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
libxo imposes a large burden on system utilities. In the case of ls, that
burden is difficult to justify -- any language that can interact with json
output can use readdir(3) and stat(2).
Logically, this reverts r291607, r285857, r285803, r285734, r285425,
r284494, r284489, r284252, and r284198.
Kyua tests continue to pass (libxo integration was entirely untested).
Reported by: many
Reviewed by: imp
Discussed with: manu, bdrewery
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D13959
pathconf(2) and fpathconf(2) both return a long. The kern_[f]pathconf()
functions now accept a pointer to a long value rather than modifying
td_retval directly. Instead, the system calls explicitly store the
returned long value in td_retval[0].
Requested by: bde
Reviewed by: kib
Sponsored by: Chelsio Communications
r326454.
bwn(4)/bhnd(4) has been tested with most chipsets currently supported by
bwn(4), and this change should be transparent to existing bwn(4) users;
please report any regressions that you do encounter.
To revert to using siba_bwn(4) instead of bhnd(4), place the following
lines in loader.conf(5):
hw.bwn_pci.preferred="0"
Once we're satisfied that the switch to bhnd(4) has seen sufficient broader
testing, bwn(4) will be migrated to use the native bhnd(9) interface
directly, and support for siba_bwn(4) will be dropped (see D13518).
Sponsored by: The FreeBSD Foundation
Address style issues including some previously raised in D13923.
- Use designated initializers for structs
- Always use bracketed return style
- No initialization in declarations
- Align function prototype names
- Remove old commented code/unused includes
Submitted by: Mitchell Horne <mhorne063@gmail.com>
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D13943
Basic use of mallocarray to prevent overflows: static analyzers are also
likely to perform additional checks.
Since mallocarray expects unsigned parameters, unsign some
related variables to minimize sign conversions.
Reviewed by: mckusick
check-hash after making changes to the cylinder group. The problem
was that the journal-recovery code was calling the libufs bwrite()
function instead of the cgput() function. The cgput() function updates
the cylinder-group check-hash before writing the cylinder group.
This change required the additions of the cgget() and cgput() functions
to the libufs API to avoid a gratuitous bcopy of every cylinder group
to be read or written. These new functions have been added to the
libufs manual pages. This was the first opportunity that I have had
to use and document the use of the EDOOFUS error code.
Reviewed by: kib
Reported by: emaste and others
Allow usage of X86-prefixes as separate instrs.
Differential Revision: https://reviews.llvm.org/D42102
This should fix parse errors when x86 prefixes (such as 'lock' and
'rep') are followed by various non-mnemonic tokens, e.g. comments, .byte
directives and labels.
PR: 224669,225054
It fixes a crash with a socket in top mode.
Ex:
# pmcstat -R 127.0.0.1:8080 -T -w1
then
# pmcstat -n1 -Sclock.prof -Slock.failed -O 127.0.0.1:8080
MFC after: 1 week
Sponsored by: Stormshield
pmcstat request for close will generate a close event.
This event will be in turn received by pmcstat to close the file.
Reviewed by: kib
Tested by: pho
MFC after: 1 week
Sponsored by: Stormshield
The implementation of the Kernel Page Table Isolation (KPTI) for
amd64, first version. It provides a workaround for the 'meltdown'
vulnerability. PTI is turned off by default for now, enable with the
loader tunable vm.pmap.pti=1.
The pmap page table is split into kernel-mode table and user-mode
table. Kernel-mode table is identical to the non-PTI table, while
usermode table is obtained from kernel table by leaving userspace
mappings intact, but only leaving the following parts of the kernel
mapped:
kernel text (but not modules text)
PCPU
GDT/IDT/user LDT/task structures
IST stacks for NMI and doublefault handlers.
Kernel switches to user page table before returning to usermode, and
restores full kernel page table on the entry. Initial kernel-mode
stack for PTI trampoline is allocated in PCPU, it is only 16
qwords. Kernel entry trampoline switches page tables. then the
hardware trap frame is copied to the normal kstack, and execution
continues.
