Commit Graph

7418 Commits

Author SHA1 Message Date
kib
e0c4faece4 Split kerne timekeep ABI structure vdso_sv_tk out of the struct
sysentvec.  This allows the timekeep data to be shared between similar
ABIs which cannot share sysentvec.

Make the timekeep_push_vdso() tick callback to the timekeep structures
instead of sysentvecs.  If several sysentvec share the vdso_sv_tk
structure, we would update the userspace data several times on each
tick, without the change.

Only allocate vdso_sv_tk in the exec_sysvec_init() sysinit when
sysentvec is marked with the new SV_TIMEKEEP flag.  This saves
allocation and update of unneeded vdso_sv_tk for ABIs which do not
provide userspace gettimeofday yet, which are PowerPCs arches right
now.

Make vdso_sv_tk allocator public, namely split out and export
alloc_sv_tk() and alloc_sv_tk_compat32().  ABIs which share timekeep
data now can allocate it manually and share as appropriate.

Requested by:	nwhitehorn
Tested by:	nwhitehorn, pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2015-11-23 07:09:35 +00:00
markj
3e47d7787e Remove unneeded includes of opt_kdtrace.h.
As of r258541, KDTRACE_HOOKS is defined in opt_global.h, so opt_kdtrace.h
is not needed when defining SDT(9) probes.
2015-11-22 02:01:01 +00:00
jhb
c1d9f70889 Export various helper variables describing the layout and size of
certain kernel structures for use by debuggers. This mostly aids
in examining cores from a kernel without debug symbols as a debugger
can infer these values if debug symbols are available.

One set of variables describes the layout of 'struct linker_file' to
walk the list of loaded kernel modules.

A second set of variables describes the layout of 'struct proc' and
'struct thread' to walk the list of processes in the kernel and the
threads in each process.

The 'pcb_size' variable is used to index into the stoppcbs[] array.

The 'vm_maxuser_address' is used to distinguish kernel virtual addresses
from user addresses. This doesn't have to be perfect, and
'vm_maxuser_address' is a cheap and simple way to differentiate kernel
pointers from simple values like TIDs and PIDs.

While here, annotate the fields in struct pcb used by kgdb on amd64
and i386 to note that their ABI should be preserved.  Annotations for
other platforms will be added in the future.

Reviewed by:	kib
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D3773
2015-11-12 22:00:59 +00:00
cem
dffa7f0590 pmap_change_attr: Only fixup DMAP for DMAPed ranges
pmap_change_attr must change the memory type of both the requested KVA
and the corresponding DMAP mappings (if such mappings exist), to satisfy
an Intel requirement that two or more mappings to the same physical
pages must have the same memory type.

However, not all kernel mapped pages have corresponding DMAP mappings --
for example, 64-bit BARs.  Skip fixing up the DMAP for out-of-bounds
addresses.

Submitted by:	Steve Wahl <steve_wahl@dell.com>
Reviewed by:	alc, jhb
Sponsored by:	Dell Compellent
Differential Revision:	https://reviews.freebsd.org/D4030
2015-10-29 19:07:00 +00:00
jhb
9ee931e10a Update for LINUX32 rename. The assembler didn't complain about undefined
symbols but just used 0 after the rename.
2015-10-29 15:20:47 +00:00
jhb
617f6c60b6 Fix build with DEBUG defined.
Reported by:	hselasky
2015-10-29 15:16:47 +00:00
mckusick
485c0ddc22 Bring the tags and links entries for amd64 up to date.
Based on how out of date it is, I doubt that anyone
other than me and my code-reading students still use it.
2015-10-27 22:59:24 +00:00
kib
919ebacc13 Intel SDM before revision 56 described the CLFLUSH instruction as only
ordered with the MFENCE instruction.  Similar weak guarantees are also
specified by the AMD APM vol. 3 rev. 3.22.  x86 pmap methods
pmap_invalidate_cache_range() and pmap_invalidate_cache_pages() braced
CLFLUSH loop with MFENCE both before and after the loop.

In the revision 56 of SDM, Intel stated that all existing
implementations of CLFLUSH are strict, CLFLUSH instructions execution
is ordered WRT other CLFLUSH and writes.  Also, the strict behaviour
is made architectural.

A new instruction CLFLUSHOPT (which was documented for some time in
the Instruction Set Extensions Programming Reference) provides the
weak behaviour which was previously attributed to CLFLUSH.

Use CLFLUSHOPT when available.  When CLFLUSH is used on Intel CPUs, do
not execute MFENCE before and after the flushing loop.

Reviewed by:	alc
Sponsored by:	The FreeBSD Foundation
2015-10-24 21:37:47 +00:00
kib
7eb36dd3f9 Add CLFLUSHOPT instruction wrappers.
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-10-23 11:45:38 +00:00
jhb
4a875c71d5 Regen for linux32 rename and linux64 systrace. 2015-10-22 21:33:37 +00:00
jhb
9740ac3060 Rename remaining linux32 symbols such as linux_sysent[] and
linux_syscallnames[] from linux_* to linux32_* to avoid conflicts with
linux64.ko.  While here, add support for linux64 binaries to systrace.
- Update NOPROTO entries in amd64/linux/syscalls.master to match the
  main table to fix systrace build.
- Add a special case for union l_semun arguments to the systrace
  generation.
- The systrace_linux32 module now only builds the systrace_linux32.ko.
  module on amd64.
- Add a new systrace_linux module that builds on both i386 and amd64.
  For i386 it builds the existing systrace_linux.ko.  For amd64 it
  builds a systrace_linux.ko for 64-bit binaries.

Reviewed by:	markj
Differential Revision:	https://reviews.freebsd.org/D3954
2015-10-22 21:28:20 +00:00
jhb
2705fe5cc1 Merge r289055 to amd64/linux32:
linux: fix handling of out-of-bounds syscall attempts

Due to an off by one the code would read an entry past the table, as
opposed to the last entry which contains the nosys handler.
2015-10-22 21:23:58 +00:00
ed
7fb0afec66 Refactoring: move out generic bits from cloudabi64_sysvec.c.
In order to make it easier to support CloudABI on ARM64, move out all of
the bits from the AMD64 cloudabi_sysvec.c into a new file
cloudabi_module.c that would otherwise remain identical. This reduces
the AMD64 specific code to just ~160 lines.

Reviewed by:	kib
Differential Revision:	https://reviews.freebsd.org/D3974
2015-10-22 09:07:53 +00:00
royger
d31f5fb7b9 x86/xen: Consolidate xen-os.h in a single place
amd64 and i386 platform code contain very similar xen/xen-os.h

The only differences are:
 - Functions/variables/types which were unused in i386/xen/xen-os.h:
    * xen_xchg
    * __xchg_dummy
    * __xg
    * __xchg
    * atomic_t
    * atomic_inc
    * rdtscll

The functions/variables/types unused in xen-os.h can be dropped and there
is no more differences betwen amd64 and i386.

The new header is placed in x86/include/xen and each platform will have
dummy headers include x86/xen/*.h. This is to be able to include
machine/xen/*.h in the PV drivers.

Submitted by:		Julien Grall <julien.grall@citrix.com>
Reviewed by:		royger
Differential Revision:	https://reviews.freebsd.org/D3880
Sponsored by:		Citrix Systems R&D
2015-10-21 10:04:35 +00:00
mav
64d53c4c7d Remove compatibility shims for legacy ATA device names.
We got new ATA stack in FreeBSD 8.x, switched to it at 9.x, completely
removed old stack at 10.x, so at 11.x it is time to remove compat shims.
2015-10-11 13:01:51 +00:00
mjg
d8dc4fc1ae linux: fix handling of out-of-bounds syscall attempts
Due to an off by one the code would read an entry past the table, as
opposed to the last entry which contains the nosys handler.

Reported by:	Pawel Biernacki <pawel.biernacki gmail.com>
2015-10-08 21:08:35 +00:00
royger
375ecc42de xen/console: Introduce a new console driver for Xen guest
The current Xen console driver is crashing very quickly when using it on
an ARM guest. This is because the console lock is recursive and it may
lead to recursion on the tty lock and/or corrupt the ring pointer.

Furthermore, the console lock is not always taken where it should be and has
to be released too early because of the way the console has been designed.

Over the years, code has been modified to support various new features but
the driver has not been reworked.

This new driver has been rewritten with the idea of only having a small set
of specific function to write either via the shared ring or the hypercall
interface.

Note that HVM support has been left aside for now because it requires
additional features which are not yet supported. A follow-up patch will be
sent with HVM guest support.

List of items that may be good to have but not mandatory:
 - Avoid to flush for each character written when using the tty
 - Support multiple consoles

Submitted by:		Julien Grall <julien.grall@citrix.com>
Reviewed by:		royger
Differential Revision:	https://reviews.freebsd.org/D3698
Sponsored by:		Citrix Systems R&D
2015-10-08 16:39:43 +00:00
royger
c1bb2e3246 Update Xen headers from 4.2 to 4.6
Pull the latest headers for Xen which allow us to add support for ARM and
use new features in FreeBSD.

