22 Feb, 2016
1 commit
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It may be useful to debug writes to the readonly sections of memory,
so provide a cmdline "rodata=off" to allow for this. This can be
expanded in the future to support "log" and "write" modes, but that
will need to be architecture-specific.This also makes KDB software breakpoints more usable, as read-only
mappings can now be disabled on any kernel.Suggested-by: H. Peter Anvin
Signed-off-by: Kees Cook
Cc: Andy Lutomirski
Cc: Arnd Bergmann
Cc: Borislav Petkov
Cc: Brian Gerst
Cc: David Brown
Cc: Denys Vlasenko
Cc: Emese Revfy
Cc: Linus Torvalds
Cc: Mathias Krause
Cc: Michael Ellerman
Cc: PaX Team
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: kernel-hardening@lists.openwall.com
Cc: linux-arch
Link: http://lkml.kernel.org/r/1455748879-21872-3-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar
05 Dec, 2015
1 commit
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Makes it easier to handle init vs core cleanly, though the change is
fairly invasive across random architectures.It simplifies the rbtree code immediately, however, while keeping the
core data together in the same cachline (now iff the rbtree code is
enabled).Acked-by: Peter Zijlstra
Reviewed-by: Josh Poimboeuf
Signed-off-by: Rusty Russell
Signed-off-by: Jiri Kosina
20 Feb, 2015
8 commits
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On non-developer devices, kgdb prevents the device from rebooting
after a panic.Incase of panics and exceptions, to allow the device to reboot, prevent
entering debug mode to avoid getting stuck waiting for the user to
interact with debugger.To avoid entering the debugger on panic/exception without any extra
configuration, panic_timeout is being used which can be set via
/proc/sys/kernel/panic at run time and CONFIG_PANIC_TIMEOUT sets the
default value.Setting panic_timeout indicates that the user requested machine to
perform unattended reboot after panic. We dont want to get stuck waiting
for the user input incase of panic.Cc: Andrew Morton
Cc: kgdb-bugreport@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org
Cc: Android Kernel Team
Cc: John Stultz
Cc: Sumit Semwal
Signed-off-by: Colin Cross
[Kiran: Added context to commit message.
panic_timeout is used instead of break_on_panic and
break_on_exception to honor CONFIG_PANIC_TIMEOUT
Modified the commit as per community feedback]
Signed-off-by: Kiran Raparthy
Signed-off-by: Daniel Thompson
Signed-off-by: Jason Wessel -
All current callers of kdb_getstr() can pass constant pointers via the
prompt argument. This patch adds a const qualification to make explicit
the fact that this is safe.Signed-off-by: Daniel Thompson
Signed-off-by: Jason Wessel -
Currently kdb allows the output of comamnds to be filtered using the
| grep feature. This is useful but does not permit the output emitted
shortly after a string match to be examined without wading through the
entire unfiltered output of the command. Such a feature is particularly
useful to navigate function traces because these traces often have a
useful trigger string *before* the point of interest.This patch reuses the existing filtering logic to introduce a simple
forward search to kdb that can be triggered from the more prompt.Signed-off-by: Daniel Thompson
Signed-off-by: Jason Wessel -
Currently when the "| grep" feature is used to filter the output of a
command then the prompt is not displayed for the subsequent command.
Likewise any characters typed by the user are also not echoed to the
display. This rather disconcerting problem eventually corrects itself
when the user presses Enter and the kdb_grepping_flag is cleared as
kdb_parse() tries to make sense of whatever they typed.This patch resolves the problem by moving the clearing of this flag
from the middle of command processing to the beginning.Signed-off-by: Daniel Thompson
Signed-off-by: Jason Wessel -
Issuing a stack dump feels ergonomically wrong when entering due to NMI.
Entering due to NMI is normally a reaction to a user request, either the
NMI button on a server or a "magic knock" on a UART. Therefore the
backtrace behaviour on entry due to NMI should be like SysRq-g (no stack
dump) rather than like oops.Note also that the stack dump does not offer any information that
cannot be trivial retrieved using the 'bt' command.Signed-off-by: Daniel Thompson
Signed-off-by: Jason Wessel -
Currently when kdb traps printk messages then the raw log level prefix
(consisting of '\001' followed by a numeral) does not get stripped off
before the message is issued to the various I/O handlers supported by
kdb. This causes annoying visual noise as well as causing problems
grepping for ^. It is also a change of behaviour compared to normal usage
of printk() usage. For example -h ends up with different output to
that of kdb's "sr h".This patch addresses the problem by stripping log levels from messages
before they are issued to the I/O handlers. printk() which can also
act as an i/o handler in some cases is special cased; if the caller
provided a log level then the prefix will be preserved when sent to
printk().The addition of non-printable characters to the output of kdb commands is a
regression, albeit and extremely elderly one, introduced by commit
04d2c8c83d0e ("printk: convert the format for KERN_ to a 2 byte
pattern"). Note also that this patch does *not* restore the original
behaviour from v3.5. Instead it makes printk() from within a kdb command
display the message without any prefix (i.e. like printk() normally does).Signed-off-by: Daniel Thompson
Cc: Joe Perches
Cc: stable@vger.kernel.org
Signed-off-by: Jason Wessel -
There was a follow on replacement patch against the prior
"kgdb: Timeout if secondary CPUs ignore the roundup".See: https://lkml.org/lkml/2015/1/7/442
This patch is the delta vs the patch that was committed upstream:
* Fix an off-by-one error in kdb_cpu().
* Replace NR_CPUS with CONFIG_NR_CPUS to tell checkpatch that we
really want a static limit.
* Removed the "KGDB: " prefix from the pr_crit() in debug_core.c
(kgdb-next contains a patch which introduced pr_fmt() to this file
to the tag will now be applied automatically).Cc: Daniel Thompson
Cc:
Signed-off-by: Jason Wessel -
The output of KDB 'summary' command should report MemTotal, MemFree
and Buffers output in kB. Current codes report in unit of pages.A define of K(x) as
is defined in the code, but not used.This patch would apply the define to convert the values to kB.
Please include me on Cc on replies. I do not subscribe to linux-kernel.Signed-off-by: Jay Lan
Cc:
Signed-off-by: Jason Wessel
23 Jan, 2015
1 commit
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Pull module and param fixes from Rusty Russell:
"Surprising number of fixes this merge window :(The first two are minor fallout from the param rework which went in
this merge window.The next three are a series which fixes a longstanding (but never
previously reported and unlikely , so no CC stable) race between
kallsyms and freeing the init section.Finally, a minor cleanup as our module refcount will now be -1 during
unload"* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
module: make module_refcount() a signed integer.
module: fix race in kallsyms resolution during module load success.
module: remove mod arg from module_free, rename module_memfree().
module_arch_freeing_init(): new hook for archs before module->module_init freed.
param: fix uninitialized read with CONFIG_DEBUG_LOCK_ALLOC
param: initialize store function to NULL if not available.
22 Jan, 2015
1 commit
-
James Bottomley points out that it will be -1 during unload. It's
only used for diagnostics, so let's not hide that as it could be a
clue as to what's gone wrong.Cc: Jason Wessel
Acked-and-documention-added-by: James Bottomley
Reviewed-by: Masami Hiramatsu
Signed-off-by: Rusty Russell
11 Nov, 2014
10 commits
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-Convert printk( to pr_foo()
-Add pr_fmt
-Coalesce formatsCc: Jason Wessel
Cc: Andrew Morton
Cc: Joe Perches
Signed-off-by: Fabian Frederick
Signed-off-by: Jason Wessel -
Currently if an active CPU fails to respond to a roundup request the CPU
that requested the roundup will become stuck. This needlessly reduces the
robustness of the debugger.This patch introduces a timeout allowing the system state to be examined
even when the system contains unresponsive processors. It also modifies
kdb's cpu command to make it censor attempts to switch to unresponsive
processors and to report their state as (D)ead.Signed-off-by: Daniel Thompson
Cc: Jason Wessel
Signed-off-by: Andrew Morton
Signed-off-by: Jason Wessel -
Currently kiosk mode must be explicitly requested by the bootloader or
userspace. It is convenient to be able to change the default value in a
similar manner to CONFIG_MAGIC_SYSRQ_DEFAULT_MASK.Signed-off-by: Daniel Thompson
Cc: Jason Wessel
Signed-off-by: Jason Wessel -
Currently all kdb commands are enabled whenever kdb is deployed. This
makes it difficult to deploy kdb to help debug certain types of
systems.Android phones provide one example; the FIQ debugger found on some
Android devices has a deliberately weak set of commands to allow the
debugger to enabled very late in the production cycle.Certain kiosk environments offer another interesting case where an
engineer might wish to probe the system state using passive inspection
commands without providing sufficient power for a passer by to root it.Without any restrictions, obtaining the root rights via KDB is a matter of
a few commands, and works everywhere. For example, log in as a normal
user:cbou:~$ id
uid=1001(cbou) gid=1001(cbou) groups=1001(cbou)Now enter KDB (for example via sysrq):
Entering kdb (current=0xffff8800065bc740, pid 920) due to Keyboard Entry
kdb> ps
23 sleeping system daemon (state M) processes suppressed,
use 'ps A' to see all.
Task Addr Pid Parent [*] cpu State Thread Command
0xffff8800065bc740 920 919 1 0 R 0xffff8800065bca20 *bash0xffff880007078000 1 0 0 0 S 0xffff8800070782e0 init
[...snip...]
0xffff8800065be3c0 918 1 0 0 S 0xffff8800065be6a0 getty
0xffff8800065b9c80 919 1 0 0 S 0xffff8800065b9f60 login
0xffff8800065bc740 920 919 1 0 R 0xffff8800065bca20 *bashAll we need is the offset of cred pointers. We can look up the offset in
the distro's kernel source, but it is unnecessary. We can just start
dumping init's task_struct, until we see the process name:kdb> md 0xffff880007078000
0xffff880007078000 0000000000000001 ffff88000703c000 ................
0xffff880007078010 0040210000000002 0000000000000000 .....!@.........
[...snip...]
0xffff8800070782b0 ffff8800073e0580 ffff8800073e0580 ..>.......>.....
0xffff8800070782c0 0000000074696e69 0000000000000000 init............^ Here, 'init'. Creds are just above it, so the offset is 0x02b0.
Now we set up init's creds for our non-privileged shell:
kdb> mm 0xffff8800065bc740+0x02b0 0xffff8800073e0580
0xffff8800065bc9f0 = 0xffff8800073e0580
kdb> mm 0xffff8800065bc740+0x02b8 0xffff8800073e0580
0xffff8800065bc9f8 = 0xffff8800073e0580And thus gaining the root:
kdb> go
cbou:~$ id
uid=0(root) gid=0(root) groups=0(root)
cbou:~$ bash
root:~#p.s. No distro enables kdb by default (although, with a nice KDB-over-KMS
feature availability, I would expect at least some would enable it), so
it's not actually some kind of a major issue.Signed-off-by: Anton Vorontsov
Signed-off-by: John Stultz
Signed-off-by: Daniel Thompson
Cc: Jason Wessel
Signed-off-by: Jason Wessel -
This patch introduces several new flags to collect kdb commands into
groups (later allowing them to be optionally disabled).This follows similar prior art to enable/disable magic sysrq
commands.The commands have been categorized as follows:
Always on: go (w/o args), env, set, help, ?, cpu (w/o args), sr,
dmesg, disable_nmi, defcmd, summary, grephelp
Mem read: md, mdr, mdp, mds, ef, bt (with args), per_cpu
Mem write: mm
Reg read: rd
Reg write: go (with args), rm
Inspect: bt (w/o args), btp, bta, btc, btt, ps, pid, lsmod
Flow ctrl: bp, bl, bph, bc, be, bd, ss
Signal: kill
Reboot: reboot
All: cpu, kgdb, (and all of the above), nmi_consoleSigned-off-by: Daniel Thompson
Cc: Jason Wessel
Signed-off-by: Jason Wessel -
Since we now treat KDB_REPEAT_* as flags, there is no need to
pass KDB_REPEAT_NONE. It's just the default behaviour when no
flags are specified.Signed-off-by: Anton Vorontsov
Signed-off-by: John Stultz
Signed-off-by: Daniel Thompson
Cc: Jason Wessel
Signed-off-by: Jason Wessel -
The actual values of KDB_REPEAT_* enum values and overall logic stayed
the same, but we now treat the values as flags.This makes it possible to add other flags and combine them, plus makes
the code a lot simpler and shorter. But functionality-wise, there should
be no changes.Signed-off-by: Anton Vorontsov
Signed-off-by: John Stultz
Signed-off-by: Daniel Thompson
Cc: Jason Wessel
Signed-off-by: Jason Wessel -
We're about to add more options for commands behaviour, so let's give
a more generic name to the low-level kdb command registration function.There are just various renames, no functional changes.
