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author | David Howells <dhowells@redhat.com> | 2011-03-18 16:54:32 +0000 |
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committer | David Howells <dhowells@redhat.com> | 2011-03-18 16:54:32 +0000 |
commit | 5141c46c6137f4866eb5f29e25ed0556bcc4c634 (patch) | |
tree | 321b2be3281fdc91a4f7d6b4e6c1bac272387f97 /arch/mn10300/include | |
parent | 044264bbe34085b550e6429ce97ef310667be9dc (diff) | |
download | blackbird-op-linux-5141c46c6137f4866eb5f29e25ed0556bcc4c634.tar.gz blackbird-op-linux-5141c46c6137f4866eb5f29e25ed0556bcc4c634.zip |
MN10300: Emulate single stepping in KGDB on MN10300
Emulate single stepping in KGDB on MN10300 by way of temporary breakpoint
insertion. These breakpoints are never actually seen by KGDB, and will overlay
KGDB's own breakpoints.
The breakpoints are removed by switch_to() and reinstalled on switching back so
that if preemption occurs, the preempting task doesn't hit them (though it will
still hit KGDB's regular breakpoints). If KGDB is reentered for any reason,
then the single step breakpoint is completely erased and must be set again by
the debugger.
We take advantage of the fact that KGDB will effectively halt all other CPUs
whilst this CPU is single-stepping to avoid SMP problems.
If the single-stepping task is preempted and killed without KGDB being
reinvoked, then the breakpoint(s) will be cleared and KGDB will be jumped back
into.
Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'arch/mn10300/include')
-rw-r--r-- | arch/mn10300/include/asm/thread_info.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/mn10300/include/asm/thread_info.h b/arch/mn10300/include/asm/thread_info.h index aa07a4a5d794..c139fa17e2e4 100644 --- a/arch/mn10300/include/asm/thread_info.h +++ b/arch/mn10300/include/asm/thread_info.h @@ -129,7 +129,11 @@ static inline unsigned long current_stack_pointer(void) #define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL) #endif +#ifndef CONFIG_KGDB #define free_thread_info(ti) kfree((ti)) +#else +extern void free_thread_info(struct thread_info *); +#endif #define get_thread_info(ti) get_task_struct((ti)->task) #define put_thread_info(ti) put_task_struct((ti)->task) |