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>

16 files changed, 22 insertions, 22 deletions

diff --git a/arch/arm/mach-sa1100/assabet.c b/arch/arm/mach-sa1100/assabet.c
index aa265ede5730..2012fa8c28cf 100644
--- a/arch/arm/mach-sa1100/assabet.c
+++ b/arch/arm/mach-sa1100/assabet.c
@@ -652,7 +652,7 @@ static void __init map_sa1100_gpio_regs( void )
  */
 static void __init get_assabet_scr(void)
 {
-	unsigned long uninitialized_var(scr), i;
+	unsigned long scr, i;
 
 	GPDR |= 0x3fc;			/* Configure GPIO 9:2 as outputs */
 	GPSR = 0x3fc;			/* Write 0xFF to GPIO 9:2 */
diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c
index 81a627e6e1c5..f4bfc1cac91a 100644
--- a/arch/arm/mm/alignment.c
+++ b/arch/arm/mm/alignment.c
@@ -799,7 +799,7 @@ static int alignment_get_thumb(struct pt_regs *regs, u16 *ip, u16 *inst)
 static int
 do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 {
-	union offset_union uninitialized_var(offset);
+	union offset_union offset;
 	unsigned long instrptr;
 	int (*handler)(unsigned long addr, u32 instr, struct pt_regs *regs);
 	unsigned int type;
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 96dfb9e4b16f..da55b41ae33e 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -445,7 +445,7 @@ static void
 do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg)
 {
 	unsigned long mask, sp, nat_bits = 0, ar_rnat, urbs_end, cfm;
-	unsigned long uninitialized_var(ip);	/* GCC be quiet */
+	unsigned long ip;
 	elf_greg_t *dst = arg;
 	struct pt_regs *pt;
 	char nat;
diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c
index dd8284bcbf16..da810ca234da 100644
--- a/arch/ia64/mm/discontig.c
+++ b/arch/ia64/mm/discontig.c
@@ -180,7 +180,7 @@ static void *per_cpu_node_setup(void *cpu_data, int node)
 void __init setup_per_cpu_areas(void)
 {
 	struct pcpu_alloc_info *ai;
-	struct pcpu_group_info *uninitialized_var(gi);
+	struct pcpu_group_info *gi;
 	unsigned int *cpu_map;
 	void *base;
 	unsigned long base_offset;
diff --git a/arch/ia64/mm/tlb.c b/arch/ia64/mm/tlb.c
index 72cc568bc841..71c19918e387 100644
--- a/arch/ia64/mm/tlb.c
+++ b/arch/ia64/mm/tlb.c
@@ -369,7 +369,7 @@ EXPORT_SYMBOL(flush_tlb_range);
 
 void ia64_tlb_init(void)
 {
-	ia64_ptce_info_t uninitialized_var(ptce_info); /* GCC be quiet */
+	ia64_ptce_info_t ptce_info;
 	u64 tr_pgbits;
 	long status;
 	pal_vm_info_1_u_t vm_info_1;
diff --git a/arch/mips/lib/dump_tlb.c b/arch/mips/lib/dump_tlb.c
index 5a418ba5e75f..4256423632c4 100644
--- a/arch/mips/lib/dump_tlb.c
+++ b/arch/mips/lib/dump_tlb.c
@@ -79,7 +79,7 @@ static void dump_tlb(int first, int last)
 	unsigned int pagemask, guestctl1 = 0, c0, c1, i;
 	unsigned long asidmask = cpu_asid_mask(&current_cpu_data);
 	int asidwidth = DIV_ROUND_UP(ilog2(asidmask) + 1, 4);
-	unsigned long uninitialized_var(s_mmid);
+	unsigned long s_mmid;
 #ifdef CONFIG_32BIT
 	bool xpa = cpu_has_xpa && (read_c0_pagegrain() & PG_ELPA);
 	int pwidth = xpa ? 11 : 8;
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 336b58173dc7..6c7bbfe35ba3 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -83,7 +83,7 @@ void setup_zero_pages(void)
 static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot)
 {
 	enum fixed_addresses idx;
-	unsigned int uninitialized_var(old_mmid);
+	unsigned int old_mmid;
 	unsigned long vaddr, flags, entrylo;
 	unsigned long old_ctx;
 	pte_t pte;
diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
index 6677dcb72580..38e2894d5fa3 100644
--- a/arch/mips/mm/tlb-r4k.c
+++ b/arch/mips/mm/tlb-r4k.c
@@ -119,7 +119,7 @@ void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 		if (size <= (current_cpu_data.tlbsizeftlbsets ?
 			     current_cpu_data.tlbsize / 8 :
 			     current_cpu_data.tlbsize / 2)) {
-			unsigned long old_entryhi, uninitialized_var(old_mmid);
+			unsigned long old_entryhi, old_mmid;
 			int newpid = cpu_asid(cpu, mm);
 
 			old_entryhi = read_c0_entryhi();
@@ -213,7 +213,7 @@ void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 	int cpu = smp_processor_id();
 
 	if (cpu_context(cpu, vma->vm_mm) != 0) {
-		unsigned long uninitialized_var(old_mmid);
+		unsigned long old_mmid;
 		unsigned long flags, old_entryhi;
 		int idx;
 
@@ -382,7 +382,7 @@ void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
 #ifdef CONFIG_XPA
 	panic("Broken for XPA kernels");
 #else
-	unsigned int uninitialized_var(old_mmid);
+	unsigned int old_mmid;
 	unsigned long flags;
 	unsigned long wired;
 	unsigned long old_pagemask;
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index 6a73714759ba..777aa5625d5f 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -33,7 +33,7 @@ unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
 					      gva_t eaddr, void *to, void *from,
 					      unsigned long n)
 {
-	int uninitialized_var(old_pid), old_lpid;
+	int old_pid, old_lpid;
 	unsigned long quadrant, ret = n;
 	bool is_load = !!to;
 
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index dd7d141e33e8..aaa7b62f2f82 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -1110,7 +1110,7 @@ static inline u32 dp_to_sp(u64 fprd)
 static void kvmppc_complete_mmio_load(struct kvm_vcpu *vcpu)
 {
 	struct kvm_run *run = vcpu->run;
-	u64 uninitialized_var(gpr);
+	u64 gpr;
 
 	if (run->mmio.len > sizeof(gpr)) {
 		printk(KERN_ERR "bad MMIO length: %d\n", run->mmio.len);
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
index fc98912f42cf..76a8102bdb98 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_pic.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
@@ -340,7 +340,7 @@ static int mpc52xx_irqhost_map(struct irq_domain *h, unsigned int virq,
 {
 	int l1irq;
 	int l2irq;
-	struct irq_chip *uninitialized_var(irqchip);
+	struct irq_chip *irqchip;
 	void *hndlr;
 	int type;
 	u32 reg;
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index e6be63ff162a..c2181471ac63 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -146,7 +146,7 @@ static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
 
 static inline int pcpu_stopped(struct pcpu *pcpu)
 {
-	u32 uninitialized_var(status);
+	u32 status;
 
 	if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
 			0, &status) != SIGP_CC_STATUS_STORED)
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index 896d74cb5081..1b10717c9321 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -95,7 +95,7 @@ static void ich_force_hpet_resume(void)
 static void ich_force_enable_hpet(struct pci_dev *dev)
 {
 	u32 val;
-	u32 uninitialized_var(rcba);
+	u32 rcba;
 	int err = 0;
 
 	if (hpet_address || force_hpet_address)
@@ -185,7 +185,7 @@ static void hpet_print_force_info(void)
 static void old_ich_force_hpet_resume(void)
 {
 	u32 val;
-	u32 uninitialized_var(gen_cntl);
+	u32 gen_cntl;
 
 	if (!force_hpet_address || !cached_dev)
 		return;
@@ -207,7 +207,7 @@ static void old_ich_force_hpet_resume(void)
 static void old_ich_force_enable_hpet(struct pci_dev *dev)
 {
 	u32 val;
-	u32 uninitialized_var(gen_cntl);
+	u32 gen_cntl;
 
 	if (hpet_address || force_hpet_address)
 		return;
@@ -298,7 +298,7 @@ static void vt8237_force_hpet_resume(void)
 
 static void vt8237_force_enable_hpet(struct pci_dev *dev)
 {
-	u32 uninitialized_var(val);
+	u32 val;
 
 	if (hpet_address || force_hpet_address)
 		return;
@@ -429,7 +429,7 @@ static void nvidia_force_hpet_resume(void)
 
 static void nvidia_force_enable_hpet(struct pci_dev *dev)
 {
-	u32 uninitialized_var(val);
+	u32 val;
 
 	if (hpet_address || force_hpet_address)
 		return;
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 76817d13c86e..deafcced65d2 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1986,7 +1986,7 @@ static int kvm_age_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
 			 unsigned long data)
 {
 	u64 *sptep;
-	struct rmap_iterator uninitialized_var(iter);
+	struct rmap_iterator iter;
 	int young = 0;
 
 	for_each_rmap_spte(rmap_head, &iter, sptep)
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index bd70ece1ef8b..275564a0ebdb 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -314,7 +314,7 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
 {
 	int ret;
 	pt_element_t pte;
-	pt_element_t __user *uninitialized_var(ptep_user);
+	pt_element_t __user *ptep_user;
 	gfn_t table_gfn;
 	u64 pt_access, pte_access;
 	unsigned index, accessed_dirty, pte_pkey;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3b92db412335..598d5be960c9 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9927,7 +9927,7 @@ void kvm_arch_sync_events(struct kvm *kvm)
 int __x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa, u32 size)
 {
 	int i, r;
-	unsigned long hva, uninitialized_var(old_npages);
+	unsigned long hva, old_npages;
 	struct kvm_memslots *slots = kvm_memslots(kvm);
 	struct kvm_memory_slot *slot;