Commit Graph

12944 Commits

Author SHA1 Message Date
Warner Losh
5625fe9246 Remove Micro Channel Architecture support. Of the commonly available
machines, only a few 486 machines that used it, and those haven't had
enough memory to run FreeBSD for quite some time (often limited to
16MB).

Not to be confused with the Machine Check Architecture, which is still
very much alive and used (and untouched by this commit).

No Objection From: arch@
2017-02-15 23:04:25 +00:00
John Baldwin
bb9b710477 Regenerate all the system call tables to drop "created from" lines.
One of the ibcs2 files contains some actual changes (new headers) as
it hasn't been regenerated after older changes to makesyscalls.sh.
2017-02-10 19:45:02 +00:00
Dmitry Chagin
12bc0fb56f Regen after r313284.
MFC after:	2 week
2017-02-05 14:19:19 +00:00
Dmitry Chagin
8b756d40a7 Update syscall.master to 4.10-rc6. Also fix comments, a typo,
and wrong numbering for a few unimplemented syscalls.

For 32-bit Linuxulator, socketcall() syscall was historically
the entry point for the sockets API. Starting in Linux 4.3, direct
syscalls are provided for the sockets API. Enable it.

The initial version of patch was provided by trasz@ and extended by me.

Submitted by:	trasz
MFC after:	2 week
Differential Revision:	https://reviews.freebsd.org/D9381
2017-02-05 14:17:09 +00:00
Konstantin Belousov
57f6622f92 For i386, remove config options CPU_DISABLE_CMPXCHG, CPU_DISABLE_SSE
and device npx.

This means that FPU is always initialized and handled when available,
and SSE+ register file and exception are handled when available.  This
makes the kernel FPU code much easier to maintain by the cost of
slight bloat for CPUs older than 25 years.

CPU_DISABLE_CMPXCHG outlived its usefulness, see the removed comment
explaining the original purpose.

Suggested by and discussed with:	bde
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	3 weeks
2017-02-03 12:51:40 +00:00
Konstantin Belousov
9c16356ccd Use ANSI definitions for some i386 functions.
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-02-02 22:02:10 +00:00
Mateusz Guzik
ed869ff019 i386: fixup fcmpset
An incorrect output specifier was used which worked with clang by accident,
but breaks with the in-tree gcc version.

While here plug a whitespace nit.

Reported by:	bde
2017-02-02 01:33:08 +00:00
Edward Tomasz Napierala
ae6b6ef6cb Replace sys_ftruncate() with kern_ftruncate() in various compats.
Reviewed by:	kib@
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D9368
2017-01-30 11:50:54 +00:00
Mateusz Guzik
e7a98aef79 i386: add atomic_fcmpset
Tested by:	pho
2017-01-30 02:24:54 +00:00
Konstantin Belousov
a0f64f38a1 Do not leave stale 4K TLB entries on pde (superpage) removal or
protection change.

On superpage promotion, x86 pmaps do not invalidate existing 4K
entries for the superpage range, because they are compatible with the
promoted 2/4M entry.  But the invalidation on superpage removal or
protection change only did single INVLPG with the base address of the
superpage.  This reliably flushed superpage TLB entry, and 4K entry
for the first page of the superpage, potentially leaving other 4K TLB
entries lingering.  Do the invalidation of the whole superpage range
to correct the problem.

Note that the precise invalidation is done by x86 code for kernel_pmap
only, for user pmaps whole (per-AS) TLB is flushed.  This made the bug
well hidden, because promotions of the kernel mappings require
specific load.

Reported and tested by:	Jonathan Looney <jtl@netflix.com> (previous version)
Reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-01-29 19:14:48 +00:00
Jason A. Harmening
d986450859 Implement get_pcpu() for i386 and use it to replace pcpu_find(curcpu)
in the i386 pmap.

The curcpu macro loads the per-cpu data pointer as its first step,
so the remaining steps of pcpu_find(curcpu) are circular.

get_pcpu() is already implemented for arm, arm64, and risc-v.
My plan is to implement it for the remaining architectures and use
it to replace several instances of pcpu_find(curcpu) in MI code.

Reviewed by:	kib
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D9370
2017-01-29 16:54:55 +00:00
Yoshihiro Takahashi
f7c79dd679 Garbage collect the FPU_ERROR_BROKEN option.
It is for pc98 only.
2017-01-28 03:53:53 +00:00
Yoshihiro Takahashi
2b375b4edd Remove pc98 support completely.
I thank all developers and contributors for pc98.

Relnotes:	yes
2017-01-28 02:22:15 +00:00
Konstantin Belousov
5611aaa195 Use SFENCE for ordering CLFLUSHOPT.
SDM states that CLFLUSHOPT instructions can be ordered with other
writes by SFENCE, heavier MFENCE is not required.

Reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2017-01-20 19:08:44 +00:00
Ed Schouten
4423244072 Catch up with changes to structure member names.
Pointer/length pairs are now always named ${name} and ${name}_len.
2017-01-17 22:05:52 +00:00
Jason A. Harmening
86785b54a5 Add comment explaining relative order of sched_unpin() and mtx_unlock().
Suggested by:	alc
MFC after:	1 week
2017-01-14 19:35:36 +00:00
Jason A. Harmening
28699efd43 For i386 temporary mappings, unpin the thread before releasing
the cmap lock.  Releasing the lock first may result in the thread
being immediately rescheduled and bound to the same CPU, only to
unpin itself upon resuming execution.

Noted by:	skra (in review for armv6 equivalent)
MFC after:	1 week
2017-01-14 09:56:01 +00:00
Mark Johnston
bd7abab0c9 Coalesce TLB shootdowns of global PTEs in pmap_advise() on x86.
We would previously invalidate such entries individually, resulting in more
IPIs than necessary.

Reviewed by:	alc, kib
MFC after:	3 weeks
Differential Revision:	https://reviews.freebsd.org/D9094
2017-01-10 21:52:48 +00:00
Sean Bruno
f2d6ace4a6 Migrate e1000 to the IFLIB framework:
- em(4) igb(4) and lem(4)
- deprecate the igb device from kernel configurations
- create a symbolic link in /boot/kernel from if_em.ko to if_igb.ko

Devices tested:
- 82574L
- I218-LM
- 82546GB
- 82579LM
- I350
- I217

Please report problems to freebsd-net@freebsd.org

Partial review from jhb and suggestions on how to *not* brick folks who
originally would have lost their igbX device.

Submitted by:	mmacy@nextbsd.org
MFC after:	2 weeks
Relnotes:	yes
Sponsored by:	Limelight Networks and Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D8299
2017-01-10 03:23:22 +00:00
Konstantin Belousov
2f304845e2 Do not allocate struct statfs on kernel stack.
Right now size of the structure is 472 bytes on amd64, which is
already large and stack allocations are indesirable.  With the ino64
work, MNAMELEN is increased to 1024, which will make it impossible to have
struct statfs on the stack.

Extracted from:	ino64 work by gleb
Discussed with:	mckusick
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-01-05 17:19:26 +00:00
Jason A. Harmening
43aabbefd8 Move the objects used to create temporary mappings for i386 pmap zero and copy
operations to the MD PCPU region.  Change sysmap initialization to only
allocate KVA pages for CPUs that are actually present.  As a minor
optimization, this also prevents false sharing between adjacent sysmap objects
since the pcpu struct is already cacheline-aligned.

While here, move pc_qmap_addr initialization for the BSP into
pmap_bootstrap(), which allows use of pmap_quick* functions during early boot.

Reviewed by:	kib
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D8833
2016-12-23 15:14:56 +00:00
John Baldwin
b663816443 Enable EARLY_AP_STARTUP on amd64 and i386 kernels by default.
PR:		199321, 203682
MFC after:	2 months
Sponsored by:	Netflix
2016-12-16 21:10:37 +00:00
Konrad Witaszczyk
480f31c214 Add support for encrypted kernel crash dumps.
Changes include modifications in kernel crash dump routines, dumpon(8) and
savecore(8). A new tool called decryptcore(8) was added.

A new DIOCSKERNELDUMP I/O control was added to send a kernel crash dump
configuration in the diocskerneldump_arg structure to the kernel.
The old DIOCSKERNELDUMP I/O control was renamed to DIOCSKERNELDUMP_FREEBSD11 for
backward ABI compatibility.

dumpon(8) generates an one-time random symmetric key and encrypts it using
an RSA public key in capability mode. Currently only AES-256-CBC is supported
but EKCD was designed to implement support for other algorithms in the future.
The public key is chosen using the -k flag. The dumpon rc(8) script can do this
automatically during startup using the dumppubkey rc.conf(5) variable.  Once the
keys are calculated dumpon sends them to the kernel via DIOCSKERNELDUMP I/O
control.

When the kernel receives the DIOCSKERNELDUMP I/O control it generates a random
IV and sets up the key schedule for the specified algorithm. Each time the
kernel tries to write a crash dump to the dump device, the IV is replaced by
a SHA-256 hash of the previous value. This is intended to make a possible
differential cryptanalysis harder since it is possible to write multiple crash
dumps without reboot by repeating the following commands:
# sysctl debug.kdb.enter=1
db> call doadump(0)
db> continue
# savecore

A kernel dump key consists of an algorithm identifier, an IV and an encrypted
symmetric key. The kernel dump key size is included in a kernel dump header.
The size is an unsigned 32-bit integer and it is aligned to a block size.
The header structure has 512 bytes to match the block size so it was required to
make a panic string 4 bytes shorter to add a new field to the header structure.
If the kernel dump key size in the header is nonzero it is assumed that the
kernel dump key is placed after the first header on the dump device and the core
dump is encrypted.

Separate functions were implemented to write the kernel dump header and the
kernel dump key as they need to be unencrypted. The dump_write function encrypts
data if the kernel was compiled with the EKCD option. Encrypted kernel textdumps
are not supported due to the way they are constructed which makes it impossible
to use the CBC mode for encryption. It should be also noted that textdumps don't
contain sensitive data by design as a user decides what information should be
dumped.

savecore(8) writes the kernel dump key to a key.# file if its size in the header
is nonzero. # is the number of the current core dump.

decryptcore(8) decrypts the core dump using a private RSA key and the kernel
dump key. This is performed by a child process in capability mode.
If the decryption was not successful the parent process removes a partially
decrypted core dump.

Description on how to encrypt crash dumps was added to the decryptcore(8),
dumpon(8), rc.conf(5) and savecore(8) manual pages.

EKCD was tested on amd64 using bhyve and i386, mipsel and sparc64 using QEMU.
The feature still has to be tested on arm and arm64 as it wasn't possible to run
FreeBSD due to the problems with QEMU emulation and lack of hardware.

Designed by:	def, pjd
Reviewed by:	cem, oshogbo, pjd
Partial review:	delphij, emaste, jhb, kib
Approved by:	pjd (mentor)
Differential Revision:	https://reviews.freebsd.org/D4712
2016-12-10 16:20:39 +00:00
Mark Johnston
7f68a896dc Add a COMPAT_FREEBSD11 kernel option.
Use it wherever COMPAT_FREEBSD10 is currently specified.

Reviewed by:	glebius, imp, jhb
Differential Revision:	https://reviews.freebsd.org/D8736
2016-12-09 18:54:12 +00:00
Alan Cox
e94965d82e Previously, vm_radix_remove() would panic if the radix trie didn't
contain a vm_page_t at the specified index.  However, with this
change, vm_radix_remove() no longer panics.  Instead, it returns NULL
if there is no vm_page_t at the specified index.  Otherwise, it
returns the vm_page_t.  The motivation for this change is that it
simplifies the use of radix tries in the amd64, arm64, and i386 pmap
implementations.  Instead of performing a lookup before every remove,
the pmap can simply perform the remove.

Reviewed by:	kib, markj
Differential Revision:	https://reviews.freebsd.org/D8708
2016-12-08 04:29:29 +00:00
John Baldwin
3cf1f0c347 MFamd64: Various fatal page fault fixes.
- If a page fault is triggered due to reserved bits in a PTE, treat it
  as a fatal fault and panic.
- If PG_NX is in use, report whether a fatal page fault is due to an
  instruction fetch or a data access.
- If a fatal page fault is due to reserved bits in a PTE, report that as
  the page fault type rather than a protection violation.

MFC after:	1 month
2016-11-19 01:36:44 +00:00
Bryan Drewery
28323add09 Fix improper use of "its".
Sponsored by:	Dell EMC Isilon
2016-11-08 23:59:41 +00:00
Konstantin Belousov
d3e4d71f1d Handle pmap_enter() over an existing 4/2M page in KVA on i386.
The userspace case was already handled by pmap_allocpte().  For kernel
VA, page table page must exist, and demote cannot fail, so we need to
just call pmap_demote_pde().  Also note that due to the machine AS
layout, promotions in the KVA on i386 are highly unlikely, so this
change is mostly for completeness.

Reviewed by:	alc, markj
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D8323
2016-10-28 11:53:22 +00:00
John Baldwin
16dcd7734f MFamd64: Add bounds checks on addresses used with /dev/mem.
Reject attempts to read from or memory map offsets in /dev/mem that are
beyond the maximum-supported physical address of the current CPU.

Reviewed by:	kib
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D7408
2016-10-27 21:23:14 +00:00
John Baldwin
726f4773ec Enable EFER_NXE properly on APs.
EFER_NXE is set in the EFER MSR by initializecpu() and must be set on all
CPUs in the system.  When PG_NX support was added to PAE on i386, the
block to enable EFER_NXE was placed in a section of initializecpu() that
only runs if 'cpu == CPU_686'.  During early boot, locore does an
initial pass to set cpu that sets it to CPU_686 on all CPUs later than
a Pentium.  Later, printcpuinfo() adjusts the 'cpu' variable on
PII and later CPUs to one of CPU_PII, CPU_PIII, or CPU_P4.  However,
printcpuinfo() is called after initializecpu() on the BSP, so the BSP
would enable EFER_NXE and pg_nx.  The APs execute initializecpu() much
later after printcpuinfo() has run.  The end result on a modern CPU was
that cpu was set to CPU_PIII when the APs invoked initializecpu(), so
they did not enable EFER_NXE.  As a result, the APs would fault when
trying to access any pages marked with PG_NX set.

When booting a 2 CPU PAE kernel in bhyve this manifested as a hang before
single user mode.  The attempt to execute /bin/init tried to copy out
the exec strings (argv, etc.) to a non-executable mapping while running
on the AP.  The instruction kept faulting due to invalid bits in the PTE
in an infinite loop.

Fix this by moving the code to enable EFER_NXE out of the switch statement
on 'cpu' and always doing it if 'amd_feature' supports AMDID_NX.

MFC after:	2 weeks
2016-10-26 18:47:47 +00:00
Konstantin Belousov
295f4b6cfe Follow-up to r307866:
- Make !KDB config buildable.
- Simplify interface to nmi_handle_intr() by evaluating panic_on_nmi
  in one place, namely nmi_call_kdb().  This allows to remove do_panic
  argument from the functions, and to remove i386/amd64 duplication of
  the variable and sysctl definitions.  Note that now NMI causes
  panic(9) instead of trap_fatal() reporting and then panic(9),
  consistently for NMIs delivered while CPU operated in ring 0 and 3.

Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2016-10-24 20:47:46 +00:00
Konstantin Belousov
835c2787be Handle broadcast NMIs.
On several Intel chipsets, diagnostic NMIs sent from BMC or NMIs
reporting hardware errors are broadcasted to all CPUs.

When kernel is configured to enter kdb on NMI, the outcome is
problematic, because each CPU tries to enter kdb.  All CPUs are
executing NMI handlers, which set the latches disabling the nested NMI
delivery; this means that stop_cpus_hard(), used by kdb_enter() to
stop other cpus by broadcasting IPI_STOP_HARD NMI, cannot work.  One
indication of this is the harmless but annoying diagnostic "timeout
stopping cpus".

Much more harming behaviour is that because all CPUs try to enter kdb,
and if ddb is used as debugger, all CPUs issue prompt on console and
race for the input, not to mention the simultaneous use of the ddb
shared state.

Try to fix this by introducing a pseudo-lock for simultaneous attempts
to handle NMIs.  If one core happens to enter NMI trap handler, other
cores see it and simulate reception of the IPI_STOP_HARD.  More,
generic_stop_cpus() avoids sending IPI_STOP_HARD and avoids waiting
for the acknowledgement, relying on the nmi handler on other cores
suspending and then restarting the CPU.

Since it is impossible to detect at runtime whether some stray NMI is
broadcast or unicast, add a knob for administrator (really developer)
to configure debugging NMI handling mode.

The updated patch was debugged with the help from Andrey Gapon (avg)
and discussed with him.

Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D8249
2016-10-24 16:40:27 +00:00
Jung-uk Kim
69d410eeb1 Implement BPF_MOD and BPF_XOR instructions.
These two ALU instructions first appeared on Linux.  Then, libpcap adopted
and made them available since 1.6.2.  Now more platforms including NetBSD
have them in kernel.  So do we.
 --이 줄 이하는 자동으로 제거됩니다--
2016-10-21 06:55:07 +00:00
Jung-uk Kim
730b3be34f Redude code for conditional jumps. 2016-10-21 06:09:30 +00:00
Jung-uk Kim
99e3ae6839 Fix compiler warnings for user land. 2016-10-21 06:06:54 +00:00
John Baldwin
31dc1e9681 Drop support for using mmap() with /dev/kmem.
Using the device pager with /dev/kmem is not stable since KVA mappings
are transient, but the device pager caches the PA associated with a
given offset forever.  Interestingly, mips' implementation of
memmap() already refused requests for /dev/kmem.

