Commit Graph

403 Commits

Author SHA1 Message Date
Ryan Libby
3e5e9939cd ddb: enable the use of ^C and ^S/^Q
This lets one interrupt DDB's output, which is useful if paging is
disabled and the output device is slow.

This follows a previous implementation in svn r311952 / git
5fddef7999 which was reverted because it
broke DDB type-ahead.

Now, try this again, but with a 512-byte type-ahead buffer.  While there
is buffer space, control input is handled and non-control input is
buffered.  When the buffer is exhausted, the default is to print a
warning and drop further non-control input in order to continue handling
control input.  sysctl debug.ddb.prioritize_control_input can be set to
0 to instead preserve all input but lose immediate handling of control
input.  This could for example effect pasting of a large script into the
ddb console.

Suggested by:	Anton Rang <rang@acm.org>
Reviewed by:	markj
Discussed with:	imp
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D28676
2021-03-14 16:04:27 -07:00
Ryan Libby
d8404b7ec3 ddb: just move cursor when the lexer backs up
Get rid of db_look_char because it's not compatible with db_get_line().
This fixes the following issue:

db> script lockinfo=show alllocks
db> run lockinfo
db:0:lockinfo> how alllocks
No such command; use "help" to list available commands

Reported by:	markj
Reviewed by:	markj
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D28725
2021-02-24 15:56:16 -08:00
Ryan Libby
d85c9cef13 ddb: reliably fail with ambiguous commands
db_cmd_match had an even/odd bug, where if a third command was partially
matched (or any odd number greater than one) the search result would be
set back from CMD_AMBIGUOUS to CMD_FOUND, causing the last command in
the list to be executed instead of failing the match.

Reported by:	mlaier
Reviewed by:	markj, mlaier, vangyzen
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D28659
2021-02-24 15:56:16 -08:00
Alex Richardson
fa2528ac64 Use atomic loads/stores when updating td->td_state
KCSAN complains about racy accesses in the locking code. Those races are
fine since they are inside a TD_SET_RUNNING() loop that expects the value
to be changed by another CPU.

Use relaxed atomic stores/loads to indicate that this variable can be
written/read by multiple CPUs at the same time. This will also prevent
the compiler from doing unexpected re-ordering.

Reported by:	GENERIC-KCSAN
Test Plan:	KCSAN no longer complains, kernel still runs fine.
Reviewed By:	markj, mjg (earlier version)
Differential Revision: https://reviews.freebsd.org/D28569
2021-02-18 14:02:48 +00:00
mhorne
088a7eef95 ddb: add ability to print user registers
The debugger is always entered after some kind of kernel trap, often a
breakpoint in kdb_enter(). This means that the most recent trapframe
will include kernel state at the time of the trap, when often it is
desirable to the developer to view the contents of the previous
trapframe. This trapframe often corresponds to the entry from userspace.

The ddb(4) man page claims the ability to display user register state
via the 'u' modifier to `show registers`, but this appears untrue. It is
not obvious from a quick search of the history when this feature was
added, or when it was removed. (Re)implement this feature in
db_show_regs, noting that it is not necessarily populated with userspace
state.

Reviewed by:	jhb (earlier version), markj, bcr (manpages)
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D27705
2021-01-08 14:53:06 -04:00
John Baldwin
b4247e0cdf ddb: Display process flags (p_flag and p_flag2) in 'show proc'.
Reviewed by:	kib
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D27872
2020-12-31 16:01:52 -08:00
John Baldwin
3e06c7da02 Use kdb_thr_* to iterate over threads consistently in DDB.
The "findstack", "show all trace", and "show active trace" commands
were iterating over allproc to enumerate threads.  This missed threads
executing in exit1() after being removed from allproc.

Reviewed by:	kib
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D27829
2020-12-31 16:01:35 -08:00
John Baldwin
ae450907c6 Use kdb_thr_from_pid() in db_lookup_thread().
The code is identical, so this should be a no-op.

Reviewed by:	kib
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D27828
2020-12-31 16:01:27 -08:00
John Baldwin
825d234144 Don't check P_INMEM in kdb_thr_*().
Not all debugger operations that enumerate threads require thread
stacks to be resident in memory to be useful.  Instead, push P_INMEM
checks (if needed) into callers.

