being incomplete, it currently has to know how to drop and pick back
up the vm_object's mutex if it has to sleep and drop the page queue
mutex. The problem with this is that if the page is busy, while we
are sleeping, the page can be freed and object disappear. When trying
to lock m->object, we'd get a stale or NULL pointer and crash.
The object is now cached, but this makes the assumption that
the object is referenced in some manner and will not itself
disappear while it is unlocked. Since this only happens if
the object is locked, I had to remove an assumption earlier in
contigmalloc() that reversed the order of locking the object and
doing vm_page_sleep_if_busy(), not the normal order.
(WITNESS) for code paths that always call uma_zalloc_arg() shortly
after where the check was, because uma_zalloc_arg() already does
a similar check.
No objections from Alfred. Thanks Alfred.
RTF_BLACKHOLE as well.
To quote the submitter:
The uRPF loose-check implementation by the industry vendors, at least on Cisco
and possibly Juniper, will fail the check if the route of the source address
is pointed to Null0 (on Juniper, discard or reject route). What this means is,
even if uRPF Loose-check finds the route, if the route is pointed to blackhole,
uRPF loose-check must fail. This allows people to utilize uRPF loose-check mode
as a pseudo-packet-firewall without using any manual filtering configuration --
one can simply inject a IGP or BGP prefix with next-hop set to a static route
that directs to null/discard facility. This results in uRPF Loose-check failing
on all packets with source addresses that are within the range of the nullroute.
Submitted by: James Jun <james@towardex.com>
work very infrequently, and often results in a compound panic which
confuses debugging; locking/SMP have made the layering violation (and
risks) of this more obvious over time.
Discussed with: green, bde, et al.
the thread ID and call db_trace_thread().
Since arm has all the logic in db_stack_trace_cmd(), rename the
new DB_COMMAND function to db_stack_trace to avoid conflicts on
arm.
While here, have db_stack_trace parse its own arguments so that
we can use a more natural radix for IDs. If the ID is not a thread
ID, or more precisely when no thread exists with the ID, try if
there's a process with that ID and return the first thread in it.
This makes it easier to print stack traces from the ps output.
requested by: rwatson@
tested on: amd64, i386, ia64
init and fini handlers. Our vm system removes all userland mappings at
exit prior to calling pmap_release. It just so happens that we might
as well reuse the pmap for the next process since the userland slate
has already been wiped clean.
However. There is a functional benefit to this as well. For platforms
that share userland and kernel context in the same pmap, it means that
the kernel portion of a pmap remains valid after the vmspace has been
freed (process exit) and while it is in uma's cache. This is significant
for i386 SMP systems with kernel context borrowing because it avoids
a LOT of IPIs from the pmap_lazyfix() cleanup in the usual case.
Tested on: amd64, i386, sparc64, alpha
Glanced at by: alc
Also introduce a macro to be called by persistent nodes to signal their
persistence during shutdown to hide this mechanism from the node author.
Make node flags have a consistent style in naming.
Document the change.
- Return meaningful return errorcodes.
- Free previously allocated connection in error cases.
In ng_device_rcvdata():
- Return meaningful return errorcodes.
- Detach mbuf from netgraph item, and free the item before
doing any other actions that may return from method.
- Do not call strange malloc() for buffer. [1]
- In case of any error jump to end, where mbuf is freed.
In ng_device_disconnect():
- Return meaningful return errorcodes.
- Free disconnected connection.
style(9) in mentioned above functions:
- Remove '/* NGD_DEBUG */', when only one line is ifdef'ed.
- Remove extra braces to easier reading.
- Add space after comma in function calls.
PR: kern/41881 (part)
Reviewed by: marks
Approved by: julian (mentor)
2. Sort includes, while here.
3. s/NULL/0/ in NG_SEND_MSG_HOOK(), since ng_ID_t is integer.
PR: kern/41881 (part)
Reviewed by: marks
Approved by: julian (mentor)
we construct the EFI image. It doesn't seem to actually end up
in the EFI image, AFAICT.
o Replace .quad, .long and .short with data8, data4 and data2 resp.
The former are gnuisms.
o Redefine _start_plabel as a data16 with @iplt(_start) as its
value. This is the preferred way to create user PLT entries.
binutils 2.15. The linker now creates a .rela.dyn section for
dynamic relocations, while our script created a .rela section.
Likewise, we copied the .rela section to the EFI image, but not
the .rela.dyn section. The fix is to rename .rela to .rela.dyn
in the linker script so that all relocations end up in the same
section again. This we copy into the EFI image.
gcc is using. This fixes devstat consumers (like vmstat, iostat,
systat) so they don't print crazy zillion digit numbers for
disk transfers and bandwidth.
According to gcc, long doubles are 64-bits, rather than 128 bits
like the SVR4 ABI spec wants them to be.. Note that MacOSX also treats
long doubles as 64-bits, and not 128 bits, so we are in good company.
Reviewed by: das
Approved by: grehan
