Some architectures (including ARMv6/v7) do not have separate single step
events and cannot see difference between breakpoint and single step.
Add db_pc_is_singlestep() to avoid skipping instruction we stepped on
to trigger debug event.
This commit does not change the existing functionality but adds possibility
to implement custom db_pc_is_singlestep().
Reviewed by: imp
Submitted by: Zbigniew Bodek <zbb@semihalf.com>
Obtained from: Semihalf
Sponsored by: Juniper Networks Inc.
Differential Revision: https://reviews.freebsd.org/D4036
initial thread stack is not adjusted by the tunable, the stack is
allocated too early to get access to the kernel environment. See
TD0_KSTACK_PAGES for the thread0 stack sizing on i386.
The tunable was tested on x86 only. From the visual inspection, it
seems that it might work on arm and powerpc. The arm
USPACE_SVC_STACK_TOP and powerpc USPACE macros seems to be already
incorrect for the threads with non-default kstack size. I only
changed the macros to use variable instead of constant, since I cannot
test.
On arm64, mips and sparc64, some static data structures are sized by
KSTACK_PAGES, so the tunable is disabled.
Sponsored by: The FreeBSD Foundation
MFC after: 2 week
- Fix segment registers to only display the low 16 bits.
- Remove unused handlers and entries for the debug registers.
- Display xcr0 (if valid) in 'show sysregs'.
- Add '0x' prefix to MSR values to match other values in 'show sysregs'.
- MFamd64: Display various MSRs in 'show sysregs'.
- Add a 'show dbregs' to display the value of debug registers.
- Dynamically size the column width for register values to properly
align columns on 64-bit platforms.
- Display %gs for i386 in 'show registers'.
Differential Revision: https://reviews.freebsd.org/D2784
Reviewed by: kib, markj
MFC after: 2 weeks
Undefined symbols have a value of zero, so it makes no sense to return
such a symbol when performing a lookup by value. This occurs for example
when unwinding the stack after calling a NULL function pointer, and we
confusingly report the faulting function as uart_sab82532_class() on
amd64.
Convert db_print_loc_and_inst() to only attempt disassembly if we managed
to find a symbol corresponding to the IP. Otherwise we may fault and
re-enter the debugger.
Reviewed by: jhb
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D2858
If KSTACK_PAGES was changed to anything alse than the default,
the value from param.h was taken instead in some places and
the value from KENRCONF in some others. This resulted in
inconsistency which caused corruption in SMP envorinment.
Ensure all places where KSTACK_PAGES are used the opt_kstack_pages.h
is included.
The file opt_kstack_pages.h could not be included in param.h
because was breaking the toolchain compilation.
Reviewed by: kib
Obtained from: Semihalf
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3094
The replacement started at r283088 was necessarily incomplete without
replacing boolean_t with bool. This also involved cleaning some type
mismatches and ansifying old C function declarations.
Pointed out by: bde
Discussed with: bde, ian, jhb
When the FreeBSD kernel is loaded from Xen the symtab and strtab are
not loaded the same way as the native boot loader. This patch adds
three new global variables to ddb that can be used to specify the
exact position and size of those tables, so they can be directly used
as parameters to db_add_symbol_table. A new helper is introduced, so callers
that used to set ksym_start and ksym_end can use this helper to set the new
variables.
It also adds support for loading them from the Xen PVH port, that was
previously missing those tables.
Sponsored by: Citrix Systems R&D
Reviewed by: kib
ddb/db_main.c:
- Add three new global variables: ksymtab, kstrtab, ksymtab_size that
can be used to specify the position and size of the symtab and
strtab.
- Use those new variables in db_init in order to call db_add_symbol_table.
- Move the logic in db_init to db_fetch_symtab in order to set ksymtab,
kstrtab, ksymtab_size from ksym_start and ksym_end.
ddb/ddb.h:
- Add prototype for db_fetch_ksymtab.
- Declate the extern variables ksymtab, kstrtab and ksymtab_size.
x86/xen/pv.c:
- Add support for finding the symtab and strtab when booted as a Xen
PVH guest. Since Xen loads the symtab and strtab as NetBSD expects
to find them we have to adapt and use the same method.
amd64/amd64/machdep.c:
arm/arm/machdep.c:
i386/i386/machdep.c:
mips/mips/machdep.c:
pc98/pc98/machdep.c:
powerpc/aim/machdep.c:
powerpc/booke/machdep.c:
sparc64/sparc64/machdep.c:
- Use the newly introduced db_fetch_ksymtab in order to set ksymtab,
kstrtab and ksymtab_size.
Allow textdumps to be called explicitly from DDB.
If "dump" is called in DDB and textdumps are enabled then abort the
dump and tell the user to turn off textdumps.
Add options TEXTDUMP_PREFERRED to turn textdumps on by default.
Add options TEXTDUMP_VERBOSE to be a bit more verbose while textdumping.
Reviewed by: rwatson
MFC after: 2 weeks
It is implemented via db_trace_thread() for DDB and not implemented
for GDB. This should have been part of r234190.
Pointy hat to: jhb
Reported by: jkim
MFC after: 1 week
It seems strchr() and strrchr() are used more often than index() and
rindex(). Therefore, simply migrate all kernel code to use it.
For the XFS code, remove an empty line to make the code identical to
the code in the Linux kernel.
improvements:
(1) Implement new model in previously missed at91 UART driver
(2) Move BREAK_TO_DEBUGGER and ALT_BREAK_TO_DEBUGGER from opt_comconsole.h
to opt_kdb.h (spotted by np)
(3) Garbage collect now-unused opt_comconsole.h
MFC after: 3 weeks
Approved by: re (bz)
for it. Do not not expect a developer to call doadump(). Calling
doadump does not necessarily work when it's declared static. Nor
does it necessarily do what was intended in the context of text
dumps. The dump command always creates a core dump.
Move printing of error messages from doadump to the dump command,
now that we don't have to worry about being called from DDB.
the watchdog, via the watchdog(9) interface.
For that, the WD_LASTVAL bitwise operation is used. It is mutually
exclusive with any explicit timout passing to the watchdogs.
The last timeout can be returned via the wdog_kern_last_timeout()
KPI.
- Add the possibility to pat the watchdogs installed via the watchdog(9)
interface from the kernel.
In order to do that the new KPI wdog_kern_pat() is offered and it does
accept normalized nanoseconds or WD_LASTVAL.
- Avoid to pass WD_ACTIVE down in the watchdog handlers. All the control
bit processing should over to the upper layer functions and not passed
down to the handlers at all.
These changes are intended to be used in order to fix up the watchdog
tripping in situation when the userland is busted, but protection is still
wanted (examples: shutdown syncing / disk dumping).
Sponsored by: Sandvine Incorporated
Reviewed by: emaste, des, cognet
MFC after: 2 weeks
value.
The timeout is expressed in the form T(N) = (2^N * nanoseconds) and can
be easilly extracted from the watchdog interface as a WD_TO_* macro.
That new functionality is supposed to fix re-entering the kernel from DDB
re-enabling the watchdog again (previously disabled) and also offer the
possibility to break for deadlocked DDB commands.
Please note that retro-compatibility is retained.
Sponsored by: Sandvine Incorporated
Approved by: des
MFC after: 10 days
the debugger back-end has changed. This means that switching from ddb
to gdb no longer requires a "step" which can be dangerous on an
already-crashed kernel.
Also add a capability to get from the gdb back-end back to ddb, by
typing ^C in the console window.
While here, simplify kdb_sysctl_available() by using
sbuf_new_for_sysctl(), and use strlcpy() instead of strncpy() since the
strlcpy semantic is desired.
MFC after: 1 month
Implement an optional delay to the ddb reset/reboot command.
This allows textdumps to be run automatically with unattended reboots
after a resonable timeout, while still permitting an administrator to
break into debugger if attached to the console at the time of the
event for further debugging. Cap the maximum delay at 1 week to avoid
highly accidental results, and default to 15s in case of problems
parsing the timeout value.
Move hex2dec helper function from db_thread.c to db_command.c to make
it generally available and prefix it with a "db_" to avoid namespace
collisions.
Reviewed by: rwatson
MFC after: 4 weeks
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
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks. Minor cleanups are done in the process,
and comments updated to reflect these changes.
Reviewed by: bz
Approved by: re (vimage blanket)
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator. Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...). This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.
Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack. Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory. Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.
Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy. Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address. When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.
This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.
Bump __FreeBSD_version and update UPDATING.
Portions submitted by: bz
Reviewed by: bz, zec
Discussed with: gnn, jamie, jeff, jhb, julian, sam
Suggested by: peter
Approved by: re (kensmith)
The system hostname is now stored in prison0, and the global variable
"hostname" has been removed, as has the hostname_mtx mutex. Jails may
have their own host information, or they may inherit it from the
parent/system. The proper way to read the hostname is via
getcredhostname(), which will copy either the hostname associated with
the passed cred, or the system hostname if you pass NULL. The system
hostname can still be accessed directly (and without locking) at
prison0.pr_host, but that should be avoided where possible.
The "similar information" referred to is domainname, hostid, and
hostuuid, which have also become prison parameters and had their
associated global variables removed.
Approved by: bz (mentor)
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
In order to CATER this, DDB buffered output can be choosen at compile
time through the option DDB_BUFR_SIZE=nbytes where nbytes choose the size
of the buffer (suggested size is 128 bytes), which should be manually
specified in any interested config file.
Sponsored by: Nokia
virtualization work done by Marko Zec (zec@).
This is the first in a series of commits over the course
of the next few weeks.
Mark all uses of global variables to be virtualized
with a V_ prefix.
Use macros to map them back to their global names for
now, so this is a NOP change only.
We hope to have caught at least 85-90% of what is needed
so we do not invalidate a lot of outstanding patches again.
Obtained from: //depot/projects/vimage-commit2/...
Reviewed by: brooks, des, ed, mav, julian,
jamie, kris, rwatson, zec, ...
(various people I forgot, different versions)
md5 (with a bit of help)
Sponsored by: NLnet Foundation, The FreeBSD Foundation
X-MFC after: never
V_Commit_Message_Reviewed_By: more people than the patch
value at the requested address as a symbol. For example, "ex /S
aio_swake" prints the name of the function currently registered in
via aio_swake hook.
The change as committed differs slightly from the patch in the PR,
as I force the size of the retrieved value (and the automatic
address increment) to be sizeof(void *). This seems to provide
the most useful auto-increment behavior, and defaults using the
default size (4), which is not sizeof(void *) on 64-bit platforms.
MFC after: 3 days
PR: 57976
Submitted by: Dan Strick <strick at covad.net>
> 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>
hold the newline and nul terminator. Otherwise, there are cases where
garbage may end up in the command history due to a lack of a nul
terminator, or input may end up without room for a newline.
MFC after: 3 days
PR: 119079
Submitted by: Michael Plass <mfp49_freebsd@plass-family.net>
the input field from the current cursor location, rather than the end of
the input line, as the cursor may not be at the end of the line.
Otherwise, we may overshoot, overwriting a bit of the previous line and
failing to fully overwrite the current line.
MFC after: 3 days
PR: 119079
Submitted by: Michael Plass <mfp49_freebsd@plass-family.net>
overridden at compile-time using kernel options of the same names.
Rather than doing a compile-time CTASSERT of buffer sizes being
even multiples of block sizes, just adjust them at boottime, as
the failure mode is more user-friendly.
MFC after: 2 months
PR: 119993
Suggested by: Scot Hetzel <swhetzel at gmail dot com>
exposed as kernel compile options, they have more meaningful names.
PR: 119993
MFC after: 2 months
Suggested by: Scot Hetzel <swhetzel at gmail dot com>
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
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
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
- p_sflag was mostly protected by PROC_LOCK rather than the PROC_SLOCK or
previously the sched_lock. These bugs have existed for some time.
- Allow swapout to try each thread in a process individually and then
swapin the whole process if any of these fail. This allows us to move
most scheduler related swap flags into td_flags.
- Keep ki_sflag for backwards compat but change all in source tools to
use the new and more correct location of P_INMEM.
Reported by: pho
Reviewed by: attilio, kib
Approved by: re (kensmith)
Make part of John Birrell's KSE patch permanent..
Specifically, remove:
Any reference of the ksegrp structure. This feature was
never fully utilised and made things overly complicated.
All code in the scheduler that tried to make threaded programs
fair to unthreaded programs. Libpthread processes will already
do this to some extent and libthr processes already disable it.
Also:
Since this makes such a big change to the scheduler(s), take the opportunity
to rename some structures and elements that had to be moved anyhow.
This makes the code a lot more readable.
The ULE scheduler compiles again but I have no idea if it works.
The 4bsd scheduler still reqires a little cleaning and some functions that now do
ALMOST nothing will go away, but I thought I'd do that as a separate commit.
Tested by David Xu, and Dan Eischen using libthr and libpthread.
