Roel Kluin reported an error found with Parfait. Where we want to ensure that that kgdb_info[-1] never gets accessed.
Also check to ensure any negative tid does not exceed the size of the shadow CPU array, else report critical debug context because it is an internal kgdb failure. Reported-by: Roel Kluin <[email protected]> Signed-off-by: Jason Wessel <[email protected]> --- kernel/kgdb.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/kernel/kgdb.c b/kernel/kgdb.c index 7d70146..29357a9 100644 --- a/kernel/kgdb.c +++ b/kernel/kgdb.c @@ -541,12 +541,17 @@ static struct task_struct *getthread(struct pt_regs *regs, int tid) */ if (tid == 0 || tid == -1) tid = -atomic_read(&kgdb_active) - 2; - if (tid < 0) { + if (tid < -1 && tid > -NR_CPUS - 2) { if (kgdb_info[-tid - 2].task) return kgdb_info[-tid - 2].task; else return idle_task(-tid - 2); } + if (tid <= 0) { + printk(KERN_ERR "KGDB: Internal thread select error\n"); + dump_stack(); + return NULL; + } /* * find_task_by_pid_ns() does not take the tasklist lock anymore -- 1.6.4.rc1 ------------------------------------------------------------------------------ Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev _______________________________________________ Kgdb-bugreport mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport
