linux-toradex.git/kernel/kgdb.c, branch v2.6.32.50

repair gdbstub to match the gdbserial protocol specification

2011-04-14T23:53:40+00:00

commit fb82c0ff27b2c40c6f7a3d1a94cafb154591fa80 upstream.

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.

Backport-request-by: Frank Pan 
Signed-off-by: Jason Wessel 
Signed-off-by: Dongdong Deng 
Signed-off-by: Greg Kroah-Hartman

sysrq, intel_fb: fix sysrq g collision

2009-05-15T12:56:24+00:00

Commit 79e539453b34e35f39299a899d263b0a1f1670bd introduced a
regression where you cannot use sysrq 'g' to enter kgdb.  The solution
is to move the intel fb sysrq over to V for video instead of G for
graphics.  The SMP VOYAGER code to register for the sysrq-v is not
anywhere to be found in the mainline kernel, so the comments in the
code were cleaned up as well.

This patch also cleans up the sysrq definitions for kgdb to make it
generic for the kernel debugger, such that the sysrq 'g' can be used
in the future to enter a gdbstub or another kernel debugger.

Signed-off-by: Jason Wessel 
Acked-by: Jesse Barnes 
Acked-by: Randy Dunlap 
Signed-off-by: Andrew Morton

kgdb: call touch_softlockup_watchdog on resume

2008-10-06T18:50:59+00:00

The softlockup watchdog needs to be touched when resuming the from the
kgdb stopped state to avoid the printk that a CPU is stuck if the
debugger was active for longer than the softlockup threshold.

Signed-off-by: Jason Wessel

kgdb, x86, arm, mips, powerpc: ignore user space single stepping

2008-09-26T15:36:41+00:00

On the x86 arch, user space single step exceptions should be ignored
if they occur in the kernel space, such as ptrace stepping through a
system call.

First check if it is kgdb that is executing a single step, then ensure
it is not an accidental traversal into the user space, while in kgdb,
any other time the TIF_SINGLESTEP is set, kgdb should ignore the
exception.

On x86, arm, mips and powerpc, the kgdb_contthread usage was
inconsistent with the way single stepping is implemented in the kgdb
core.  The arch specific stub should always set the
kgdb_cpu_doing_single_step correctly if it is single stepping.  This
allows kgdb to correctly process an instruction steps if ptrace
happens to be requesting an instruction step over a system call.

Signed-off-by: Jason Wessel

kgdb: could not write to the last of valid memory with kgdb

2008-09-26T15:36:41+00:00

On the ARM architecture, kgdb will crash the kernel if the last byte
of valid memory is written due to a flush_icache_range flushing
beyond the memory boundary.

Signed-off-by: Atsuo Igarashi 
Signed-off-by: Jason Wessel

kgdb: fix gdb serial thread queries

2008-08-01T13:39:35+00:00

The command "info threads" did not work correctly with kgdb.  It would
result in a silent kernel hang if used.

This patach addresses several problems.
 - Fix use of deprecated NR_CPUS
 - Fix kgdb to not walk linearly through the pid space
 - Correctly implement shadow pids
 - Change the threads per query to a #define
 - Fix kgdb_hex2long to work with negated values

The threads 0 and -1 are reserved to represent the current task.  That
means that CPU 0 will start with a shadow thread id of -2, and CPU 1
will have a shadow thread id of -3, etc...

From the debugger you can switch to a shadow thread to see what one of
the other cpus was doing, however it is not possible to execute run
control operations on any other cpu execept the cpu executing the
kgdb_handle_exception().

Signed-off-by: Jason Wessel

kgdb: fix kgdb_validate_break_address to perform a mem write

2008-08-01T13:39:34+00:00

A regression to the kgdb core was found in the case of using the
CONFIG_DEBUG_RODATA kernel option.  When this option is on, a breakpoint
cannot be written into any readonly memory page.  When an external
debugger requests a breakpoint to get set, the
kgdb_validate_break_address() was only checking to see if the address
to place the breakpoint was readable and lacked a write check.

This patch changes the validate routine to try reading (via the
breakpoint set request) and also to try immediately writing the break
point.  If either fails, an error is correctly returned and the
debugger behaves correctly.  Then an end user can make the
descision to use hardware breakpoints.

Also update the documentation to reflect that using
CONFIG_DEBUG_RODATA will inhibit the use of software breakpoints.

Signed-off-by: Jason Wessel

kgdb: sparse fix

2008-06-24T15:52:55+00:00

- Fix warning reported by sparse
kernel/kgdb.c:1502:6: warning: symbol 'kgdb_console_write' was not declared.
	Should it be static?

Signed-off-by: Jason Wessel

kgdb: use common ascii helpers and put_unaligned_be32 helper

2008-05-28T17:49:56+00:00

Signed-off-by: Harvey Harrison 
Signed-off-by: Andrew Morton 
Signed-off-by: Jason Wessel

lib: create common ascii hex array

2008-05-15T02:11:14+00:00

Add a common hex array in hexdump.c so everyone can use it.

Add a common hi/lo helper to avoid the shifting masking that is
done to get the upper and lower nibbles of a byte value.

Pull the pack_hex_byte helper from kgdb as it is opencoded many
places in the tree that will be consolidated.

Signed-off-by: Harvey Harrison 
Acked-by: Paul Mundt 
Cc: Jason Wessel 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds