Focus on code where we are doing multiplications within malloc(9). None of
these ire likely to overflow, however the change is still useful as some
static checkers can benefit from the allocation attributes we use for
mallocarray.
This initial sweep only covers malloc(9) calls with M_NOWAIT. No good
reason but I started doing the changes before r327796 and at that time it
was convenient to make sure the sorrounding code could handle NULL values.
X-Differential revision: https://reviews.freebsd.org/D13837
domains can be done by the _domain() API variants. UMA also supports a
first-touch policy via the NUMA zone flag.
The slab layer is now segregated by VM domains and is precise. It handles
iteration for round-robin directly. The per-cpu cache layer remains
a mix of domains according to where memory is allocated and freed. Well
behaved clients can achieve perfect locality with no performance penalty.
The direct domain allocation functions have to visit the slab layer and
so require per-zone locks which come at some expense.
Reviewed by: Attilio (a slightly older version)
Tested by: pho
Sponsored by: Netflix, Dell/EMC Isilon
An lld-linked i386 kernel hangs on boot, after em(4) starts. This seems
similar to the issue that prompted us to disable VIMAGE on arm64 in
r326179. Disable VIMAGE on i386 for now while we investigate.
PR: 225077
Sponsored by: The FreeBSD Foundation
We already clear %RFLAGS.DF on the kernel entry due to the compiler's
ABI requirements.
Suggested by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Iwasaki-san's copyright over. Remove FIXME code that couldn't possibly
work. Call tc_settime() with our estimate of the delta we've been
alseep (the one we print) to adjust the time. Not sure what to do
about callouts, so keep the small #ifdef in place there.
Differential Revision: https://reviews.freebsd.org/D13823
inline ccbque.h into scsi_low.h. The file isn't MD, so shouldn't live
in i386/isa. It's only used by scsi_low, so move it there so no new
clients accidentally grow. scsi_low may not even still work, and the
locking here is still SPL based. CAM should do the right thing, but
I've received no reports of these cards still working. At least it
compiles still and there's one fewer files in sys/i386/isa. While I'm
here, ansify and de-splize. CCB_MWANTED appears to be a clear-only
flag, but I've not changed that.
Differential Review: https://reviews.freebsd.org/D13672
It does not change anything in the behavior of trap_pfault(), while
eliminating obfuscation of jumping to the code which checks for the
condition reversed of the goto cause. Also avoid force initialize the
rv variable, since it is now only accessed after storing vm_fault()
return value.
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D13725
The ep(4) driver is the only consumer of the two functions from
elink.c. I removed the standalone module as well, and most likely,
the module metadata is not needed anywhere, but this is for later
cleanup.
Discussed with: imp, jhb
Sponsored by: The FreeBSD Foundation
The i386 FPU (AKA npx) code does not depend on ISA devices at all,
after the support for IRQ13 FPU exceptions was removed. Put the file
into the expected place in the kernel source tree.
Discussed with: jhb
Sponsored by: The FreeBSD Foundation
Make it easier to identify the point where we started diverging from
NetBSD. Newer versions of these files have been updated to a new license
so this information may become useful some day.
Obtained from: NetBSD
They provide relaxed-ordered atomic access semantic. Due to the
FreeBSD memory model, the operations are syntaxical wrappers around
the volatile accesses. The volatile qualifier is used to ensure that
the access not optimized out and in turn depends on the volatile
semantic as implemented by supported compilers.
The motivation for adding the operation is to help people coming from
other systems or knowing the C11/C++ standards where atomics have
special type and require use of the special access operations. It is
still the case that FreeBSD requires plain load and stores of aligned
integer types to be atomic.
Suggested by: jhb
Reviewed by: alc, jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D13534
of low physical memory:
Update the comment about leaving the permanent mapping in place. This
also improves the wording of the comment. PTD 0 is still left alone
because it is fairly important that it was unmapped earlier, and the
comment now describes the unmapping of the other low PTDs that the code
actually does.
Reviewed by: kib
it by a transient double mapping for the one instruction in ACPI wakeup
where it is needed (and for many surrounding instructions in ACPI resume).
Invalidate the TLB as soon as convenient after undoing the transient
mapping. ACPI resume already has the strict ordering needed for this.
This fixes the non-trapping of null pointers and other garbage pointers
below NBPDR (except transiently). NBPDR is quite large (4MB, or 2MB for
PAE).
This fixes spurious traps at the first instruction in VM86 bioscalls.
The traps are for transiently missing read permission in the first
VM86 page (physical page 0) which was just written to at KERNBASE in
the kernel. The mechanism is unknown (it is not simply PG_G).
locore uses a similar but larger transient double mapping and needs
it for 2 instructions instead of 1. Unmap the first PDE in it after
the 2 instructions to detect most garbage pointers while bootstrapping.
pmap_bootstrap() finishes the unmapping.
Remove the avoidance of the double mapping for a recently fixed special
case. ACPI resume could use this avoidance (made non-special) to avoid
any problems with the transient double mapping, but no such problems
are known.
Update comments in locore. Many were for old versions of FreeBSD which
tried to map low memory r/o except for special cases, or might have
allowed access to low memory via physical offsets. Now all kernel
maps are r/w, and removal of of the double map disallows use of physical
offsets again.
when KERNLOAD is smaller than NBPDR (not the default) and PG_G is
enabled (the default if the CPU supports it). This case has relatively
minor problems with coherency of the permanent double mapping, but the
fix in r167869 to improve coherency creates page tables with 3 different
errors so never worked.
The permanent double mapping is fundamentally broken and will be removed
soon. It fundamentally breaks trapping for null pointers and requires
complications to avoid cache coherency bugs. It is currently used for
only a single instruction in ACPI resume,
Many fixes VM86 and/or ACPI and/or the double map were attempted near
r1200000. r167869 attempted to fix cache coherency bugs in an unusual
case, but the bugs were unreachable because older errors in page tables
caused a crash first.
This commit just makes r167869 work as intended. Part 1 of these fixes
fixed the other errors, but also stopped mapping the PDE for KERNBASE
as a large page, so double mapping of this PDE only causes the same
problems as when KERNLOAD is the default. Except for the problem of
trapping null pointers, r167869 could be used to fix these problems,
but it is inactive in usual cases. The only known other problem is
that incoherent permissions for page 0 cause spurious traps in VM86
BIOS calls.
Reviewed by: kib
when KERNLOAD is not a multiple of NBPDR (not the default) and PSE is
enabled (the default if the CPU supports it). Addresses in PDEs must
be a multiple of NBPDR in the PSE case, but were not so in the crashing
case.
KERNLOAD defaults to NBPDR. NBPDR is 4 MB for !PAE and 2 MB for PAE.
The default can be changed by editing i386/include/vmparam.h or using
makeoptions. It can be changed to less than NBPDR to save real and
virtual memory at a small cost in time, or to more than NBPDR to waste
real and virtual memory. It must be larger than 1 MB and a multiple of
PAGE_SIZE. When it is less than NBPDR, it is necessarily not a multiple
of NBPDR. This case has much larger bugs which will be fixed in part 2.
The fix is to only use PSE for physical addresses above <KERNLOAD
rounded _up_ to an NBPDR boundary>. When the rounding is non-null,
this leaves part of the kernel not using large pages. Rounding down
would avoid this pessimization, but would break setting of PAT bits
on i/o pages if it goes below 1MB. Since rounding down always goes
below 1MB when KERNLOAD < NBPDR and the KERNLOAD > NBPDR case is not
useful, never round down.
Fix related style bugs (e.g., wrong literal values for NBPDR in comments).
Reviewed by: kib
memory:
Load the kernel eflags less magically, as in locore. The magic increased
when I removed eflags from the pcb in r305899.
Remove a jump to low memory that became garbage when the i386 version was
mostly replaced by the amd64 version in r235622.
The amd64 version is very similar. It still loads the flags magically,
but is not missing comments about using the special page table.