This is a verbatim copy of the xen/include/public so every headers which
don't exits anymore in the Xen repositories have been dropped.

Note the interface version hasn't been bumped, it will be done in a
follow-up. Although, it requires fix in the code to get it compiled:

 - sys/xen/xen_intr.h: evtchn_port_t is already defined in the headers so
   drop it.

 - {amd64,i386}/include/intr_machdep.h: NR_EVENT_CHANNELS now depends on
   xen/interface/event_channel.h, so include it.

 - {amd64,i386}/{amd64,i386}/support.S: It's not neccessary to include
   machine/intr_machdep.h. This is also fixing build compilation with the
   new headers.

 - dev/xen/blkfront/blkfront.c: The typedef for blkif_request_segmenthas
   been dropped. So directly use struct blkif_request_segment

Finally, modify xen/interface/xen-compat.h to throw a preprocessing error if
__XEN_INTERFACE_VERSION__ is not set. This is allow us to catch any file
where xen/xen-os.h is not correctly included.

Submitted by:		Julien Grall <julien.grall@citrix.com>
Reviewed by:		royger
Differential Revision:	https://reviews.freebsd.org/D3805
Sponsored by:		Citrix Systems R&D
2015-10-06 11:29:44 +00:00
alc
57f2addb31 Exploit r288122 to address a cosmetic issue. Since PV chunk pages don't
belong to a vm object, they can't be paged out.  Since they can't be paged
out, they are never enqueued in a paging queue.  Nonetheless, passing
PQ_INACTIVE to vm_page_unwire() creates the appearance that these pages
are being enqueued in the inactive queue.  As of r288122, we can avoid
this false impression by passing PQ_NONE.

Submitted by:	kmacy (an earlier version)
Differential Revision:	https://reviews.freebsd.org/D1674
2015-09-26 07:18:05 +00:00
mjg
0ea1d42c18 amd64: plug redundant bootAP declaration
Reported by:	gcc5
2015-09-22 21:07:47 +00:00
kib
518734671f Add support for weak symbols to the kernel linkers. It means that
linkers no longer raise an error when undefined weak symbols are
found, but relocate as if the symbol value was 0.  Note that we do not
repeat the mistake of userspace dynamic linker of making the symbol
lookup prefer non-weak symbol definition over the weak one, if both
are available.  In fact, kernel linker uses the first definition
found, and ignores duplicates.

Signature of the elf_lookup() and elf_obj_lookup() functions changed
to split result/error code and the symbol address returned.
Otherwise, it is impossible to return zero address as the symbol
value, to MD relocation code.  This explains the mechanical changes in
elf_machdep.c sources.

The powerpc64 R_PPC_JMP_SLOT handler did not checked error from the
lookup() call, the patch leaves the code as is (untested).

Reported by:	glebius
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2015-09-20 01:27:59 +00:00
markj
e8967c8bd9 Add stack_save_td_running(), a function to trace the kernel stack of a
running thread.

It is currently implemented only on amd64 and i386; on these
architectures, it is implemented by raising an NMI on the CPU on which
the target thread is currently running. Unlike stack_save_td(), it may
fail, for example if the thread is running in user mode.

This change also modifies the kern.proc.kstack sysctl to use this function,
so that stacks of running threads are shown in the output of "procstat -kk".
This is handy for debugging threads that are stuck in a busy loop.

Reviewed by:	bdrewery, jhb, kib
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D3256
2015-09-11 03:54:37 +00:00
markj
dfb0cc5c03 Merge stack(9) implementations for i386 and amd64 under x86/.
Reviewed by:	jhb, kib
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D3255
2015-09-11 03:24:07 +00:00
kib
98df6be028 Do not hold the process around the vm_fault() call from the trap()s.
The only operation which is prevented by the hold is the kernel stack
swapout for the faulted thread, which should be fine to allow.

Remove useless checks for NULL curproc or curproc->p_vmspace from the
trap_pfault() wrappers on x86 and powerpc.

Reviewed by:	alc (previous version)
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2015-09-10 17:46:48 +00:00
markj
c72177e471 Remove an unneeded instruction.
MFC after:	1 week
2015-08-28 00:17:21 +00:00
cem
06ccf4bc96 Import ioat(4) driver
I/OAT is also referred to as Crystal Beach DMA and is a Platform Storage
Extension (PSE) on some Intel server platforms.

This driver currently supports DMA descriptors only and is part of a
larger effort to upstream an interconnect between multiple systems using
the Non-Transparent Bridge (NTB) PSE.

For now, this driver is only built on AMD64 platforms.  It may be ported
to work on i386 later, if that is desired.  The hardware is exclusive to
x86.

Further documentation on ioat(4), including API documentation and usage,
can be found in the new manual page.

Bring in a test tool, ioatcontrol(8), in tools/tools/ioat.  The test
tool is not hooked up to the build and is not intended for end users.

Submitted by:	jimharris, Carl Delsey <carl.r.delsey@intel.com>
Reviewed by:	jimharris (reviewed my changes)
Approved by:	markj (mentor)
Relnotes:	yes
Sponsored by:	Intel
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D3456
2015-08-24 19:32:03 +00:00
royger
5b319fbe38 preload_search_info: make sure mod is set
Add a check to preload_search_info to make sure mod is set. Most of the
callers of preload_search_info don't check that the mod parameter is
set, which can cause page faults. While at it, remove some now unnecessary
checks before calling preload_search_info.

Sponsored by:		Citrix Systems R&D
Reviewed by:		kib
Differential Revision:	https://reviews.freebsd.org/D3440
2015-08-21 15:57:57 +00:00
bapt
95d9fae2fd Add a kern.features.cloudabi64 entry when the module is loaded to helps the
userland to be able to test is cloudabi64 is supported or not

Reviewed by:	ed
Differential Revision:	https://reviews.freebsd.org/D3430
2015-08-19 15:18:32 +00:00
marcel
a428fe7759 Add 24 more page table pages we allocate on boot-up. 16MB slop
is a little tight in and by itself, but severily insufficient
when one needs to map a large frame buffer as part of console
initialization. 64MB slop should be enough for a while. As an
example: a 15" MacBook Pro with retina display needs ~28MB of
KVA for the frame buffer.

PR:		193745
2015-08-18 01:53:41 +00:00
kib
6e1eb32ced XEN/amd64 may initiate i/o over the pages not mapped by the direct
map.  Handle busdma bouncing and ata PIO accesses by using global
frame used by the current CPU locally for the duration of
pmap_quick_enter/remove_page().  A spin mutex protects the concurent
frame use and prevents thread migration.

Noted by:	royger
Reviewed by:	alc, jah, royger (previous version)
Sponsored by:	The FreeBSD Foundation
2015-08-17 18:42:45 +00:00
marcel
bacabe8a7e Better support memory mapped console devices, such as VGA and EFI
frame buffers and memory mapped UARTs.

1.  Delay calling cninit() until after pmap_bootstrap(). This makes
    sure we have PMAP initialized enough to add translations. Keep
    kdb_init() after cninit() so that we have console when we need
    to break into the debugger on boot.
2.  Unfortunately, the ATPIC code had be moved as well so as to
    avoid a spurious trap #30. The reason for which is not known
    at this time.
3.  In pmap_mapdev_attr(), when we need to map a device prior to the
    VM system being initialized, use virtual_avail as the KVA to map
    the device at. In particular, avoid using the direct map on amd64
    because we can't demote by virtue of not being able to allocate
    yet. Keep track of the translation.
    Re-use the translation after the VM has been initialized to not
    waste KVA and to satisfy the assumption in uart(4) that the handle
    returned for the low-level console is the same as later returned
    when the device is probed and attached.
4.  In pmap_unmapdev() remove the mapping from the table when called
    pre-init. Otherwise keep the mapping. During bus probe and attach
    device resources are mapped and unmapped multiple times, which
    would have us destroy the mapping used by the low-level console.
5.  In pmap_init(), set pmap_initialized to signal that we're not
    pre-init anymore. On amd64, bring the direct map in sync with the
    translations created at that time.
6.  Implement bus_space_map() and bus_space_unmap() for real: when
    the tag corresponds to memory space, call the corresponding
    pmap_mapdev() and pmap_unmapdev() functions to construct and
    actual handle.
7.  In efifb.c and vt_vga.c, remove the crutches and hacks and simply
    call pmap_mapdev_attr() or bus_space_map() as desired.

Notes:
1.  uart(4) already used bus_space_map() during low-level console
    setup but since serial ports have traditionally been I/O port
    based, the lack of a proper implementation for said function
    was not a problem. It has always supported memory mapped UARTs
    for low-level consoles by setting hw.uart.console accordingly.
2.  The use of the direct map on amd64 without setting caching
    attributes has been a bigger problem than previously thought.
    This change has the fortunate (and unexpected) side-effect of
    fixing various EFI frame buffer problems (though not all).

PR: 191564, 194952

Special thanks to:
1.  XipLink, Inc -- generously donated an Intel Bay Trail E3800
    based eval board (ADLE3800PC).
2.  The FreeBSD Foundation, in particular emaste@ -- for UEFI
    support in general and testing.
3.  Everyone who tested the proposed for PR 191564.
4.  jhb@ and kib@ for being a soundboard and applying a clue bat
    if so needed.
2015-08-12 15:26:32 +00:00
kib
9458aa2b57 Initialization of smp_tlb_wait does not require release semantic, no
data is synchronized by store/load to the variable.  The
lapic_write_icr() function ensures that store buffers are flushed
before IPI command is issued.

Discussed with:	bde
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2015-08-12 09:46:39 +00:00
kib
bff0ec5bef AP should load aps_ready with acquire semantic to see BSP updates to
the SMP structures, synchronized with the load by release store in
release_aps().

The change is formal, x86 strong memory model implicitely provided
the guarantees.

Discussed with:	bde
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2015-08-12 09:43:12 +00:00
kib
9033c894a1 Make kstack_pages a tunable on arm, x86, and powepc. On i386, the
initial thread stack is not adjusted by the tunable, the stack is
allocated too early to get access to the kernel environment. See
TD0_KSTACK_PAGES for the thread0 stack sizing on i386.

The tunable was tested on x86 only.  From the visual inspection, it
seems that it might work on arm and powerpc.  The arm
USPACE_SVC_STACK_TOP and powerpc USPACE macros seems to be already
incorrect for the threads with non-default kstack size.  I only
changed the macros to use variable instead of constant, since I cannot
test.

On arm64, mips and sparc64, some static data structures are sized by
KSTACK_PAGES, so the tunable is disabled.

Sponsored by:	The FreeBSD Foundation
MFC after:	2 week
2015-08-10 17:18:21 +00:00
jhb
47d8edd4b1 Remove some more vestiges of the Xen PV domu support. Specifically,
use vtophys() directly instead of vtomach() and retire the no-longer-used
headers <machine/xenfunc.h> and <machine/xenvar.h>.

Reported by:	bde (stale bits in <machine/xenfunc.h>)
Reviewed by:	royger (earlier version)
Differential Revision:	https://reviews.freebsd.org/D3266
2015-08-06 17:07:21 +00:00
emaste
002d9943c1 Rationalize BSD license on sys/*/include/in_cksum.h
Remove the advertising clause from the Regents of the University of
California's license, per the letter dated July 22, 1999.

Update clause numbering.
2015-08-05 19:05:12 +00:00
jah
b8c4d76738 Add two new pmap functions:
vm_offset_t pmap_quick_enter_page(vm_page_t m)
void pmap_quick_remove_page(vm_offset_t kva)

These will create and destroy a temporary, CPU-local KVA mapping of a specified page.

Guarantees:
--Will not sleep and will not fail.
--Safe to call under a non-sleepable lock or from an ithread

Restrictions:
--Not guaranteed to be safe to call from an interrupt filter or under a spin mutex on all platforms
--Current implementation does not guarantee more than one page of mapping space across all platforms. MI code should not make nested calls to pmap_quick_enter_page.
--MI code should not perform locking while holding onto a mapping created by pmap_quick_enter_page

The idea is to use this in busdma, for bounce buffer copies as well as virtually-indexed cache maintenance on mips and arm.

NOTE: the non-i386, non-amd64 implementations of these functions still need review and testing.

Reviewed by:	kib
Approved by:	kib (mentor)
Differential Revision:	http://reviews.freebsd.org/D3013
2015-08-04 19:46:13 +00:00
imp
04e6a60087 Add pmspvc device back to GENERIC. The issues with the device playing
grabby hands with other driver's devices has been solved.

MFC After: 3 weeks
2015-08-03 13:49:46 +00:00
ed
4f67d9c92c Let CloudABI use the SV_CAPSICUM flag.
CloudABI processes will now start up in capabilities mode.

Reviewed by:	kib
2015-08-03 13:42:52 +00:00
kib
b31c115daa Clear the IA32_MISC_ENABLE MSR bit, which limits the max CPUID
reported, on APs.  We already did this on BSP.

Otherwise, the userspace software which depends on the features
reported by the high CPUID levels is misbehaving.  In particular, AVX
detection is non-functional, depending on which CPU thread happens to
execute when doing CPUID.  Another victim is the libthr signal
handlers interposer, which needs to save full FPU extended state.

Reported and tested by:	Andre Meiser <ortadur@web.de>
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2015-08-03 12:14:42 +00:00
ed
c2712ff846 Set p_osrel to __FreeBSD_version on process startup.
Certain system calls have quirks applied to make them work as if called
on an older version of FreeBSD. As CloudABI executables don't have the
FreeBSD OS release number in the ELF header, this value is set to zero,
making the system calls fall back to typically historic, non-standard
behaviour.

Reviewed by:	kib
2015-08-03 07:29:57 +00:00
gjb
8ddbbce4f6 Pull pmspcv (pms(4)) from GENERIC. It has PCI ID conflicts
with ahd(4), mvs(4), and likely other drivers.

MFC after:	immediately
With hat:	re
Sponsored by:	The FreeBSD Foundation
2015-07-31 15:23:48 +00:00
kib
88c35d6516 Improve comments.
Submitted by:	bde
MFC after:	2 weeks
2015-07-30 15:47:53 +00:00
kib
45167e7aef Remove full barrier from the amd64 atomic_load_acq_*(). Strong
ordering semantic of x86 CPUs makes only the compiler barrier
neccessary to give the acquire behaviour.

Existing implementation ensured sequentially consistent semantic for
load_acq, making much stronger guarantee than required by standard's
definition of the load acquire.  Consumers which depend on the barrier
are believed to be identified and already fixed to use proper
operations.

Noted by:	alc (long time ago)
Reviewed by:	alc, bde
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2015-07-28 07:04:51 +00:00
alc
268d180ee5 Add a comment discussing the appropriate use of the atomic_*() functions
with acquire and release semantics versus the *mb() functions on amd64
processors.

Reviewed by:	bde (an earlier version), kib
Sponsored by:	EMC / Isilon Storage Division
2015-07-24 19:43:18 +00:00
jhb
d3b87ae234 Various changes to the registers displayed in DDB for x86.
- Fix segment registers to only display the low 16 bits.
- Remove unused handlers and entries for the debug registers.
- Display xcr0 (if valid) in 'show sysregs'.
- Add '0x' prefix to MSR values to match other values in 'show sysregs'.
- MFamd64: Display various MSRs in 'show sysregs'.
- Add a 'show dbregs' to display the value of debug registers.
- Dynamically size the column width for register values to properly
  align columns on 64-bit platforms.
- Display %gs for i386 in 'show registers'.

Differential Revision:	https://reviews.freebsd.org/D2784
Reviewed by:	kib, markj
MFC after:	2 weeks
2015-07-22 01:09:02 +00:00
markj
825752c2e5 Let the unwinder handle faults during function prologues or epilogues.
The i386 and amd64 DDB stack unwinders contain code to detect and handle
the case where the first frame is not completely set up or torn down. This
code was accidentally unused however, since db_backtrace() was never called
with a non-NULL trap frame. This change fixes that.

Also remove get_rsp() from the amd64 code. It appears to have come from
i386, which needs to take into account whether the exception triggered a
CPL switch, since SS:ESP is only pushed onto the stack if so. On amd64,
SS:RSP is pushed regardless, so get_rsp() was doing the wrong thing for
kernel-mode exceptions. As a result, we can also remove custom print
functions for these registers.

Reviewed by:	jhb
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D2881
2015-07-21 23:22:23 +00:00
markj
0f1eab2023 Improve stack unwinding on i386 and amd64 after an IP fault.
If we can't find a symbol corresponding to the faulting instruction, assume
that the previously-executed function is a call and attempt to find the
calling function using the return address on the stack. Otherwise we end
up associating the last stack frame with the current call, which is
incorrect and causes the unwinder to skip printing of the calling function,
resulting in a confusing backtrace.

Reviewed by:	jhb
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D2859
2015-07-21 23:13:11 +00:00
markj
2d0eee8395 Remove some dead code from DDB's amd64 stack unwinder.
The amd64 port copied some code from i386 to fetch function arguments and
display them in backtraces. However, it was commented out and can't easily
be implemented since the function arguments are passed in
registers rather than on the stack in amd64. Remove it in preparation for
some bug fixes in this area.

Reviewed by:	jhb
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D2857
2015-07-21 23:03:21 +00:00
ed
9ab04b81ba Describe COMPAT_CLOUDABI64 in the amd64 configuration NOTES file. 2015-07-21 12:53:47 +00:00