We need to address the following warnings in arch/x86/mm/pgtable.c before we can enable -Wstriongop-overflow globally:
CC arch/x86/mm/pgtable.o
arch/x86/mm/pgtable.c: In function ‘pgd_alloc’:
arch/x86/mm/pgtable.c:437:13: warning: ‘preallocate_pmds.constprop’ accessing 8 bytes in a region of size 0 [-Wstringop-overflow=]
437 | if (preallocate_pmds(mm, pmds, PREALLOCATED_PMDS) != 0)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/mm/pgtable.c:437:13: note: referencing argument 2 of type ‘pmd_t **’
arch/x86/mm/pgtable.c:225:12: note: in a call to function ‘preallocate_pmds.constprop’
225 | static int preallocate_pmds(struct mm_struct *mm, pmd_t *pmds[], int count)
| ^~~~~~~~~~~~~~~~
arch/x86/mm/pgtable.c:440:13: warning: ‘preallocate_pmds.constprop’ accessing 8 bytes in a region of size 0 [-Wstringop-overflow=]
440 | if (preallocate_pmds(mm, u_pmds, PREALLOCATED_USER_PMDS) != 0)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/mm/pgtable.c:440:13: note: referencing argument 2 of type ‘pmd_t **’
arch/x86/mm/pgtable.c:225:12: note: in a call to function ‘preallocate_pmds.constprop’
225 | static int preallocate_pmds(struct mm_struct *mm, pmd_t *pmds[], int count)
| ^~~~~~~~~~~~~~~~
arch/x86/mm/pgtable.c:462:9: warning: ‘free_pmds.constprop’ accessing 8 bytes in a region of size 0 [-Wstringop-overflow=]
462 | free_pmds(mm, u_pmds, PREALLOCATED_USER_PMDS);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/mm/pgtable.c:462:9: note: referencing argument 2 of type ‘pmd_t **’
arch/x86/mm/pgtable.c:213:13: note: in a call to function ‘free_pmds.constprop’
213 | static void free_pmds(struct mm_struct *mm, pmd_t *pmds[], int count)
| ^~~~~~~~~
arch/x86/mm/pgtable.c:455:9: warning: ‘pgd_prepopulate_user_pmd’ accessing 8 bytes in a region of size 0 [-Wstringop-overflow=]
455 | pgd_prepopulate_user_pmd(mm, pgd, u_pmds);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/mm/pgtable.c:455:9: note: referencing argument 3 of type ‘pmd_t **’
arch/x86/mm/pgtable.c:320:13: note: in a call to function ‘pgd_prepopulate_user_pmd’
320 | static void pgd_prepopulate_user_pmd(struct mm_struct *mm,
| ^~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/mm/pgtable.c:464:9: warning: ‘free_pmds.constprop’ accessing 8 bytes in a region of size 0 [-Wstringop-overflow=]
464 | free_pmds(mm, pmds, PREALLOCATED_PMDS);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/mm/pgtable.c:464:9: note: referencing argument 2 of type ‘pmd_t **’
arch/x86/mm/pgtable.c:213:13: note: in a call to function ‘free_pmds.constprop’
213 | static void free_pmds(struct mm_struct *mm, pmd_t *pmds[], int count)
| ^~~~~~~~~
We need to address the following warnings in arch/x86/mm/pgtable.c before we can enable -Wstriongop-overflow globally: