diff options
| -rw-r--r-- | arch/s390/include/asm/skey.h | 32 | ||||
| -rw-r--r-- | arch/s390/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/s390/kernel/skey.c | 48 | ||||
| -rw-r--r-- | arch/s390/kernel/vmlinux.lds.S | 7 |
4 files changed, 88 insertions, 1 deletions
diff --git a/arch/s390/include/asm/skey.h b/arch/s390/include/asm/skey.h new file mode 100644 index 000000000000..84e7cf28b712 --- /dev/null +++ b/arch/s390/include/asm/skey.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_SKEY_H +#define __ASM_SKEY_H + +#include <asm/rwonce.h> + +struct skey_region { + unsigned long start; + unsigned long end; +}; + +#define SKEY_REGION(_start, _end) \ + stringify_in_c(.section .skey_region,"a";) \ + stringify_in_c(.balign 8;) \ + stringify_in_c(.quad (_start);) \ + stringify_in_c(.quad (_end);) \ + stringify_in_c(.previous) + +extern int skey_regions_initialized; +extern struct skey_region __skey_region_start[]; +extern struct skey_region __skey_region_end[]; + +void __skey_regions_initialize(void); + +static inline void skey_regions_initialize(void) +{ + if (READ_ONCE(skey_regions_initialized)) + return; + __skey_regions_initialize(); +} + +#endif /* __ASM_SKEY_H */ diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index ea5ed6654050..eb06ff888314 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -41,7 +41,7 @@ obj-y += processor.o syscall.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o obj-y += debug.o irq.o ipl.o dis.o vdso.o cpufeature.o obj-y += sysinfo.o lgr.o os_info.o ctlreg.o obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o -obj-y += entry.o reipl.o kdebugfs.o alternative.o +obj-y += entry.o reipl.o kdebugfs.o alternative.o skey.o obj-y += nospec-branch.o ipl_vmparm.o machine_kexec_reloc.o unwind_bc.o obj-y += smp.o text_amode31.o stacktrace.o abs_lowcore.o facility.o uv.o wti.o obj-y += diag/ diff --git a/arch/s390/kernel/skey.c b/arch/s390/kernel/skey.c new file mode 100644 index 000000000000..ba049fd103c2 --- /dev/null +++ b/arch/s390/kernel/skey.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <asm/rwonce.h> +#include <asm/page.h> +#include <asm/skey.h> + +int skey_regions_initialized; + +static inline unsigned long load_real_address(unsigned long address) +{ + unsigned long real; + + asm volatile( + " lra %[real],0(%[address])\n" + : [real] "=d" (real) + : [address] "a" (address) + : "cc"); + return real; +} + +/* + * Initialize storage keys of registered memory regions with the + * default key. This is useful for code which is executed with a + * non-default access key. + */ +void __skey_regions_initialize(void) +{ + unsigned long address, real; + struct skey_region *r, *end; + + r = __skey_region_start; + end = __skey_region_end; + while (r < end) { + address = r->start & PAGE_MASK; + do { + real = load_real_address(address); + page_set_storage_key(real, PAGE_DEFAULT_KEY, 1); + address += PAGE_SIZE; + } while (address < r->end); + r++; + } + /* + * Make sure storage keys are initialized before + * skey_regions_initialized is changed. + */ + barrier(); + WRITE_ONCE(skey_regions_initialized, 1); +} diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S index ff1ddba96352..1c606dfa595d 100644 --- a/arch/s390/kernel/vmlinux.lds.S +++ b/arch/s390/kernel/vmlinux.lds.S @@ -71,6 +71,13 @@ SECTIONS . = ALIGN(PAGE_SIZE); __end_ro_after_init = .; + . = ALIGN(8); + .skey_region_table : { + __skey_region_start = .; + KEEP(*(.skey_region)) + __skey_region_end = .; + } + .data.rel.ro : { *(.data.rel.ro .data.rel.ro.*) } |