[PATCH -next] mm: Use sysfs_emit functions not sprintf

From: Joe Perches
Date: Tue Oct 06 2020 - 12:28:25 EST


Convert the various uses of sprintf/snprintf/scnprintf to
format sysfs output to sysfs_emit and sysfs_emit_at to make
clear the output is sysfs related and to avoid any possible
buffer overrun of the PAGE_SIZE buffer.

Done with cocci scripts and some typing.

Miscellanea:

o dmapool: Renamed show_pools to pools_show to use DEVICE_ATTR_RO
o hugemem: Convert multiple if (foo) return to cascaded if/else if
with a single return sysfs_emit
o slub: Convert a couple uses like
if (foo)
len += sprintf(buf, len, "%d/%d/%d", a, b, c);
else
len += sprintf(buf, len, "%d", a);
to
len += sysfs_emit_at(buf, len, "%d", a);
if (foo)
len += sysfs_emit_at(buf, len, "/%d/%d", b, c);
o whitespace neatening around these changes

Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---
Depends on next-20201006
commit 2efc459d06f1 ("sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output")

mm/backing-dev.c | 8 ++--
mm/dmapool.c | 27 ++++-------
mm/huge_memory.c | 56 ++++++++++++++---------
mm/hugetlb.c | 14 +++---
mm/khugepaged.c | 22 ++++-----
mm/ksm.c | 32 ++++++-------
mm/slub.c | 133 ++++++++++++++++++++++++++-----------------------------
mm/swap_state.c | 3 +-
8 files changed, 148 insertions(+), 147 deletions(-)

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 408d5051d05b..faa4baf1931d 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -154,7 +154,7 @@ static ssize_t name##_show(struct device *dev, \
{ \
struct backing_dev_info *bdi = dev_get_drvdata(dev); \
\
- return snprintf(page, PAGE_SIZE-1, "%lld\n", (long long)expr); \
+ return sysfs_emit(page, "%lld\n", (long long)expr); \
} \
static DEVICE_ATTR_RW(name);

@@ -200,11 +200,11 @@ BDI_SHOW(max_ratio, bdi->max_ratio)

static ssize_t stable_pages_required_show(struct device *dev,
struct device_attribute *attr,
- char *page)
+ char *buf)
{
dev_warn_once(dev,
- "the stable_pages_required attribute has been removed. Use the stable_writes queue attribute instead.\n");
- return snprintf(page, PAGE_SIZE-1, "%d\n", 0);
+ "the stable_pages_required attribute has been removed. Use the stable_writes queue attribute instead.\n");
+ return sysfs_emit(buf, "%d\n", 0);
}
static DEVICE_ATTR_RO(stable_pages_required);

diff --git a/mm/dmapool.c b/mm/dmapool.c
index a97c97232337..c0082c8f8399 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -62,20 +62,13 @@ static DEFINE_MUTEX(pools_lock);
static DEFINE_MUTEX(pools_reg_lock);

static ssize_t
-show_pools(struct device *dev, struct device_attribute *attr, char *buf)
+pools_show(struct device *dev, struct device_attribute *attr, char *buf)
{
- unsigned temp;
- unsigned size;
- char *next;
struct dma_page *page;
struct dma_pool *pool;
+ int len;

- next = buf;
- size = PAGE_SIZE;
-
- temp = scnprintf(next, size, "poolinfo - 0.1\n");
- size -= temp;
- next += temp;
+ len = sysfs_emit(buf, "poolinfo - 0.1\n");

mutex_lock(&pools_lock);
list_for_each_entry(pool, &dev->dma_pools, pools) {
@@ -90,19 +83,17 @@ show_pools(struct device *dev, struct device_attribute *attr, char *buf)
spin_unlock_irq(&pool->lock);

/* per-pool info, no real statistics yet */
- temp = scnprintf(next, size, "%-16s %4u %4zu %4zu %2u\n",
- pool->name, blocks,
- pages * (pool->allocation / pool->size),
- pool->size, pages);
- size -= temp;
- next += temp;
+ len += sysfs_emit_at(buf, len, "%-16s %4u %4zu %4zu %2u\n",
+ pool->name, blocks,
+ pages * (pool->allocation / pool->size),
+ pool->size, pages);
}
mutex_unlock(&pools_lock);

- return PAGE_SIZE - size;
+ return len;
}

-static DEVICE_ATTR(pools, 0444, show_pools, NULL);
+static DEVICE_ATTR_RO(pools);

/**
* dma_pool_create - Creates a pool of consistent memory blocks, for dma.
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index cba3812a5c3e..02412cb27168 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -163,12 +163,17 @@ static struct shrinker huge_zero_page_shrinker = {
static ssize_t enabled_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
+ const char *output;
+
if (test_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags))
- return sprintf(buf, "[always] madvise never\n");
- else if (test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags))
- return sprintf(buf, "always [madvise] never\n");
+ output = "[always] madvise never";
+ else if (test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
+ &transparent_hugepage_flags))
+ output = "always [madvise] never";
else
- return sprintf(buf, "always madvise [never]\n");
+ output = "always madvise [never]";
+
+ return sysfs_emit(buf, "%s\n", output);
}

static ssize_t enabled_store(struct kobject *kobj,
@@ -200,11 +205,11 @@ static struct kobj_attribute enabled_attr =
__ATTR(enabled, 0644, enabled_show, enabled_store);

ssize_t single_hugepage_flag_show(struct kobject *kobj,
- struct kobj_attribute *attr, char *buf,
- enum transparent_hugepage_flag flag)
+ struct kobj_attribute *attr, char *buf,
+ enum transparent_hugepage_flag flag)
{
- return sprintf(buf, "%d\n",
- !!test_bit(flag, &transparent_hugepage_flags));
+ return sysfs_emit(buf, "%d\n",
+ !!test_bit(flag, &transparent_hugepage_flags));
}

ssize_t single_hugepage_flag_store(struct kobject *kobj,
@@ -232,15 +237,24 @@ ssize_t single_hugepage_flag_store(struct kobject *kobj,
static ssize_t defrag_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags))
- return sprintf(buf, "[always] defer defer+madvise madvise never\n");
- if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags))
- return sprintf(buf, "always [defer] defer+madvise madvise never\n");
- if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags))
- return sprintf(buf, "always defer [defer+madvise] madvise never\n");
- if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags))
- return sprintf(buf, "always defer defer+madvise [madvise] never\n");
- return sprintf(buf, "always defer defer+madvise madvise [never]\n");
+ const char *output;
+
+ if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG,
+ &transparent_hugepage_flags))
+ output = "[always] defer defer+madvise madvise never";
+ else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG,
+ &transparent_hugepage_flags))
+ output = "always [defer] defer+madvise madvise never";
+ else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG,
+ &transparent_hugepage_flags))
+ output = "always defer [defer+madvise] madvise never";
+ else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
+ &transparent_hugepage_flags))
+ output = "always defer defer+madvise [madvise] never";
+ else
+ output = "always defer defer+madvise madvise [never]";
+
+ return sysfs_emit(buf, "%s\n", output);
}

static ssize_t defrag_store(struct kobject *kobj,
@@ -281,10 +295,10 @@ static struct kobj_attribute defrag_attr =
__ATTR(defrag, 0644, defrag_show, defrag_store);

static ssize_t use_zero_page_show(struct kobject *kobj,
- struct kobj_attribute *attr, char *buf)
+ struct kobj_attribute *attr, char *buf)
{
return single_hugepage_flag_show(kobj, attr, buf,
- TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG);
+ TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG);
}
static ssize_t use_zero_page_store(struct kobject *kobj,
struct kobj_attribute *attr, const char *buf, size_t count)
@@ -296,9 +310,9 @@ static struct kobj_attribute use_zero_page_attr =
__ATTR(use_zero_page, 0644, use_zero_page_show, use_zero_page_store);

static ssize_t hpage_pmd_size_show(struct kobject *kobj,
- struct kobj_attribute *attr, char *buf)
+ struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%lu\n", HPAGE_PMD_SIZE);
+ return sysfs_emit(buf, "%lu\n", HPAGE_PMD_SIZE);
}
static struct kobj_attribute hpage_pmd_size_attr =
__ATTR_RO(hpage_pmd_size);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index fe76f8fd5a73..d919542ff6e5 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2837,7 +2837,7 @@ static ssize_t nr_hugepages_show_common(struct kobject *kobj,
else
nr_huge_pages = h->nr_huge_pages_node[nid];

