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author | 2009-06-03 14:06:57 -0500 | |
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committer | 2010-05-20 21:04:26 -0500 | |
commit | 1cee5e35f15d0893be1ba944f1aec8676e43ab76 (patch) | |
tree | 634f5365300cfb555c8e894ade79735bb91a690e /kernel/debug | |
parent | mips,kgdb: kdb low level trap catch and stack trace (diff) | |
download | linux-1cee5e35f15d0893be1ba944f1aec8676e43ab76.tar.gz linux-1cee5e35f15d0893be1ba944f1aec8676e43ab76.tar.bz2 linux-1cee5e35f15d0893be1ba944f1aec8676e43ab76.zip |
kgdb: Add the ability to schedule a breakpoint via a tasklet
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>
Diffstat (limited to 'kernel/debug')
-rw-r--r-- | kernel/debug/debug_core.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 375e42f0baf0..fff59019cca0 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -114,6 +114,7 @@ EXPORT_SYMBOL_GPL(kgdb_active); */ static atomic_t passive_cpu_wait[NR_CPUS]; static atomic_t cpu_in_kgdb[NR_CPUS]; +static atomic_t kgdb_break_tasklet_var; atomic_t kgdb_setting_breakpoint; struct task_struct *kgdb_usethread; @@ -789,6 +790,31 @@ static void kgdb_unregister_callbacks(void) } } +/* + * There are times a tasklet needs to be used vs a compiled in + * break point so as to cause an exception outside a kgdb I/O module, + * such as is the case with kgdboe, where calling a breakpoint in the + * I/O driver itself would be fatal. + */ +static void kgdb_tasklet_bpt(unsigned long ing) +{ + kgdb_breakpoint(); + atomic_set(&kgdb_break_tasklet_var, 0); +} + +static DECLARE_TASKLET(kgdb_tasklet_breakpoint, kgdb_tasklet_bpt, 0); + +void kgdb_schedule_breakpoint(void) +{ + if (atomic_read(&kgdb_break_tasklet_var) || + atomic_read(&kgdb_active) != -1 || + atomic_read(&kgdb_setting_breakpoint)) + return; + atomic_inc(&kgdb_break_tasklet_var); + tasklet_schedule(&kgdb_tasklet_breakpoint); +} +EXPORT_SYMBOL_GPL(kgdb_schedule_breakpoint); + static void kgdb_initial_breakpoint(void) { kgdb_break_asap = 0; |