Poking-mm initialization might require to duplicate the PGD in early stage. Initialize the PGD cache earlier to prevent boot failures.
Cc: Stephen Rothwell <[email protected]> Cc: Rick Edgecombe <[email protected]> Cc: Peter Zijlstra <[email protected]> Fixes: 4fc19708b165 ("x86/alternatives: Initialize temporary mm for patching") Reported-by: kernel test robot <[email protected]> Signed-off-by: Nadav Amit <[email protected]> --- arch/x86/include/asm/pgtable.h | 1 + arch/x86/mm/pgtable.c | 10 ++++++---- init/main.c | 1 + 3 files changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 6b6bfdfe83aa..9635662e1163 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -1027,6 +1027,7 @@ static inline int pgd_none(pgd_t pgd) extern int direct_gbpages; void init_mem_mapping(void); +void pgd_cache_init(void); void early_alloc_pgt_buf(void); extern void memblock_find_dma_reserve(void); diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 3dbf440d4114..1f67b1e15bf6 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -373,14 +373,14 @@ static void pgd_prepopulate_user_pmd(struct mm_struct *mm, static struct kmem_cache *pgd_cache; -static int __init pgd_cache_init(void) +void __init pgd_cache_init(void) { /* * When PAE kernel is running as a Xen domain, it does not use * shared kernel pmd. And this requires a whole page for pgd. */ if (!SHARED_KERNEL_PMD) - return 0; + return; /* * when PAE kernel is not running as a Xen domain, it uses @@ -390,9 +390,7 @@ static int __init pgd_cache_init(void) */ pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_ALIGN, SLAB_PANIC, NULL); - return 0; } -core_initcall(pgd_cache_init); static inline pgd_t *_pgd_alloc(void) { @@ -420,6 +418,10 @@ static inline void _pgd_free(pgd_t *pgd) } #else +void __init pgd_cache_init(void) +{ +} + static inline pgd_t *_pgd_alloc(void) { return (pgd_t *)__get_free_pages(PGALLOC_GFP, PGD_ALLOCATION_ORDER); diff --git a/init/main.c b/init/main.c index 949eed8015ec..7fac4ac2fede 100644 --- a/init/main.c +++ b/init/main.c @@ -537,6 +537,7 @@ static void __init mm_init(void) init_espfix_bsp(); /* Should be run after espfix64 is set up. */ pti_init(); + pgd_cache_init(); } void __init __weak arch_call_rest_init(void) -- 2.17.1
