diff options
| -rw-r--r-- | arch/s390/Kbuild | 1 | ||||
| -rw-r--r-- | arch/s390/Kconfig | 4 | ||||
| -rw-r--r-- | arch/s390/include/asm/purgatory.h | 17 | ||||
| -rw-r--r-- | arch/s390/kernel/asm-offsets.c | 5 | ||||
| -rw-r--r-- | arch/s390/purgatory/Makefile | 37 | ||||
| -rw-r--r-- | arch/s390/purgatory/head.S | 96 | ||||
| -rw-r--r-- | arch/s390/purgatory/purgatory.c | 38 |
7 files changed, 198 insertions, 0 deletions
diff --git a/arch/s390/Kbuild b/arch/s390/Kbuild index 9fdff3fe1a42..e63940bb57cd 100644 --- a/arch/s390/Kbuild +++ b/arch/s390/Kbuild @@ -8,3 +8,4 @@ obj-$(CONFIG_APPLDATA_BASE) += appldata/ obj-y += net/ obj-$(CONFIG_PCI) += pci/ obj-$(CONFIG_NUMA) += numa/ +obj-$(CONFIG_ARCH_HAS_KEXEC_PURGATORY) += purgatory/ diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 32a0d5b958bf..5b8d0859b317 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -51,6 +51,10 @@ config KEXEC def_bool y select KEXEC_CORE +config ARCH_HAS_KEXEC_PURGATORY + def_bool y + depends on KEXEC_FILE + config AUDIT_ARCH def_bool y diff --git a/arch/s390/include/asm/purgatory.h b/arch/s390/include/asm/purgatory.h new file mode 100644 index 000000000000..e297bcfc476f --- /dev/null +++ b/arch/s390/include/asm/purgatory.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright IBM Corp. 2018 + * + * Author(s): Philipp Rudo <prudo@linux.vnet.ibm.com> + */ + +#ifndef _S390_PURGATORY_H_ +#define _S390_PURGATORY_H_ +#ifndef __ASSEMBLY__ + +#include <linux/purgatory.h> + +int verify_sha256_digest(void); + +#endif /* __ASSEMBLY__ */ +#endif /* _S390_PURGATORY_H_ */ diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c index cfe2c45c5180..eb2a5c0443cd 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -10,6 +10,7 @@ #include <linux/kbuild.h> #include <linux/kvm_host.h> #include <linux/sched.h> +#include <linux/purgatory.h> #include <asm/idle.h> #include <asm/vdso.h> #include <asm/pgtable.h> @@ -204,5 +205,9 @@ int main(void) OFFSET(__GMAP_ASCE, gmap, asce); OFFSET(__SIE_PROG0C, kvm_s390_sie_block, prog0c); OFFSET(__SIE_PROG20, kvm_s390_sie_block, prog20); + /* kexec_sha_region */ + OFFSET(__KEXEC_SHA_REGION_START, kexec_sha_region, start); + OFFSET(__KEXEC_SHA_REGION_LEN, kexec_sha_region, len); + DEFINE(__KEXEC_SHA_REGION_SIZE, sizeof(struct kexec_sha_region)); return 0; } diff --git a/arch/s390/purgatory/Makefile b/arch/s390/purgatory/Makefile new file mode 100644 index 000000000000..e9525bc1b4a6 --- /dev/null +++ b/arch/s390/purgatory/Makefile @@ -0,0 +1,37 @@ +# SPDX-License-Identifier: GPL-2.0 + +OBJECT_FILES_NON_STANDARD := y + +purgatory-y := head.o purgatory.o string.o sha256.o mem.o + +targets += $(purgatory-y) purgatory.ro kexec-purgatory.c +PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y)) + +$(obj)/sha256.o: $(srctree)/lib/sha256.c + $(call if_changed_rule,cc_o_c) + +$(obj)/mem.o: $(srctree)/arch/s390/lib/mem.S + $(call if_changed_rule,as_o_S) + +$(obj)/string.o: $(srctree)/arch/s390/lib/string.c + $(call if_changed_rule,cc_o_c) + +LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib +LDFLAGS_purgatory.ro += -z nodefaultlib +KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes +KBUILD_CFLAGS += -Wno-pointer-sign -Wno-sign-compare +KBUILD_CFLAGS += -fno-zero-initialized-in-bss -fno-builtin -ffreestanding +KBUILD_CFLAGS += -c -MD -Os -m64 +KBUILD_CFLAGS += $(call cc-option,-fno-PIE) + +$(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE + $(call if_changed,ld) + +CMD_BIN2C = $(objtree)/scripts/basic/bin2c +quiet_cmd_bin2c = BIN2C $@ + cmd_bin2c = $(CMD_BIN2C) kexec_purgatory < $< > $@ + +$(obj)/kexec-purgatory.c: $(obj)/purgatory.ro FORCE + $(call if_changed,bin2c) + +obj-$(CONFIG_ARCH_HAS_KEXEC_PURGATORY) += kexec-purgatory.o diff --git a/arch/s390/purgatory/head.S b/arch/s390/purgatory/head.S new file mode 100644 index 000000000000..8735409d0280 --- /dev/null +++ b/arch/s390/purgatory/head.S @@ -0,0 +1,96 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Purgatory setup code + * + * Copyright IBM Corp. 2018 + * + * Author(s): Philipp Rudo <prudo@linux.vnet.ibm.com> + */ + +#include <linux/linkage.h> +#include <asm/asm-offsets.h> +#include <asm/page.h> +#include <asm/sigp.h> + +/* The purgatory is the code running between two kernels. It's main purpose + * is to verify that the next kernel was not corrupted after load and to + * start it. + */ + +.macro START_NEXT_KERNEL base + lg %r4,kernel_entry-\base(%r13) + lg %r5,load_psw_mask-\base(%r13) + ogr %r4,%r5 + stg %r4,0(%r0) + + xgr %r0,%r0 + diag %r0,%r0,0x308 +.endm + +.text +.align PAGE_SIZE +ENTRY(purgatory_start) + /* The purgatory might be called after a diag308 so better set + * architecture and addressing mode. + */ + lhi %r1,1 + sigp %r1,%r0,SIGP_SET_ARCHITECTURE + sam64 + + larl %r5,gprregs + stmg %r6,%r15,0(%r5) + + basr %r13,0 +.base_crash: + + /* Setup stack */ + larl %r15,purgatory_end + aghi %r15,-160 + +.do_checksum_verification: + brasl %r14,verify_sha256_digest + + cghi %r2,0 /* checksum match */ + jne .disabled_wait + + /* start normal kernel */ + START_NEXT_KERNEL .base_crash + +.disabled_wait: + lpswe disabled_wait_psw-.base_crash(%r13) + + +load_psw_mask: + .long 0x00080000,0x80000000 + + .align 8 +disabled_wait_psw: + .quad 0x0002000180000000 + .quad 0x0000000000000000 + .do_checksum_verification + +gprregs: + .rept 10 + .quad 0 + .endr + +purgatory_sha256_digest: + .global purgatory_sha256_digest + .rept 32 /* SHA256_DIGEST_SIZE */ + .byte 0 + .endr + +purgatory_sha_regions: + .global purgatory_sha_regions + .rept 16 * __KEXEC_SHA_REGION_SIZE /* KEXEC_SEGMENTS_MAX */ + .byte 0 + .endr + +kernel_entry: + .global kernel_entry + .quad 0 + + .align PAGE_SIZE +stack: + .skip PAGE_SIZE + .align PAGE_SIZE +purgatory_end: diff --git a/arch/s390/purgatory/purgatory.c b/arch/s390/purgatory/purgatory.c new file mode 100644 index 000000000000..52b92f2bf0b9 --- /dev/null +++ b/arch/s390/purgatory/purgatory.c @@ -0,0 +1,38 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Purgatory code running between two kernels. + * + * Copyright IBM Corp. 2018 + * + * Author(s): Philipp Rudo <prudo@linux.vnet.ibm.com> + */ + +#include <linux/kexec.h> +#include <linux/sha256.h> +#include <linux/string.h> +#include <asm/purgatory.h> + +struct kexec_sha_region purgatory_sha_regions[KEXEC_SEGMENT_MAX]; +u8 purgatory_sha256_digest[SHA256_DIGEST_SIZE]; + +u64 kernel_entry; + +int verify_sha256_digest(void) +{ + struct kexec_sha_region *ptr, *end; + u8 digest[SHA256_DIGEST_SIZE]; + struct sha256_state sctx; + + sha256_init(&sctx); + end = purgatory_sha_regions + ARRAY_SIZE(purgatory_sha_regions); + + for (ptr = purgatory_sha_regions; ptr < end; ptr++) + sha256_update(&sctx, (uint8_t *)(ptr->start), ptr->len); + + sha256_final(&sctx, digest); + + if (memcmp(digest, purgatory_sha256_digest, sizeof(digest))) + return 1; + + return 0; +} |