kdb: Fix breakpoint enable to be silent if already enabled

Fix the breakpoint enable command (be) to a logic that is inline with the
breakpoint disable command (bd) in which if the breakpoint is alr

kdb: Fix breakpoint enable to be silent if already enabled

Fix the breakpoint enable command (be) to a logic that is inline with the
breakpoint disable command (bd) in which if the breakpoint is already in
an enabled state, do not print the message of enabled again to the user.

Also a small nit fix of the new line in a separate print.

Signed-off-by: Nir Lichtman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Daniel Thompson <[email protected]>

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kdb: Rename members of struct kdbtab_t

Remove redundant prefix "cmd_" from name of members in struct kdbtab_t
for better readibility.

Suggested-by: Doug Anderson <[email protected]>
Signed-off-

kdb: Rename members of struct kdbtab_t

Remove redundant prefix "cmd_" from name of members in struct kdbtab_t
for better readibility.

Suggested-by: Doug Anderson <[email protected]>
Signed-off-by: Sumit Garg <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Daniel Thompson <[email protected]>

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kdb: Simplify kdb commands registration

Simplify kdb commands registration via using linked list instead of
static array for commands storage.

Signed-off-by: Sumit Garg <[email protected]>
Link

kdb: Simplify kdb commands registration

Simplify kdb commands registration via using linked list instead of
static array for commands storage.

Signed-off-by: Sumit Garg <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Douglas Anderson <[email protected]>
[[email protected]: Removed a bunch of .cmd_minline = 0
initializers]
Signed-off-by: Daniel Thompson <[email protected]>

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kgdb: Honour the kprobe blocklist when setting breakpoints

Currently kgdb has absolutely no safety rails in place to discourage or
prevent a user from placing a breakpoint in dangerous places such a

kgdb: Honour the kprobe blocklist when setting breakpoints

Currently kgdb has absolutely no safety rails in place to discourage or
prevent a user from placing a breakpoint in dangerous places such as
the debugger's own trap entry/exit and other places where it is not safe
to take synchronous traps.

Introduce a new config symbol KGDB_HONOUR_BLOCKLIST and modify the
default implementation of kgdb_validate_break_address() so that we use
the kprobe blocklist to prohibit instrumentation of critical functions
if the config symbol is set. The config symbol dependencies are set to
ensure that the blocklist will be enabled by default if we enable KGDB
and are compiling for an architecture where we HAVE_KPROBES.

Suggested-by: Peter Zijlstra <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
Reviewed-by: Masami Hiramatsu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Daniel Thompson <[email protected]>

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kdb: remove redundant assignment to pointer bp

The point bp is assigned a value that is never read, it is being
re-assigned later to bp = &kdb_breakpoints[lowbp] in a for-loop.
Remove the redundant

kdb: remove redundant assignment to pointer bp

The point bp is assigned a value that is never read, it is being
re-assigned later to bp = &kdb_breakpoints[lowbp] in a for-loop.
Remove the redundant assignment.

Addresses-Coverity ("Unused value")
Signed-off-by: Colin Ian King <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Daniel Thompson <[email protected]>

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kdb: bl: don't use tab character in output

The "bl" (list breakpoints) command prints a '\t' (tab) character
in its output, but on a console (video device), that just prints
some odd graphics charac

kdb: bl: don't use tab character in output

The "bl" (list breakpoints) command prints a '\t' (tab) character
in its output, but on a console (video device), that just prints
some odd graphics character. Instead of printing a tab character,
just align the output with spaces.

Signed-off-by: Randy Dunlap <[email protected]>
Cc: Daniel Thompson <[email protected]>
Cc: Jason Wessel <[email protected]>
Cc: [email protected]
Signed-off-by: Jason Wessel <[email protected]>

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mm/init: Add 'rodata=off' boot cmdline parameter to disable read-only kernel mappings

It may be useful to debug writes to the readonly sections of memory,
so provide a cmdline "rodata=off" to allow

mm/init: Add 'rodata=off' boot cmdline parameter to disable read-only kernel mappings

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 <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: David Brown <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Emese Revfy <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mathias Krause <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: PaX Team <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: linux-arch <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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kdb: Categorize kdb commands (similar to SysRq categorization)

This patch introduces several new flags to collect kdb commands into
groups (later allowing them to be optionally disabled).

This foll

kdb: Categorize kdb commands (similar to SysRq categorization)

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_console

Signed-off-by: Daniel Thompson <[email protected]>
Cc: Jason Wessel <[email protected]>
Signed-off-by: Jason Wessel <[email protected]>

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kdb: Remove KDB_REPEAT_NONE flag

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: Anto

kdb: Remove KDB_REPEAT_NONE flag

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 <[email protected]>
Signed-off-by: John Stultz <[email protected]>
Signed-off-by: Daniel Thompson <[email protected]>
Cc: Jason Wessel <[email protected]>
Signed-off-by: Jason Wessel <[email protected]>

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kdb: Rename kdb_register_repeat() to kdb_register_flags()

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

kdb: Rename kdb_register_repeat() to kdb_register_flags()

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 <[email protected]>
Signed-off-by: John Stultz <[email protected]>
Signed-off-by: Daniel Thompson <[email protected]>
Cc: Jason Wessel <[email protected]>
Signed-off-by: Jason Wessel <[email protected]>

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kdb: replace strnicmp with strncasecmp

The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncas

kdb: replace strnicmp with strncasecmp

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 <[email protected]>
Cc: Jason Wessel <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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kdb: Remove unhandled ssb command

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 <vince

kdb: Remove unhandled ssb command

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 <[email protected]>
Signed-off-by: Jason Wessel <[email protected]>

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kdb: Add message about CONFIG_DEBUG_RODATA on failure to install breakpoint

On x86, if CONFIG_DEBUG_RODATA is set, one cannot set breakpoints
via KDB. Apparently this is a well-known problem, as at

kdb: Add message about CONFIG_DEBUG_RODATA on failure to install breakpoint

On x86, if CONFIG_DEBUG_RODATA is set, one cannot set breakpoints
via KDB. Apparently this is a well-known problem, as at least one distribution
now ships with both KDB enabled and CONFIG_DEBUG_RODATA=y for security reasons.

This patch adds an printk message to the breakpoint failure case,
in order to provide suggestions about how to use the debugger.

Reported-by: Tim Bird <[email protected]>
Signed-off-by: Jason Wessel <[email protected]>
Acked-by: Tim Bird <[email protected]>

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gcc-4.6: kernel/*: Fix unused but set warnings

No real bugs I believe, just some dead code.

Signed-off-by: Andi Kleen <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: andi@first

gcc-4.6: kernel/*: Fix unused but set warnings

No real bugs I believe, just some dead code.

Signed-off-by: Andi Kleen <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: [email protected]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>

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kdb: core for kgdb back end (1 of 2)

This patch contains only the kdb core. Because the change set was
large, it was split. The next patch in the series includes the
instrumentation into the core

kdb: core for kgdb back end (1 of 2)

This patch contains only the kdb core. Because the change set was
large, it was split. The next patch in the series includes the
instrumentation into the core kernel which are mainly helper functions
for kdb.

This work is directly derived from kdb v4.4 found at:

ftp://oss.sgi.com/projects/kdb/download/v4.4/

The kdb internals have been re-organized to make them mostly platform
independent and to connect everything to the debug core which is used by
gdbstub (which has long been known as kgdb).

The original version of kdb was 58,000 lines worth of changes to
support x86. From that implementation only the kdb shell, and basic
commands for memory access, runcontrol, lsmod, and dmesg where carried
forward.

This is a generic implementation which aims to cover all the current
architectures using the kgdb core: ppc, arm, x86, mips, sparc, sh and
blackfin. More archictectures can be added by implementing the
architecture specific kgdb functions.

[[email protected]: Compile fix with hugepages enabled]
[[email protected]: Clean breakpoint code renaming kdba_ -> kdb_]
[[email protected]: fix new line after printing registers]
[[email protected]: Remove the concept of global vs. local breakpoints]
[[email protected]: Rework kdb_si_swapinfo to use more generic name]
[[email protected]: fix the information dump macros, remove 'arch' from the names]
[[email protected]: include fixup to include linux/slab.h]

CC: [email protected]
Signed-off-by: Jason Wessel <[email protected]>
Signed-off-by: Martin Hicks <[email protected]>

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