1 files changed, 652 insertions, 0 deletions
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
new file mode 100644
index 000000000..7af69948b
--- /dev/null
+++ b/arch/s390/kernel/crash_dump.c
@@ -0,0 +1,652 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * S390 kdump implementation
+ *
+ * Copyright IBM Corp. 2011
+ * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
+ */
+
+#include <linux/crash_dump.h>
+#include <asm/lowcore.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/gfp.h>
+#include <linux/slab.h>
+#include <linux/memblock.h>
+#include <linux/elf.h>
+#include <linux/uio.h>
+#include <asm/asm-offsets.h>
+#include <asm/os_info.h>
+#include <asm/elf.h>
+#include <asm/ipl.h>
+#include <asm/sclp.h>
+#include <asm/maccess.h>
+
+#define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
+#define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
+#define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
+
+static struct memblock_region oldmem_region;
+
+static struct memblock_type oldmem_type = {
+	.cnt = 1,
+	.max = 1,
+	.total_size = 0,
+	.regions = &oldmem_region,
+	.name = "oldmem",
+};
+
+struct save_area {
+	struct list_head list;
+	u64 psw[2];
+	u64 ctrs[16];
+	u64 gprs[16];
+	u32 acrs[16];
+	u64 fprs[16];
+	u32 fpc;
+	u32 prefix;
+	u32 todpreg;
+	u64 timer;
+	u64 todcmp;
+	u64 vxrs_low[16];
+	__vector128 vxrs_high[16];
+};
+
+static LIST_HEAD(dump_save_areas);
+
+/*
+ * Allocate a save area
+ */
+struct save_area * __init save_area_alloc(bool is_boot_cpu)
+{
+	struct save_area *sa;
+
+	sa = memblock_alloc(sizeof(*sa), 8);
+	if (!sa)
+		return NULL;
+
+	if (is_boot_cpu)
+		list_add(&sa->list, &dump_save_areas);
+	else
+		list_add_tail(&sa->list, &dump_save_areas);
+	return sa;
+}
+
+/*
+ * Return the address of the save area for the boot CPU
+ */
+struct save_area * __init save_area_boot_cpu(void)
+{
+	return list_first_entry_or_null(&dump_save_areas, struct save_area, list);
+}
+
+/*
+ * Copy CPU registers into the save area
+ */
+void __init save_area_add_regs(struct save_area *sa, void *regs)
+{
+	struct lowcore *lc;
+
+	lc = (struct lowcore *)(regs - __LC_FPREGS_SAVE_AREA);
+	memcpy(&sa->psw, &lc->psw_save_area, sizeof(sa->psw));
+	memcpy(&sa->ctrs, &lc->cregs_save_area, sizeof(sa->ctrs));
+	memcpy(&sa->gprs, &lc->gpregs_save_area, sizeof(sa->gprs));
+	memcpy(&sa->acrs, &lc->access_regs_save_area, sizeof(sa->acrs));
+	memcpy(&sa->fprs, &lc->floating_pt_save_area, sizeof(sa->fprs));
+	memcpy(&sa->fpc, &lc->fpt_creg_save_area, sizeof(sa->fpc));
+	memcpy(&sa->prefix, &lc->prefixreg_save_area, sizeof(sa->prefix));
+	memcpy(&sa->todpreg, &lc->tod_progreg_save_area, sizeof(sa->todpreg));
+	memcpy(&sa->timer, &lc->cpu_timer_save_area, sizeof(sa->timer));
+	memcpy(&sa->todcmp, &lc->clock_comp_save_area, sizeof(sa->todcmp));
+}
+
+/*
+ * Copy vector registers into the save area
+ */
+void __init save_area_add_vxrs(struct save_area *sa, __vector128 *vxrs)
+{
+	int i;
+
+	/* Copy lower halves of vector registers 0-15 */
+	for (i = 0; i < 16; i++)
+		sa->vxrs_low[i] = vxrs[i].low;
+	/* Copy vector registers 16-31 */
+	memcpy(sa->vxrs_high, vxrs + 16, 16 * sizeof(__vector128));
+}
+
+static size_t copy_oldmem_iter(struct iov_iter *iter, unsigned long src, size_t count)
+{
+	size_t len, copied, res = 0;
+
+	while (count) {
+		if (!oldmem_data.start && src < sclp.hsa_size) {
+			/* Copy from zfcp/nvme dump HSA area */
+			len = min(count, sclp.hsa_size - src);
+			copied = memcpy_hsa_iter(iter, src, len);
+		} else {
+			/* Check for swapped kdump oldmem areas */
+			if (oldmem_data.start && src - oldmem_data.start < oldmem_data.size) {
+				src -= oldmem_data.start;
+				len = min(count, oldmem_data.size - src);
+			} else if (oldmem_data.start && src < oldmem_data.size) {
+				len = min(count, oldmem_data.size - src);
+				src += oldmem_data.start;
+			} else {
+				len = count;
+			}
+			copied = memcpy_real_iter(iter, src, len);
+		}
+		count -= copied;
+		src += copied;
+		res += copied;
+		if (copied < len)
+			break;
+	}
+	return res;
+}
+
+int copy_oldmem_kernel(void *dst, unsigned long src, size_t count)
+{
+	struct iov_iter iter;
+	struct kvec kvec;
+
+	kvec.iov_base = dst;
+	kvec.iov_len = count;
+	iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count);
+	if (copy_oldmem_iter(&iter, src, count) < count)
+		return -EFAULT;
+	return 0;
+}
+
+/*
+ * Copy one page from "oldmem"
+ */
+ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize,
+			 unsigned long offset)
+{
+	unsigned long src;
+
+	src = pfn_to_phys(pfn) + offset;
+	return copy_oldmem_iter(iter, src, csize);
+}
+
+/*
+ * Remap "oldmem" for kdump
+ *
+ * For the kdump reserved memory this functions performs a swap operation:
+ * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
+ */
+static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
+					unsigned long from, unsigned long pfn,
+					unsigned long size, pgprot_t prot)
+{
+	unsigned long size_old;
+	int rc;
+
+	if (pfn < oldmem_data.size >> PAGE_SHIFT) {
+		size_old = min(size, oldmem_data.size - (pfn << PAGE_SHIFT));
+		rc = remap_pfn_range(vma, from,
+				     pfn + (oldmem_data.start >> PAGE_SHIFT),
+				     size_old, prot);
+		if (rc || size == size_old)
+			return rc;
+		size -= size_old;
+		from += size_old;
+		pfn += size_old >> PAGE_SHIFT;
+	}
+	return remap_pfn_range(vma, from, pfn, size, prot);
+}
+
+/*
+ * Remap "oldmem" for zfcp/nvme dump
+ *
+ * We only map available memory above HSA size. Memory below HSA size
+ * is read on demand using the copy_oldmem_page() function.
+ */
+static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
+					   unsigned long from,
+					   unsigned long pfn,
+					   unsigned long size, pgprot_t prot)
+{
+	unsigned long hsa_end = sclp.hsa_size;
+	unsigned long size_hsa;
+
+	if (pfn < hsa_end >> PAGE_SHIFT) {
+		size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT));
+		if (size == size_hsa)
+			return 0;
+		size -= size_hsa;
+		from += size_hsa;
+		pfn += size_hsa >> PAGE_SHIFT;
+	}
+	return remap_pfn_range(vma, from, pfn, size, prot);
+}
+
+/*
+ * Remap "oldmem" for kdump or zfcp/nvme dump
+ */
+int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
+			   unsigned long pfn, unsigned long size, pgprot_t prot)
+{
+	if (oldmem_data.start)
+		return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
+	else
+		return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
+						       prot);
+}
+
+static const char *nt_name(Elf64_Word type)
+{
+	const char *name = "LINUX";
+
+	if (type == NT_PRPSINFO || type == NT_PRSTATUS || type == NT_PRFPREG)
+		name = KEXEC_CORE_NOTE_NAME;
+	return name;
+}
+
+/*
+ * Initialize ELF note
+ */
+static void *nt_init_name(void *buf, Elf64_Word type, void *desc, int d_len,
+			  const char *name)
+{
+	Elf64_Nhdr *note;
+	u64 len;
+
+	note = (Elf64_Nhdr *)buf;
+	note->n_namesz = strlen(name) + 1;
+	note->n_descsz = d_len;
+	note->n_type = type;
+	len = sizeof(Elf64_Nhdr);
+
+	memcpy(buf + len, name, note->n_namesz);
+	len = roundup(len + note->n_namesz, 4);
+
+	memcpy(buf + len, desc, note->n_descsz);
+	len = roundup(len + note->n_descsz, 4);
+
+	return PTR_ADD(buf, len);
+}
+
+static inline void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len)
+{
+	return nt_init_name(buf, type, desc, d_len, nt_name(type));
+}
+
+/*
+ * Calculate the size of ELF note
+ */
+static size_t nt_size_name(int d_len, const char *name)
+{
+	size_t size;
+
+	size = sizeof(Elf64_Nhdr);
+	size += roundup(strlen(name) + 1, 4);
+	size += roundup(d_len, 4);
+
+	return size;
+}
+
+static inline size_t nt_size(Elf64_Word type, int d_len)
+{
+	return nt_size_name(d_len, nt_name(type));
+}
+
+/*
+ * Fill ELF notes for one CPU with save area registers
+ */
+static void *fill_cpu_elf_notes(void *ptr, int cpu, struct save_area *sa)
+{
+	struct elf_prstatus nt_prstatus;
+	elf_fpregset_t nt_fpregset;
+
+	/* Prepare prstatus note */
+	memset(&nt_prstatus, 0, sizeof(nt_prstatus));
+	memcpy(&nt_prstatus.pr_reg.gprs, sa->gprs, sizeof(sa->gprs));
+	memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
+	memcpy(&nt_prstatus.pr_reg.acrs, sa->acrs, sizeof(sa->acrs));
+	nt_prstatus.common.pr_pid = cpu;
+	/* Prepare fpregset (floating point) note */
+	memset(&nt_fpregset, 0, sizeof(nt_fpregset));
+	memcpy(&nt_fpregset.fpc, &sa->fpc, sizeof(sa->fpc));
+	memcpy(&nt_fpregset.fprs, &sa->fprs, sizeof(sa->fprs));
+	/* Create ELF notes for the CPU */
+	ptr = nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus));
+	ptr = nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset));
+	ptr = nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer));
+	ptr = nt_init(ptr, NT_S390_TODCMP, &sa->todcmp, sizeof(sa->todcmp));
+	ptr = nt_init(ptr, NT_S390_TODPREG, &sa->todpreg, sizeof(sa->todpreg));
+	ptr = nt_init(ptr, NT_S390_CTRS, &sa->ctrs, sizeof(sa->ctrs));
+	ptr = nt_init(ptr, NT_S390_PREFIX, &sa->prefix, sizeof(sa->prefix));
+	if (MACHINE_HAS_VX) {
+		ptr = nt_init(ptr, NT_S390_VXRS_HIGH,
+			      &sa->vxrs_high, sizeof(sa->vxrs_high));
+		ptr = nt_init(ptr, NT_S390_VXRS_LOW,
+			      &sa->vxrs_low, sizeof(sa->vxrs_low));
+	}
+	return ptr;
+}
+
+/*
+ * Calculate size of ELF notes per cpu
+ */
+static size_t get_cpu_elf_notes_size(void)
+{
+	struct save_area *sa = NULL;
+	size_t size;
+
+	size =	nt_size(NT_PRSTATUS, sizeof(struct elf_prstatus));
+	size +=  nt_size(NT_PRFPREG, sizeof(elf_fpregset_t));
+	size +=  nt_size(NT_S390_TIMER, sizeof(sa->timer));
+	size +=  nt_size(NT_S390_TODCMP, sizeof(sa->todcmp));
+	size +=  nt_size(NT_S390_TODPREG, sizeof(sa->todpreg));
+	size +=  nt_size(NT_S390_CTRS, sizeof(sa->ctrs));
+	size +=  nt_size(NT_S390_PREFIX, sizeof(sa->prefix));
+	if (MACHINE_HAS_VX) {
+		size += nt_size(NT_S390_VXRS_HIGH, sizeof(sa->vxrs_high));
+		size += nt_size(NT_S390_VXRS_LOW, sizeof(sa->vxrs_low));
+	}
+
+	return size;
+}
+
+/*
+ * Initialize prpsinfo note (new kernel)
+ */
+static void *nt_prpsinfo(void *ptr)
+{
+	struct elf_prpsinfo prpsinfo;
+
+	memset(&prpsinfo, 0, sizeof(prpsinfo));
+	prpsinfo.pr_sname = 'R';
+	strcpy(prpsinfo.pr_fname, "vmlinux");
+	return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo));
+}
+
+/*
+ * Get vmcoreinfo using lowcore->vmcore_info (new kernel)
