by: jhb
MFC after: 1 week
startup and genericize it so it can be reused to map other tables as well:
- Add a routine to walk a list of ACPI subtables such as those used in the
APIC and SRAT tables in the MI acpi(4) driver.
- Move the routines for mapping and unmapping an ACPI table as well as
mapping the RSDT or XSDT and searching for a table with a given signature
out into acpica_machdep.c for both amd64 and i386.
amd64 similar to i386. This fixes a bug on amd64 where overlapping
entries would not cause the SMAP parsing to stop.
- Change the SMAP parsing code to do a sorted insertion into physmap[]
instead of an append to support systems with out-of-order SMAP entries.
PR: amd64/138220
Reported by: James R. Van Artsdalen james of jrv org
MFC after: 3 days
then trapsignal is called with ksi.ksi_signo = 0. For debugging kernels,
that should end up in panic, for non-debugging kernels behaviour is
undefined.
Do panic regardeless of execution mode at the moment of trap.
Reviewed by: jhb
MFC after: 1 month
- Add vesa kernel options for amd64.
- Connect libvgl library and splash kernel modules to amd64 build.
- Connect manual page dpms(4) to amd64 build.
- Remove old vesa/dpms files.
Submitted by: paradox <ddkprog yahoo com> [1], swell k at gmail.com
(with some minor tweaks)
based Intel Macs. Since r189055, these platforms started freezing when
ACPI is being initialized for unknown reason. For these platforms, we just
use the old PAT layout. Note this change is not enough to boot fully on
these platforms because of other problems but it makes debugging possible.
Note MacBook5,2 may be affected as well but it was not added here because
of lack of hardware to test.
- Initialize PAT MSR fully instead of reading and modifying it for safety.
Reported by: rpaulo, hps, Eygene Ryabinkin (rea-fbsd at codelabs dot ru)
Reviewed by: jhb
when removing an interrupt handler from an IRQ during shutdown. During
shutdown we are already bound to CPU 0 and this was triggering a panic.
MFC after: 3 days
- Always calculate the cache bits instead of doing it on-demand.
- Always set changed to TRUE rather than only doing it if it is false.
Discussed with: alc
MFC after: 3 days
correctly and do not match a colliding Debian GNU/kFreeBSD
brandinfo statements.
For this mark the Debian GNU/kFreeBSD brandinfo that it must have
an .note.ABI-tag section and ignore the old EI_OSABI brandinfo
when comparing a possibly colliding set of options.
Due to SYSINIT we add the brandinfo in a non-deterministic order,
so native FreeBSD is not always first. We may want to consider
to force native FreeBSD to come first as well.
The only way a problem could currently be noticed is when running an
i386 binary without the .note.ABI-tag on amd64 and the Debian GNU/kFreeBSD
brandinfo was matched first, as the fallback to ld-elf32.so.1 does
not exist in that case.
Reported and tested by: ticso
In collaboration with: kib
MFC after: 3 days
Handle GNU/Linux according to LSB Core Specification 4.0,
Chapter 11. Object Format, 11.8. ABI note tag.
Also check the first word of desc, not only name, according to
glibc abi-tags specification to distinguish between Linux and
kFreeBSD.
Add explicit handling for Debian GNU/kFreeBSD, which runs
on our kernels as well [2].
In {amd64,i386}/trap.c, when checking osrel of the current process,
also check the ABI to not change the signal behaviour for Linux
binary processes, now that we save an osrel version for all three
from the lists above in struct proc [2].
These changes make it possible to run FreeBSD, Debian GNU/kFreeBSD
and Linux binaries on the same machine again for at least i386 and
amd64, and no longer break kFreeBSD which was detected as GNU(/Linux).
PR: kern/135468
Submitted by: dchagin [1] (initial patch)
Suggested by: kib [2]
Tested by: Petr Salinger (Petr.Salinger seznam.cz) for kFreeBSD
Reviewed by: kib
MFC after: 3 days
less than "avail memory", fall back to Maxmem to avoid user confusion.
We use SMBIOS information to display "real memory" since r190599 but
some broken SMBIOS implementation reported only half of actual memory.
Tested by: bz
Approved by: re (kib)
when pmap_demote_pde() allocates a page table page to implement a
user-space demotion, it must increment the pmap's resident page count.
Not doing so, can lead to an underflow during address space termination
that causes pmap_remove() to exit prematurely, before it has destroyed
all of the mappings within the specified range. The ultimate effect or
symptom of this error is an assertion failure in vm_page_free_toq()
because the page being freed is still mapped.
This error is only possible when superpage promotion is enabled. Thus,
it only affects FreeBSD versions greater than 7.2.
Tested by: pho, alc
Reviewed by: alc
Approved by: re (rwatson)
MFC after: 1 week
- Provide lapic_disable_pmc(), lapic_enable_pmc(), and lapic_reenable_pmc()
routines in the local APIC code that the hwpmc(4) driver can use to
manage the local APIC PMC interrupt vector.
- Do not enable the local APIC PMC interrupt vector by default when
HWPMC_HOOKS is enabled. Instead, the hwpmc(4) driver explicitly
enables the interrupt when it is succesfully initialized and disables
the interrupt when it is unloaded. This avoids enabling the interrupt
on unsupported CPUs which may result in spurious NMIs.
Reported by: rnoland
Reviewed by: jkoshy
Approved by: re (kib)
MFC after: 2 weeks
has proven to have a good effect when entering KDB by using a NMI,
but it completely violates all the good rules about interrupts
disabled while holding a spinlock in other occasions. This can be the
cause of deadlocks on events where a normal IPI_STOP is expected.
* Adds an new IPI called IPI_STOP_HARD on all the supported architectures.
This IPI is responsible for sending a stop message among CPUs using a
privileged channel when disponible. In other cases it just does match a
normal IPI_STOP.
Right now the IPI_STOP_HARD functionality uses a NMI on ia32 and amd64
architectures, while on the other has a normal IPI_STOP effect. It is
responsibility of maintainers to eventually implement an hard stop
when necessary and possible.
* Use the new IPI facility in order to implement a new userend SMP kernel
function called stop_cpus_hard(). That is specular to stop_cpu() but
it does use the privileged channel for the stopping facility.
* Let KDB use the newly introduced function stop_cpus_hard() and leave
stop_cpus() for all the other cases
* Disable interrupts on CPU0 when starting the process of APs suspension.
* Style cleanup and comments adding
This patch should fix the reboot/shutdown deadlocks many users are
constantly reporting on mailing lists.
Please don't forget to update your config file with the STOP_NMI
option removal
Reviewed by: jhb
Tested by: pho, bz, rink
Approved by: re (kib)
a device pager (OBJT_DEVICE) object in that it uses fictitious pages to
provide aliases to other memory addresses. The primary difference is that
it uses an sglist(9) to determine the physical addresses for a given offset
into the object instead of invoking the d_mmap() method in a device driver.
Reviewed by: alc
Approved by: re (kensmith)
MFC after: 2 weeks
