* 'kms-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
kgdb,docs: Update the kgdb docs to include kms
drm_fb_helper: Preserve capability to use atomic kms
i915: when kgdb is active display compression should be off
drm/i915: use new fb debug hooks
drm: add KGDB/KDB support
fb: add hooks to handle KDB enter/exit
kgdboc: Add call backs to allow kernel mode switching
vt,console,kdb: automatically set kdb LINES variable
vt,console,kdb: implement atomic console enter/leave functions
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
debug_core,kdb: fix crash when arch does not have single step
kgdb,x86: use macro HBP_NUM to replace magic number 4
kgdb,mips: remove unused kgdb_cpu_doing_single_step operations
mm,kdb,kgdb: Add a debug reference for the kdb kmap usage
KGDB: Remove set but unused newPC
ftrace,kdb: Allow dumping a specific cpu's buffer with ftdump
ftrace,kdb: Extend kdb to be able to dump the ftrace buffer
kgdb,powerpc: Replace hardcoded offset by BREAK_INSTR_SIZE
arm,kgdb: Add ability to trap into debugger on notify_die
gdbstub: do not directly use dbg_reg_def[] in gdb_cmd_reg_set()
gdbstub: Implement gdbserial 'p' and 'P' packets
kgdb,arm: Individual register get/set for arm
kgdb,mips: Individual register get/set for mips
kgdb,x86: Individual register get/set for x86
kgdb,kdb: individual register set and and get API
gdbstub: Optimize kgdb's "thread:" response for the gdb serial protocol
kgdb: remove custom hex_to_bin()implementation
The kernel console interface stores the number of lines it is
configured to use. The kdb debugger can greatly benefit by knowing how
many lines there are on the console for the pager functionality
without having the end user compile in the setting or have to
repeatedly change it at run time.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
CC: David Airlie <airlied@linux.ie>
CC: Andrew Morton <akpm@linux-foundation.org>
When an arch such as mips and microblaze does not implement either HW
or software single stepping the debug core should re-enter kdb. The
kdb code will properly ignore the single step operation. Attempting
to single step the kernel without software or hardware support causes
unpredictable kernel crashes.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Presently the usable registers definitions on x86 are not contiguous
for kgdb. The x86 kgdb uses a case statement for the sparse register
accesses. The array which defines the registers (dbg_reg_def) should
not be used directly in order to safely work with sparse register
definitions.
Specifically there was a problem when gdb accesses ORIG_AX, which is
accessed only through the case statement.
This patch encodes register memory using the size information provided
from the debugger which avoids the need to look up the size of the
register. The dbg_set_reg() function always further validates the
inputs from the debugger.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
The gdbserial 'p' and 'P' packets allow gdb to individually get and
set registers instead of querying for all the available registers.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The kdb shell specification includes the ability to get and set
architecture specific registers by name.
For the time being individual register get and set will be implemented
on a per architecture basis. If an architecture defines
DBG_MAX_REG_NUM > 0 then kdb and the gdbstub will use the capability
for individually getting and setting architecture specific registers.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The gdb debugger understands how to parse short versions of the thread
reference string as long as the bytes are paired in sets of two
characters. The kgdb implementation was always sending 8 leading
zeros which could be omitted, and further optimized in the case of
non-negative thread numbers. The negative numbers are used to
reference a specific cpu in the case of kgdb.
An example of the previous i386 stop packet looks like:
T05thread:00000000000003bb;
New stop packet response:
T05thread:03bb;
The previous ThreadInfo response looks like:
m00000000fffffffe,0000000000000001,0000000000000002,0000000000000003,0000000000000004,0000000000000005,0000000000000006,0000000000000007,000000000000000c,0000000000000088,000000000000008a,000000000000008b,000000000000008c,000000000000008d,000000000000008e,00000000000000d4,00000000000000d5,00000000000000dd
New ThreadInfo response:
mfffffffe,01,02,03,04,05,06,07,0c,88,8a,8b,8c,8d,8e,d4,d5,dd
A few bytes saved means better response time when using kgdb over a
serial line.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The kdb code should not toggle the sysrq state in case an end user
wants to try and resume the normal kernel execution.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Immediately following an exit from the kdb shell the kgdb_connected
variable should be set to zero, unless there are breakpoints planted.
If the kgdb_connected variable is not zeroed out with kdb, it is
impossible to turn off kdb.
This patch is merely a work around for now, the real fix will check
for the breakpoints.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
In the process of merging kdb to the mainline, the kdb lsmod command
stopped printing the base load address of kernel modules. This is
needed for using kdb in conjunction with external tools such as gdb.
Simply restore the functionality by adding a kdb_printf for the base
load address of the kernel modules.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The gdbserial protocol handler should return an empty packet instead
of an error string when ever it responds to a command it does not
implement.
The problem cases come from a debugger client sending
qTBuffer, qTStatus, qSearch, qSupported.
The incorrect response from the gdbstub leads the debugger clients to
not function correctly. Recent versions of gdb will not detach correctly as a result of this behavior.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Without this patch the "ll" linked-list traversal command won't
terminate when you hit q/Q.
Signed-off-by: Martin Hicks <mort@sgi.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The kernel debugger can operate well before mm_init(), but the x86
hardware breakpoint code which uses the perf api requires that the
kernel allocators are initialized.
This means the kernel debug core needs to provide an optional arch
specific call back to allow the initialization functions to run after
the kernel has been further initialized.
The kdb shell already had a similar restriction with an early
initialization and late initialization. The kdb_init() was moved into
the debug core's version of the late init which is called
dbg_late_init();
CC: kgdb-bugreport@lists.sourceforge.net
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Certain calls from the kdb shell will call out to printk(), and any of
these calls should get vectored back to the kdb_printf() so that the
kdb pager and processing can be used, as well as to properly channel
I/O to the polled I/O devices.
CC: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
If kdb is open on a serial port that is not actually a console make
sure to call the poll routines to emit and receive characters.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Martin Hicks <mort@sgi.com>
Some kgdb I/O modules require the ability to create a breakpoint
tasklet, such as kgdboc and external modules such as kgdboe. The
breakpoint tasklet is used as an asynchronous entry point into the
debugger which will have a different function scope than the current
execution path where it might not be safe to have an inline
breakpoint. This is true of some of the kgdb I/O drivers which share
code with kgdb and rest of the kernel users.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The only way the debugger can handle a trap in inside rcu_lock,
notify_die, or atomic_notifier_call_chain without a triple fault is
to have a low level "first opportunity handler" in the int3 exception
handler.
Generally this will be something the vast majority of folks will not
need, but for those who need it, it is added as a kernel .config
option called KGDB_LOW_LEVEL_TRAP.
CC: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: H. Peter Anvin <hpa@zytor.com>
CC: x86@kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Remove all the references to the kgdb_post_primary_code. This
function serves no useful purpose because you can obtain the same
information from the "struct kgdb_state *ks" from with in the
debugger, if for some reason you want the data.
Also remove the unintentional duplicate assignment for ks->ex_vector.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