+ */
+static void *get_vmcoreinfo_old(unsigned long *size)
+{
+	char nt_name[11], *vmcoreinfo;
+	unsigned long addr;
+	Elf64_Nhdr note;
+
+	if (copy_oldmem_kernel(&addr, __LC_VMCORE_INFO, sizeof(addr)))
+		return NULL;
+	memset(nt_name, 0, sizeof(nt_name));
+	if (copy_oldmem_kernel(&note, addr, sizeof(note)))
+		return NULL;
+	if (copy_oldmem_kernel(nt_name, addr + sizeof(note),
+			       sizeof(nt_name) - 1))
+		return NULL;
+	if (strcmp(nt_name, VMCOREINFO_NOTE_NAME) != 0)
+		return NULL;
+	vmcoreinfo = kzalloc(note.n_descsz, GFP_KERNEL);
+	if (!vmcoreinfo)
+		return NULL;
+	if (copy_oldmem_kernel(vmcoreinfo, addr + 24, note.n_descsz)) {
+		kfree(vmcoreinfo);
+		return NULL;
+	}
+	*size = note.n_descsz;
+	return vmcoreinfo;
+}
+
+/*
+ * Initialize vmcoreinfo note (new kernel)
+ */
+static void *nt_vmcoreinfo(void *ptr)
+{
+	const char *name = VMCOREINFO_NOTE_NAME;
+	unsigned long size;
+	void *vmcoreinfo;
+
+	vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
+	if (vmcoreinfo)
+		return nt_init_name(ptr, 0, vmcoreinfo, size, name);
+
+	vmcoreinfo = get_vmcoreinfo_old(&size);
+	if (!vmcoreinfo)
+		return ptr;
+	ptr = nt_init_name(ptr, 0, vmcoreinfo, size, name);
+	kfree(vmcoreinfo);
+	return ptr;
+}
+
+static size_t nt_vmcoreinfo_size(void)
+{
+	const char *name = VMCOREINFO_NOTE_NAME;
+	unsigned long size;
+	void *vmcoreinfo;
+
+	vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
+	if (vmcoreinfo)
+		return nt_size_name(size, name);
+
+	vmcoreinfo = get_vmcoreinfo_old(&size);
+	if (!vmcoreinfo)
+		return 0;
+
+	kfree(vmcoreinfo);
+	return nt_size_name(size, name);
+}
+
+/*
+ * Initialize final note (needed for /proc/vmcore code)
+ */
+static void *nt_final(void *ptr)
+{
+	Elf64_Nhdr *note;
+
+	note = (Elf64_Nhdr *) ptr;
+	note->n_namesz = 0;
+	note->n_descsz = 0;
+	note->n_type = 0;
+	return PTR_ADD(ptr, sizeof(Elf64_Nhdr));
+}
+
+/*
+ * Initialize ELF header (new kernel)
+ */
+static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt)
+{
+	memset(ehdr, 0, sizeof(*ehdr));
+	memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
+	ehdr->e_ident[EI_CLASS] = ELFCLASS64;
+	ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
+	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
+	memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
+	ehdr->e_type = ET_CORE;
+	ehdr->e_machine = EM_S390;
+	ehdr->e_version = EV_CURRENT;
+	ehdr->e_phoff = sizeof(Elf64_Ehdr);
+	ehdr->e_ehsize = sizeof(Elf64_Ehdr);
+	ehdr->e_phentsize = sizeof(Elf64_Phdr);
+	ehdr->e_phnum = mem_chunk_cnt + 1;
+	return ehdr + 1;
+}
+
+/*
+ * Return CPU count for ELF header (new kernel)
+ */
+static int get_cpu_cnt(void)
+{
+	struct save_area *sa;
+	int cpus = 0;
+
+	list_for_each_entry(sa, &dump_save_areas, list)
+		if (sa->prefix != 0)
+			cpus++;
+	return cpus;
+}
+
+/*
+ * Return memory chunk count for ELF header (new kernel)
+ */
+static int get_mem_chunk_cnt(void)
+{
+	int cnt = 0;
+	u64 idx;
+
+	for_each_physmem_range(idx, &oldmem_type, NULL, NULL)
+		cnt++;
+	return cnt;
+}
+
+/*
+ * Initialize ELF loads (new kernel)
+ */
+static void loads_init(Elf64_Phdr *phdr, u64 loads_offset)
+{
+	phys_addr_t start, end;
+	u64 idx;
+
+	for_each_physmem_range(idx, &oldmem_type, &start, &end) {
+		phdr->p_filesz = end - start;
+		phdr->p_type = PT_LOAD;
+		phdr->p_offset = start;
+		phdr->p_vaddr = start;
+		phdr->p_paddr = start;
