diff options
| author | Jason Wessel <jason.wessel@windriver.com> | 2010-05-21 08:46:00 -0500 |
|---|---|---|
| committer | Jason Wessel <jason.wessel@windriver.com> | 2010-10-22 15:34:13 -0500 |
| commit | 495363d380b4f4745bd8677912688654afc44020 (patch) | |
| tree | 647032c22f9e77f91578dcae864776849dbcbfa8 /kernel/debug/debug_core.c | |
| parent | dfee3a7b92208b30f77876068aece9ea571270c2 (diff) | |
| download | linux-495363d380b4f4745bd8677912688654afc44020.tar.bz2 | |
kdb,debug_core: adjust master cpu switch logic against new debug_core locking
The kdb shell needs to enforce switching back to the original CPU that
took the exception before restoring normal kernel execution. Resuming
from a different CPU than what took the original exception will cause
problems with spin locks that are freed from the a different processor
than had taken the lock.
The special logic in dbg_cpu_switch() can go away entirely with
because the state of what cpus want to be masters or slaves will
remain unchanged between entry and exit of the debug_core exception
context.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Diffstat (limited to 'kernel/debug/debug_core.c')
| -rw-r--r-- | kernel/debug/debug_core.c | 16 |
1 files changed, 2 insertions, 14 deletions
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 26dbdc37d219..fec596da9bd0 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -460,19 +460,6 @@ static int kgdb_reenter_check(struct kgdb_state *ks) return 1; } -static void dbg_cpu_switch(int cpu, int next_cpu) -{ - /* Mark the cpu we are switching away from as a slave when it - * holds the kgdb_active token. This must be done so that the - * that all the cpus wait in for the debug core will not enter - * again as the master. */ - if (cpu == atomic_read(&kgdb_active)) { - kgdb_info[cpu].exception_state |= DCPU_IS_SLAVE; - kgdb_info[cpu].exception_state &= ~DCPU_WANT_MASTER; - } - kgdb_info[next_cpu].exception_state |= DCPU_NEXT_MASTER; -} - static void dbg_touch_watchdogs(void) { touch_softlockup_watchdog_sync(); @@ -638,7 +625,8 @@ cpu_master_loop: if (error == DBG_PASS_EVENT) { dbg_kdb_mode = !dbg_kdb_mode; } else if (error == DBG_SWITCH_CPU_EVENT) { - dbg_cpu_switch(cpu, dbg_switch_cpu); + kgdb_info[dbg_switch_cpu].exception_state |= + DCPU_NEXT_MASTER; goto cpu_loop; } else { kgdb_info[cpu].ret_state = error; |