arch/openrisc/mm/init.c:125:10: warning: Uninitialized variable: region [uninitvar]

From: kernel test robot
Date: Fri May 07 2021 - 01:46:29 EST

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 9f67672a817ec046f7554a885f0fe0d60e1bf99f
commit: b10d6bca87204cdafd0cd7aaa837ad30b4eb8c20 arch, drivers: replace for_each_membock() with for_each_mem_range()
compiler: or1k-linux-gcc (GCC) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>


cppcheck possible warnings: (new ones prefixed by >>, may not real problems)

>> arch/openrisc/mm/init.c:125:10: warning: Uninitialized variable: region [uninitvar]
region->base, region->base + region->size);
^

vim +125 arch/openrisc/mm/init.c

61e85e367535a7 Jonas Bonn 2011-06-04 58
61e85e367535a7 Jonas Bonn 2011-06-04 59 /*
61e85e367535a7 Jonas Bonn 2011-06-04 60 * Map all physical memory into kernel's address space.
61e85e367535a7 Jonas Bonn 2011-06-04 61 *
61e85e367535a7 Jonas Bonn 2011-06-04 62 * This is explicitly coded for two-level page tables, so if you need
61e85e367535a7 Jonas Bonn 2011-06-04 63 * something else then this needs to change.
61e85e367535a7 Jonas Bonn 2011-06-04 64 */
61e85e367535a7 Jonas Bonn 2011-06-04 65 static void __init map_ram(void)
61e85e367535a7 Jonas Bonn 2011-06-04 66 {
b10d6bca87204c Mike Rapoport 2020-10-13 67 phys_addr_t start, end;
61e85e367535a7 Jonas Bonn 2011-06-04 68 unsigned long v, p, e;
61e85e367535a7 Jonas Bonn 2011-06-04 69 pgprot_t prot;
61e85e367535a7 Jonas Bonn 2011-06-04 70 pgd_t *pge;
b187fb7fca9cc4 Mike Rapoport 2020-06-04 71 p4d_t *p4e;
61e85e367535a7 Jonas Bonn 2011-06-04 72 pud_t *pue;
61e85e367535a7 Jonas Bonn 2011-06-04 73 pmd_t *pme;
61e85e367535a7 Jonas Bonn 2011-06-04 74 pte_t *pte;
b10d6bca87204c Mike Rapoport 2020-10-13 75 u64 i;
61e85e367535a7 Jonas Bonn 2011-06-04 76 /* These mark extents of read-only kernel pages...
61e85e367535a7 Jonas Bonn 2011-06-04 77 * ...from vmlinux.lds.S
61e85e367535a7 Jonas Bonn 2011-06-04 78 */
61e85e367535a7 Jonas Bonn 2011-06-04 79 struct memblock_region *region;
61e85e367535a7 Jonas Bonn 2011-06-04 80
61e85e367535a7 Jonas Bonn 2011-06-04 81 v = PAGE_OFFSET;
61e85e367535a7 Jonas Bonn 2011-06-04 82
b10d6bca87204c Mike Rapoport 2020-10-13 83 for_each_mem_range(i, &start, &end) {
b10d6bca87204c Mike Rapoport 2020-10-13 84 p = (u32) start & PAGE_MASK;
b10d6bca87204c Mike Rapoport 2020-10-13 85 e = (u32) end;
61e85e367535a7 Jonas Bonn 2011-06-04 86
61e85e367535a7 Jonas Bonn 2011-06-04 87 v = (u32) __va(p);
61e85e367535a7 Jonas Bonn 2011-06-04 88 pge = pgd_offset_k(v);
61e85e367535a7 Jonas Bonn 2011-06-04 89
61e85e367535a7 Jonas Bonn 2011-06-04 90 while (p < e) {
61e85e367535a7 Jonas Bonn 2011-06-04 91 int j;
b187fb7fca9cc4 Mike Rapoport 2020-06-04 92 p4e = p4d_offset(pge, v);
b187fb7fca9cc4 Mike Rapoport 2020-06-04 93 pue = pud_offset(p4e, v);
61e85e367535a7 Jonas Bonn 2011-06-04 94 pme = pmd_offset(pue, v);
61e85e367535a7 Jonas Bonn 2011-06-04 95
61e85e367535a7 Jonas Bonn 2011-06-04 96 if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) {
61e85e367535a7 Jonas Bonn 2011-06-04 97 panic("%s: OR1K kernel hardcoded for "
61e85e367535a7 Jonas Bonn 2011-06-04 98 "two-level page tables",
61e85e367535a7 Jonas Bonn 2011-06-04 99 __func__);
61e85e367535a7 Jonas Bonn 2011-06-04 100 }
61e85e367535a7 Jonas Bonn 2011-06-04 101
61e85e367535a7 Jonas Bonn 2011-06-04 102 /* Alloc one page for holding PTE's... */
fb054d0d91dbe3 Mike Rapoport 2019-03-11 103 pte = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
fb054d0d91dbe3 Mike Rapoport 2019-03-11 104 if (!pte)
fb054d0d91dbe3 Mike Rapoport 2019-03-11 105 panic("%s: Failed to allocate page for PTEs\n",
fb054d0d91dbe3 Mike Rapoport 2019-03-11 106 __func__);
61e85e367535a7 Jonas Bonn 2011-06-04 107 set_pmd(pme, __pmd(_KERNPG_TABLE + __pa(pte)));
61e85e367535a7 Jonas Bonn 2011-06-04 108
61e85e367535a7 Jonas Bonn 2011-06-04 109 /* Fill the newly allocated page with PTE'S */
f47706099bdb8c Stefan Kristiansson 2014-01-11 110 for (j = 0; p < e && j < PTRS_PER_PTE;
61e85e367535a7 Jonas Bonn 2011-06-04 111 v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) {
61e85e367535a7 Jonas Bonn 2011-06-04 112 if (v >= (u32) _e_kernel_ro ||
61e85e367535a7 Jonas Bonn 2011-06-04 113 v < (u32) _s_kernel_ro)
61e85e367535a7 Jonas Bonn 2011-06-04 114 prot = PAGE_KERNEL;
61e85e367535a7 Jonas Bonn 2011-06-04 115 else
61e85e367535a7 Jonas Bonn 2011-06-04 116 prot = PAGE_KERNEL_RO;
61e85e367535a7 Jonas Bonn 2011-06-04 117
61e85e367535a7 Jonas Bonn 2011-06-04 118 set_pte(pte, mk_pte_phys(p, prot));
61e85e367535a7 Jonas Bonn 2011-06-04 119 }
61e85e367535a7 Jonas Bonn 2011-06-04 120
61e85e367535a7 Jonas Bonn 2011-06-04 121 pge++;
61e85e367535a7 Jonas Bonn 2011-06-04 122 }
61e85e367535a7 Jonas Bonn 2011-06-04 123
61e85e367535a7 Jonas Bonn 2011-06-04 124 printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__,
61e85e367535a7 Jonas Bonn 2011-06-04 @125 region->base, region->base + region->size);
61e85e367535a7 Jonas Bonn 2011-06-04 126 }
61e85e367535a7 Jonas Bonn 2011-06-04 127 }
61e85e367535a7 Jonas Bonn 2011-06-04 128

:::::: The code at line 125 was first introduced by commit
:::::: 61e85e367535a7b6385b404bef93928768140f96 OpenRISC: Memory management

:::::: TO: Jonas Bonn <jonas@xxxxxxxxxxxx>
:::::: CC: Jonas Bonn <jonas@xxxxxxxxxxxx>

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