From 9c24624727f6d6c460e45762a408ca5f5b9b8ef2 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Tue, 9 Dec 2008 13:14:27 -0800 Subject: 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 Cc: Christoph Lameter Cc Miles Lane Acked-by: Pekka Enberg Acked-by: Steven Rostedt Acked-by: Frederic Weisbecker Cc: Rusty Russell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slub.c | 2 +- mm/vmalloc.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'mm') diff --git a/mm/slub.c b/mm/slub.c index 749588a50a5a..a2cd47d89e0a 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) break; len += sprintf(buf + len, "%7ld ", l->count); diff --git a/mm/vmalloc.c b/mm/vmalloc.c index f3f6e0758562..1ddb77ba3995 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); -- cgit v1.2.2