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/kdb | |
| 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/kdb')
| -rw-r--r-- | kernel/debug/kdb/kdb_debugger.c | 3 | ||||
| -rw-r--r-- | kernel/debug/kdb/kdb_main.c | 12 |
2 files changed, 7 insertions, 8 deletions
diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c index bf6e8270e957..dd0b1b7dd02c 100644 --- a/kernel/debug/kdb/kdb_debugger.c +++ b/kernel/debug/kdb/kdb_debugger.c @@ -86,7 +86,7 @@ int kdb_stub(struct kgdb_state *ks) } /* Set initial kdb state variables */ KDB_STATE_CLEAR(KGDB_TRANS); - kdb_initial_cpu = ks->cpu; + kdb_initial_cpu = atomic_read(&kgdb_active); kdb_current_task = kgdb_info[ks->cpu].task; kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo; /* Remove any breakpoints as needed by kdb and clear single step */ @@ -105,7 +105,6 @@ int kdb_stub(struct kgdb_state *ks) ks->pass_exception = 1; KDB_FLAG_SET(CATASTROPHIC); } - kdb_initial_cpu = ks->cpu; if (KDB_STATE(SSBPT) && reason == KDB_REASON_SSTEP) { KDB_STATE_CLEAR(SSBPT); KDB_STATE_CLEAR(DOING_SS); diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 4226f32517d1..d7bda21a106b 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -1749,13 +1749,13 @@ static int kdb_go(int argc, const char **argv) int nextarg; long offset; + if (raw_smp_processor_id() != kdb_initial_cpu) { + kdb_printf("go must execute on the entry cpu, " + "please use \"cpu %d\" and then execute go\n", + kdb_initial_cpu); + return KDB_BADCPUNUM; + } if (argc == 1) { - if (raw_smp_processor_id() != kdb_initial_cpu) { - kdb_printf("go <address> must be issued from the " - "initial cpu, do cpu %d first\n", - kdb_initial_cpu); - return KDB_ARGCOUNT; - } nextarg = 1; diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL); |