path: root/mm
diff options
authorHugh Dickins <hugh@veritas.com>2008-12-09 13:14:27 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2008-12-10 08:01:54 -0800
commit9c24624727f6d6c460e45762a408ca5f5b9b8ef2 (patch)
tree39f41dc5e46a9f0e1151963eb1d4f2b7ff77ee3d /mm
parent6ee5a399d6a92a52646836a6e10faf255c16393e (diff)
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>
Diffstat (limited to 'mm')
2 files changed, 2 insertions, 2 deletions
diff --git a/mm/slub.c b/mm/slub.c
index 749588a50a5..a2cd47d89e0 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3597,7 +3597,7 @@ static int list_locations(struct kmem_cache *s, char *buf,
for (i = 0; i < t.count; i++) {
struct location *l = &t.loc[i];
- if (len > PAGE_SIZE - 100)
+ if (len > PAGE_SIZE - KSYM_SYMBOL_LEN - 100)
len += sprintf(buf + len, "%7ld ", l->count);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index f3f6e075856..1ddb77ba399 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1717,7 +1717,7 @@ static int s_show(struct seq_file *m, void *p)
v->addr, v->addr + v->size, v->size);
if (v->caller) {
- char buff[2 * KSYM_NAME_LEN];
+ char buff[KSYM_SYMBOL_LEN];
seq_putc(m, ' ');
sprint_symbol(buff, (unsigned long)v->caller);