Commit 9c246247 authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds
Browse files

KSYM_SYMBOL_LEN fixes 



Miles Lane tailing /sys files hit a BUG which Pekka Enberg has tracked
to my 966c8c12 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: default avatarHugh Dickins <hugh@veritas.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc Miles Lane <miles.lane@gmail.com>
Acked-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
Acked-by: default avatarSteven Rostedt <srostedt@redhat.com>
Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6ee5a399

fs/proc/base.c

+1 −1
Original line number Diff line number Diff line
@@ -371,7 +371,7 @@ static int lstats_show_proc(struct seq_file *m, void *v) 
				task->latency_record[i].time,

				task->latency_record[i].max);

			for (q = 0; q < LT_BACKTRACEDEPTH; q++) {

				char sym[KSYM_NAME_LEN];

				char sym[KSYM_SYMBOL_LEN];

				char *c;

				if (!task->latency_record[i].backtrace[q])

					break;

include/linux/ftrace.h

+2 −1
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
#include <linux/ktime.h>

#include <linux/init.h>

#include <linux/types.h>

#include <linux/module.h>

#include <linux/kallsyms.h>



#ifdef CONFIG_FUNCTION_TRACER
@@ -231,7 +232,7 @@ ftrace_init_module(unsigned long *start, unsigned long *end) { } 


struct boot_trace {

	pid_t			caller;

	char			func[KSYM_NAME_LEN];

	char			func[KSYM_SYMBOL_LEN];

	int			result;

	unsigned long long	duration;		/* usecs */

	ktime_t			calltime;

kernel/latencytop.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

mm/slub.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

mm/vmalloc.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

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