Commit Graph

120227 Commits

Author SHA1 Message Date
Edward Tomasz Napierala
42e42a9aa4 Add missing SPDX tags; the rest of the license text is the same as in other
USB templates.

MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
2018-01-20 14:03:55 +00:00
Edward Tomasz Napierala
83d02512b4 Add usb_template(4) to RPI-B kernel config. This is to support the USB OTG
functionality on Raspberry Pi 0.

Reviewed by:	hselasky@
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D13924
2018-01-20 14:00:07 +00:00
Edward Tomasz Napierala
8e06491a4e Add sysctls to control device side USB identifiers. This makes it
possible to change string and numeric vendor and product identifiers,
as well as anything else there might be to change for a particular
device side template, eg the MAC address.

Reviewed by:	hselasky@
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D13920
2018-01-20 13:58:34 +00:00
Konstantin Belousov
1c5196c3ed Assign map->header values to avoid boundary checks.
In several places, entry start and end field are checked, after
excluding the possibility that the entry is map->header.  By assigning
max and min values to the start and end fields of map->header in
vm_map_init, the explicit map->header checks become unnecessary.

Submitted by:	Doug Moore <dougm@rice.edu>
Reviewed by:	alc, kib, markj (previous version)
Tested by:	pho (previous version)
MFC after:	1 week
Differential Revision:  https://reviews.freebsd.org/D13735
2018-01-20 12:19:02 +00:00
Jean-Sébastien Pédron
b9b766ae47 psm: Don't try to detect trackpoint packets if the Elantech device has none
This fixes a panic when `EVDEV_SUPPORT` is enabled: if a trackpoint
packet was detected but there was no trackpoint, we still tried to emit an
evdev event even though the associated relative evdev device (`evdev_r`)
was not initialized.

PR:		225339
MFC after:	1 week
2018-01-20 11:21:22 +00:00
Jean-Sébastien Pédron
9402bd96df psm: Skip sync check when PSM_CONFIG_NOCHECKSYNC is set
In psmprobe(), we set the initial `syncmask` to the vendor default value
if the `PSM_CONFIG_NOCHECKSYNC` bit is unset. However, we currently only
set it for the Elantech touchpad later in psmattach(), thus `syncmask`
is always configured.

Now, we check `PSM_CONFIG_NOCHECKSYNC` and skip sync check if it is set.
This fixes Elantech touchpad support for units which have `hascrc` set.

To clarify that, when we log the `syncmask` and `syncbits` fields, also
mention if they are actually used.

Finally, when we set `PSM_CONFIG_NOCHECKSYNC`, clear `PSM_NEED_SYNCBITS`
flag.

PR:		225338
MFC after:	1 week
2018-01-20 11:02:18 +00:00
Landon J. Fuller
f248a99a0e bhnd_chipc(4): Fix leak of child device ivars by explicitly deleting
any children prior to detach.

With the newbus child deletion ordering changes introduced in r307518,
parent devices are now detached (and their driver set to NULL) prior to
detaching and deleting child devices; child-related bus methods (e.g.
BUS_CHILD_DETACHED, BUS_CHILD_DELETED) are no longer be dispatched to the
parent device driver after it returns 0 (success) from DEVICE_DETACH.

Sponsored by:   The FreeBSD Foundation
2018-01-20 01:55:34 +00:00
Landon J. Fuller
a225321fbc bhnd/bwn(4): Define a bhnd(4) softmodem device class for the v.90 modem
codec core, and mark the core as unpopulated on all BCM4306 bwn(4) devices.

Sponsored by:	The FreeBSD Foundation
2018-01-19 22:43:08 +00:00
Landon J. Fuller
72759b4824 bwn(4): Add missing BCM4306 PCI IDs.
Sponsored by:	The FreeBSD Foundation
2018-01-19 22:37:48 +00:00
Landon J. Fuller
aea6ca2486 bwn(4): Fix DMA translation lookup on devices limited to 30-bit host
addressing. The host addressing constraint does not apply to device address
space, and shouldn't be passed to bhnd_get_dma_translation() as the
maximum supported device address width.