Note that kvm_read/kvm_write do not use mmap, but use read and write on
/dev/kmem, so this should not affect libkvm users.

Reviewed by:	kib
MFC after:	2 months
2016-10-14 20:01:07 +00:00
Warner Losh
b2a7ac4802 Fix building on i386 and arm. But 'public domain' headers on the files
with no creative content. Include "lost" changes from git:
o Use /dev/efi instead of /dev/efidev
o Remove redundant NULL checks.

Submitted by: kib@, dim@, zbb@, emaste@
2016-10-13 06:56:23 +00:00
Jonathan T. Looney
bd79708dbf In the TCP stack, the hhook(9) framework provides hooks for kernel modules
to add actions that run when a TCP frame is sent or received on a TCP
session in the ESTABLISHED state. In the base tree, this functionality is
only used for the h_ertt module, which is used by the cc_cdg, cc_chd, cc_hd,
and cc_vegas congestion control modules.

Presently, we incur overhead to check for hooks each time a TCP frame is
sent or received on an ESTABLISHED TCP session.

This change adds a new compile-time option (TCP_HHOOK) to determine whether
to include the hhook(9) framework for TCP. To retain backwards
compatibility, I added the TCP_HHOOK option to every configuration file that
already defined "options INET". (Therefore, this patch introduces no
functional change. In order to see a functional difference, you need to
compile a custom kernel without the TCP_HHOOK option.) This change will
allow users to easily exclude this functionality from their kernel, should
they wish to do so.

Note that any users who use a custom kernel configuration and use one of the
congestion control modules listed above will need to add the TCP_HHOOK
option to their kernel configuration.

Reviewed by:	rrs, lstewart, hiren (previous version), sjg (makefiles only)
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D8185
2016-10-12 02:16:42 +00:00
Warner Losh
f79d484dff Create /dev/efidev to provide an ioctl interface to
userland.  It supports userland interfaces to UEFI Runtime Services. This is
indended to the the MI portion of EFI RuntimeServices support.

Differential Revision: https://reviews.freebsd.org/D8128
Reviewed by: kib@, wblock@, Ganael Laplanche
2016-10-11 22:24:30 +00:00
Konstantin Belousov
83c001d3c2 Re-apply r306516 (by cem):
Reduce the cost of TLB invalidation on x86 by using per-CPU completion flags

Reduce contention during TLB invalidation operations by using a per-CPU
completion flag, rather than a single atomically-updated variable.

On a Westmere system (2 sockets x 4 cores x 1 threads), dtrace measurements
show that smp_tlb_shootdown is about 50% faster with this patch; observations
with VTune show that the percentage of time spent in invlrng_single_page on an
interrupt (actually doing invalidation, rather than synchronization) increases
from 31% with the old mechanism to 71% with the new one.  (Running a basic file
server workload.)

Submitted by:	Anton Rang <rang at acm.org>
Reviewed by:	cem (earlier version)
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D8041
2016-10-04 17:01:24 +00:00
Hans Petter Selasky
97549c34ec Move the ConnectX-3 and ConnectX-2 driver from sys/ofed into sys/dev/mlx4
like other PCI network drivers. The sys/ofed directory is now mainly
reserved for generic infiniband code, with exception of the mthca driver.

- Add new manual page, mlx4en(4), describing how to configure and load
mlx4en.

- All relevant driver C-files are now prefixed mlx4, mlx4_en and
mlx4_ib respectivly to avoid object filename collisions when compiling
the kernel. This also fixes an issue with proper dependency file
generation for the C-files in question.

- Device mlxen is now device mlx4en and depends on device mlx4, see
mlx4en(4). Only the network device name remains unchanged.

- The mlx4 and mlx4en modules are now built by default on i386 and
amd64 targets. Only building the mlx4ib module depends on
WITH_OFED=YES .

Sponsored by:	Mellanox Technologies
2016-09-30 08:23:06 +00:00
Bruce Evans
9eeaa0ea1f Minor fixes for 160-bit disassembly:
(1) Print the default segment %ss before adresses relative to %bp.
    This is too cluttered for me, but so is printing some other default
    prefixes, and this is a reasonable reminder that %ss is quite
    likely to be different from %ds in 16-bit mode.

    db_disasm still handles prefixes poorly, by trying to discard
    redundant ones.  This loses information, and sometimes the result
    is wrong or misleading.

    Clean up nearby initializations and dead code.

(2) Fix decoding of operand and address size prefixes in 16-bit mode.
    They reverse the default in all modes.

Obtained from:            (1) is partly from r1.4 (2003/11/08) in DFlyBSD (?)
2016-09-25 18:39:24 +00:00
Tijl Coosemans
81d7ca7761 MFamd64: r266901
Allocate a zeroed LDT.

Failing to do this might result in the LDT appearing to run out of free
descriptors because of random junk in the descriptor's 'sd_type' field.

http://lists.freebsd.org/pipermail/freebsd-amd64/2014-May/016088.html

PR:		212639
Submitted by:	wheelcomplex@gmail.com
MFC after:	2 weeks
2016-09-25 18:29:02 +00:00
Bruce Evans
808cf02c24 Determine the operand/address size of %cs in a new function
db_segsize().

Use db_segsize() to set the default operand/address size for
disassembling.  Allow overriding this with the "alternate" display
format /I.  The API of db_disasm() should be debooleanized to pass a
more general request (amd64 needs overrides to sizes of 16, 32, and
64, but this commit doesn't implement anything for amd64 since much
larger changes are needed to restore the amd64 disassmbler's support
for non-default sizes).

Fix db_print_loc_and_inst() to ask for the normal format and not the
alternate in normal operation.

This is most useful for vm86 mode, but also works for 16-bit protected
mode.

Use db_segsize() to avoid trying to print a garbage stack trace if %cs
is 16 bits.  Print something like the stack trace termination message
for a trap boundary instead.

Document that the alternate format is now useful on i386.
2016-09-25 16:30:29 +00:00
Bruce Evans
f5435b8bbe Fix vm86 initialization, part 3 of 2 and a half. (Actually, just fix
early printfs and debugging of vm86 initialization and some other early
initialization in some cases.)  Add an option debug.late_console (with
default 1=off) to move console and kdb initialization back where it was.
Do the same for amd64 although there is no vm86 there.

On my test system, debug.late_console=0 works for the syscons, sio and
uart console drivers on amd64 and i386, and for vt on i386 but not on
amd64.

The early printfs fixed by debug.late_console=0 are:
- on i386, the message about lost memory above 4G
- with -v in otherwise normal use, about 20 printfs for SMAP
- other debugging messages for memory sizing.  Mostly under -v and
  not printed in normal use.

Document in a comment how much earlier the initialization and early
printf()s can be.  That is very early for the console.  Not much more
than curthread is needed.  kdb use obviously needs to be not so early,
since it needs IDT initialization and that is done relatively late
for convenience and historical reasons.
2016-09-25 14:56:24 +00:00
Mark Johnston
bdaf6d6913 Regenerate syscall provider argument strings. 2016-09-22 04:50:03 +00:00
Bruce Evans
1d3c0fa7b2 Remove all kernel uses of pcb_psl, but keep in in the struct to
preserve the ABI and API for applications.  It was removed in the port
to amd64, but was remained as garbage giving a micro-pessimization and
spurious single-step traps on i386.

pcb_psl was intended to be used just to do a context switch of PSL_I,
but this context switch was null in most or all versions, and
mis-switching of PSL_T was done instead.

Some history:
- in 386BSD-0.0, cpu_switch() ran at splhigh() and splhigh() did too
  much interrupt disabling, so interrupts were hard-disabled across
  cpu_switch() and too many other places
- in 386BSD-0.0-patchkit through FreeBSD-4 and FreeBSD-5 before
  SMPng, splhigh() did soft interrupt masking, and cpu_switch() was
  excessively cautious and did a cli at the start and a sti at the
  end to hard-disable interrupts across the switch
- SMPng replaced the spl's and cli's by spinlocks (just sched_lock?),
  so interrupts were hard-disabled across cpu_switch() and too many
  other places again
- initial attempts to fix this intended to restore some soft
  interrupt disabling, but to support variations in this cpu_switch()
  used pushfl/popfl into pcb_psl to avoid hard-coding the assumption
  that the initial and final states have PSL_I enabled.  But the
  version with soft interrupt disabling wasn't used for long, or was
  never committed, (except I always used my different version of it
  for UP) so the pushfl/popl and pcb_psl to hold them have been doing
  less than nothing for about 14 years.
2016-09-17 14:00:52 +00:00
Bruce Evans
c2d4aad4e0 (1) Ifdef the new dr6 variable for KDB.
While here, avoid using the old variable 'code' and remove it
in trap().  ('code' was meant for holding things like %dr6,
but is too small to hold %dr6 on amd64 and was reduced to an
obfuscation of tf_err, with early truncation on amd64.)

