Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

7 files changed, 426 insertions, 0 deletions

diff --git a/arch/s390/purgatory/.gitignore b/arch/s390/purgatory/.gitignore
new file mode 100644
index 0000000000..97ca527794
--- /dev/null
+++ b/arch/s390/purgatory/.gitignore
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+purgatory
+purgatory.chk
+purgatory.lds
+purgatory.ro
diff --git a/arch/s390/purgatory/Makefile b/arch/s390/purgatory/Makefile
new file mode 100644
index 0000000000..4e930f5668
--- /dev/null
+++ b/arch/s390/purgatory/Makefile
@@ -0,0 +1,54 @@
+# 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.lds purgatory purgatory.chk purgatory.ro
+PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y))
+
+$(obj)/sha256.o: $(srctree)/lib/crypto/sha256.c FORCE
+	$(call if_changed_rule,cc_o_c)
+
+CFLAGS_sha256.o := -D__DISABLE_EXPORTS -D__NO_FORTIFY
+
+$(obj)/mem.o: $(srctree)/arch/s390/lib/mem.S FORCE
+	$(call if_changed_rule,as_o_S)
+
+KCOV_INSTRUMENT := n
+GCOV_PROFILE := n
+UBSAN_SANITIZE := n
+KASAN_SANITIZE := n
+KCSAN_SANITIZE := n
+
+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 += -Os -m64 -msoft-float -fno-common
+KBUILD_CFLAGS += -fno-stack-protector
+KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
+KBUILD_CFLAGS += $(CLANG_FLAGS)
+KBUILD_CFLAGS += $(call cc-option,-fno-PIE)
+KBUILD_AFLAGS := $(filter-out -DCC_USING_EXPOLINE,$(KBUILD_AFLAGS))
+
+# Since we link purgatory with -r unresolved symbols are not checked, so we
+# also link a purgatory.chk binary without -r to check for unresolved symbols.
+PURGATORY_LDFLAGS := -nostdlib -z nodefaultlib
+LDFLAGS_purgatory := -r $(PURGATORY_LDFLAGS) -T
+LDFLAGS_purgatory.chk := -e purgatory_start $(PURGATORY_LDFLAGS)
+$(obj)/purgatory: $(obj)/purgatory.lds $(PURGATORY_OBJS) FORCE
+		$(call if_changed,ld)
+
+$(obj)/purgatory.chk: $(obj)/purgatory FORCE
+		$(call if_changed,ld)
+
+OBJCOPYFLAGS_purgatory.ro := -O elf64-s390
+OBJCOPYFLAGS_purgatory.ro += --remove-section='*debug*'
+OBJCOPYFLAGS_purgatory.ro += --remove-section='.comment'
+OBJCOPYFLAGS_purgatory.ro += --remove-section='.note.*'
+$(obj)/purgatory.ro: $(obj)/purgatory $(obj)/purgatory.chk FORCE
+		$(call if_changed,objcopy)
+
+$(obj)/kexec-purgatory.o: $(obj)/purgatory.ro
+
+obj-y += kexec-purgatory.o
diff --git a/arch/s390/purgatory/head.S b/arch/s390/purgatory/head.S
new file mode 100644
index 0000000000..0f93f2e72e
--- /dev/null
+++ b/arch/s390/purgatory/head.S
@@ -0,0 +1,265 @@
+/* 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>
+#include <asm/ptrace.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.
+ *
+ * If the next kernel is a crash kernel there are some peculiarities to
+ * consider:
+ *
+ * First the purgatory is called twice. Once only to verify the
+ * sha digest. So if the crash kernel got corrupted the old kernel can try
+ * to trigger a stand-alone dumper. And once to actually load the crash kernel.
+ *
+ * Second the purgatory also has to swap the crash memory region with its
+ * destination at address 0. As the purgatory is part of crash memory this
+ * requires some finesse. The tactic here is that the purgatory first copies
+ * itself to the end of the destination and then swaps the rest of the
+ * memory running from there.
+ */
+
+#define bufsz purgatory_end-stack
+
+.macro MEMCPY dst,src,len
+	lgr	%r0,\dst
+	lgr	%r1,\len
+	lgr	%r2,\src
+	lgr	%r3,\len
+
+20:	mvcle	%r0,%r2,0
+	jo	20b
+.endm
+
+.macro MEMSWAP dst,src,buf,len
+10:	larl	%r0,purgatory_end
+	larl	%r1,stack
+	slgr	%r0,%r1
+	cgr	\len,%r0
+	jh	11f
+	lgr	%r4,\len
+	j	12f
+11:	lgr	%r4,%r0
+
+12:	MEMCPY	\buf,\dst,%r4
+	MEMCPY	\dst,\src,%r4
+	MEMCPY	\src,\buf,%r4
+
+	agr	\dst,%r4
+	agr	\src,%r4
+	sgr	\len,%r4
+
+	cghi	\len,0
+	jh	10b
+.endm
+
+.macro START_NEXT_KERNEL base subcode
+	lg	%r4,kernel_entry-\base(%r13)
+	lg	%r5,load_psw_mask-\base(%r13)
+	ogr	%r4,%r5
+	stg	%r4,0(%r0)
+
+	xgr	%r0,%r0
+	lghi	%r1,\subcode
+	diag	%r0,%r1,0x308
+.endm
+
+	.text
+	.balign PAGE_SIZE
+SYM_CODE_START(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-STACK_FRAME_OVERHEAD
+
+	/* If the next kernel is KEXEC_TYPE_CRASH the purgatory is called
+	 * directly with a flag passed in %r2 whether the purgatory shall do
+	 * checksum verification only (%r2 = 0 -> verification only).
+	 *
+	 * Check now and preserve over C function call by storing in
+	 * %r10 with
+	 *	1 -> checksum verification only
+	 *	0 -> load new kernel
+	 */
+	lghi	%r10,0
+	lg	%r11,kernel_type-.base_crash(%r13)
+	cghi	%r11,1		/* KEXEC_TYPE_CRASH */
+	jne	.do_checksum_verification
+	cghi	%r2,0		/* checksum verification only */
+	jne	.do_checksum_verification
+	lghi	%r10,1
+
+.do_checksum_verification:
+	brasl	%r14,verify_sha256_digest
+
+	cghi	%r10,1		/* checksum verification only */
+	je	.return_old_kernel
+	cghi	%r2,0		/* checksum match */
+	jne	.disabled_wait
+
+	/* If the next kernel is a crash kernel the purgatory has to swap
+	 * the mem regions first.
+	 */
+	cghi	%r11,1 /* KEXEC_TYPE_CRASH */
+	je	.start_crash_kernel
+
+	/* start normal kernel */
+	START_NEXT_KERNEL .base_crash 0
+
+.return_old_kernel:
+	lmg	%r6,%r15,gprregs-.base_crash(%r13)
+	br	%r14
+
+.disabled_wait:
+	lpswe	disabled_wait_psw-.base_crash(%r13)
+
+.start_crash_kernel:
+	/* Location of purgatory_start in crash memory */
+	larl	%r0,.base_crash
+	larl	%r1,purgatory_start
+	slgr	%r0,%r1
+	lgr	%r8,%r13
+	sgr	%r8,%r0
+
+	/* Destination for this code i.e. end of memory to be swapped. */
+	larl	%r0,purgatory_end
+	larl	%r1,purgatory_start
+	slgr	%r0,%r1
+	lg	%r9,crash_size-.base_crash(%r13)
+	sgr	%r9,%r0
+
+	/* Destination in crash memory, i.e. same as r9 but in crash memory. */
+	lg	%r10,crash_start-.base_crash(%r13)
+	agr	%r10,%r9
+
+	/* Buffer location (in crash memory) and size. As the purgatory is
+	 * behind the point of no return it can re-use the stack as buffer.
+	 */
+	larl	%r11,purgatory_end
+	larl	%r12,stack
+	slgr	%r11,%r12
+
+	MEMCPY	%r12,%r9,%r11	/* dst	-> (crash) buf */
+	MEMCPY	%r9,%r8,%r11	/* self -> dst */
+
+	/* Jump to new location. */
+	lgr	%r7,%r9
+	larl	%r0,.jump_to_dst
+	larl	%r1,purgatory_start
+	slgr	%r0,%r1
+	agr	%r7,%r0
+	br	%r7
+
+.jump_to_dst:
+	basr	%r13,0
+.base_dst:
+
+	/* clear buffer */
+	MEMCPY	%r12,%r10,%r11	/* (crash) buf -> (crash) dst */
+
+	/* Load new buffer location after jump */
+	larl	%r7,stack
+	lgr	%r0,%r7
+	larl	%r1,purgatory_start
+	slgr	%r0,%r1
+	agr	%r10,%r0
+	MEMCPY	%r10,%r7,%r11	/* (new) buf -> (crash) buf */
+
+	/* Now the code is set up to run from its designated location. Start
+	 * swapping the rest of crash memory now.