Sponsored by:	The FreeBSD Foundation
2018-01-19 22:33:25 +00:00
Landon J. Fuller
711221efd8 bhndb_pci(4): Implement bridge support for CardBus-attached devices.
- Extend the probe method to accept devclasses that inherit from the pci
   devclass (e.g. cardbus).
 - Some BCM4306-based CardBus adapters appear to advertise 4K SPROM, but
   only the first 2K is mapped into BAR0. We can safely assume that the
   SPROM data fits within the first 2K of the SPROM, rather than rejecting
   the SPROM mapping as invalid.

Sponsored by:	The FreeBSD Foundation
2018-01-19 22:22:02 +00:00
Nathan Whitehorn
7790e46cf0 On AIM systems without a software-managed SLB, such as POWER9 systems using
either hardware segment tables or radix-tree-based page tables, do not try
to install SLB entries at trap boundaries.
2018-01-19 22:19:50 +00:00
Nathan Whitehorn
ad6b97e7ca Define PHYS_TO_DMAP() and DMAP_TO_PHYS() as panics on the architectures
(i386 and arm) that never implement them. This allows the removal of
#ifdef PHYS_TO_DMAP on code otherwise protected by a runtime check on
PMAP_HAS_DMAP. It also fixes the build on ARM and i386 after I forgot an
#ifdef in r328168.

Reported by:	Milan Obuch
Pointy hat to:	me
2018-01-19 22:17:13 +00:00
Konstantin Belousov
b4dfc9d7ad PTI: Trap if we returned to userspace with kernel (full) page table
still active.

Map userspace portion of VA in the PTI kernel-mode page table as
non-executable. This way, if we ever miss reloading ucr3 into %cr3 on
the return to usermode, the process traps instead of executing in
potentially vulnerable setup.  Catch the condition of such trap and
verify user-mode %cr3, which is saved by page fault handler.

I peek this trick in some article about Linux implementation.

Reviewed by:	alc, markj (previous version)
Sponsored by:	The FreeBSD Foundation
MFC after:	12 days
DIfferential revision:	https://reviews.freebsd.org/D13956
2018-01-19 22:10:29 +00:00
Landon J. Fuller
1c8edc1ed8 bhnd(4): fix a few bugs in pwrctl/fixed-clock device support.
- Do not panic on siba(4) detach when the bhnd(4) bus calls
   bhnd_get_pmu_info() on a PMU-less device.
 - Fix bhnd_pwrctl attach/detach on fixed-clock devices:
    - Treat bhnd_pwrctl_updateclk() as a no-op on fixed-clock devices.
    - Use bhnd_pwrctl_updateclk() to perform the appropriate clock
      transition on detach.

Sponsored by:	The FreeBSD Foundation
2018-01-19 21:58:48 +00:00
Landon J. Fuller
5ad00fa2cf bhnd_chipc(4): Fix the assignment of non-wildcard child unit numbers
introduced in r326102 and r326109; all chipc children should be added with
a wildcard unit (-1).

Sponsored by:	The FreeBSD Foundation
2018-01-19 21:36:28 +00:00
Scott Long
c35fca48b3 Fix compile errors in r328165
Reported by:	O. Hartmann
Sponsored by:	Netflix
2018-01-19 19:18:14 +00:00
Nathan Whitehorn
9a8196ce19 Remove SFBUF_OPTIONAL_DIRECT_MAP and such hacks, replacing them across the
kernel by PHYS_TO_DMAP() as previously present on amd64, arm64, riscv, and
powerpc64. This introduces a new MI macro (PMAP_HAS_DMAP) that can be
evaluated at runtime to determine if the architecture has a direct map;
if it does not (or does) unconditionally and PMAP_HAS_DMAP is either 0 or
1, the compiler can remove the conditional logic.

As part of this, implement PHYS_TO_DMAP() on sparc64 and mips64, which had
similar things but spelled differently. 32-bit MIPS has a partial direct-map
that maps poorly to this concept and is unchanged.

Reviewed by:		kib
Suggestions from:	marius, alc, kib
Runtime tested on:	amd64, powerpc64, powerpc, mips64
2018-01-19 17:46:31 +00:00
Ed Maste
b3327f62f0 Enable KPTI by default on amd64 for non-AMD CPUs
Kernel Page Table Isolation (KPTI) was introduced in r328083 as a
mitigation for the 'Meltdown' vulnerability.  AMD CPUs are not affected,
per https://www.amd.com/en/corporate/speculative-execution:

    We believe AMD processors are not susceptible due to our use of
    privilege level protections within paging architecture and no
    mitigation is required.

Thus default KPTI to off for AMD CPUs, and to on for others.  This may
be refined later as we obtain more specific information on the sets of
CPUs that are and are not affected.

Submitted by:	Mitchell Horne
Reviewed by:	cem
Relnotes:	Yes
Security:	CVE-2017-5754
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D13971
2018-01-19 15:42:34 +00:00
Scott Long
19641ce893 Revert ABI breakage to CAM that came in with MMC/SD support in r320844.
Make it possible to retrieve mmc parameters via the XPT_GET_ADVINFO
call instead.  Convert camcontrol to the new scheme.

Reviewed by:	imp. kibab
Sponsored by:	Netflix
Differential Revision:	D13868
2018-01-19 15:32:27 +00:00
Pedro F. Giffuni
7326b4e68c libnv: Use mallocarray(9) for the nv_calloc. 2018-01-19 14:50:53 +00:00
Hans Petter Selasky
77e7601e6d Add new USB ID to U3G driver.
PR:		134299
MFC after:	1 week
Sponsored by:	Mellanox Technologies
2018-01-19 13:06:36 +00:00
Hans Petter Selasky
cdadbbb03d Improve support for USB based 3G/4G/5G dongles from Huawei.
PR:		192345
Sponsored by:	Mellanox Technologies
2018-01-19 12:59:14 +00:00
Andrey V. Elsukov
d38344208e Add UDPLite support to ipfw(4).
Now it is possible to use UDPLite's port numbers in rules,
create dynamic states for UDPLite packets and see "UDPLite" for matched
packets in log.

Obtained from:	Yandex LLC
MFC after:	2 weeks
Sponsored by:	Yandex LLC
2018-01-19 12:50:03 +00:00
Conrad Meyer
d3f8974a32 Unbreak i386 build
The logical result of a right shift >= the width of a type is zero, but our
compiler decides this is a warning (and thus, error).  Just remove ccp(4)
from i386.

Reported by:	cy
Sponsored by:	Dell EMC Isilon
2018-01-19 04:34:06 +00:00
John Baldwin
68fd3b0ef5 Use a dedicated per-CPU stack for machine check exceptions.
Similar to NMIs, machine check exceptions can fire at any time and are
not masked by IF.  This means that machine checks can fire when the
kstack is too deep to hold a trap frame, or at critical sections in
trap handlers when a user %gs is used with a kernel %cs.  Use the same
strategy used for NMIs of using a dedicated per-CPU stack configured
in IST 3.  Store the CPU's pcpu pointer at the stop of the stack so
that the machine check handler can reliably find the proper value for
%gs (also borrowed from NMIs).

This should also fix a similar issue with PTI with a MC# occurring
while the CPU is executing on the trampoline stack.

While here, bypass trap() entirely and just call mca_intr().  This
avoids a bogus call to kdb_reenter() (there's no reason to try to
reenter kdb if a MC# is raised).

Reviewed by:	kib
Tested by:	avg (on AMD without PTI)
Differential Revision:	https://reviews.freebsd.org/D13962
2018-01-18 23:50:21 +00:00
John Baldwin
f36b1fe0bd Remove two no-longer-used labels from the NMI interrupt handler.
Reviewed by:	kib
2018-01-18 22:13:53 +00:00
Conrad Meyer
844d9543dc Add ccp(4): experimental driver for AMD Crypto Co-Processor
* Registers TRNG source for random(4)
* Finds available queues, LSBs; allocates static objects
* Allocates a shared MSI-X for all queues.  The hardware does not have
  separate interrupts per queue.  Working interrupt mode driver.
* Computes SHA hashes, HMAC.  Passes cryptotest.py, cryptocheck tests.
* Does AES-CBC, CTR mode, and XTS.  cryptotest.py and cryptocheck pass.
* Support for "authenc" (AES + HMAC).  (SHA1 seems to result in
  "unaligned" cleartext inputs from cryptocheck -- which the engine
  cannot handle.  SHA2 seems to work fine.)
* GCM passes for block-multiple AAD, input lengths

Largely based on ccr(4), part of cxgbe(4).

Rough performance averages on AMD Ryzen 1950X (4kB buffer):
aesni:      SHA1: ~8300 Mb/s    SHA256: ~8000 Mb/s
ccp:               ~630 Mb/s    SHA256:  ~660 Mb/s  SHA512:  ~700 Mb/s
cryptosoft:       ~1800 Mb/s    SHA256: ~1800 Mb/s  SHA512: ~2700 Mb/s

As you can see, performance is poor in comparison to aesni(4) and even
cryptosoft (due to high setup cost).  At a larger buffer size (128kB),
throughput is a little better (but still worse than aesni(4)):

aesni:      SHA1:~10400 Mb/s    SHA256: ~9950 Mb/s
ccp:              ~2200 Mb/s    SHA256: ~2600 Mb/s  SHA512: ~3800 Mb/s
cryptosoft:       ~1750 Mb/s    SHA256: ~1800 Mb/s  SHA512: ~2700 Mb/s

AES performance has a similar story:

aesni:      4kB: ~11250 Mb/s    128kB: ~11250 Mb/s
ccp:               ~350 Mb/s    128kB:  ~4600 Mb/s
cryptosoft:       ~1750 Mb/s    128kB:  ~1700 Mb/s

This driver is EXPERIMENTAL.  You should verify cryptographic results on
typical and corner case inputs from your application against a known- good
implementation.

Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D12723
2018-01-18 22:01:30 +00:00
Conrad Meyer
f5b26e1334 Add Elf_Nhdr definition to match NetBSD, OpenBSD, Linux
The mesa port started to use this type and fails to build without it.

NetBSD: http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/sys/exec_elf.h.diff?r1=1.26&r2=1.27&f=h
OpenBSD: http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/sys/sys/exec_elf.h.diff?r1=1.21&r2=1.22&f=h

PR:		225302
Reported by:	Greg V <greg AT unrelenting.technology>
Sponsored by:	Dell EMC Isilon
2018-01-18 21:19:57 +00:00
John Baldwin
7f513d17b2 Adjust branch target in NMI handler for the !PTI case.
In the !PTI case the NMI handler jumped past the instructions that set
%rdi to point to the current PCB, but the target instructions assumed %rdi
were set.

Reviewed by:	kib
Tested by:	pho
2018-01-18 20:12:12 +00:00
John Baldwin
9a7a98a0dc Update various statements in vmstat(8) to match reality.
- The process stats are actually thread counts rather than process
  counts.
- Simplify various descriptions to remove mention of stats that are
  updated every 5 seconds (all VM related stats are now "instant",
  only the load average is updated every 5 seconds).
- Don't make any mention of special treatment for processes that have
  been active in the last 20 seconds.  We don't track that stat.
- Rework the description of active virtual memory.  Call it mapped
  virtual memory and explicitly point out it is not the same as the
  active page queue (which corresponds to "Active" in top(1)), and
  also hint at the possible bogusness of the value (e.g. if a process
  maps a single page out of a multiple GB file, the entire file's size
  is considered mapped).
- Simplify a few descriptions that implied their output was a value
  per interval.  All of the "rate" values are per-second rates scaled
  across the interval.
- Update a few comments for 'struct vmtotal' along similar lines.