Signed-off-by: Anton Vorontsov
Signed-off-by: John Stultz
Signed-off-by: Daniel Thompson
Cc: Jason Wessel
Signed-off-by: Jason Wessel -
We're about to add more options for command behaviour, so let's expand
the meaning of kdb_repeat_t.So far we just do various renames, there should be no functional changes.
Signed-off-by: Anton Vorontsov
Signed-off-by: John Stultz
Signed-off-by: Daniel Thompson
Cc: Jason Wessel
Signed-off-by: Jason Wessel -
The struct member is never used in the code, so we can remove it.
We will introduce real flags soon by renaming cmd_repeat to cmd_flags.
Signed-off-by: Anton Vorontsov
Signed-off-by: John Stultz
Signed-off-by: Daniel Thompson
Cc: Jason Wessel
Signed-off-by: Jason Wessel
14 Oct, 2014
1 commit
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The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.Signed-off-by: Rasmus Villemoes
Cc: Jason Wessel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Jun, 2014
1 commit
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do_posix_clock_monotonic_gettime() is a leftover from the initial
posix timer implementation which maps to ktime_get_ts().Signed-off-by: Thomas Gleixner
Cc: John Stultz
Cc: Peter Zijlstra
Cc: Jason Wessel
Link: http://lkml.kernel.org/r/20140611234607.261629142@linutronix.de
Signed-off-by: Thomas Gleixner
05 Jun, 2014
1 commit
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... instead of naked numbers.
Stuff in sysrq.c used to set it to 8 which is supposed to mean above
default level so set it to DEBUG instead as we're terminating/killing all
tasks and we want to be verbose there.Also, correct the check in x86_64_start_kernel which should be >= as
we're clearly issuing the string there for all debug levels, not only
the magical 10.Signed-off-by: Borislav Petkov
Acked-by: Kees Cook
Acked-by: Randy Dunlap
Cc: Joe Perches
Cc: Valdis Kletnieks
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
18 Apr, 2014
1 commit
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Mostly scripted conversion of the smp_mb__* barriers.
Signed-off-by: Peter Zijlstra
Acked-by: Paul E. McKenney
Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org
Cc: Linus Torvalds
Cc: linux-arch@vger.kernel.org
Signed-off-by: Ingo Molnar
08 Apr, 2014
1 commit
-
This patch is a continuation of efforts trying to optimize find_vma(),
avoiding potentially expensive rbtree walks to locate a vma upon faults.
The original approach (https://lkml.org/lkml/2013/11/1/410), where the
largest vma was also cached, ended up being too specific and random,
thus further comparison with other approaches were needed. There are
two things to consider when dealing with this, the cache hit rate and
the latency of find_vma(). Improving the hit-rate does not necessarily
translate in finding the vma any faster, as the overhead of any fancy
caching schemes can be too high to consider.We currently cache the last used vma for the whole address space, which
provides a nice optimization, reducing the total cycles in find_vma() by
up to 250%, for workloads with good locality. On the other hand, this
simple scheme is pretty much useless for workloads with poor locality.
Analyzing ebizzy runs shows that, no matter how many threads are
running, the mmap_cache hit rate is less than 2%, and in many situations
below 1%.The proposed approach is to replace this scheme with a small per-thread
cache, maximizing hit rates at a very low maintenance cost.
Invalidations are performed by simply bumping up a 32-bit sequence
number. The only expensive operation is in the rare case of a seq
number overflow, where all caches that share the same address space are
flushed. Upon a miss, the proposed replacement policy is based on the
page number that contains the virtual address in question. Concretely,
the following results are seen on an 80 core, 8 socket x86-64 box:1) System bootup: Most programs are single threaded, so the per-thread
scheme does improve ~50% hit rate by just adding a few more slots to
the cache.+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline | 50.61% | 19.90 |
| patched | 73.45% | 13.58 |
+----------------+----------+------------------+2) Kernel build: This one is already pretty good with the current
approach as we're dealing with good locality.+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline | 75.28% | 11.03 |
| patched | 88.09% | 9.31 |
+----------------+----------+------------------+3) Oracle 11g Data Mining (4k pages): Similar to the kernel build workload.
+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline | 70.66% | 17.14 |
| patched | 91.15% | 12.57 |
+----------------+----------+------------------+4) Ebizzy: There's a fair amount of variation from run to run, but this
approach always shows nearly perfect hit rates, while baseline is just
about non-existent. The amounts of cycles can fluctuate between
anywhere from ~60 to ~116 for the baseline scheme, but this approach
reduces it considerably. For instance, with 80 threads:+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline | 1.06% | 91.54 |
| patched | 99.97% | 14.18 |
+----------------+----------+------------------+[akpm@linux-foundation.org: fix nommu build, per Davidlohr]
[akpm@linux-foundation.org: document vmacache_valid() logic]
[akpm@linux-foundation.org: attempt to untangle header files]
[akpm@linux-foundation.org: add vmacache_find() BUG_ON]
[hughd@google.com: add vmacache_valid_mm() (from Oleg)]
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: adjust and enhance comments]
Signed-off-by: Davidlohr Bueso
Reviewed-by: Rik van Riel
Acked-by: Linus Torvalds
Reviewed-by: Michel Lespinasse
Cc: Oleg Nesterov
Tested-by: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
26 Feb, 2014
1 commit
-
The function kgdb_breakpoint() sets up break point at
compile time by calling arch_kgdb_breakpoint();
Though this call is surrounded by wmb() barrier,
the compile can still re-order the break point,
because this scheduling barrier is not a code motion
barrier in gcc.Making kgdb_breakpoint() as noinline solves this problem
of code reording around break point instruction and also
avoids problem of being called as inline function from
other placesMore details about discussion on this can be found here
http://comments.gmane.org/gmane.linux.ports.arm.kernel/269732Signed-off-by: Vijaya Kumar K
Acked-by: Will Deacon
Acked-by: Jason Wessel
Signed-off-by: Catalin Marinas
25 Jan, 2014
1 commit
-
Some code added to the debug_core module had KDB dependencies
that it shouldn't have. Move the KDB dependent REASON back to
the caller to remove the dependency in the debug core code.Update the call from the UV NMI handler to conform to the new
interface.Signed-off-by: Mike Travis
Reviewed-by: Hedi Berriche
Cc: Russ Anderson
Cc: Jason Wessel
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
Link: http://lkml.kernel.org/r/20140114162551.318251993@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar
04 Oct, 2013
1 commit
-
This patch adds a kgdb_nmicallin() interface that can be used by
external NMI handlers to call the KGDB/KDB handler. The primary
need for this is for those types of NMI interrupts where all the
CPUs have already received the NMI signal. Therefore no
send_IPI(NMI) is required, and in fact it will cause a 2nd
unhandled NMI to occur. This generates the "Dazed and Confuzed"
messages.Since all the CPUs are getting the NMI at roughly the same time,
it's not guaranteed that the first CPU that hits the NMI handler
will manage to enter KGDB and set the dbg_master_lock before the
slaves start entering. The new argument "send_ready" was added
for KGDB to signal the NMI handler to release the slave CPUs for
entry into KGDB.Signed-off-by: Mike Travis
Acked-by: Jason Wessel
Reviewed-by: Dimitri Sivanich
Reviewed-by: Hedi Berriche
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
Link: http://lkml.kernel.org/r/20131002151417.928886849@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar
01 May, 2013
1 commit
-
Currently help message of /proc/sysrq-trigger highlight its upper-case
characters, like below:SysRq : HELP : loglevel(0-9) reBoot Crash terminate-all-tasks(E)
memory-full-oom-kill(F) kill-all-tasks(I) ...this would confuse user trigger sysrq by upper-case character, which is
inconsistent with the real lower-case character registed key.This inconsistent help message will also lead more confused when
26 upper-case letters put into use in future.This patch fix kgdb sysrq key: "debug(g)"
Signed-off-by: zhangwei(Jovi)
Cc: Jason Wessel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Mar, 2013
1 commit
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Pull KGDB/KDB fixes and cleanups from Jason Wessel:
"For a change we removed more code than we added. If people aren't
using it we shouldn't be carrying it. :-)Cleanups:
- Remove kdb ssb command - there is no in kernel disassembler to
support it- Remove kdb ll command - Always caused a kernel oops and there were
no bug reports so no one was using this command- Use kernel ARRAY_SIZE macro instead of array computations
Fixes:
- Stop oops in kdb if user executes kdb_defcmd with args- kdb help command truncated text
- ppc64 support for kgdbts
- Add missing kconfig option from original kdb port for dealing with
catastrophic kernel crashes such that you can reboot automatically
on continue from kdb"* tag 'for_linux-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
kdb: Remove unhandled ssb command
kdb: Prevent kernel oops with kdb_defcmd
kdb: Remove the ll command
kdb_main: fix help print
kdb: Fix overlap in buffers with strcpy
Fixed dead ifdef block by adding missing Kconfig option.
kdb: Setup basic kdb state before invoking commands via kgdb
kdb: use ARRAY_SIZE where possible
kgdb/kgdbts: support ppc64
kdb: A fix for kdb command table expansion
02 Mar, 2013
8 commits
-
The 'ssb' command can only be handled when we have a disassembler, to check for
branches, so remove the 'ssb' command for now.Signed-off-by: Vincent Stehlé
Signed-off-by: Jason Wessel -
The kdb_defcmd can only be used to display the available command aliases
while using the kernel debug shell. If you try to define a new macro
while the kernel debugger is active it will oops. The debug shell
macros must use pre-allocated memory set aside at the time kdb_init()
is run, and the kdb_defcmd is restricted to only working at the time
that the kdb_init sequence is being run, which only occurs if you
actually activate the kernel debugger.Signed-off-by: Jason Wessel
-
Recently some code inspection was done after fixing a problem with
kmalloc used while in the kernel debugger context (which is not
legal), and it turned up the fact that kdb ll command will oops the
kernel.Given that there have been zero bug reports on the command combined
with the fact it will oops the kernel it is clearly not being used.
Instead of fixing it, it will be removed.Signed-off-by: Jason Wessel
-
The help command was chopping all the usage instructions such that
they were not readable.Example:
bta [D|R|S|T|C|Z|E|U|I| Backtrace all processes matching state flag
per_cpu [] [ [] []
Display per_cpu variablesAll that is needed is to check the how long the cmd_usage is and jump
to the next line when appropriate.Signed-off-by: Jason Wessel
-
Maxime reported that strcpy(s->usage, s->usage+1) has no definitive
guarantee that it will work on all archs the same way when you have
overlapping memory. The fix is simple for the kdb code because we
still have the original string memory in the function scope, so we
just have to use that as the argument instead.Reported-by: Maxime Villard
Signed-off-by: Jason Wessel -
Although invasive kdb commands are not supported via kgdb, some useful
non-invasive commands like bt* require basic kdb state to be setup before
calling into the kdb code. Factor out some of this code and call it before
and after executing kdb commands via kgdb.Signed-off-by: Matt Klein
Signed-off-by: Jason Wessel -
Signed-off-by: Sasha Levin
Signed-off-by: Jason Wessel -
When locally adding in some additional kdb commands, I stumbled
across an issue with the dynamic expansion of the kdb command table.
When the number of kdb commands exceeds the size of the statically
allocated kdb_base_commands[] array, additional space is allocated in
the kdb_register_repeat() routine.The unused portion of the newly allocated array was not being initialized
to zero properly and this would result in segfaults when help '?' was
executed or when a search for a non-existing command would traverse the
command table beyond the end of valid command entries and then attempt
to use the non-zeroed area as actual command entries.Signed-off-by: John Blackwood
Signed-off-by: Jason Wessel