Reviewed by:	kib
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D27827
2020-12-31 16:01:12 -08:00
John Baldwin
47877889f2 ddb ps: Use the pidhash to enumerate processes not in allproc.
Exiting processes that have been removed from allproc but are still
executing are not yet marked PRS_ZOMBIE, so they were not listed (for
example, if a thread panics during exit1()).  To detect these
processes, clear p_list.le_prev to NULL explicitly after removing a
process from the allproc list and check for this sentinel rather than
PRS_ZOMBIE when walking the pidhash.

While here, simplify the pidhash walk to use a single outer loop.

Reviewed by:	kib
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D27824
2020-12-31 16:00:05 -08:00
John Baldwin
5941edfcdc Add a kstack_contains() helper function.
This is useful for stack unwinders which need to avoid out-of-bounds
reads of a kernel stack which can trigger kernel faults.

Reviewed by:	kib, markj
Obtained from:	CheriBSD
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D27356
2020-12-01 17:04:46 +00:00
Eric van Gyzen
8310609fdd db_search_symbol: prevent pollution from bogus symbols
The kernel will never map the first page, so any symbols in that
range cannot refer to addresses.  Some third-party assembly files
define internal constants which appear in their symbol table.
Avoiding the lookup for those symbols avoids replacing small offsets
with those symbols during disassembly.

Reported by:	Anton Rang <rang%acm.org>
Reviewed by:	Anton Rang <rang%acm.org>, markj
MFC after:	2 weeks
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D26895
2020-10-26 16:42:53 +00:00
Mateusz Guzik
b10bc5a1d5 ddb: clean up empty lines in .c and .h files 2020-09-01 22:14:30 +00:00
Brandon Bergren
40b664f64b [PowerPC] More relocation fixes
It turns out relocating the symbol table itself can cause issues, like fbt
crashing because it applies the offsets to the kernel twice.

This had been previously brought up in rS333447 when the stoffs hack was
added, but I had been unaware of this and reimplemented symtab relocation.

Instead of relocating the symbol table, keep track of the relocation base
in ddb, so the ddb symbols behave like the kernel linker-provided symbols.

This is intended to be NFC on platforms other than PowerPC, which do not
use fully relocatable kernels. (The relbase will always be 0)

 * Remove the rest of the stoffs hack.
 * Remove my half-baked displace_symbol_table() function.
 * Extend ddb initialization to cope with having a relocation offset on the
   kernel symbol table.
 * Fix my kernel-as-initrd hack to work with booke64 by using a temporary
   mapping to access the data.
 * Fix another instance of __powerpc__ that is actually RELOCATABLE_KERNEL.
 * Change the behavior or X_db_symbol_values to apply the relocation base
   when updating valp, to match link_elf_symbol_values() behavior.

Reviewed by:	jhibbits
Sponsored by:	Tag1 Consulting, Inc.
Differential Revision:	https://reviews.freebsd.org/D25223
2020-06-21 03:39:26 +00:00
Kyle Evans
c79cee7136 kernel: provide panicky version of __unreachable
__builtin_unreachable doesn't raise any compile-time warnings/errors on its
own, so problems with its usage can't be easily detected. While it would be
nice for this situation to change and compilers to at least add a warning
for trivial cases where local state means the instruction can't be reached,
this isn't the case at the moment and likely will not happen.

This commit adds an __assert_unreachable, whose intent is incredibly clear:
it asserts that this instruction is unreachable. On INVARIANTS builds, it's
a panic(), and on non-INVARIANTS it expands to  __unreachable().

Existing users of __unreachable() are converted to __assert_unreachable,
to improve debuggability if this assumption is violated.

Reviewed by:	mjg
Differential Revision:	https://reviews.freebsd.org/D23793
2020-05-13 18:07:37 +00:00
Pawel Biernacki
7029da5c36 Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many)
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.

This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.

Mark all obvious cases as MPSAFE.  All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT

Approved by:	kib (mentor, blanket)
Commented by:	kib, gallatin, melifaro
Differential Revision:	https://reviews.freebsd.org/D23718
2020-02-26 14:26:36 +00:00
Mateusz Guzik
879e0604ee Add KERNEL_PANICKED macro for use in place of direct panicstr tests 2020-01-12 06:07:54 +00:00
Conrad Meyer
fea73412a0 sleep(9), sleepqueue(9): const'ify wchan pointers
_sleep(9), wakeup(9), sleepqueue(9), et al do not dereference or modify the
channel pointers provided in any way; they are merely used as intptrs into a
dictionary structure to match waiters with wakers.  Correctly annotate this
such that _sleep() and wakeup() may be used on const pointers without
invoking ugly patterns like __DECONST().  Plumb const through all of the
underlying sleepqueue bits.

No functional change.

Reviewed by:	rlibby
Discussed with:	kib, markj
Differential Revision:	https://reviews.freebsd.org/D22914
2019-12-24 16:19:33 +00:00
Conrad Meyer
25b3370cfd ddb(4): Add some support for lexing IPv6 addresses
Allow commands to specify that (hex) numbers may start with A-F, by adding
the DRT_HEX flag for db_read_token_flags().  As before, numbers containing
invalid digits for the current radix are rejected.

Also, lex ':' and '::' tokens as tCOLON and tCOLONCOLON respectively.

There is a mild conflict here with lexed "identifiers" (tIDENT): ddb
identifiers may contain arbitrary colons, and the ddb lexer is greedy.  So
the identifier lex will swallow any colons it finds inside identifiers, and
consumers are still unable to expect the token sequence 'tIDENT tCOLON'.
That limitation does not matter for IPv6 addresses, because the lexer always
attempts to lex numbers before identifiers.

Reviewed by:	markj
Differential Revision:	https://reviews.freebsd.org/D21509
2019-09-09 16:32:23 +00:00
Conrad Meyer
e0c5dd431b ddb(4): Enhance lexer functionality for specialized commands
Add a db_read_token_flags() variant of db_read_token() with configurable
parameters.

Allow specifying an explicit radix for tNUMBER lexing.  It overrides the
default inference and db_radix setting.

Also provide the option of yielding any lexed whitespace (tWSPACE) (instead
of ignoring it).  This is useful for whitespace-sensitive CS_OWN commands.

Reviewed by:	markj
Differential Revision:	https://reviews.freebsd.org/D21459
2019-09-09 16:31:14 +00:00
Conrad Meyer
3c40d3fc54 ddb(4): Move an extern variable declaration to a header
Trivial cleanup, no functional change.
2019-09-09 01:33:45 +00:00
Mateusz Guzik
88cc62e5a5 proc: eliminate the zombproc list
It is not needed by anything in the kernel and it slightly drives up contention
on both proctree and allproc locks.

Reviewed by:	kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D21447
2019-08-28 16:18:23 +00:00
Jeff Roberson
0b26119b21 Cache kernel stacks in UMA. This gives us NUMA support, better concurrency,
and more statistics.

Reviewed by:	kib, markj
Tested by:	pho
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D20931
2019-08-06 23:15:34 +00:00
Ryan Libby
a6d2a24c3e ddb show proc typo 2019-06-22 05:35:23 +00:00
Conrad Meyer
e2e050c8ef Extract eventfilter declarations to sys/_eventfilter.h
This allows replacing "sys/eventfilter.h" includes with "sys/_eventfilter.h"
in other header files (e.g., sys/{bus,conf,cpu}.h) and reduces header
pollution substantially.

EVENTHANDLER_DECLARE and EVENTHANDLER_LIST_DECLAREs were moved out of .c
files into appropriate headers (e.g., sys/proc.h, powernv/opal.h).

As a side effect of reduced header pollution, many .c files and headers no
longer contain needed definitions.  The remainder of the patch addresses
adding appropriate includes to fix those files.

LOCK_DEBUG and LOCK_FILE_LINE_ARG are moved to sys/_lock.h, as required by
sys/mutex.h since r326106 (but silently protected by header pollution prior
to this change).

