diff options
-rw-r--r-- | arch/arm/cpu/Kconfig | 1 | ||||
-rw-r--r-- | arch/arm/cpu/mmu_64.c | 13 | ||||
-rw-r--r-- | include/zero_page.h | 54 | ||||
-rw-r--r-- | lib/Kconfig | 3 |
4 files changed, 70 insertions, 1 deletions
diff --git a/arch/arm/cpu/Kconfig b/arch/arm/cpu/Kconfig index f9f52a6252..ca3bd98962 100644 --- a/arch/arm/cpu/Kconfig +++ b/arch/arm/cpu/Kconfig @@ -89,6 +89,7 @@ config CPU_V8 select ARM_EXCEPTIONS select GENERIC_FIND_NEXT_BIT select ARCH_HAS_STACK_DUMP + select ARCH_HAS_ZERO_PAGE config CPU_XSC3 bool diff --git a/arch/arm/cpu/mmu_64.c b/arch/arm/cpu/mmu_64.c index 7e9ae84810..06049e0003 100644 --- a/arch/arm/cpu/mmu_64.c +++ b/arch/arm/cpu/mmu_64.c @@ -10,6 +10,7 @@ #include <init.h> #include <mmu.h> #include <errno.h> +#include <zero_page.h> #include <linux/sizes.h> #include <asm/memory.h> #include <asm/pgtable64.h> @@ -168,6 +169,16 @@ static void mmu_enable(void) set_cr(get_cr() | CR_M | CR_C | CR_I); } +void zero_page_access(void) +{ + create_sections(0x0, 0x0, PAGE_SIZE, CACHED_MEM); +} + +void zero_page_faulting(void) +{ + create_sections(0x0, 0x0, PAGE_SIZE, 0x0); +} + /* * Prepare MMU for usage enable it. */ @@ -194,7 +205,7 @@ void __mmu_init(bool mmu_on) create_sections(bank->start, bank->start, bank->size, CACHED_MEM); /* Make zero page faulting to catch NULL pointer derefs */ - create_sections(0x0, 0x0, 0x1000, 0x0); + zero_page_faulting(); mmu_enable(); } diff --git a/include/zero_page.h b/include/zero_page.h new file mode 100644 index 0000000000..ad6861f240 --- /dev/null +++ b/include/zero_page.h @@ -0,0 +1,54 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef __ZERO_PAGE_H +#define __ZERO_PAGE_H + +#include <common.h> + +#if defined CONFIG_ARCH_HAS_ZERO_PAGE + +/* + * zero_page_faulting - fault when accessing the zero page + */ +void zero_page_faulting(void); + +/* + * zero_page_access - allow accesses to the zero page + * + * Disable the null pointer trap on the zero page if access to the zero page + * is actually required. Disable the trap with care and re-enable it + * immediately after the access to properly trap null pointers. + */ +void zero_page_access(void); + +#else + +static inline void zero_page_faulting(void) +{ +} + +static inline void zero_page_access(void) +{ +} + +#endif + +static inline bool zero_page_contains(unsigned long addr) +{ + return addr < PAGE_SIZE; +} + +/* + * zero_page_memcpy - copy to or from an address located in the zero page + */ +static inline void *zero_page_memcpy(void *dest, const void *src, size_t count) +{ + void *ret; + + zero_page_access(); + ret = memcpy(dest, src, count); + zero_page_faulting(); + + return ret; +} + +#endif /* __ZERO_PAGE_H */ diff --git a/lib/Kconfig b/lib/Kconfig index 887f50ff00..e5831ecdb9 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -182,6 +182,9 @@ config ARCH_HAS_STACK_DUMP config ARCH_HAS_DATA_ABORT_MASK bool +config ARCH_HAS_ZERO_PAGE + bool + config HAVE_EFFICIENT_UNALIGNED_ACCESS bool |