2008-02-06 12:15:57

by Jan Kiszka

Subject: [PATCH] beautification of debugger_active usage

Just a beautification of using debugger_active for checking the debugger
state.

Signed-off-by: Jan Kiszka <[email protected]>

---
arch/x86/kernel/kgdb.c | 6 +++---
include/linux/kgdb.h | 7 ++++++-
kernel/kgdb.c | 8 ++++----
kernel/sched.c | 7 +------
4 files changed, 14 insertions(+), 14 deletions(-)

Index: b/arch/x86/kernel/kgdb.c
===================================================================
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -442,14 +442,14 @@ static int kgdb_notify(struct notifier_b

switch (cmd) {
case DIE_NMI:
- if (atomic_read(&debugger_active)) {
+ if (kgdb_active()) {
/* KGDB CPU roundup */
kgdb_nmihook(raw_smp_processor_id(), regs);
return NOTIFY_STOP;
}
return NOTIFY_DONE;
case DIE_NMI_IPI:
- if (atomic_read(&debugger_active)) {
+ if (kgdb_active()) {
/* KGDB CPU roundup */
if (kgdb_nmihook(raw_smp_processor_id(), regs))
return NOTIFY_DONE;
@@ -457,7 +457,7 @@ static int kgdb_notify(struct notifier_b
}
return NOTIFY_DONE;
case DIE_NMIWATCHDOG:
- if (atomic_read(&debugger_active)) {
+ if (kgdb_active()) {
/* KGDB CPU roundup */
kgdb_nmihook(raw_smp_processor_id(), regs);
return NOTIFY_STOP;
Index: b/include/linux/kgdb.h
===================================================================
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -285,8 +285,13 @@ int kgdb_nmihook(int cpu, void *regs);
extern int debugger_step;
extern atomic_t debugger_active;

+static inline int kgdb_active(void)
+{
+ return (atomic_read(&debugger_active) != 0);
+}
+
#else /* !CONFIG_KGDB */
-static const atomic_t debugger_active = ATOMIC_INIT(0);
+#define kgdb_active() 0
#endif /* !CONFIG_KGDB */

#endif /* _KGDB_H_ */
Index: b/kernel/kgdb.c
===================================================================
--- a/kernel/kgdb.c
+++ b/kernel/kgdb.c
@@ -774,7 +774,7 @@ static void kgdb_wait(struct pt_regs *re
* gaurd in case the master CPU had not been selected if
* this was an entry via nmi.
*/
- while (!atomic_read(&debugger_active))
+ while (!kgdb_active())
cpu_relax();

/* Wait till master CPU goes completely into the debugger. */
@@ -1901,7 +1901,7 @@ int kgdb_nmihook(int cpu, void *regs)
static int
kgdb_panic_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
{
- if (atomic_read(&debugger_active) != 0) {
+ if (kgdb_active()) {
printk(KERN_ERR "KGDB: Cannot handle panic while"
"debugger active\n");
dump_stack();
@@ -1923,7 +1923,7 @@ void kgdb_console_write(struct console *

/* If we're debugging, or KGDB has not connected, don't try
* and print. */
- if (!kgdb_connected || atomic_read(&debugger_active) != 0)
+ if (!kgdb_connected || kgdb_active())
return;

local_irq_save(flags);
@@ -2104,7 +2104,7 @@ kgdb_notify_reboot(struct notifier_block
* If we're debugging, or KGDB has not connected, don't try
* and print:
*/
- if (!kgdb_connected || atomic_read(&debugger_active) != 0)
+ if (!kgdb_connected || kgdb_active())
return 0;

if (code == SYS_RESTART || code == SYS_HALT || code == SYS_POWER_OFF) {
Index: b/kernel/sched.c
===================================================================
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -7264,12 +7264,7 @@ void __might_sleep(char *file, int line)
#ifdef in_atomic
static unsigned long prev_jiffy; /* ratelimiting */

-#ifdef CONFIG_KGDB
- if (atomic_read(&debugger_active))
- return;
-#endif
-
- if ((in_atomic() || irqs_disabled()) &&
+ if ((in_atomic() || irqs_disabled()) && !kgdb_active() &&
system_state == SYSTEM_RUNNING && !oops_in_progress) {
if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
return;

2008-02-06 12:31:15

by Jason Wessel

Subject: Re: [Kgdb-bugreport] [PATCH] beautification of debugger_active usage

Jan Kiszka wrote:
> Just a beautification of using debugger_active for checking the debugger
> state.
>
> Signed-off-by: Jan Kiszka <[email protected]>
>
> ---
> arch/x86/kernel/kgdb.c | 6 +++---
> include/linux/kgdb.h | 7 ++++++-
> kernel/kgdb.c | 8 ++++----
> kernel/sched.c | 7 +------
> 4 files changed, 14 insertions(+), 14 deletions(-)
>
>
committed to:
http://git.kernel.org/?p=linux/kernel/git/jwessel/linux-2.6-kgdb.git;a=shortlog;h=kgdb_2.6.25

Jason.