Commit Graph

81 Commits

Author SHA1 Message Date
Konstantin Belousov
a3de221dbe Among signal generation syscalls, only sigqueue(2) is allowed by POSIX
to fail due to lack of resources to queue siginfo. Add KSI_SIGQ flag
that allows sigqueue_add() to fail while trying to allocate memory for
new siginfo. When the flag is not set, behaviour is the same as for
KSI_TRAP: if memory cannot be allocated, set bit in sq_kill. KSI_TRAP is
kept to preserve KBI.

Add SI_KERNEL si_code, to be used in siginfo.si_code when signal is
generated by kernel. Deliver siginfo when signal is generated by kill(2)
family of syscalls (SI_USER with properly filled si_uid and si_pid), or
by kernel (SI_KERNEL, mostly job control or SIGIO). Since KSI_SIGQ flag
is not set for the ksi, low memory condition cause old behaviour.

Keep psignal(9) KBI intact, but modify it to generate SI_KERNEL
si_code. Pgsignal(9) and gsignal(9) now take ksi explicitely. Add
pksignal(9) that behaves like psignal but takes ksi, and ddb kill
command implemented as pksignal(..., ksi = NULL) to not do allocation
while in debugger.

While there, remove some register specifiers and use ANSI C prototypes.

Reviewed by:	davidxu
MFC after:	1 month
2009-11-17 11:39:15 +00:00
John Baldwin
93d4804b62 Initialize the DDB command list when initializing DDB so that the basic
commands are available from 'boot -d'.

Suggested by:	dfr
2008-09-25 19:50:14 +00:00
Sam Leffler
39297ba455 Make ddb command registration dynamic so modules can extend
the command set (only so long as the module is present):
o add db_command_register and db_command_unregister to add and remove
  commands, respectively
o replace linker sets with SYSINIT's (and SYSUINIT's) that register
  commands
o expose 3 list heads: db_cmd_table, db_show_table, and db_show_all_table
  for registering top-level commands, show operands, and show all operands,
  respectively

While here also:
o sort command lists
o add DB_ALIAS, DB_SHOW_ALIAS, and DB_SHOW_ALL_ALIAS to add aliases
  for existing commands
o add "show all trace" as an alias for "show alltrace"
o add "show all locks" as an alias for "show alllocks"

Submitted by:	Guillaume Ballet <gballet@gmail.com> (original version)
Reviewed by:	jhb
MFC after:	1 month
2008-09-15 22:45:14 +00:00
Sam Leffler
9e340a6190 enable dynamic addition of "show all" commands
MFC after:	3 weeks
2008-03-25 20:36:32 +00:00
Robert Watson
3755dbd805 When killing a user process from DDB, check that the requested signal is
> 0 rather than >= 0, or we will panic when trying to deliver the signal.

MFC after:	3 days
PR:		100802
Submitted by:	Valerio Daelli <valerio.daelli at gmail.com>
2008-03-07 14:26:30 +00:00
Robert Watson
618c7db30a Add textdump(4) facility, which provides an alternative form of kernel
dump using mechanically generated/extracted debugging output rather than
a simple memory dump.  Current sources of debugging output are:

- DDB output capture buffer, if there is captured output to save
- Kernel message buffer
- Kernel configuration, if included in kernel
- Kernel version string
- Panic message

Textdumps are stored in swap/dump partitions as with regular dumps, but
are laid out as ustar files in order to allow multiple parts to be stored
as a stream of sequentially written blocks.  Blocks are written out in
reverse order, as the size of a textdump isn't known a priori.  As with
regular dumps, they will be extracted using savecore(8).

One new DDB(4) command is added, "textdump", which accepts "set",
"unset", and "status" arguments.  By default, normal kernel dumps are
generated unless "textdump set" is run in order to schedule a textdump.
It can be canceled using "textdump unset" to restore generation of a
normal kernel dump.

Several sysctls exist to configure aspects of textdumps;
debug.ddb.textdump.pending can be set to check whether a textdump is
pending, or set/unset in order to control whether the next kernel dump
will be a textdump from userspace.

While textdumps don't have to be generated as a result of a DDB script
run automatically as part of a kernel panic, this is a particular useful
way to use them, as instead of generating a complete memory dump, a
simple transcript of an automated DDB session can be captured using the
DDB output capture and textdump facilities.  This can be used to
generate quite brief kernel bug reports rich in debugging information
but not dependent on kernel symbol tables or precisely synchronized
source code.  Most textdumps I generate are less than 100k including
the full message buffer.  Using textdumps with an interactive debugging
session is also useful, with capture being enabled/disabled in order to
record some but not all of the DDB session.

MFC after:	3 months
2007-12-26 11:32:33 +00:00
Robert Watson
c9b0cc3b96 Add a simple scripting facility to DDB(4), allowing the user to
define a set of named scripts.  Each script consists of a list of DDB
commands separated by ";"s that will be executed verbatim.  No higher
level language constructs, such as branching, are provided for:
scripts are executed by sequentially injecting commands into the DDB
input buffer.

Four new commands are present in DDB: "run" to run a specific script,
"script" to define or print a script, "scripts" to list currently
defined scripts, and "unscript" to delete a script, modeled on shell
alias commands.  Scripts may also be manipulated using sysctls in the
debug.ddb.scripting MIB space, although users will prefer to use the
soon-to-be-added ddb(8) tool for usability reasons.

Scripts with certain names are automatically executed on various DDB
events, such as entering the debugger via a panic, a witness error,
watchdog, breakpoint, sysctl, serial break, etc, allowing customized
handling.

MFC after:	3 months
2007-12-26 09:33:19 +00:00
Robert Watson
086fec574e Add a new DDB(4) facility, output capture. Input and output from DDB may be
captured to a memory buffer for later inspection using sysctl(8), or in the
future, to a textdump.

A new DDB command, "capture", is added, which accepts arguments "on", "off",
"reset", and "status".

A new DDB sysctl tree, debug.ddb.capture, is added, which can be used to
resize the capture buffer and extract buffer contents.

MFC after:	3 months
2007-12-25 23:06:51 +00:00
Xin LI
f67af5c918 Use FOREACH_PROC_IN_SYSTEM instead of using its unrolled form. 2007-01-17 15:05:52 +00:00
Konstantin Belousov
9641e38966 On trap while inside ddb, the trap handler calls kdb_reenter(), that
longjmp to the default context. As result, "alltrace" command may
be prematurely terminated (without error message). This is happens,
for instance, when system is low on memory and referenced page in
kernel-mode thread stack is swapped out.

Protect "alltrace" against termination on trap by setting temporary
kdb_jmpbuf context.

Submitted by:	Peter Holm
2006-11-02 11:47:38 +00:00
Bruce Evans
e4b732cff1 The powerpc and sparc64 MD `reboot' commands should never have existed
since they just duplicated the MI `reset' command.  Instead of removing
them, make `reboot' an MI alias for `reboot' since this gives a better
way of killing the `r' alias for `reset'.  Remove the `registers' command
that was used to kill the alias.

Turn the powerpc and sparc64 MD `halt' command into an MI command.

A copy of sparc64/db_interface.c grew in sun4v just after I found the
extra reboot commands.  It has not been changed, and is now not
identical.  Duplicated commands come out duplicated in ddb's online
help, but cause large problems when used (e.g., on i386's with 2 halt's
and an hwatch, typing h doesn' give the expected message about an
ambiguous command, but hangs like the halt command or a looping parseri
would).
2006-10-10 07:26:54 +00:00
Bruce Evans
75149ab872 Added some aliases:
- `b' is now an official alias for `break'.  It used to be an unofficial
  alias, but this was broken by adding the `bt' alias for `trace'.
- `t' is now an official alias for `trace'.  It used to be an unofficial
  alias, but this was broken by adding the `thread' command.
- `registers' is now an alias for `show registers'.  This is a hack to
  break the unofficial `r' alias for `reset'.  `r' really means
  `registers' in some debuggers, so I sometimes type it accidentally and
  am annoyed when it resets the system.  A short command shouldn't have
  such a large effect.  Now at least `res' must be typed to disambiguate
  `reset'.
2006-10-08 18:37:00 +00:00
Bruce Evans
2481da7487 Fixed formatting of printing of command tables. WIth the default max
output width of 79, only 6 columns of width 12 each fit, but 7 columns
were printed.

The fix is to pass the width of the next output to db_end_line() and
not assume there that this width is always 1.

Related unfixed bugs:
- 1 character is wasted for a space after the last column
- suppression of trailing spaces used to limit the misformatting, but
  seems to have been lost
- in db_examine(), the width of the next output is not know and is
  still assumed to be 1.
2006-10-08 18:15:08 +00:00
John Baldwin
15cc91d345 Disable the pager for 'panic' and 'call' to be paranoid. 2006-07-19 18:26:53 +00:00
John Baldwin
19e9205a23 Simplify the pager support in DDB. Allowing different db commands to
install custom pager functions didn't actually happen in practice (they
all just used the simple pager and passed in a local quit pointer).  So,
just hardcode the simple pager as the only pager and make it set a global
db_pager_quit flag that db commands can check when the user hits 'q' (or a
suitable variant) at the pager prompt.  Also, now that it's easy to do so,
enable paging by default for all ddb commands.  Any command that wishes to
honor the quit flag can do so by checking db_pager_quit.  Note that the
pager can also be effectively disabled by setting $lines to 0.

Other fixes:
- 'show idt' on i386 and pc98 now actually checks the quit flag and
  terminates early.
- 'show intr' now actually checks the quit flag and terminates early.
2006-07-12 21:22:44 +00:00
John Baldwin
cf93bc6617 Use LIST_FOREACH(). 2006-04-21 20:39:51 +00:00
John Baldwin
e1e31c0e43 Clean up the way we handle auxiliary commands for a given ddb command
table.  Previously, the ddb code knew of each linker set of auxiliary
commands and which explicit command list they were tied to.  These changes
add a simple command_table struct that contains both the static list of
commands and the pointers for any auxiliary linker set of additional
commands.  This also makes it possible for other arbitrary command tables
to be defined in other parts of the kernel w/o having to edit ddb itself.

The DB_SET macro has also been trimmed down to just creating an entry in
a linker set.  A new DB_FUNC macro does what the old DB_SET did which is
to not only add an entry to the linker set but also to include a function
prototype for the function being added.  With these changes, it's now also
possible to create aliases for ddb functions using DB_SET() directly if
desired.
2006-03-07 22:17:06 +00:00
John Baldwin
3924da21a3 - Rename 'traceall' to 'alltrace' so that the 'tr' shortcut for 'trace'
still works.  Also, this is consistent with 'show pcpu' vs
  'show allpcpu'.  (And 'show allstacks' on OS X for that matter.)
- Add 'bt' as an alias for 'trace'.  We already have a 'where' alias as
  well, so this makes it easier for gdb-wired hands to work in ddb.

Ok'd by:	rwatson (1)
Requested by:	scottl (2)
MFC after:	1 day
2005-10-24 15:21:36 +00:00
Olivier Houchard
da927f93bd - Call db_setup_paging() for traceall.
- Make it so one can't call db_setup_paging() if it has already been called
before. traceall needs this, or else the db_setup_paging() call from
db_trace_thread() will reset the printed line number, and override its
argument.
This is not perfect for traceall, because even if one presses 'q' while in
the middle of printing a backtrace it will finish printing the backtrace
before exiting, as db_trace_thread() won't be notified it should stop, but
it is hard to do better without reworking the pager interface a lot more.
2005-10-02 22:57:31 +00:00
Robert Watson
a7ad956bdf Add a DDB "traceall" function, which stack traces all known process
threads.  This is quite useful if generating a debug log for post-mortem
by another developer, in which case the person at the console may not
know which threads are of interest.  The output of this can be quite
long.

Discussed with:	kris
MFC after:	3 days
2005-10-02 11:41:12 +00:00
David E. O'Brien
cec9a4bf57 Remove the need to forward declare statics by moving them around. 2005-08-10 07:08:14 +00:00
Marcel Moolenaar
a2aeb24eff Implement functions calls from within DDB on ia64. On ia64 a function
pointer doesn't point to the first instruction of that function, but
rather to a descriptor. The descriptor has the address of the first
instruction, as well as the value of the global pointer. The symbol
table doesn't know anything about descriptors, so if you lookup the
name of a function you get the address of the first instruction. The
cast from the address, which is the result of the symbol lookup, to a
function pointer as is done in db_fncall is therefore invalid.
Abstract this detail behind the DB_CALL macro. By default DB_CALL is
defined as db_fncall_generic, which yields the old behaviour. On ia64
the macro is defined as db_fncall_ia64, in which a descriptor is
constructed to yield a valid function pointer.

While here, introduce DB_MAXARGS. DB_MAXARGS replaces the existing
(local) MAXARGS. The DB_MAXARGS macro can be defined by platforms to
create a convenient maximum. By default this will be the legacy 10.
On ia64 we define this macro to be 8, for 8 is the maximum number of
arguments that can be passed in registers. This avoids having to
implement spilling of arguments on the memory stack.

