diff options
author | Sven Schnelle <svens@linux.ibm.com> | 2021-07-28 21:02:53 +0200 |
---|---|---|
committer | Heiko Carstens <hca@linux.ibm.com> | 2021-07-30 17:09:02 +0200 |
commit | e41ba1115a351dd037c21ac75660638219d51485 (patch) | |
tree | 11beecdfc9fa677a0e4cd1c1ad638d96532decda /arch/s390 | |
parent | f99e12b21b84feb1fd9d845a15096772f1659461 (diff) | |
download | linux-e41ba1115a351dd037c21ac75660638219d51485.tar.bz2 |
s390: add support for KFENCE
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
[hca@linux.ibm.com: simplify/rework code]
Link: https://lore.kernel.org/r/20210728190254.3921642-4-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r-- | arch/s390/Kconfig | 1 | ||||
-rw-r--r-- | arch/s390/include/asm/kfence.h | 42 | ||||
-rw-r--r-- | arch/s390/mm/fault.c | 9 | ||||
-rw-r--r-- | arch/s390/mm/init.c | 3 | ||||
-rw-r--r-- | arch/s390/mm/pageattr.c | 3 |
5 files changed, 54 insertions, 4 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index a0e2130f0100..f20467af2ab2 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -138,6 +138,7 @@ config S390 select HAVE_ARCH_JUMP_LABEL_RELATIVE select HAVE_ARCH_KASAN select HAVE_ARCH_KASAN_VMALLOC + select HAVE_ARCH_KFENCE select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_SOFT_DIRTY diff --git a/arch/s390/include/asm/kfence.h b/arch/s390/include/asm/kfence.h new file mode 100644 index 000000000000..d55ba878378b --- /dev/null +++ b/arch/s390/include/asm/kfence.h @@ -0,0 +1,42 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _ASM_S390_KFENCE_H +#define _ASM_S390_KFENCE_H + +#include <linux/mm.h> +#include <linux/kfence.h> +#include <asm/set_memory.h> +#include <asm/page.h> + +void __kernel_map_pages(struct page *page, int numpages, int enable); + +static __always_inline bool arch_kfence_init_pool(void) +{ + return true; +} + +#define arch_kfence_test_address(addr) ((addr) & PAGE_MASK) + +/* + * Do not split kfence pool to 4k mapping with arch_kfence_init_pool(), + * but earlier where page table allocations still happen with memblock. + * Reason is that arch_kfence_init_pool() gets called when the system + * is still in a limbo state - disabling and enabling bottom halves is + * not yet allowed, but that is what our page_table_alloc() would do. + */ +static __always_inline void kfence_split_mapping(void) +{ +#ifdef CONFIG_KFENCE + unsigned long pool_pages = KFENCE_POOL_SIZE >> PAGE_SHIFT; + + set_memory_4k((unsigned long)__kfence_pool, pool_pages); +#endif +} + +static inline bool kfence_protect_page(unsigned long addr, bool protect) +{ + __kernel_map_pages(virt_to_page(addr), 1, !protect); + return true; +} + +#endif /* _ASM_S390_KFENCE_H */ diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index e33c43b38afe..52d82410486e 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -31,6 +31,7 @@ #include <linux/kprobes.h> #include <linux/uaccess.h> #include <linux/hugetlb.h> +#include <linux/kfence.h> #include <asm/asm-offsets.h> #include <asm/diag.h> #include <asm/gmap.h> @@ -356,6 +357,7 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access) unsigned long address; unsigned int flags; vm_fault_t fault; + bool is_write; tsk = current; /* @@ -369,6 +371,8 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access) mm = tsk->mm; trans_exc_code = regs->int_parm_long; + address = trans_exc_code & __FAIL_ADDR_MASK; + is_write = (trans_exc_code & store_indication) == 0x400; /* * Verify that the fault happened in user space, that @@ -379,6 +383,8 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access) type = get_fault_type(regs); switch (type) { case KERNEL_FAULT: + if (kfence_handle_page_fault(address, is_write, regs)) + return 0; goto out; case USER_FAULT: case GMAP_FAULT: @@ -387,12 +393,11 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access) break; } - address = trans_exc_code & __FAIL_ADDR_MASK; perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); flags = FAULT_FLAG_DEFAULT; if (user_mode(regs)) flags |= FAULT_FLAG_USER; - if (access == VM_WRITE || (trans_exc_code & store_indication) == 0x400) + if (access == VM_WRITE || is_write) flags |= FAULT_FLAG_WRITE; mmap_read_lock(mm); diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index 8ac710de1ab1..f3db3caa8447 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -34,6 +34,7 @@ #include <asm/processor.h> #include <linux/uaccess.h> #include <asm/pgalloc.h> +#include <asm/kfence.h> #include <asm/ptdump.h> #include <asm/dma.h> #include <asm/lowcore.h> @@ -200,7 +201,7 @@ void __init mem_init(void) high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); pv_init(); - + kfence_split_mapping(); /* Setup guest page hinting */ cmma_init(); diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c index 2ad95e5c79c1..dd45010f0e8d 100644 --- a/arch/s390/mm/pageattr.c +++ b/arch/s390/mm/pageattr.c @@ -8,6 +8,7 @@ #include <asm/cacheflush.h> #include <asm/facility.h> #include <asm/pgalloc.h> +#include <asm/kfence.h> #include <asm/page.h> #include <asm/set_memory.h> @@ -326,7 +327,7 @@ int __set_memory(unsigned long addr, int numpages, unsigned long flags) return change_page_attr(addr, addr + numpages * PAGE_SIZE, flags); } -#ifdef CONFIG_DEBUG_PAGEALLOC +#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE) static void ipte_range(pte_t *pte, unsigned long address, int nr) { |