No functional change (intended).  Of course, any out of tree modules that
relied on header pollution for sys/eventhandler.h, sys/lock.h, or
sys/mutex.h inclusion need to be fixed.  __FreeBSD_version has been bumped.
2019-05-20 00:38:23 +00:00
Ryan Libby
64e0efab39 db show thread: avoid overflow in tick conversion
The previous calculations for displaying the time since last switch
easily overflowed, after less than 36 min for hz=1000.  Now overflow
takes 2000 times longer (as long as ticks takes to wrap).

Reviewed by:	cem, markj
Sponsored by:	Dell EMC Isilon
Differential revision:	https://reviews.freebsd.org/D20273
2019-05-16 05:29:54 +00:00
Justin Hibbits
517ba0d3f1 ddb: Print the thread's pcb in 'show thread'
This can aid with debugging when a thread is running and has no backtrace.
State can be estimated based on the pcb, and refined from there, for
example, to get a rough idea of the stack pointer.
2019-02-09 21:08:19 +00:00
Conrad Meyer
e41793db2c ddb: Enable 'thread <address>'
Currently, the 'thread' command (to switch the debugger to another thread)
only accepts decimal-encoded tids.  Use the same parsing logic as 'show
thread <arg>' to accept hex-encoded thread pointers in addition to
decimal-encoded tids.

Document the 'thread' command in ddb.4 and expand the 'show thread'
documentation to cover the tid usage.

Reported by:	bwidawsk
Reviewed by:	bwidawsk (earlier version), kib (earlier version), markj
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D16962
2018-10-20 20:45:49 +00:00
Andriy Gapon
27cfcd9599 add an option for ddb ps command to print process arguments
We use ps to collect the information of all processes in textdump. But
it doesn't contain process arguments which however sometimes are very
useful for debugging.  The new 'a' modifier adds that capability.

While here, remove 'm' modifier from ddb.4.  It was in the manual page
from its very first revision, but I could not find any evidence of the
code ever supporting it.

Submitted by:	Terry Hu <thu@panzura.com>
Reviewed by:	kib
MFC after:	1 week
Sponsored by:	Panzura
Differential Revision: https://reviews.freebsd.org/D16603
2018-08-09 11:21:31 +00:00
Bjoern A. Zeeb
e76bd38065 Extend show proc with reaper, sigparent, and vmspace information
I have regularly needed the last couple of months.

Sponsored by:	iXsystems, Inc.
2018-05-25 13:59:48 +00:00
Justin Hibbits
b4a0a59871 Fix PPC symbol resolution
Summary:
There were 2 issues that were preventing correct symbol resolution
on PowerPC/pseries:

1- memory corruption at chrp_attach() - this caused the inital
   part of the symbol table to become zeroed, which would cause
   the kernel linker to fail to parse it.
   (this was probably zeroing out other memory parts as well)

2- DDB symbol resolution wasn't working because symtab contained
   not relocated addresses but it was given relocated offsets.
   Although relocating the symbol table fixed this, it broke the
   linker, that already handled this case.
   Thus, the fix for this consists in adding a new DDB macro:
   DB_STOFFS(offs) that converts a (potentially) relocated offset
   into one that can be compared with symbol table values.

PR:		227093
Submitted by:	Leandro Lupori <leandro.lupori_gmail.com>
Differential Revision: https://reviews.freebsd.org/D15372
2018-05-10 03:59:48 +00:00
Warner Losh
3531bbb5ea Restore db_radix on parse error, otherwise we'll silently change it to
10 on a botched trace command.
2018-04-17 15:44:05 +00:00
Warner Losh
9d89a9f326 No need to force md code to define a macro that's the same as
_BYTE_ORDER. Use that instead.
2018-04-16 13:52:23 +00:00
Andriy Gapon
3761bead4a db_script_exec: use a saved script name when reporting commands executed
Before executing a command in a ddb script ddb prints an information
line of the form:
  db:1:my-script> command
where 1 is the script's depth level, "my-script" is the scipt's name,
and "command" is the current command in the script.
db_script_exec() uses its 'scriptname' parameter to produce that string.
In the case when db_script_exec() is called from db_run_cmd() the
argument points to db_tok_string that is a global variable used for
command parsing.  So, its value changes with every command executed.

This commit changes the code to use the script's name stored in
ds_scriptname to print the line.

MFC after:	2 weeks
2018-03-04 13:27:21 +00:00
Jeff Roberson
3f289c3fcf Implement 'domainset', a cpuset based NUMA policy mechanism. This allows
userspace to control NUMA policy administratively and programmatically.

Implement domainset based iterators in the page layer.

Remove the now legacy numa_* syscalls.

Cleanup some header polution created by having seq.h in proc.h.

Reviewed by:	markj, kib
Discussed with:	alc
Tested by:	pho
Sponsored by:	Netflix, Dell/EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D13403
2018-01-12 22:48:23 +00:00
Mark Johnston
78f57a9cde Generalize the gzio API.
We currently use a set of subroutines in kern_gzio.c to perform
compression of user and kernel core dumps. In the interest of adding
support for other compression algorithms (zstd) in this role without
complicating the API consumers, add a simple compressor API which can be
used to select an algorithm.

Also change the (non-default) GZIO kernel option to not enable
compressed user cores by default. It's not clear that such a default
would be desirable with support for multiple algorithms implemented,
and it's inconsistent in that it isn't applied to kernel dumps.

Reviewed by:	cem
Differential Revision:	https://reviews.freebsd.org/D13632
2018-01-08 21:27:41 +00:00
Andriy Gapon
6e1c5d187c ddb: fix validation of cpu id in 'set db_cpu=x'
MFC after:	1 week
2017-12-05 14:22:08 +00:00
Pedro F. Giffuni
c967e4ffa6 SPDX: oops .. not from CMU. 2017-11-30 15:58:38 +00:00
Pedro F. Giffuni
796df753f4 SPDX: Consider code from Carnegie-Mellon University.
Interesting cases, most likely from CMU Mach sources.
2017-11-30 15:48:35 +00:00
Edward Tomasz Napierala
2276703108 Make the ddb(4) "set" command list variables when called without parameters.
Obtained from:	CheriBSD
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2017-11-30 12:22:15 +00:00
Edward Tomasz Napierala
212ff84f4a Make kdb_reenter() silent when explicitly called from db_error().
This removes the useless backtrace on various ddb(4) user errors.

Reviewed by:	jhb@
Obtained from:	CheriBSD
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D13212
2017-11-28 12:53:55 +00:00
Pedro F. Giffuni
753c4e83fc sys/ddb: further adoption of SPDX licensing ID tags.
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.
2017-11-27 15:14:46 +00:00
Pedro F. Giffuni
51369649b0 sys: further adoption of SPDX licensing ID tags.
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.
2017-11-20 19:43:44 +00:00
Gavin Atkinson
c6404e6690 Point people towards our https web site for documentation, http accesses are
just redirected anyway.

MFC after:	1 week
2017-11-09 13:38:24 +00:00
Mark Johnston
01938d3666 Rename mkdumpheader() and group EKCD functions in kern_shutdown.c.
This helps simplify the code in kern_shutdown.c and reduces the number
of globally visible functions.

No functional change intended.

Reviewed by:	cem, def
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D11603
2017-08-18 04:04:09 +00:00
Warner Losh
4e38d89520 Include opt files in the kernel with "" instead of <>. 2017-07-10 05:08:01 +00:00
Edward Tomasz Napierala
81e12dd187 Make ^c work in ddb(4).
Obtained from:	CheriBSD
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2017-07-06 15:27:34 +00:00
Edward Tomasz Napierala
eeb6101e04 Make ^w work in ddb(4).
Obtained from:	CheriBSD
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2017-07-06 15:21:57 +00:00
Edward Tomasz Napierala
9990da25ea Improve ddb(4) error reporting a bit.
Obtained from:	CheriBSD
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2017-07-06 12:30:39 +00:00
Edward Tomasz Napierala
b5bd6c7383 Make ddb(4) a bit more user-friendly by improving "help".
Obtained from:	CheriBSD
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2017-07-06 12:27:14 +00:00