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
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).
suppression is only needed at ends of lines, but rev.1.32 forced it
off precisely there.
The --More-- prompt is now cleared by explicitly forcing out the
whitespace in "\r \r". It might be better to use the line
editor's clearing functions, but these are currently static and not
much different.
- `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'.
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.
- Right justify 'pid' label.
- Move the uid column to the right 2 columns so that the 3 process id
columns (pid, ppid, pgrp) are grouped together.
- Expand the uid column to 5 chars.
- Don't indent the tid for multithreaded processes.
Requested by: bde (1, 2, 4)
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.
in parallel in several threads, one symbol lookup could
clear db_last_symtab when another one going to use it as
starting point for traversal.
Approved by: pjd (mentor)
MFC after: 1 month
now back to using fixed-size columns for output and each line of output
should fit in 80 columns on both 32-bit and 64-bit architectures. In
general the output is close to that of the userland ps(1) with the
exception that the 'wmesg' field is mostly similar to the "state" field
in top(1) in that it will show either a wmesg, a lock name (prefixed with
an *), "CPU xx" (for a running thread), or nothing if none of those three
conditions are true. It also respects td_name when listing threads in
a multithreaded process. There is a somewhat evilly-defined PTR64 macro
I use to make account for the change in the size of the 'wchan' column
in the formatted output (wchan is now the only pointer in the ps output
and is available so it can be passed to 'show sleepq', 'show turnstile',
or 'show lock').
- Add two new commands "show proc [process]" and "show thread [thread]"
that show details about the specified process or thread (specified
either by pid/tid or pointer), respectively. If an address it not
specified, it uses the current kdb thread.
take the addr value passed to a ddb command and attempt to use it to
lookup a struct thread * or struct proc *, respectively. Each function
first reparses the passed in value as if it was an ID entered in base 10.
For threads the ID is treated as a thread ID, for proceses the ID is
treated as a PID. If a thread or proc matching the ID is found, it is
returned. For db_lookup_thread(), if the check_pid argument is true and
it didn't find a thread with a matching thread ID, it will treat the ID as
a PID and look for a matching process. If it finds one it returns the
first thread in the process. If none of the ID lookups succeeded, then
the functions assume that the passed in address is a thread or proc
pointer, respectively. This allows one to use tids, pids, or structure
pointers interchangeably in ddb functions that want to lookup threads or
processes if desired.
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.
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
- 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.
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
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)
was satisified for the rest of the kernel on the i386 build except for
these two files. Rather than adding a submarine include to pcb.h, I've
added proc.h here.
I forgot to include these with the original commit. Sorry folks.
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.
control the number of lines per page rather than a constant. The variable
can be examined and changed in ddb as '$lines'. Setting the variable to
0 will effectively turn off paging.
- Change db_putchar() to force out pending whitespace before outputting
newlines and carriage returns so that one can rub out content on the
current line via '\r \r' type strings.
- Change the simple pager to rub out the --More-- prompt explicitly when
the routine exits.
- Add some aliases to the simple pager to make it more compatible with
more(1): 'e' and 'j' do a single line. 'd' does half a page, and
'f' does a full page.
MFC after: 1 month
Inspired by: kris
but with slightly cleaned up interfaces.
The KSE structure has become the same as the "per thread scheduler
private data" structure. In order to not make the diffs too great
one is #defined as the other at this time.
The KSE (or td_sched) structure is now allocated per thread and has no
allocation code of its own.
Concurrency for a KSEGRP is now kept track of via a simple pair of counters
rather than using KSE structures as tokens.
Since the KSE structure is different in each scheduler, kern_switch.c
is now included at the end of each scheduler. Nothing outside the
scheduler knows the contents of the KSE (aka td_sched) structure.
The fields in the ksegrp structure that are to do with the scheduler's
queueing mechanisms are now moved to the kg_sched structure.
(per ksegrp scheduler private data structure). In other words how the
scheduler queues and keeps track of threads is no-one's business except
the scheduler's. This should allow people to write experimental
schedulers with completely different internal structuring.
A scheduler call sched_set_concurrency(kg, N) has been added that
notifies teh scheduler that no more than N threads from that ksegrp
should be allowed to be on concurrently scheduled. This is also
used to enforce 'fainess' at this time so that a ksegrp with
10000 threads can not swamp a the run queue and force out a process
with 1 thread, since the current code will not set the concurrency above
NCPU, and both schedulers will not allow more than that many
onto the system run queue at a time. Each scheduler should eventualy develop
their own methods to do this now that they are effectively separated.