- return sprintf(buf, "%lu\n", nr_huge_pages);
+ return sysfs_emit(buf, "%lu\n", nr_huge_pages);
}

static ssize_t __nr_hugepages_store_common(bool obey_mempolicy,
@@ -2910,7 +2910,8 @@ HSTATE_ATTR(nr_hugepages);
* huge page alloc/free.
*/
static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj,
- struct kobj_attribute *attr, char *buf)
+ struct kobj_attribute *attr,
+ char *buf)
{
return nr_hugepages_show_common(kobj, attr, buf);
}
@@ -2928,7 +2929,7 @@ static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct hstate *h = kobj_to_hstate(kobj, NULL);
- return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages);
+ return sysfs_emit(buf, "%lu\n", h->nr_overcommit_huge_pages);
}

static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,
@@ -2966,7 +2967,7 @@ static ssize_t free_hugepages_show(struct kobject *kobj,
else
free_huge_pages = h->free_huge_pages_node[nid];

- return sprintf(buf, "%lu\n", free_huge_pages);
+ return sysfs_emit(buf, "%lu\n", free_huge_pages);
}
HSTATE_ATTR_RO(free_hugepages);

@@ -2974,7 +2975,8 @@ static ssize_t resv_hugepages_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
struct hstate *h = kobj_to_hstate(kobj, NULL);
- return sprintf(buf, "%lu\n", h->resv_huge_pages);
+
+ return sysfs_emit(buf, "%lu\n", h->resv_huge_pages);
}
HSTATE_ATTR_RO(resv_hugepages);

@@ -2991,7 +2993,7 @@ static ssize_t surplus_hugepages_show(struct kobject *kobj,
else
surplus_huge_pages = h->surplus_huge_pages_node[nid];

- return sprintf(buf, "%lu\n", surplus_huge_pages);
+ return sysfs_emit(buf, "%lu\n", surplus_huge_pages);
}
HSTATE_ATTR_RO(surplus_hugepages);

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index f1d5f6dde47c..28dcaca63f2b 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -124,7 +124,7 @@ static ssize_t scan_sleep_millisecs_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
- return sprintf(buf, "%u\n", khugepaged_scan_sleep_millisecs);
+ return sysfs_emit(buf, "%u\n", khugepaged_scan_sleep_millisecs);
}

static ssize_t scan_sleep_millisecs_store(struct kobject *kobj,
@@ -152,7 +152,7 @@ static ssize_t alloc_sleep_millisecs_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
- return sprintf(buf, "%u\n", khugepaged_alloc_sleep_millisecs);
+ return sysfs_emit(buf, "%u\n", khugepaged_alloc_sleep_millisecs);
}

static ssize_t alloc_sleep_millisecs_store(struct kobject *kobj,
@@ -180,7 +180,7 @@ static ssize_t pages_to_scan_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
- return sprintf(buf, "%u\n", khugepaged_pages_to_scan);
+ return sysfs_emit(buf, "%u\n", khugepaged_pages_to_scan);
}
static ssize_t pages_to_scan_store(struct kobject *kobj,
struct kobj_attribute *attr,
@@ -205,7 +205,7 @@ static ssize_t pages_collapsed_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
- return sprintf(buf, "%u\n", khugepaged_pages_collapsed);
+ return sysfs_emit(buf, "%u\n", khugepaged_pages_collapsed);
}
static struct kobj_attribute pages_collapsed_attr =
__ATTR_RO(pages_collapsed);
@@ -214,7 +214,7 @@ static ssize_t full_scans_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
- return sprintf(buf, "%u\n", khugepaged_full_scans);
+ return sysfs_emit(buf, "%u\n", khugepaged_full_scans);
}
static struct kobj_attribute full_scans_attr =
__ATTR_RO(full_scans);
@@ -223,7 +223,7 @@ static ssize_t khugepaged_defrag_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return single_hugepage_flag_show(kobj, attr, buf,
- TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG);
+ TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG);
}
static ssize_t khugepaged_defrag_store(struct kobject *kobj,
struct kobj_attribute *attr,
@@ -248,7 +248,7 @@ static ssize_t khugepaged_max_ptes_none_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
- return sprintf(buf, "%u\n", khugepaged_max_ptes_none);
+ return sysfs_emit(buf, "%u\n", khugepaged_max_ptes_none);
}
static ssize_t khugepaged_max_ptes_none_store(struct kobject *kobj,
struct kobj_attribute *attr,
@@ -273,7 +273,7 @@ static ssize_t khugepaged_max_ptes_swap_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
- return sprintf(buf, "%u\n", khugepaged_max_ptes_swap);
+ return sysfs_emit(buf, "%u\n", khugepaged_max_ptes_swap);
}

static ssize_t khugepaged_max_ptes_swap_store(struct kobject *kobj,
@@ -297,10 +297,10 @@ static struct kobj_attribute khugepaged_max_ptes_swap_attr =
khugepaged_max_ptes_swap_store);

static ssize_t khugepaged_max_ptes_shared_show(struct kobject *kobj,
- struct kobj_attribute *attr,
- char *buf)
+ struct kobj_attribute *attr,
+ char *buf)
{
- return sprintf(buf, "%u\n", khugepaged_max_ptes_shared);
+ return sysfs_emit(buf, "%u\n", khugepaged_max_ptes_shared);
}

static ssize_t khugepaged_max_ptes_shared_store(struct kobject *kobj,
diff --git a/mm/ksm.c b/mm/ksm.c
index 9afccc36dbd2..3c7f7a1101c5 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -2833,7 +2833,7 @@ static void wait_while_offlining(void)
static ssize_t sleep_millisecs_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%u\n", ksm_thread_sleep_millisecs);
+ return sysfs_emit(buf, "%u\n", ksm_thread_sleep_millisecs);
}

static ssize_t sleep_millisecs_store(struct kobject *kobj,
@@ -2857,7 +2857,7 @@ KSM_ATTR(sleep_millisecs);
static ssize_t pages_to_scan_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%u\n", ksm_thread_pages_to_scan);
+ return sysfs_emit(buf, "%u\n", ksm_thread_pages_to_scan);
}

static ssize_t pages_to_scan_store(struct kobject *kobj,
@@ -2880,7 +2880,7 @@ KSM_ATTR(pages_to_scan);
static ssize_t run_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
- return sprintf(buf, "%lu\n", ksm_run);
+ return sysfs_emit(buf, "%lu\n", ksm_run);
}

static ssize_t run_store(struct kobject *kobj, struct kobj_attribute *attr,
@@ -2927,9 +2927,9 @@ KSM_ATTR(run);

#ifdef CONFIG_NUMA
static ssize_t merge_across_nodes_show(struct kobject *kobj,
- struct kobj_attribute *attr, char *buf)
+ struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%u\n", ksm_merge_across_nodes);
+ return sysfs_emit(buf, "%u\n", ksm_merge_across_nodes);
}

static ssize_t merge_across_nodes_store(struct kobject *kobj,
@@ -2984,9 +2984,9 @@ KSM_ATTR(merge_across_nodes);
#endif

static ssize_t use_zero_pages_show(struct kobject *kobj,
- struct kobj_attribute *attr, char *buf)
+ struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%u\n", ksm_use_zero_pages);
+ return sysfs_emit(buf, "%u\n", ksm_use_zero_pages);
}
static ssize_t use_zero_pages_store(struct kobject *kobj,
struct kobj_attribute *attr,
@@ -3008,7 +3008,7 @@ KSM_ATTR(use_zero_pages);
static ssize_t max_page_sharing_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%u\n", ksm_max_page_sharing);
+ return sysfs_emit(buf, "%u\n", ksm_max_page_sharing);
}

static ssize_t max_page_sharing_store(struct kobject *kobj,
@@ -3049,21 +3049,21 @@ KSM_ATTR(max_page_sharing);
static ssize_t pages_shared_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%lu\n", ksm_pages_shared);
+ return sysfs_emit(buf, "%lu\n", ksm_pages_shared);
}
KSM_ATTR_RO(pages_shared);

static ssize_t pages_sharing_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%lu\n", ksm_pages_sharing);
+ return sysfs_emit(buf, "%lu\n", ksm_pages_sharing);
}
KSM_ATTR_RO(pages_sharing);

static ssize_t pages_unshared_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%lu\n", ksm_pages_unshared);
+ return sysfs_emit(buf, "%lu\n", ksm_pages_unshared);
}
KSM_ATTR_RO(pages_unshared);

@@ -3080,21 +3080,21 @@ static ssize_t pages_volatile_show(struct kobject *kobj,
*/
if (ksm_pages_volatile < 0)
ksm_pages_volatile = 0;
- return sprintf(buf, "%ld\n", ksm_pages_volatile);
+ return sysfs_emit(buf, "%ld\n", ksm_pages_volatile);
}
KSM_ATTR_RO(pages_volatile);

static ssize_t stable_node_dups_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%lu\n", ksm_stable_node_dups);
+ return sysfs_emit(buf, "%lu\n", ksm_stable_node_dups);
}
KSM_ATTR_RO(stable_node_dups);

static ssize_t stable_node_chains_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%lu\n", ksm_stable_node_chains);
+ return sysfs_emit(buf, "%lu\n", ksm_stable_node_chains);
}
KSM_ATTR_RO(stable_node_chains);

@@ -3103,7 +3103,7 @@ stable_node_chains_prune_millisecs_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
- return sprintf(buf, "%u\n", ksm_stable_node_chains_prune_millisecs);
+ return sysfs_emit(buf, "%u\n", ksm_stable_node_chains_prune_millisecs);
}

static ssize_t
@@ -3127,7 +3127,7 @@ KSM_ATTR(stable_node_chains_prune_millisecs);
static ssize_t full_scans_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%lu\n", ksm_scan.seqnr);
+ return sysfs_emit(buf, "%lu\n", ksm_scan.seqnr);
}
KSM_ATTR_RO(full_scans);

diff --git a/mm/slub.c b/mm/slub.c
index 8f66de8a5ab3..7ae323bd77ac 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4735,7 +4735,7 @@ static int list_locations(struct kmem_cache *s, char *buf,

if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
GFP_KERNEL)) {
- return sprintf(buf, "Out of memory\n");
+ return sysfs_emit(buf, "Out of memory\n");
}
/* Push back cpu slabs */
flush_all(s);
@@ -4758,50 +4758,41 @@ 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 - KSYM_SYMBOL_LEN - 100)
- break;
- len += sprintf(buf + len, "%7ld ", l->count);
+ len += sysfs_emit_at(buf, len, "%7ld ", l->count);

if (l->addr)
- len += sprintf(buf + len, "%pS", (void *)l->addr);
+ len += sysfs_emit_at(buf, len, "%pS", (void *)l->addr);
else
- len += sprintf(buf + len, "<not-available>");
+ len += sysfs_emit_at(buf, len, "<not-available>");

- if (l->sum_time != l->min_time) {
- len += sprintf(buf + len, " age=%ld/%ld/%ld",
- l->min_time,
- (long)div_u64(l->sum_time, l->count),
- l->max_time);
- } else
- len += sprintf(buf + len, " age=%ld",
- l->min_time);
+ len += sysfs_emit_at(buf, len, " age=%ld", l->min_time);
+ if (l->sum_time != l->min_time)
+ len += sysfs_emit_at(buf, len, "%ld/%ld",
+ (long)div_u64(l->sum_time,
+ l->count),
+ l->max_time);

+ len += sysfs_emit_at(buf, len, " pid=%ld", l->min_pid);
if (l->min_pid != l->max_pid)
- len += sprintf(buf + len, " pid=%ld-%ld",
- l->min_pid, l->max_pid);
- else
- len += sprintf(buf + len, " pid=%ld",
- l->min_pid);
+ len += sysfs_emit_at(buf, len, "-%ld", l->max_pid);

if (num_online_cpus() > 1 &&
- !cpumask_empty(to_cpumask(l->cpus)) &&
- len < PAGE_SIZE - 60)
- len += scnprintf(buf + len, PAGE_SIZE - len - 50,
- " cpus=%*pbl",
- cpumask_pr_args(to_cpumask(l->cpus)));
-
- if (nr_online_nodes > 1 && !nodes_empty(l->nodes) &&
- len < PAGE_SIZE - 60)
- len += scnprintf(buf + len, PAGE_SIZE - len - 50,
- " nodes=%*pbl",
- nodemask_pr_args(&l->nodes));
-
- len += sprintf(buf + len, "\n");
+ !cpumask_empty(to_cpumask(l->cpus)))
+ len += sysfs_emit_at(buf, len, " cpus=%*pbl",
+ cpumask_pr_args(to_cpumask(l->cpus)));
+
+ if (nr_online_nodes > 1 && !nodes_empty(l->nodes))
+ len += sysfs_emit_at(buf, len, " nodes=%*pbl",
+ nodemask_pr_args(&l->nodes));
+
+ len += sysfs_emit_at(buf, len, "\n");
}

free_loc_track(&t);
+
if (!t.count)
- len += sprintf(buf, "No data\n");
+ len += sysfs_emit_at(buf, len, "No data\n");
+
return len;
}
#endif /* CONFIG_SLUB_DEBUG */
@@ -4903,6 +4894,7 @@ static ssize_t show_slab_objects(struct kmem_cache *s,
unsigned long total = 0;
int node;
int x;
+ int len;
unsigned long *nodes;

nodes = kcalloc(nr_node_ids, sizeof(unsigned long), GFP_KERNEL);
@@ -4992,15 +4984,17 @@ static ssize_t show_slab_objects(struct kmem_cache *s,
nodes[node] += x;
}
}
- x = sprintf(buf, "%lu", total);
+
+ len = sysfs_emit(buf, "%lu", total);
#ifdef CONFIG_NUMA
for (node = 0; node < nr_node_ids; node++)
if (nodes[node])
- x += sprintf(buf + x, " N%d=%lu",
- node, nodes[node]);
+ len += sysfs_emit_at(buf, len, " N%d=%lu",
+ node, nodes[node]);
#endif
kfree(nodes);
- return x + sprintf(buf + x, "\n");
+ len += sysfs_emit_at(buf, len, "\n");
+ return len;
}

#define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
@@ -5022,37 +5016,37 @@ struct slab_attribute {

static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%u\n", s->size);
+ return sysfs_emit(buf, "%u\n", s->size);
}
SLAB_ATTR_RO(slab_size);

static ssize_t align_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%u\n", s->align);
+ return sysfs_emit(buf, "%u\n", s->align);
}
SLAB_ATTR_RO(align);

static ssize_t object_size_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%u\n", s->object_size);
+ return sysfs_emit(buf, "%u\n", s->object_size);
}
SLAB_ATTR_RO(object_size);

static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%u\n", oo_objects(s->oo));
+ return sysfs_emit(buf, "%u\n", oo_objects(s->oo));
}
SLAB_ATTR_RO(objs_per_slab);

static ssize_t order_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%u\n", oo_order(s->oo));
+ return sysfs_emit(buf, "%u\n", oo_order(s->oo));
}
SLAB_ATTR_RO(order);

static ssize_t min_partial_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%lu\n", s->min_partial);
+ return sysfs_emit(buf, "%lu\n", s->min_partial);
}

static ssize_t min_partial_store(struct kmem_cache *s, const char *buf,
@@ -5072,7 +5066,7 @@ SLAB_ATTR(min_partial);

static ssize_t cpu_partial_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%u\n", slub_cpu_partial(s));
+ return sysfs_emit(buf, "%u\n", slub_cpu_partial(s));
}

static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf,
@@ -5097,13 +5091,13 @@ static ssize_t ctor_show(struct kmem_cache *s, char *buf)
{
if (!s->ctor)
return 0;
- return sprintf(buf, "%pS\n", s->ctor);
+ return sysfs_emit(buf, "%pS\n", s->ctor);
}
SLAB_ATTR_RO(ctor);

static ssize_t aliases_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%d\n", s->refcount < 0 ? 0 : s->refcount - 1);
+ return sysfs_emit(buf, "%d\n", s->refcount < 0 ? 0 : s->refcount - 1);
}
SLAB_ATTR_RO(aliases);

@@ -5149,20 +5143,19 @@ static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf)
}
}

- len = sprintf(buf, "%d(%d)", objects, pages);
+ len = sysfs_emit(buf, "%d(%d)", objects, pages);