Approved by: re (dwhite)
2005-07-02 23:52:37 +00:00
Warner Losh
dd3cb56845 Start each of the license/copyright comments with /*- 2005-01-06 01:34:41 +00:00
Robert Watson
a13aca1a8e When printing a stack trace for a thread, also print the pid and tid.
When a series of traces is included in a bug report, this will make it
easier to tie the trace information back to ps or threads output,
each of which will show the pid or the tid, but usually not both.
2004-11-23 23:11:47 +00:00
Marcel Moolenaar
026c3aaa60 Oops... Add the CS_OWN flag to the trace and where commands so that
db_stack_trace() actually has a chance to parse its own arguments.
2004-07-21 05:55:51 +00:00
Marcel Moolenaar
fd32d93b97 Unify db_stack_trace_cmd(). All it did was look up the thread given
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
2004-07-21 05:07:09 +00:00
Marcel Moolenaar
f3be7cb3e9 Re-add the gdb command. It was removed to be replaced by something
more generic, but that didn't actually happen. Since the feature to
switch backends (and historically this means from DDB to GDB) is
important, make sure people can do just that until such the generic
mechanism actually sees the light of day.

Suggested by: rwatson@
2004-07-12 01:38:07 +00:00
Marcel Moolenaar
37224cd3fc Mega update for the KDB framework: turn DDB into a KDB backend.
Most of the changes are a direct result of adding thread awareness.
Typically, DDB_REGS is gone. All registers are taken from the
trapframe and backtraces use the PCB based contexts. DDB_REGS was
defined to be a trapframe on all platforms anyway.
Thread awareness introduces the following new commands:
	thread X	switch to thread X (where X is the TID),
	show threads	list all threads.

The backtrace code has been made more flexible so that one can
create backtraces for any thread by giving the thread ID as an
argument to trace.

With this change, ia64 has support for breakpoints.
2004-07-10 23:47:20 +00:00
Poul-Henning Kamp
74cc032b41 Give DDB a "watchdog" command which disables all watchdogs. 2004-02-29 09:55:32 +00:00
Marcel Moolenaar
26502503e5 Further cleanup <machine/cpu.h> and <machine/md_var.h>: move the MI
prototypes of cpu_halt(), cpu_reset() and swi_vm() from md_var.h to
cpu.h. This affects db_command.c and kern_shutdown.c.

ia64: move all MD prototypes from cpu.h to md_var.h. This affects
madt.c, interrupt.c and mp_machdep.c. Remove is_physical_memory().
It's not used (vm_machdep.c).

alpha: the MD prototypes have been left in cpu.h with a comment
that they should be there. Moving them is left for later. It was
expected that the impact would be significant enough to be done in
a seperate commit.

powerpc: MD prototypes left in cpu.h. Comment added.

Suggested by: bde
Tested with: make universe (pc98 incomplete)
2003-08-16 16:57:57 +00:00
John Baldwin
1e16f6098b Add a one-shot callout facility to db_printf() that executes the registered
callout when a specified number of lines have been output.  This can be
used to implement pagers for ddb commands that output a lot of text.  A
simple paging function is included that automatically rearms itself when
fired.

Reviewed by:	bde, julian
2003-07-31 17:27:52 +00:00
David E. O'Brien
753960f7c4 Use __FBSDID(). 2003-06-10 22:09:23 +00:00
Poul-Henning Kamp
04361c8c3a Make "where" an alias for "trace" 2003-06-01 09:06:23 +00:00
Poul-Henning Kamp
029f0b69a4 Change "dev_t gdbdev" to "void *gdb_arg", some possible paths for GDB
will not have a dev_t.
2003-02-16 19:22:21 +00:00
Julian Elischer
93a7aa79d6 Add code to ddb to allow backtracing an arbitrary thread.
(show thread {address})

Remove the IDLE kse state and replace it with a change in
the way threads sahre KSEs. Every KSE now has a thread, which is
considered its "owner" however a KSE may also be lent to other
threads in the same group to allow completion of in-kernel work.
n this case the owner remains the same and the KSE will revert to the
owner when the other work has been completed.

All creations of upcalls etc. is now done from
kse_reassign() which in turn is called from mi_switch or
thread_exit(). This means that special code can be removed from
msleep() and cv_wait().

kse_release() does not leave a KSE with no thread any more but
converts the existing thread into teh KSE's owner, and sets it up
for doing an upcall. It is just inhibitted from being scheduled until
there is some reason to do an upcall.

Remove all trace of the kse_idle queue since it is no-longer needed.
"Idle" KSEs are now on the loanable queue.
2002-12-28 01:23:07 +00:00
Poul-Henning Kamp
c2476fafad Indentation indicates missing braces.
Spotted by:	FlexeLint
2002-10-01 21:59:46 +00:00
Mark Murray
bda9921d3f Constify to kill some warnings. 2002-09-21 17:29:36 +00:00
Bruce Evans
763df83622 Fixed some style bugs in the removal of __P(()). Continuation lines
were not outdented to preserve non-KNF lining up of code with parentheses.
Switch to KNF formatting.
2002-03-23 11:53:03 +00:00
Alfred Perlstein
14e10f9952 Remove __P. 2002-03-20 05:14:42 +00:00
Matt Jacob
e30e3e9e48 pid is 'long' on alpha. 2002-01-17 02:14:44 +00:00
Dima Dorfman
19d2c78f34 Implement a "kill" DDB command which is an interface to psignal() that
respects locks.  Before SMPng, one was able to call psignal()
using the "call" command, but this is no longer possible because it
does not respect locks by itself.  This is very useful when one has
gotten their machine into a state where it is impossible to spawn
ps/kill or su to root.

In this case, respecting locks essentially means trying to aquire the
proc lock before calling psignal().  We can't block in the debugger,
so if trylock fails, the operation fails.  This also means that we
can't use pfind(), since that will attempt to lock the process for us.

Reviewed by:	jhb
2001-11-27 19:56:28 +00:00
Andrew R. Reiter
99b95aa20b - Include machine/md_var.h to get rid of cpu_reset() warning. (-Wall)
Approved by: jhb
2001-11-05 21:50:55 +00:00
Peter Wemm
5370c3b634 Add a 'reset' command. This is useful for panics really early before
any symbols are loaded.  Especially for unattended machines.
2001-11-03 04:55:48 +00:00
Kris Kennaway
58d9a05948 Quiet a variable format-string warning.
MFC after:	1 week
2001-07-19 02:05:00 +00:00
Brian S. Dean
17bbfb5897 Add 'hwatch' and 'dhwatch' ddb commands analogous to 'watch' and
'dwatch'.  The new commands install hardware watchpoints if supported
by the architecture and if there are enough registers to cover the
desired memory area.

No objection by: audit@, hackers@

MFC after: 2 weeks
2001-07-11 03:15:25 +00:00
Julian Elischer
0b1ae8097d A set of changes to reduce the number of include files the kernel
takes from /usr/include. I cannot check them on alpha.. (will try beast)

Briefly looked at by: Warner Losh <imp@harmony.village.org>
2001-07-08 04:56:07 +00:00
Peter Wemm
f41325db5f With this commit, I hereby pronounce gensetdefs past its use-by date.
Replace the a.out emulation of 'struct linker_set' with something
a little more flexible.  <sys/linker_set.h> now provides macros for
accessing elements and completely hides the implementation.

The linker_set.h macros have been on the back burner in various
forms since 1998 and has ideas and code from Mike Smith (SET_FOREACH()),
John Polstra (ELF clue) and myself (cleaned up API and the conversion
of the rest of the kernel to use it).

The macros declare a strongly typed set.  They return elements with the
type that you declare the set with, rather than a generic void *.

For ELF, we use the magic ld symbols (__start_<setname> and
__stop_<setname>).  Thanks to Richard Henderson <rth@redhat.com> for the
trick about how to force ld to provide them for kld's.

For a.out, we use the old linker_set struct.

NOTE: the item lists are no longer null terminated.  This is why
the code impact is high in certain areas.

The runtime linker has a new method to find the linker set
boundaries depending on which backend format is in use.

linker sets are still module/kld unfriendly and should never be used
for anything that may be modular one day.

Reviewed by:	eivind
2001-06-13 10:58:39 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Poul-Henning Kamp
ce9edcf5b5 Merge the cons.c and cons.h to the best of my ability. alpha may or
may not compile, I can't test it.
1999-08-09 10:35:05 +00:00
Peter Wemm
1c6989fa7e Quiet warnings on Alpha. (db_expr_t is a long on alpha, int on x86) 1999-07-01 19:42:56 +00:00