+		phdr->p_memsz = end - start;
+		phdr->p_flags = PF_R | PF_W | PF_X;
+		phdr->p_align = PAGE_SIZE;
+		phdr++;
+	}
+}
+
+/*
+ * Initialize notes (new kernel)
+ */
+static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
+{
+	struct save_area *sa;
+	void *ptr_start = ptr;
+	int cpu;
+
+	ptr = nt_prpsinfo(ptr);
+
+	cpu = 1;
+	list_for_each_entry(sa, &dump_save_areas, list)
+		if (sa->prefix != 0)
+			ptr = fill_cpu_elf_notes(ptr, cpu++, sa);
+	ptr = nt_vmcoreinfo(ptr);
+	ptr = nt_final(ptr);
+	memset(phdr, 0, sizeof(*phdr));
+	phdr->p_type = PT_NOTE;
+	phdr->p_offset = notes_offset;
+	phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
+	phdr->p_memsz = phdr->p_filesz;
+	return ptr;
+}
+
+static size_t get_elfcorehdr_size(int mem_chunk_cnt)
+{
+	size_t size;
+
+	size = sizeof(Elf64_Ehdr);
+	/* PT_NOTES */
+	size += sizeof(Elf64_Phdr);
+	/* nt_prpsinfo */
+	size += nt_size(NT_PRPSINFO, sizeof(struct elf_prpsinfo));
+	/* regsets */
+	size += get_cpu_cnt() * get_cpu_elf_notes_size();
+	/* nt_vmcoreinfo */
+	size += nt_vmcoreinfo_size();
+	/* nt_final */
+	size += sizeof(Elf64_Nhdr);
+	/* PT_LOADS */
+	size += mem_chunk_cnt * sizeof(Elf64_Phdr);
+
+	return size;
+}
+
+/*
+ * Create ELF core header (new kernel)
+ */
+int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
+{
+	Elf64_Phdr *phdr_notes, *phdr_loads;
+	size_t alloc_size;
+	int mem_chunk_cnt;
+	void *ptr, *hdr;
+	u64 hdr_off;
+
+	/* If we are not in kdump or zfcp/nvme dump mode return */
+	if (!oldmem_data.start && !is_ipl_type_dump())
+		return 0;
+	/* If we cannot get HSA size for zfcp/nvme dump return error */
+	if (is_ipl_type_dump() && !sclp.hsa_size)
+		return -ENODEV;
+
+	/* For kdump, exclude previous crashkernel memory */
+	if (oldmem_data.start) {
+		oldmem_region.base = oldmem_data.start;
+		oldmem_region.size = oldmem_data.size;
+		oldmem_type.total_size = oldmem_data.size;
+	}
+
+	mem_chunk_cnt = get_mem_chunk_cnt();
+
+	alloc_size = get_elfcorehdr_size(mem_chunk_cnt);
+
+	hdr = kzalloc(alloc_size, GFP_KERNEL);
+
+	/* Without elfcorehdr /proc/vmcore cannot be created. Thus creating
+	 * a dump with this crash kernel will fail. Panic now to allow other
+	 * dump mechanisms to take over.
+	 */
+	if (!hdr)
+		panic("s390 kdump allocating elfcorehdr failed");
+
+	/* Init elf header */
+	ptr = ehdr_init(hdr, mem_chunk_cnt);
+	/* Init program headers */
+	phdr_notes = ptr;
+	ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
+	phdr_loads = ptr;
+	ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
+	/* Init notes */
+	hdr_off = PTR_DIFF(ptr, hdr);
+	ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
+	/* Init loads */
+	hdr_off = PTR_DIFF(ptr, hdr);
+	loads_init(phdr_loads, hdr_off);
+	*addr = (unsigned long long) hdr;
+	*size = (unsigned long long) hdr_off;
+	BUG_ON(elfcorehdr_size > alloc_size);
+	return 0;
+}
+
+/*
+ * Free ELF core header (new kernel)
+ */
+void elfcorehdr_free(unsigned long long addr)
+{
+	kfree((void *)(unsigned long)addr);
+}
+
+/*
+ * Read from ELF header
+ */
+ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
+{
+	void *src = (void *)(unsigned long)*ppos;
+
+	memcpy(buf, src, count);
+	*ppos += count;
+	return count;
+}
+
+/*
+ * Read from ELF notes data
+ */
+ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
+{
+	void *src = (void *)(unsigned long)*ppos;
+
+	memcpy(buf, src, count);
+	*ppos += count;
+	return count;
+}