#ifdef CONFIG_SMP
for_each_online_cpu(cpu) {
struct page *page;

page = slub_percpu_partial(per_cpu_ptr(s->cpu_slab, cpu));
-
- if (page && len < PAGE_SIZE - 20)
- len += sprintf(buf + len, " C%d=%d(%d)", cpu,
- page->pobjects, page->pages);
+ len += sysfs_emit_at(buf, len, " C%d=%d(%d)",
+ cpu, page->pobjects, page->pages);
}
#endif
- return len + sprintf(buf + len, "\n");
+ len += sysfs_emit_at(buf, len, "\n");
+ return len;
}
SLAB_ATTR_RO(slabs_cpu_partial);

@@ -5174,27 +5167,27 @@ SLAB_ATTR_RO(reclaim_account);

static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
+ return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
}
SLAB_ATTR_RO(hwcache_align);

#ifdef CONFIG_ZONE_DMA
static ssize_t cache_dma_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
+ return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
}
SLAB_ATTR_RO(cache_dma);
#endif

static ssize_t usersize_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%u\n", s->usersize);
+ return sysfs_emit(buf, "%u\n", s->usersize);
}
SLAB_ATTR_RO(usersize);

static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%d\n", !!(s->flags & SLAB_TYPESAFE_BY_RCU));
+ return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_TYPESAFE_BY_RCU));
}
SLAB_ATTR_RO(destroy_by_rcu);

@@ -5213,33 +5206,33 @@ SLAB_ATTR_RO(total_objects);

static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%d\n", !!(s->flags & SLAB_CONSISTENCY_CHECKS));
+ return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_CONSISTENCY_CHECKS));
}
SLAB_ATTR_RO(sanity_checks);

static ssize_t trace_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE));
+ return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_TRACE));
}
SLAB_ATTR_RO(trace);

static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
+ return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
}

SLAB_ATTR_RO(red_zone);

static ssize_t poison_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON));
+ return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_POISON));
}

SLAB_ATTR_RO(poison);

static ssize_t store_user_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
+ return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
}

SLAB_ATTR_RO(store_user);
@@ -5283,7 +5276,7 @@ SLAB_ATTR_RO(free_calls);
#ifdef CONFIG_FAILSLAB
static ssize_t failslab_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB));
+ return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB));
}
SLAB_ATTR_RO(failslab);
#endif
@@ -5307,7 +5300,7 @@ SLAB_ATTR(shrink);
#ifdef CONFIG_NUMA
static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf)
{
- return sprintf(buf, "%u\n", s->remote_node_defrag_ratio / 10);
+ return sysfs_emit(buf, "%u\n", s->remote_node_defrag_ratio / 10);
}

static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s,
@@ -5332,7 +5325,7 @@ SLAB_ATTR(remote_node_defrag_ratio);
#ifdef CONFIG_SLUB_STATS
static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
{
- unsigned long sum = 0;
+ unsigned long sum = 0;
int cpu;
int len;
int *data = kmalloc_array(nr_cpu_ids, sizeof(int), GFP_KERNEL);
@@ -5347,16 +5340,16 @@ static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
sum += x;
}

- len = sprintf(buf, "%lu", sum);
+ len = sysfs_emit(buf, "%lu", sum);

#ifdef CONFIG_SMP
- for_each_online_cpu(cpu) {
- if (data[cpu] && len < PAGE_SIZE - 20)
- len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]);
- }
+ for_each_online_cpu(cpu)
+ len += sysfs_emit_at(buf, len, " C%d=%u", cpu, data[cpu]);
#endif
kfree(data);
- return len + sprintf(buf + len, "\n");
+
+ len += sysfs_emit_at(buf, len, "\n");
+ return len;
}

static void clear_stat(struct kmem_cache *s, enum stat_item si)
diff --git a/mm/swap_state.c b/mm/swap_state.c
index ee465827420e..aeb5bc4d64ec 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -900,7 +900,8 @@ struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask,
static ssize_t vma_ra_enabled_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- return sprintf(buf, "%s\n", enable_vma_readahead ? "true" : "false");
+ return sysfs_emit(buf, "%s\n",
+ enable_vma_readahead ? "true" : "false");
}
static ssize_t vma_ra_enabled_store(struct kobject *kobj,
struct kobj_attribute *attr,