From: Kees Cook Date: Wed, 3 Jun 2020 20:28:45 +0000 (-0700) Subject: mm/debug_vm_pgtable: Remove uninitialized_var() usage X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=fea1120c56e2d5db1cfea67d455edea3f4f97947;p=linux.git mm/debug_vm_pgtable: 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. As a precursor to removing[2] this[3] macro[4], just initialize this variable to NULL. [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/ Fixes: 399145f9eb6c ("mm/debug: add tests validating architecture page table helpers") Reviewed-by: Nick Desaulniers Signed-off-by: Kees Cook --- diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index 61ab16fb2e36c..d315ff544f053 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -307,7 +307,7 @@ static int __init debug_vm_pgtable(void) phys_addr_t paddr; unsigned long vaddr, pte_aligned, pmd_aligned; unsigned long pud_aligned, p4d_aligned, pgd_aligned; - spinlock_t *uninitialized_var(ptl); + spinlock_t *ptl = NULL; pr_info("Validating architecture page table helpers\n"); prot = vm_get_page_prot(VMFLAGS);