of the missing functionality from procfs(4) and new functionality for
monitoring and debugging specific processes. procstat(1) operates in
the following modes:
-b Display binary information for the process.
-c Display command line arguments for the process.
-f Display file descriptor information for the process.
-k Display the stacks of kernel threads in the process.
-s Display security credential information for the process.
-t Display thread information for the process.
-v Display virtual memory mappings for the process.
Further revision and modes are expected.
Testing, ideas, etc: cognet, sam, Skip Ford <skip at menantico dot com>
Wesley Shields <wxs at atarininja dot org>
support its -k argument:
kern.proc.kstack - dump the kernel stack of a process, if debugging
is permitted.
This sysctl is present if either "options DDB" or "options STACK" is
compiled into the kernel. Having support for tracing the kernel
stacks of processes from user space makes it much easier to debug
(or understand) specific wmesg's while avoiding the need to enter
DDB in order to determine the path by which a process came to be
blocked on a particular wait channel or lock.
- Introduce per-architecture stack_machdep.c to hold stack_save(9).
- Introduce per-architecture machine/stack.h to capture any common
definitions required between db_trace.c and stack_machdep.c.
- Add new kernel option "options STACK"; we will build in stack(9) if it is
defined, or also if "options DDB" is defined to provide compatibility
with existing users of stack(9).
Add new stack_save_td(9) function, which allows the capture of a stacktrace
of another thread rather than the current thread, which the existing
stack_save(9) was limited to. It requires that the thread be neither
swapped out nor running, which is the responsibility of the consumer to
enforce.
Update stack(9) man page.
Build tested: amd64, arm, i386, ia64, powerpc, sparc64, sun4v
Runtime tested: amd64 (rwatson), arm (cognet), i386 (rwatson)
We used to allocate the domains 0-14 for userland, and leave the domain 15
for the kernel. Now supersections requires the use of domain 0, so we
switched the kernel domain to 0, and use 1-15 for userland.
How it's done currently, the kernel domain could be allocated for a
userland process.
So switch back to the previous way we did things, set the first available
domain to 0, and just add 1 to get the real domain number in the struct pmap.
Reported by: Mark Tinguely <tinguely AT casselton DOT net>
MFC After: 3 days
1. A packet comes in that is to be forwarded
2. The destination of the packet is rewritten by some firewall code
3. The next link's MTU is too small
4. The packet has the DF bit set
Then the current code is such that instead of setting the next
link's MTU in the ICMP error, ip_next_mtu() is called and a guess
is sent as to which MTU is supposed to be tried next. This is because
in this case ip_forward() is called with srcrt set to 1. In that
case the ia pointer remains NULL but it is needed to get the MTU
of the interface the packet is to be sent out from.
Thus, we always set ia to the outgoing interface.
MFC after: 2 weeks
The RAS implementation would set the end address, then the start
address. These were used by the kernel to restart a RAS sequence if
it was interrupted. When the thread switching code ran, it would
check these values and adjust the PC and clear them if it did.
However, there's a small flaw in this scheme. Thread T1, sets the end
address and gets preempted. Thread T2 runs and also does a RAS
operation. This resets end to zero. Thread T1 now runs again and
sets start and then begins the RAS sequence, but is preempted before
the RAS sequence executes its last instruction. The kernel code that
would ordinarily restart the RAS sequence doesn't because the PC isn't
between start and 0, so the PC isn't set to the start of the sequence.
So when T1 is resumed again, it is at the wrong location for RAS to
produce the correct results. This causes the wrong results for the
atomic sequence.
The window for the first race is 3 instructions. The window for the
second race is 5-10 instructions depending on the atomic operation.
This makes this failure fairly rare and hard to reproduce.
Mutexs are implemented in libthr using atomic operations. When the
above race would occur, a lock could get stuck locked, causing many
downstream problems, as you might expect.
Also, make sure to reset the start and end address when doing a syscall, or
a malicious process could set them before doing a syscall.
Reviewed by: imp, ups (thanks guys)
Pointy hat to: cognet
MFC After: 3 days
its -f and -v arguments:
kern.proc.filedesc - dump file descriptor information for a process, if
debugging is permitted, including socket addresses, open flags, file
offsets, file paths, etc.
kern.proc.vmmap - dump virtual memory mapping information for a process,
if debugging is permitted, including layout and information on
underlying objects, such as the type of object and path.
These provide a superset of the information historically available
through the now-deprecated procfs(4), and are intended to be exported
in an ABI-robust form.
January 1, 1601. The 1601 - 1970 period was in seconds rather than 100ns
units.
Remove duplication by having NdisGetCurrentSystemTime call ntoskrnl_time.
linker interfaces for looking up function names and offsets from
instruction pointers. Create two variants of each call: one that is
"DDB-safe" and avoids locking in the linker, and one that is safe for
use in live kernels, by virtue of observing locking, and in particular
safe when kernel modules are being loaded and unloaded simultaneous to
their use. This will allow them to be used outside of debugging
contexts.
Modify two of three current stack(9) consumers to use the DDB-safe
interfaces, as they run in low-level debugging contexts, such as inside
lockmgr(9) and the kernel memory allocator.
Update man page.
sx driver), change a magic value in the PLX bridge chip. Apparently later
builds of the PCI cards had corrected values in the configuration eeprom.
This change supposedly fixes some pci bus problems.
information in support of DDB(4); these functions bypass normal linker
locking as they may run in contexts where locking is unsafe (such as the
kernel debugger).
Add a new interface linker_ddb_search_symbol_name(), which looks up a
symbol name and offset given an address, and also
linker_search_symbol_name() which does the same but *does* follow the
locking conventions of the linker.
Unlike existing functions, these functions place the name in a
caller-provided buffer, which is stable even after linker locks have been
released. These functions will be used in upcoming revisions to stack(9)
to support kernel stack trace generation in contexts as part of a live,
rather than suspended, kernel.
sparc64, use ANSI function headers and specifically indicate the lack of
arguments with 'void'. Otherwise, warnings are generated at WARNS=3 for
libkse, leading to a compile failure with -Werror.
ia64, powerpc, and sparc64, use ANSI function headers and specifically
indicate the lack of arguments with 'void'. Otherwise, warnings are
generated at WARNS=3, leading to a compile failure with -Werror.
gets enabled when INVARIANTS is on instead of DIAGNOSTIC (which apparently
nobody uses). From Tor's description:
This happens when the block range spans two block maps, the first in the
inode (mapping up to NDADDR direct blocks) and the second being the first
indirect block. The current check assumes that both block maps are
indirect blocks.
Work done by: tegge
Tested by: kris, kensmith
in the tcp header. With relevant parts of the tcp header changing after
the 'signature' was computed, the signature becomes invalid.
Reviewed by: tools/regression/netinet/tcpconnect
MFC after: 3 days
Tested by: Nick Hilliard (see net@)
is required by the X.Org PCI domains code and additionally needs
a workaround for Hummingbird and Sabre bridges as these don't
allow their config headers to be read at any width, which is an
unusual behavior.
- In psycho(4) take advantage of DEFINE_CLASS_0 and use more
appropriate types for some softc members.
MFC after: 3 days
hack means you can get the units and flags to match up more easily with
serial consoles on machines with acpi tables that cause the com ports
to be probed in the wrong order (and hence get the wrong sio unit number).
This replaces the common alternative hack of editing the code to comment
out the acpi attachment. This could go away entirely when device wiring
patches are committed.
stomping on the units intended for the motherboard sio ports. This is
no real substitute for the not-yet-committed device wiring enhancements.
Code taken from sio's pci attachment.