Submitted by:	Michael Butler (imb@...)
2016-09-16 04:58:37 +00:00
Bruce Evans
bd20334ca0 Abort single stepping in ddb if the trap is not for single-stepping.
This is not very easy to do, since ddb didn't know when traps are
for single-stepping.  It more or less assumed that traps are either
breakpoints or single-step, but even for x86 this became inadequate
with the release of the i386 in ~1986, and FreeBSD passes it other
trap types for NMIs and panics.

On x86, teach ddb when a trap is for single stepping using the %dr6
register.  Unknown traps are now treated almost the same as breakpoints
instead of as the same as single-steps.  Previously, the classification
of breakpoints was almost correct and everything else was unknown so
had to be treated as a single-step.  Now the classification of single-
steps is precise, the classification of breakpoints is almost correct
(as before) and everything else is unknown and treated like a
breakpoint.

This fixes:
- breakpoints not set by ddb, including the main one in kdb_enter(),
  were treated as single-steps and not stopped on when stepping
  (except for the usual, simple case of a step with residual count 1).
  As special cases, kdb_enter() didn't stop for fatal traps or panics
- similarly for "hardware breakpoints".

Use a new MD macro IS_SSTEP_TRAP(type, code) to code to classify
single-steps.  This is excessively complicated for bug-for-bug and
backwards compatibilty.  Design errors apparently started in Mach
in ~1990 or perhaps in the FreeBSD interface in ~1993.  Common trap
types like single steps should have a unique MI code (like the TRAP*
codes for user SIGTRAP) so that debuggers don't need macros like
IS_SSTEP_TRAP() to decode them.  But 'type' is actually an ambiguous
MD trap number, and code was always 0 (now it is (int)%dr6 on x86).
So it was impossible to determine the trap type from the args.
Global variables had to be used.

There is already a classification macro db_pc_is_single_step(), but
this just gets in the way.  It is only used to recover from bugs in
IS_BREAKPOINT_TRAP().  On some arches, IS_BREAKPOINT_TRAP() just
duplicates the ambiguity in 'type' and misclassifies single-steps as
breakpoints.  It defaults to 'false', which is the opposite of what is
needed for bug-for-bug compatibility.

When this is cleaned up, MI classification bits should be passed in
'code'.  This could be done now for positive-logic bits, since 'code'
was always 0, but some negative logic is needed for compatibility so
a simple MI classificition is not usable yet.

After reading %dr6, clear the single-step bit in it so that the type
of the next debugger trap can be decoded.  This is a little
ddb-specific.  ddb doesn't understand the need to clear this bit and
doing it before calling kdb is easiest.  gdb would need to reverse
this to support hardware breakpoints, but it just doesn't support
them now since gdbstub doesn't support %dr*.

Fix a bug involving %dr6: when emulating a single-step trap for vm86,
set the bit for it in %dr6.  Userland debuggers need this.  ddb now
needs this for vm86 bios calls.  The bit gets copied to 'code' then
cleared again.

Fix related style bugs:
- when clearing bits for hardware breakpoints in %dr6, spell the mask
  as ~0xf on both amd64 and i386 to get the correct number of bits
  using sign extension and not need a comment about using the wrong
  mask on amd64 (amd64 traps for invalid results but clearing the
  reserved top bits didn't trap since they are 0).
- rewrite my old wrong comments about using %dr6 for ddb watchpoints.
2016-09-15 17:24:23 +00:00
John Baldwin
38605d7312 Remove 'cpu' and 'cpu_class' on amd64.
The 'cpu' and 'cpu_class' variables were always set to the same value
on amd64 and are legacy holdovers from i386.  Remove them entirely on
amd64.

Reviewed by:	imp, kib (older version)
Differential Revision:	https://reviews.freebsd.org/D7888
2016-09-15 17:05:54 +00:00