IST stacks are kept mapped and no trampoline is needed for
NMI/doublefault, but of course page table switch is performed.
On return to usermode, the trampoline is used again, iret frame is
copied to the trampoline stack, page tables are switched and iretq is
executed. The case of iretq faulting due to the invalid usermode
context is tricky, since the frame for fault is appended to the
trampoline frame. Besides copying the fault frame and original
(corrupted) frame to kstack, the fault frame must be patched to make
it look as if the fault occured on the kstack, see the comment in
doret_iret detection code in trap().
Currently kernel pages which are mapped during trampoline operation
are identical for all pmaps. They are registered using
pmap_pti_add_kva(). Besides initial registrations done during boot,
LDT and non-common TSS segments are registered if user requested their
use. In principle, they can be installed into kernel page table per
pmap with some work. Similarly, PCPU can be hidden from userspace
mapping using trampoline PCPU page, but again I do not see much
benefits besides complexity.
PDPE pages for the kernel half of the user page tables are
pre-allocated during boot because we need to know pml4 entries which
are copied to the top-level paging structure page, in advance on a new
pmap creation. I enforce this to avoid iterating over the all
existing pmaps if a new PDPE page is needed for PTI kernel mappings.
The iteration is a known problematic operation on i386.
The need to flush hidden kernel translations on the switch to user
mode make global tables (PG_G) meaningless and even harming, so PG_G
use is disabled for PTI case. Our existing use of PCID is
incompatible with PTI and is automatically disabled if PTI is
enabled. PCID can be forced on only for developer's benefit.
MCE is known to be broken, it requires IST stack to operate completely
correctly even for non-PTI case, and absolutely needs dedicated IST
stack because MCE delivery while trampoline did not switched from PTI
stack is fatal. The fix is pending.
Reviewed by: markj (partially)
Tested by: pho (previous version)
Discussed with: jeff, jhb
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Add missing little-endian 64-bit read and write. Since there
is no direct ASM opcode for this, perform byte swap if
necessary.
Created by: Wojciech Macek <wma@semihalf.com>
Obtained from: Semihalf
Sponsored by: QCM Technologies
Use current userspace address for segment mapping. Previously,
there was a bug which made the funciton constantly using the userspace
base address which could cause data integrity issues.
Created by: Wojciech Macek <wma@semihalf.com>
Obtained from: Semihalf
Sponsored by: QCM Technologies
Add CXGBE driver which is required for PowerNV system.
Also, remove AHCI which does not work in BigEndian.
Created by: Wojciech Macek <wma@semihalf.com>
Obtained from: Semihalf
Sponsored by: QCM Technologies
FreeBSD prints text char-by-char, which is not what OPAL
is designed to. Poll events more frequently to avoid buffer
overflow and loosing data.
Created by: Wojciech Macek <wma@semihalf.com>
Obtained from: Semihalf
Sponsored by: QCM Technologies
Fixes:
- map all devices to PE0
- use 1:1 TCE mapping
- provide the same TCE mapping for all PEs (not only PE0)
- add TCE reset and alignment (required by OPAL)
Created by: Wojciech Macek <wma@semihalf.com>
Obtained from: Semihalf
Sponsored by: QCM Technologies
On a SPROM-less device, the PCI(e) bridge core will be initialized with its
power-on-reset defaults; this can leave the SPROM-derived BHND_PCI_SRSH_PI
value pointing to the wrong backplane address. This value is used by the
PCI core when performing address translation between the static register
windows in BAR0 that map the PCI core's register block, and backplane
address space.
Previously, bhndb_pci(4) incorrectly used the potentially invalid static
BAR0 PCI register windows when attempting to correct the BHND_PCI_SRSH_PI
value in the PCI core's SPROM shadow.
Instead, we now read/update BHND_PCI_SRSH_PI by fetching the PCI core's
backplane address from the core enumeration table, and then using a dynamic
register window to explicitly map the PCI core's register block into BAR0.
Sponsored by: The FreeBSD Foundation
The static atrtc_set() function was called only from clock_settime(), so
just move its contents entirely into clock_settime() and delete atrtc_set().
Rename the struct bcd_clocktime variables from 'ct' to 'bct'. I had
originally wanted to emphasize how identical the clocktime and bcd_clocktime
structs were, but things evolved to the point where the structs are not at
all identical anymore, so now emphasizing the difference seems better.
Move the the NetBSD tag near to the related licence. Update it to reflect
better the point where we started diverging.
Use grouping parenthesis for the SPDX tag.
No functional change.
When processing a SACK advancing the cumtsn-ack in fast recovery,
increment the miss-indications for all TSN's reported as missing.
Thanks to Fabian Ising for finding the bug and to Timo Voelker
for provinding a fix.
This fix moves also CMT related initialisation of some variables
to a more appropriate place.
MFC after: 1 week
Both flags do the same thing but -n is more widely supported.
Reviewed By: jhb, emaste
Approved By: jhb (mentor)
Differential Revision: https://reviews.freebsd.org/D13936
I need these tools in order to install the crossbuilt FreeBSD and create a
disk image. Linux does not have a st_flags in struct stat so unfortunately
I need a bunch of ugly ifdefs. The resulting binaries allow me to
sucessfully install a MIPS64 world and create a disk-image that boots.
Reviewed By: brooks, bdrewery, emaste
Approved By: jhb (mentor)
Differential Revision: https://reviews.freebsd.org/D13307
In order to crossbuild FreeBSD on Mac/Linux I also need to build libnetbsd
and FILE* is not equal to struct __sFILE on those platforms.
Reviewed By: brooks, emaste
Approved By: jhb (mentor)
Differential Revision: https://reviews.freebsd.org/D13305
r328032 introduced a second round of argument parsing to proxy the request
through to a jail as needed, but failed to reset OPTIND before getting to
the second round of parsing to allow other flags to be set.
Reported by: Oleg Ginzburg <olevole olevole ru>
This adds explicit crp_mbuf and crp_uio pointers of the right type to
replace casts of crp_buf. This does not sweep through changing existing
code, but new code should use the correct fields instead of casts.
Reviewed by: kib
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D13927
Focus on code where we are doing multiplications within malloc(9). These
are not likely to overflow, however the change is still useful as some
static checkers can benefit from the allocation attributes we use for
mallocarray.
Attempting to retrieve an md_cval string from a kernel module with
kldxref would throw a offset error for modules created using lld, since
this value would be placed at the end of all allocated sections.
Add an ef_read_seg_string method to the ef interface, to allow reading
strings of varying size without attempting to read beyond the segment's
bounds.
PR: 224875
Submitted by: Mitchell Horne <mhorne063@gmail.com>
Reviewed by: cem, kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D13923
to the next int position.
Bug was introduced in r324959 ("Extract a set of pmcstat functions and
interfaces to the new internal library -- libpmcstat.")
This fixes pmcstat top mode (-T) operation.
Example: pmcstat -n1 -S clock.hard -T
Reported by: Peter Holm <peter@holm.cc>
Sponsored by: DARPA, AFRL
Make XICS to be OPAL-aware.
Created by: Nathan Whitehorn <nwhitehorn@freebsd.org>
Submitted by: Wojciech Macek <wma@semihalf.com>
Sponsored by: FreeBSD Foundation
P1022 SATA controller may set the wrong CCR bit for a command completion.
This would previously cause an interrupt storm. Solve this by marking all
commands complete, and letting the end_transaction deal with the successes.
Causes no problems on P5020.
While here, fix a minor bug in collision detection. The Freescale SATA
controller only has 16 slots, not 32.
related series of operations without doing a lock/unlock for each byte.
Use them when reading and writing the entire set of time registers.
The original rtcin() and writertc() functions which do lock/unlock on each
byte still exist, because they are public and called by outside code.
The implementation will follow (D12723). For now, get the changes to
commit-protected files out of the way.
Approved by: secteam (gordon)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D13925