Reviewed by: kib
The DTrace fasttrap entry points expect a struct reg containing the
register values of the calling thread. Perform the conversion in
fasttrap rather than in the trap handler: this reduces the number of
ifdefs and avoids wasting stack space for traps that don't involve
DTrace.
MFC after: 2 weeks
Logically, extend r286288 to cover all threads, by default.
The world has largely moved on from i386. Most FreeBSD users and developers
test on amd64 hardware. For better or worse, we have written a non-trivial
amount of kernel code that relies on stacks larger than 8 kB, and it "just
works" on amd64, so there has been little incentive to shrink it.
amd64 had its KSTACK_PAGES bumped to 4 back in Peter's initial AMD64 commit,
r114349, in 2003. Since that time, i386 has limped along on a stack half
the size. We've even observed the stack overflows years ago, but neglected
to fix the issue; see the 20121223 and 20150728 entries in UPDATING.
If anyone is concerned with this change, I suggest they configure their
AMD64 kernels with KSTACK_PAGES 2 and fix the fallout there first. Eugene
has identified a list of high stack usage functions in the first PR below.
PR: 219476, 224218
Reported by: eugen@, Shreesh Holla <hshreesh AT yahoo.com>
Relnotes: maybe
Sponsored by: Dell EMC Isilon
This variable should be pure MI except possibly for reading it in MD
dump routines. Its initialization was pure MD in 4.4BSD, but FreeBSD
changed this in r36441 in 1998. There were many imperfections in
r36441. This commit fixes only a small one, to simplify fixing the
others 1 arch at a time. (r47678 added support for
special/early/multiple message buffer initialization which I want in
a more general form, but this was too fragile to use because hacking
on the msgbufp global corrupted it, and was only used for 5 hours in
-current...)
In the linux ENOADATA is frequently #defined as ENOATTR.
The change is required for an xattrs support implementation.
MFC after: 1 week
Discussed with: netchild
Approved by: pfg
Differential Revision: https://reviews.freebsd.org/D13221
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
For FreeBSD/arm64's cloudabi32 support, I'm going to need a TO_PTR() in
this place. Also use it for all of the other source files, so that the
difference remains as minimal as possible.
MFC after: 2 weeks
Upon successful completion, the execve() system call invokes
exec_setregs() to initialize the registers of the initial thread of the
newly executed process. What is weird is that when execve() returns, it
still goes through the normal system call return path, clobbering the
registers with the system call's return value (td->td_retval).
Though this doesn't seem to be problematic for x86 most of the times (as
the value of eax/rax doesn't matter upon startup), this can be pretty
frustrating for architectures where function argument and return
registers overlap (e.g., ARM). On these systems, exec_setregs() also
needs to initialize td_retval.
Even worse are architectures where cpu_set_syscall_retval() sets
registers to values not derived from td_retval. On these architectures,
there is no way cpu_set_syscall_retval() can set registers to the way it
wants them to be upon the start of execution.
To get rid of this madness, let sys_execve() return EJUSTRETURN. This
will cause cpu_set_syscall_retval() to leave registers intact. This
makes process execution easier to understand. It also eliminates the
difference between execution of the initial process and successive ones.
The initial call to sys_execve() is not performed through a system call
context.
Reviewed by: kib, jhibbits
Differential Revision: https://reviews.freebsd.org/D13180
Mainly focus on files that use BSD 3-Clause license.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
Initially, only tag files that use BSD 4-Clause "Original" license.
RelNotes: yes
Differential Revision: https://reviews.freebsd.org/D13133
It is for console presented at 2001 and featuring Pentium III
processor. Even if any of them are still alive and run FreeBSD, we do
not have any sign of life from their users. While removing another
dozens of #ifdefs from the i386 sources reduces the aversion from
looking at the code and improves the platform vitality.
Reviewed by: cem, pfg, rink (XBOX support author)
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D13016
Some callers of fpusetregs()/npxsetregs(), most importantly
set_fpcontext(), clear reserved bits. But some did not. Do the
clearing in fpusetregs() and remove now redundand operation from
set_fpcontext().
Reported by: Maxime Villard <max@m00nbsd.net>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
