treewide: Remove uninitialized_var() usage
Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.
In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:
git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
xargs perl -pi -e \
's/\buninitialized_var\(([^\)]+)\)/\1/g;
s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'
drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.
No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.
[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/
Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>
diff --git a/mm/frontswap.c b/mm/frontswap.c
index bfa3a33..9d977b1 100644
--- a/mm/frontswap.c
+++ b/mm/frontswap.c
@@ -446,7 +446,7 @@ static int __frontswap_shrink(unsigned long target_pages,
void frontswap_shrink(unsigned long target_pages)
{
unsigned long pages_to_unuse = 0;
- int uninitialized_var(type), ret;
+ int type, ret;
/*
* we don't want to hold swap_lock while doing a very
diff --git a/mm/ksm.c b/mm/ksm.c
index 4102034..5fb176d 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -2387,7 +2387,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
static void ksm_do_scan(unsigned int scan_npages)
{
struct rmap_item *rmap_item;
- struct page *uninitialized_var(page);
+ struct page *page;
while (scan_npages-- && likely(!freezing(current))) {
cond_resched();
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1962232..c888d9b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1004,7 +1004,7 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
struct mem_cgroup *prev,
struct mem_cgroup_reclaim_cookie *reclaim)
{
- struct mem_cgroup_reclaim_iter *uninitialized_var(iter);
+ struct mem_cgroup_reclaim_iter *iter;
struct cgroup_subsys_state *css = NULL;
struct mem_cgroup *memcg = NULL;
struct mem_cgroup *pos = NULL;
diff --git a/mm/memory.c b/mm/memory.c
index 87ec87c..5b5887b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2205,7 +2205,7 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
{
pte_t *pte;
int err = 0;
- spinlock_t *uninitialized_var(ptl);
+ spinlock_t *ptl;
if (create) {
pte = (mm == &init_mm) ?
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 3813206..b9e85d4 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1234,7 +1234,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
static struct page *new_page(struct page *page, unsigned long start)
{
struct vm_area_struct *vma;
- unsigned long uninitialized_var(address);
+ unsigned long address;
vma = find_vma(current->mm, start);
while (vma) {
@@ -1629,7 +1629,7 @@ static int kernel_get_mempolicy(int __user *policy,
unsigned long flags)
{
int err;
- int uninitialized_var(pval);
+ int pval;
nodemask_t nodes;
addr = untagged_addr(addr);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 48eb0f1..b52a3a2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -961,7 +961,7 @@ static inline void __free_one_page(struct page *page,
int migratetype, bool report)
{
struct capture_control *capc = task_capc(zone);
- unsigned long uninitialized_var(buddy_pfn);
+ unsigned long buddy_pfn;
unsigned long combined_pfn;
unsigned int max_order;
struct page *buddy;
diff --git a/mm/percpu.c b/mm/percpu.c
index 696367b..b626766 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -2513,7 +2513,7 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info(
const size_t static_size = __per_cpu_end - __per_cpu_start;
int nr_groups = 1, nr_units = 0;
size_t size_sum, min_unit_size, alloc_size;
- int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */
+ int upa, max_upa, best_upa; /* units_per_alloc */
int last_allocs, group, unit;
unsigned int cpu, tcpu;
struct pcpu_alloc_info *ai;
diff --git a/mm/slub.c b/mm/slub.c
index ef30307..f226d66 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1218,7 +1218,7 @@ static noinline int free_debug_processing(
struct kmem_cache_node *n = get_node(s, page_to_nid(page));
void *object = head;
int cnt = 0;
- unsigned long uninitialized_var(flags);
+ unsigned long flags;
int ret = 0;
spin_lock_irqsave(&n->list_lock, flags);
@@ -2901,7 +2901,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
struct page new;
unsigned long counters;
struct kmem_cache_node *n = NULL;
- unsigned long uninitialized_var(flags);
+ unsigned long flags;
stat(s, FREE_SLOWPATH);
diff --git a/mm/swap.c b/mm/swap.c
index a82efc33..de257c0 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -830,8 +830,8 @@ void release_pages(struct page **pages, int nr)
LIST_HEAD(pages_to_free);
struct pglist_data *locked_pgdat = NULL;
struct lruvec *lruvec;
- unsigned long uninitialized_var(flags);
- unsigned int uninitialized_var(lock_batch);
+ unsigned long flags;
+ unsigned int lock_batch;
for (i = 0; i < nr; i++) {
struct page *page = pages[i];