Reported by:	mwlucas (indirectly)
Reviewed by:	kib
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D13905
2018-01-18 19:43:02 +00:00
Ruslan Bukin
e6dd0a0e92 UART Clock Selection Register holds a divider value for a supplied clock,
not a final baud rate. The value for this register has to be calculated.

Sponsored by:	DARPA, AFRL
2018-01-18 18:19:31 +00:00
Ruslan Bukin
9f7743f2c8 Support for UART device found in Qualcomm Snapdragon 410E SoC.
Tested on DragonBoard 410c.

Reviewed by:	andrew
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D13972
2018-01-18 17:43:32 +00:00
Ruslan Bukin
9d00c86401 Set the base address of translation table 0.
This fixes operation on Qualcomm Snapdragon and some other platforms.

During boot time on subsystems initialization we have some amount of
kernel threads created, then scheduler gives CPU time to each thread.
Eventually scheduler returns CPU execution back to thread 0. In this
case writing zero to ttbr0 in cpu_switch leads Qualcomm board to
reboot (asynchronously, CPU continues execution).

Similar to other kernel threads install a valid physical address
(kernel pmap) to user page table base register ttbr0.

Reviewed by:	andrew
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D13536
2018-01-18 16:20:09 +00:00
Emmanuel Vadot
becffb36cc nfs: Do not printf each time a lock structure is freed during module unload
There can be a lot of those structures and printing a line each time we free
one on module unload.

MFC after:	3 days
2018-01-18 15:28:49 +00:00
Konstantin Belousov
3705dda7e4 Move the kernphys declaration to machine/md_var.h.
Apparently machinde/cpu.h is supposed to contain MD implementations of
MI interfaces.  Also, remove kernphys declaration from machdep.c,
since it is already provided by md_var.h.

Requested and reviewed by:	bde
MFC after:	13 days
2018-01-18 15:15:35 +00:00
Andriy Gapon
3e4f610dad correct read-ahead calculations in vfs_bio_getpages
Previously the calculations were done as if the requested region
ended at the start of the last requested page, not its end.
The problem as actually quite minor as it affected only stats and
page prefaulting, not the actual page data, and only with specific
parameters.

Reviewed by:	kib (previous version)
MFC after:	2 weeks
2018-01-18 12:59:04 +00:00
Konstantin Belousov
ac97ccbab5 Fix compilation with gcc.
etext is already declared in machine/cpu.h, move kernphys declaration
there too.

Based on the patch by:	bde
MFC after:	13 days
2018-01-18 11:21:03 +00:00
Konstantin Belousov
406bc0da95 Fix compilation with gas.
Submitted by:	bde
MFC after:	13 days
2018-01-18 11:19:58 +00:00
Konstantin Belousov
0d6c61ec30 Remove the 'last' argument from the pmap_pti_free_page().
It is in fact unused.

Noted and reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	13 days
2018-01-18 11:01:41 +00:00
Andrew Turner
7680515c07 Add a pmap invalidate that doesn't call sched_pin.
When demoting DMAP pages curthread may be pointing to data within the
page we are demoting. Create a new invalidate that doesn't pin and use
it in the demote case.

As the demote has both interrupts disabled, and is within a critical section
this is safe from having the scheduler from switching to another CPU.

Reported by:	loos
Reviewed by:	loos
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D13955
2018-01-18 10:52:31 +00:00
Wojciech Macek
720212d30d Call platform_smp_ap_init before decr_ap_init
In platform_smp_ap_init we are doing some crucial code (eg. set LPCR register)
    which have influence over further execution.

    Practiculary in PowerNV platform we have experienced Data Storage Interrupt
    before we set apropriate LPCR. It caused code execution from location which was
    legal in bootloader (petitboot based on linux) but illegal in FreeBSD
2018-01-18 08:34:20 +00:00
Wojciech Macek
054a090d49 PPC64: fix TOC behavior on process initialization
Set stack pointer to correct value after thread's stack pointer restore

Restoring new thread's stack pointer caused stack corruption because
restored stack pointer didn't point to callee (cpu_switch) stack frame but
caller stack frame.

As a result we had mysterious errors in caller function (sched_switch).

Solution: simply set stack pointer to correct value

Also, initialize TOC to a valid pointer once the thread is being
created.

Created by:            Patryk Duda <pdk@semihalf.com>
Submitted by:          Wojciech Macek <wma@semihalf.com>
Obtained from:         Semihalf
Reviewed by:           nwhitehorn
Differential revision: https://reviews.freebsd.org/D13947
Sponsored by:          QCM Technologies
2018-01-18 07:42:51 +00:00
Wojciech Macek
8a0112ca65 PPC: machdep, zero BSS always but BookE
Zero BSS always. The only case when this operation is
ommitted is when booting on BookE.

Created by:            Wojciech Macek <wma@semihalf.com>
Obtained from:         Semihalf
Reviewed by:           imp, nwhitehorn
Differential revision: https://reviews.freebsd.org/D13948
Sponsored by:          QCM Technologies
2018-01-18 07:41:04 +00:00
Wojciech Macek
5b3e8b0725 KDB: restart only CPUs stopped by KDB
There is a case when not all CPUs went online. In that situation,
restart only APs which were operational before entering KDB.

Created by:            Wojciech Macek <wma@semihalf.com>
Obtained from:         Semihalf
Reviewed by:           nwhitehorn
Differential revision: https://reviews.freebsd.org/D13949
Sponsored by:          QCM Technologies
2018-01-18 07:38:54 +00:00
Wojciech Macek
e70f868f17 PPC64: add AHCI back to GENERIC64 2018-01-18 06:28:21 +00:00
Alan Somers
6f7f85e0e1 gnop(8): add the ability to set a nop provider's physical path
While I'm here, expand the existing tests a bit.

MFC after:	3 weeks
Differential Revision:	https://reviews.freebsd.org/D13579
2018-01-18 05:57:10 +00:00
Kyle Evans
6780e684d4 libfdt: Update to 1.4.6, switch to using libfdt for overlay support
libfdt highlights since 1.4.3:

- fdt_property_placeholder added to create a property without specifying its
value at creation time
- stringlist helper functions added to libfdt
- Improved overlay support
- Various internal cleanup

Also switch stand/fdt over to using libfdt for overlay support with this
update. Our current overlay implementation works only for limited use cases
with overlays generated only by some specific versions of our dtc(1). Swap
it out for the libfdt implementation, which supports any properly generated
overlay being applied to a properly generated base.

This will be followed up fairly soon with an update to dtc(1) in tree to
properly generate overlays.

MFC note: the <stdlib.h> include this update introduces in libfdt_env.h is
apparently not necessary in the context we use this in. It's not immediately
clear to me the motivation for it being introduced, but it came in with
overlay support. I've left it in for the sake of accuracy and because it's
not harmful here on HEAD, but MFC'ing this to stable/11 will require
wrapping the #include in an `#ifndef _STANDALONE` block or else it will
cause build failures.

Tested on:	Banana Pi-M3 (ARMv7)
Tested on:	Pine64 (aarch64)
Tested on:	PowerPC [nwhitehorn]
Reviewed by:	manu, nwhitehorn
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D13893
2018-01-18 04:39:09 +00:00
John Baldwin
65eefbe422 Save and restore guest debug registers.
Currently most of the debug registers are not saved and restored
during VM transitions allowing guest and host debug register values to
leak into the opposite context.  One result is that hardware
watchpoints do not work reliably within a guest under VT-x.

Due to differences in SVM and VT-x, slightly different approaches are
used.

