[PATCH 3.19 136/175] kdb: Fix off by one error in kdb_cpu()

Greg Kroah-Hartman
2015-03-04T06:22:33Z

From: Jason Wessel <jason.wessel@windriver.com>

commit df0036d117e6c9df36324e517728e33543065f9a upstream.

There was a follow on replacement patch against the prior
"kgdb: Timeout if secondary CPUs ignore the roundup".

See: https://lkml.org/lkml/2015/1/7/442

This patch is the delta vs the patch that was committed upstream:
* Fix an off-by-one error in kdb_cpu().
* Replace NR_CPUS with CONFIG_NR_CPUS to tell checkpatch that we
really want a static limit.
* Removed the "KGDB: " prefix from the pr_crit() in debug_core.c
(kgdb-next contains a patch which introduced pr_fmt() to this file
to the tag will now be applied automatically).

Cc: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
kernel/debug/debug_core.c | 2 +-
kernel/debug/kdb/kdb_main.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -604,7 +604,7 @@ return_normal:
online_cpus)
cpu_relax();
if (!time_left)
- pr_crit("KGDB: Timed out waiting for secondary CPUs.\n");
+ pr_crit("Timed out waiting for secondary CPUs.\n");

/*
* At this point the primary processor is completely
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -2256,7 +2256,7 @@ static int kdb_cpu(int argc, const char
/*
* Validate cpunum
*/
- if ((cpunum > NR_CPUS) || !kgdb_info[cpunum].enter_kgdb)
+ if ((cpunum >= CONFIG_NR_CPUS) || !kgdb_info[cpunum].enter_kgdb)
return KDB_BADCPUNUM;

dbg_switch_cpu = cpunum;