diff options
| -rw-r--r-- | arch/x86/include/asm/kaslr.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/pgtable.h | 15 | ||||
| -rw-r--r-- | arch/x86/include/asm/setup.h | 12 | ||||
| -rw-r--r-- | arch/x86/mm/init.c | 22 | ||||
| -rw-r--r-- | arch/x86/mm/kaslr.c | 33 |
5 files changed, 37 insertions, 47 deletions
diff --git a/arch/x86/include/asm/kaslr.h b/arch/x86/include/asm/kaslr.h index db7ba2feb947..0648190467ba 100644 --- a/arch/x86/include/asm/kaslr.h +++ b/arch/x86/include/asm/kaslr.h @@ -6,8 +6,10 @@ unsigned long kaslr_get_random_long(const char *purpose); #ifdef CONFIG_RANDOMIZE_MEMORY void kernel_randomize_memory(void); +void init_trampoline_kaslr(void); #else static inline void kernel_randomize_memory(void) { } +static inline void init_trampoline_kaslr(void) {} #endif /* CONFIG_RANDOMIZE_MEMORY */ #endif diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 4f126ddf71ce..e2b4d4c08fac 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -1071,27 +1071,14 @@ void init_mem_mapping(void); void early_alloc_pgt_buf(void); extern void memblock_find_dma_reserve(void); + #ifdef CONFIG_X86_64 -/* Realmode trampoline initialization. */ extern pgd_t trampoline_pgd_entry; -static inline void __meminit init_trampoline_default(void) -{ - /* Default trampoline pgd value */ - trampoline_pgd_entry = init_top_pgt[pgd_index(__PAGE_OFFSET)]; -} void __init poking_init(void); unsigned long init_memory_mapping(unsigned long start, unsigned long end, pgprot_t prot); - -# ifdef CONFIG_RANDOMIZE_MEMORY -void __meminit init_trampoline(void); -# else -# define init_trampoline init_trampoline_default -# endif -#else -static inline void init_trampoline(void) { } #endif /* local pte updates need not use xchg for locking */ diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h index ed8ec011a9fd..84b645cc8bc9 100644 --- a/arch/x86/include/asm/setup.h +++ b/arch/x86/include/asm/setup.h @@ -75,7 +75,17 @@ extern char _text[]; static inline bool kaslr_enabled(void) { - return !!(boot_params.hdr.loadflags & KASLR_FLAG); + return IS_ENABLED(CONFIG_RANDOMIZE_MEMORY) && + !!(boot_params.hdr.loadflags & KASLR_FLAG); +} + +/* + * Apply no randomization if KASLR was disabled at boot or if KASAN + * is enabled. KASAN shadow mappings rely on regions being PGD aligned. + */ +static inline bool kaslr_memory_enabled(void) +{ + return kaslr_enabled() && !IS_ENABLED(CONFIG_KASAN); } static inline unsigned long kaslr_offset(void) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 112d3b98a3b6..001dd7dc829f 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -680,6 +680,28 @@ static void __init memory_map_bottom_up(unsigned long map_start, } } +/* + * The real mode trampoline, which is required for bootstrapping CPUs + * occupies only a small area under the low 1MB. See reserve_real_mode() + * for details. + * + * If KASLR is disabled the first PGD entry of the direct mapping is copied + * to map the real mode trampoline. + * + * If KASLR is enabled, copy only the PUD which covers the low 1MB + * area. This limits the randomization granularity to 1GB for both 4-level + * and 5-level paging. + */ +static void __init init_trampoline(void) +{ +#ifdef CONFIG_X86_64 + if (!kaslr_memory_enabled()) + trampoline_pgd_entry = init_top_pgt[pgd_index(__PAGE_OFFSET)]; + else + init_trampoline_kaslr(); +#endif +} + void __init init_mem_mapping(void) { unsigned long end; diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c index faf02e1e1517..fb620fd9dae9 100644 --- a/arch/x86/mm/kaslr.c +++ b/arch/x86/mm/kaslr.c @@ -61,15 +61,6 @@ static inline unsigned long get_padding(struct kaslr_memory_region *region) return (region->size_tb << TB_SHIFT); } -/* - * Apply no randomization if KASLR was disabled at boot or if KASAN - * is enabled. KASAN shadow mappings rely on regions being PGD aligned. - */ -static inline bool kaslr_memory_enabled(void) -{ - return kaslr_enabled() && !IS_ENABLED(CONFIG_KASAN); -} - /* Initialize base and padding for each memory region randomized with KASLR */ void __init kernel_randomize_memory(void) { @@ -148,7 +139,7 @@ void __init kernel_randomize_memory(void) } } -static void __meminit init_trampoline_pud(void) +void __meminit init_trampoline_kaslr(void) { pud_t *pud_page_tramp, *pud, *pud_tramp; p4d_t *p4d_page_tramp, *p4d, *p4d_tramp; @@ -189,25 +180,3 @@ static void __meminit init_trampoline_pud(void) __pgd(_KERNPG_TABLE | __pa(pud_page_tramp))); } } - -/* - * The real mode trampoline, which is required for bootstrapping CPUs - * occupies only a small area under the low 1MB. See reserve_real_mode() - * for details. - * - * If KASLR is disabled the first PGD entry of the direct mapping is copied - * to map the real mode trampoline. - * - * If KASLR is enabled, copy only the PUD which covers the low 1MB - * area. This limits the randomization granularity to 1GB for both 4-level - * and 5-level paging. - */ -void __meminit init_trampoline(void) -{ - if (!kaslr_memory_enabled()) { - init_trampoline_default(); - return; - } - - init_trampoline_pud(); -} |