Rejig libthr's kernel interface to follow the same code paths as
linkse for scope system threads. This has slightly hurt libthr's performance
but I will work to recover as much of it as I can.
Thread exit code has been cleaned up greatly.
exit and exec code now transitions a process back to
'standard non-threaded mode' before taking the next step.
Reviewed by: scottl, peter
MFC after: 1 week
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
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@
db_elf.c, db_kld.c: The new KDB backend supports both at the same time.
db_sysctl.c: The functionality has been moved to sys/kern/subr_kdb.c.
db_trap.c: The DDB entry point has been moved to sys/ddb/db_main.c.
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.
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
also prints the actual numerical value of the symbol in question.
Users of addr2line(1) will be less proficient in hex arithmetic as a
consequence.
This amongst other things means that traceback lines change from:
siointr1(c4016800,c073bda0,0,c06b699c,69f) at siointr1+0xc5
to
siointr1(c4016800,c073bda0,0,c06b699c,69f) at 0xc062b0bd = siointr1+0xc5
I made this an option to avoid bikesheds.
~
~
~
debug.ddb_use_printf sysctl, output kernel debugger data to both the
console and kernel message buffer via printf. This fixes the case where
backtrace() went directly to the console and should help debugging greatly.
Thanks to Ian Dowse for the work, minor edits or any bugs are by myself.
Submitted by: iedowse
some symbols in X_db_search_symbol(). Reject the same symbols that
rev.1.13 did (all except STT_OBJECT and STT_FUNC), except don't reject
typeless symbols. This keeps the typeless symbols in non-verbosely
written assembler code visible, but makes file symbols invisible. ELF
file symbols have type STT_FILE and value 0, so this stops small values
and offsets sometimes being displayed in terms of the first file symbol
in the kernel (usually device_if.c). I think it rejects some other
unwanted symbols (small absolute symbols for things like struct offsets).
It may reject some wanted symbols (large absolute symbols for addresses
like PTmap).
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)
integer value and then to construct the integer from it. This buffer
was sizeof(int) bytes long, which was fine until the (undocumented) 'g'
modifier for 8-byte integers was introduced. Change this to sizeof(uint64_t).
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
fit on one line. Account for threads better.
* No need to report that it is on a sleep queue if it is actually sleeping
* "Normal" state is almost ubiquitous.. only report abnormal states.
* increment the #lines count for each separate thread shown in threaded
programs.
makes it less likely that a threaded program will make all the data
on a screen overflow off the top of the screen.
I'm not convinced there is anything major wrong with the patch but
them's the rules..
I am using my "David's mentor" hat to revert this as he's
offline for a while.
data structure called kse_upcall to manage UPCALL. All KSE binding
and loaning code are gone.
A thread owns an upcall can collect all completed syscall contexts in
its ksegrp, turn itself into UPCALL mode, and takes those contexts back
to userland. Any thread without upcall structure has to export their
contexts and exit at user boundary.
Any thread running in user mode owns an upcall structure, when it enters
kernel, if the kse mailbox's current thread pointer is not NULL, then
when the thread is blocked in kernel, a new UPCALL thread is created and
the upcall structure is transfered to the new UPCALL thread. if the kse
mailbox's current thread pointer is NULL, then when a thread is blocked
in kernel, no UPCALL thread will be created.
Each upcall always has an owner thread. Userland can remove an upcall by
calling kse_exit, when all upcalls in ksegrp are removed, the group is
atomatically shutdown. An upcall owner thread also exits when process is
in exiting state. when an owner thread exits, the upcall it owns is also
removed.
KSE is a pure scheduler entity. it represents a virtual cpu. when a thread
is running, it always has a KSE associated with it. scheduler is free to
assign a KSE to thread according thread priority, if thread priority is changed,
KSE can be moved from one thread to another.
When a ksegrp is created, there is always N KSEs created in the group. the
N is the number of physical cpu in the current system. This makes it is
possible that even an userland UTS is single CPU safe, threads in kernel still
can execute on different cpu in parallel. Userland calls kse_create to add more
upcall structures into ksegrp to increase concurrent in userland itself, kernel
is not restricted by number of upcalls userland provides.
The code hasn't been tested under SMP by author due to lack of hardware.
Reviewed by: julian