KSYM_SYMBOL_LEN fixes

Miles Lane tailing /sys files hit a BUG which Pekka Enberg has tracked
to my 966c8c12dc9e77f931e2281ba25d2f0244b06949 sprint_symbol(): use
less stack exposing a bug in slub's list_locations() -
kallsyms_lookup() writes a 0 to namebuf[KSYM_NAME_LEN-1], but that was
beyond the end of page provided.

The 100 slop which list_locations() allows at end of page looks roughly
enough for all the other stuff it might print after the symbol before
it checks again: break out KSYM_SYMBOL_LEN earlier than before.

Latencytop and ftrace and are using KSYM_NAME_LEN buffers where they
need KSYM_SYMBOL_LEN buffers, and vmallocinfo a 2*KSYM_NAME_LEN buffer
where it wants a KSYM_SYMBOL_LEN buffer: fix those before anyone copies
them.

[akpm@linux-foundation.org: ftrace.h needs module.h]
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc Miles Lane <miles.lane@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/latencytop.c b/kernel/latencytop.c
index 5e7b45c56923..449db466bdbc 100644
--- a/kernel/latencytop.c
+++ b/kernel/latencytop.c
@@ -191,7 +191,7 @@ static int lstats_show(struct seq_file *m, void *v)
                                 latency_record[i].time,
                                 latency_record[i].max);
                         for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
-                                char sym[KSYM_NAME_LEN];
+                                char sym[KSYM_SYMBOL_LEN];
                                 char *c;
                                 if (!latency_record[i].backtrace[q])
                                         break;