+	 *
+	 * The registers will be used as follow:
+	 *
+	 *	%r0-%r4	reserved for macros defined above
+	 *	%r5-%r6 tmp registers
+	 *	%r7	pointer to current struct sha region
+	 *	%r8	index to iterate over all sha regions
+	 *	%r9	pointer in crash memory
+	 *	%r10	pointer in old kernel
+	 *	%r11	total size (still) to be moved
+	 *	%r12	pointer to buffer
+	 */
+	lgr	%r12,%r7
+	lgr	%r11,%r9
+	lghi	%r10,0
+	lg	%r9,crash_start-.base_dst(%r13)
+	lghi	%r8,16	/* KEXEC_SEGMENTS_MAX */
+	larl	%r7,purgatory_sha_regions
+
+	j .loop_first
+
+	/* Loop over all purgatory_sha_regions. */
+.loop_next:
+	aghi	%r8,-1
+	cghi	%r8,0
+	je	.loop_out
+
+	aghi	%r7,__KEXEC_SHA_REGION_SIZE
+
+.loop_first:
+	lg	%r5,__KEXEC_SHA_REGION_START(%r7)
+	cghi	%r5,0
+	je	.loop_next
+
+	/* Copy [end last sha region, start current sha region) */
+	/* Note: kexec_sha_region->start points in crash memory */
+	sgr	%r5,%r9
+	MEMCPY	%r9,%r10,%r5
+
+	agr	%r9,%r5
+	agr	%r10,%r5
+	sgr	%r11,%r5
+
+	/* Swap sha region */
+	lg	%r6,__KEXEC_SHA_REGION_LEN(%r7)
+	MEMSWAP	%r9,%r10,%r12,%r6
+	sg	%r11,__KEXEC_SHA_REGION_LEN(%r7)
+	j	.loop_next
+
+.loop_out:
+	/* Copy rest of crash memory */
+	MEMCPY	%r9,%r10,%r11
+
+	/* start crash kernel */
+	START_NEXT_KERNEL .base_dst 1
+SYM_CODE_END(purgatory_start)
+
+SYM_DATA_LOCAL(load_psw_mask,		.long 0x00080000,0x80000000)
+	.balign	8
+SYM_DATA_LOCAL(disabled_wait_psw,	.quad 0x0002000180000000,.do_checksum_verification)
+SYM_DATA_LOCAL(gprregs,			.fill 10,8,0)
+SYM_DATA(purgatory_sha256_digest,	.skip 32)
+SYM_DATA(purgatory_sha_regions,		.skip 16*__KEXEC_SHA_REGION_SIZE)
+SYM_DATA(kernel_entry,			.skip 8)
+SYM_DATA(kernel_type,			.skip 8)
+SYM_DATA(crash_start,			.skip 8)
+SYM_DATA(crash_size,			.skip 8)
+	.balign	PAGE_SIZE
+SYM_DATA_START_LOCAL(stack)
+	/* The buffer to move this code must be as big as the code. */
+	.skip	stack-purgatory_start
+	.balign	PAGE_SIZE
+SYM_DATA_END_LABEL(stack, SYM_L_LOCAL, purgatory_end)
diff --git a/arch/s390/purgatory/kexec-purgatory.S b/arch/s390/purgatory/kexec-purgatory.S
new file mode 100644
index 0000000000..25f512b1de
--- /dev/null
+++ b/arch/s390/purgatory/kexec-purgatory.S
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/linkage.h>
+
+	.section .rodata, "a"
+
+	.balign	8
+SYM_DATA_START(kexec_purgatory)
+	.incbin	"arch/s390/purgatory/purgatory.ro"
+SYM_DATA_END_LABEL(kexec_purgatory, SYM_L_LOCAL, kexec_purgatory_end)
+
+	.balign	8
+SYM_DATA(kexec_purgatory_size, .quad kexec_purgatory_end-kexec_purgatory)
diff --git a/arch/s390/purgatory/purgatory.c b/arch/s390/purgatory/purgatory.c
new file mode 100644
index 0000000000..030efda05d
--- /dev/null
+++ b/arch/s390/purgatory/purgatory.c
@@ -0,0 +1,33 @@
+// 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/string.h>
+#include <crypto/sha2.h>
+#include <asm/purgatory.h>
+
+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;
+}
diff --git a/arch/s390/purgatory/purgatory.lds.S b/arch/s390/purgatory/purgatory.lds.S
new file mode 100644
index 0000000000..482eb4fbce
--- /dev/null
+++ b/arch/s390/purgatory/purgatory.lds.S
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <asm-generic/vmlinux.lds.h>
+
+OUTPUT_FORMAT("elf64-s390", "elf64-s390", "elf64-s390")
+OUTPUT_ARCH(s390:64-bit)
+
+ENTRY(purgatory_start)
+
+SECTIONS
+{
+	. = 0;
+	.head.text : {
+		_head = . ;
+		HEAD_TEXT
+		_ehead = . ;
+	}
+	.text :	{
+		_text = .;	/* Text */
+		*(.text)
+		*(.text.*)
+		_etext = . ;
+	}
+	.rodata : {
+		_rodata = . ;
+		*(.rodata)	 /* read-only data */
+		*(.rodata.*)
+		_erodata = . ;
+	}
+	.data :	{
+		_data = . ;
+		*(.data)
+		*(.data.*)
+		_edata = . ;
+	}
+
+	. = ALIGN(256);
+	.bss : {
+		_bss = . ;
+		*(.bss)
+		*(.bss.*)
+		*(COMMON)
+		. = ALIGN(8);	/* For convenience during zeroing */
+		_ebss = .;
+	}
+	_end = .;
+
+	/* Sections to be discarded */
+	/DISCARD/ : {
+		*(.eh_frame)
+		*(*__ksymtab*)
+		*(___kcrctab*)
+	}
+}
diff --git a/arch/s390/purgatory/string.c b/arch/s390/purgatory/string.c
new file mode 100644
index 0000000000..c98c22a72d
--- /dev/null
+++ b/arch/s390/purgatory/string.c
@@ -0,0 +1,3 @@
+// SPDX-License-Identifier: GPL-2.0
+#define __HAVE_ARCH_MEMCMP	/* arch function */
+#include "../lib/string.c"