UPSTREAM: mm/slub: fix endianness bug for alloc/free_traces attributes
On big-endian s390, the alloc/free_traces attributes produce endless output, because of always 0 idx in slab_debugfs_show(). idx is de-referenced from *v, which points to a loff_t value, with unsigned int idx = *(unsigned int *)v; This will only give the upper 32 bits on big-endian, which remain 0. Instead of only fixing this de-reference, during discussion it seemed more appropriate to change the seq_ops so that they use an explicit iterator in private loc_track struct. This patch adds idx to loc_track, which will also fix the endianness bug. Link: https://lore.kernel.org/r/20211117193932.4049412-1-gerald.schaefer@linux.ibm.com Link: https://lkml.kernel.org/r/20211126171848.17534-1-gerald.schaefer@linux.ibm.com Fixes: 64dd68497be7 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs") Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Reported-by: Steffen Maier <maier@linux.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Faiyaz Mohammed <faiyazm@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> (cherry picked from commit 005a79e5c254c3f60ec269a459cc41b55028c798) Bug: 187129171 Signed-off-by: Connor O'Brien <connoro@google.com> Change-Id: I20271f1694127973df0adc33add9d5910d11024f
This commit is contained in:

committed by
Connor O'Brien

parent
e4f41530d4
commit
900c38d4ed
15
mm/slub.c
15
mm/slub.c
@@ -4687,6 +4687,7 @@ struct loc_track {
|
|||||||
unsigned long max;
|
unsigned long max;
|
||||||
unsigned long count;
|
unsigned long count;
|
||||||
struct location *loc;
|
struct location *loc;
|
||||||
|
loff_t idx;
|
||||||
};
|
};
|
||||||
|
|
||||||
static struct dentry *slab_debugfs_root;
|
static struct dentry *slab_debugfs_root;
|
||||||
@@ -5718,11 +5719,11 @@ __initcall(slab_sysfs_init);
|
|||||||
#if defined(CONFIG_SLUB_DEBUG) && defined(CONFIG_DEBUG_FS)
|
#if defined(CONFIG_SLUB_DEBUG) && defined(CONFIG_DEBUG_FS)
|
||||||
static int slab_debugfs_show(struct seq_file *seq, void *v)
|
static int slab_debugfs_show(struct seq_file *seq, void *v)
|
||||||
{
|
{
|
||||||
|
|
||||||
struct location *l;
|
|
||||||
unsigned int idx = *(unsigned int *)v;
|
|
||||||
struct loc_track *t = seq->private;
|
struct loc_track *t = seq->private;
|
||||||
|
struct location *l;
|
||||||
|
unsigned long idx;
|
||||||
|
|
||||||
|
idx = (unsigned long) t->idx;
|
||||||
if (idx < t->count) {
|
if (idx < t->count) {
|
||||||
l = &t->loc[idx];
|
l = &t->loc[idx];
|
||||||
|
|
||||||
@@ -5771,16 +5772,18 @@ static void *slab_debugfs_next(struct seq_file *seq, void *v, loff_t *ppos)
|
|||||||
{
|
{
|
||||||
struct loc_track *t = seq->private;
|
struct loc_track *t = seq->private;
|
||||||
|
|
||||||
v = ppos;
|
t->idx = ++(*ppos);
|
||||||
++*ppos;
|
|
||||||
if (*ppos <= t->count)
|
if (*ppos <= t->count)
|
||||||
return v;
|
return ppos;
|
||||||
|
|
||||||
return NULL;
|
return NULL;
|
||||||
}
|
}
|
||||||
|
|
||||||
static void *slab_debugfs_start(struct seq_file *seq, loff_t *ppos)
|
static void *slab_debugfs_start(struct seq_file *seq, loff_t *ppos)
|
||||||
{
|
{
|
||||||
|
struct loc_track *t = seq->private;
|
||||||
|
|
||||||
|
t->idx = *ppos;
|
||||||
return ppos;
|
return ppos;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
Reference in New Issue
Block a user