For VT-x:

- Enable debug register save/restore for VM entry/exit in the VMCS for
  DR7 and MSR_DEBUGCTL.
- Explicitly save DR0-3,6 of the guest.
- Explicitly save DR0-3,6-7, MSR_DEBUGCTL, and the trap flag from
  %rflags for the host.  Note that because DR6 is "software" managed
  and not stored in the VMCS a kernel debugger which single steps
  through VM entry could corrupt the guest DR6 (since a single step
  trap taken after loading the guest DR6 could alter the DR6
  register).  To avoid this, explicitly disable single-stepping via
  the trace flag before loading the guest DR6.  A determined debugger
  could still defeat this by setting a breakpoint after the guest DR6
  was loaded and then single-stepping.

For SVM:
- Enable debug register caching in the VMCB for DR6/DR7.
- Explicitly save DR0-3 of the guest.
- Explicitly save DR0-3,6-7, and MSR_DEBUGCTL for the host.  Since SVM
  saves the guest DR6 in the VMCB, the race with single-stepping
  described for VT-x does not exist.

For both platforms, expose all of the guest DRx values via --get-drX
and --set-drX flags to bhyvectl.

Discussed with:	avg, grehan
Tested by:	avg (SVM), myself (VT-x)
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D13229
2018-01-17 23:11:25 +00:00
John Baldwin
58c4aee0d7 Require the SHF_ALLOC flag for program sections from kernel object modules.
ELF object files can contain program sections which are not supposed
to be loaded into memory (e.g. .comment).  Normally the static linker
uses these flags to decide which sections are allocated to loadable
program segments in ELF binaries and shared objects (including kernels
on all architectures and kernel modules on architectures other than
amd64).

Mapping ELF object files (such as amd64 kernel modules) into memory
directly is a bit of a grey area.  ELF object files are intended to be
used as inputs to the static linker.  As a result, there is not a
standardized definition for what the memory layout of an ELF object
should be (none of the section headers have valid virtual memory
addresses for example).

The kernel and loader were not checking the SHF_ALLOC flag but loading
any program sections with certain types such as SHT_PROGBITS.  As a
result, the kernel and loader would load into RAM some sections that
weren't marked with SHF_ALLOC such as .comment that are not loaded
into RAM for kernel modules on other architectures (which are
implemented as ELF shared objects).  Aside from possibly requiring
slightly more RAM to hold a kernel module this does not affect runtime
correctness as the kernel relocates symbols based on the layout it
uses.

Debuggers such as gdb and lldb do not extract symbol tables from a
running process or kernel.  Instead, they replicate the memory layout
of ELF executables and shared objects and use that to construct their
own symbol tables.  For executables and shared objects this works
fine.  For ELF objects the current logic in kgdb (and probably lldb
based on a simple reading) assumes that only sections with SHF_ALLOC
are memory resident when constructing a memory layout.  If the
debugger constructs a different memory layout than the kernel, then it
will compute different addresses for symbols causing symbols in the
debugger to appear to have the wrong values (though the kernel itself
is working fine).  The current port of mdb does not check SHF_ALLOC as
it replicates the kernel's logic in its existing kernel support.

The bfd linker sorts the sections in ELF object files such that all of
the allocated sections (sections with SHF_ALLOCATED) are placed first
followed by unallocated sections.  As a result, when kgdb composed a
memory layout using only the allocated sections, this layout happened
to match the layout used by the kernel and loader.  The lld linker
does not sort the sections in ELF object files and mixed allocated and
unallocated sections.  This resulted in kgdb composing a different
memory layout than the kernel and loader.

We could either patch kgdb (and possibly in the future lldb) to use
custom handling when generating memory layouts for kernel modules that
are ELF objects, or we could change the kernel and loader to check
SHF_ALLOCATED.  I chose the latter as I feel we shouldn't be loading
things into RAM that the module won't use.  This should mostly be a
NOP when linking with bfd but will allow the existing kgdb to work
with amd64 kernel modules linked with lld.

Note that we only require SHF_ALLOC for "program" sections for types
like SHT_PROGBITS and SHT_NOBITS.  Other section types such as symbol
tables, string tables, and relocations must also be loaded and are not
marked with SHF_ALLOC.

Reported by:	np
Reviewed by:	kib, emaste
MFC after:	1 month
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D13926
2018-01-17 22:51:59 +00:00