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Diffstat (limited to 'arch/riscv/kernel/elf_kexec.c')
-rw-r--r--arch/riscv/kernel/elf_kexec.c485
1 files changed, 0 insertions, 485 deletions
diff --git a/arch/riscv/kernel/elf_kexec.c b/arch/riscv/kernel/elf_kexec.c
deleted file mode 100644
index e783a72d051f..000000000000
--- a/arch/riscv/kernel/elf_kexec.c
+++ /dev/null
@@ -1,485 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Load ELF vmlinux file for the kexec_file_load syscall.
- *
- * Copyright (C) 2021 Huawei Technologies Co, Ltd.
- *
- * Author: Liao Chang (liaochang1@huawei.com)
- *
- * Based on kexec-tools' kexec-elf-riscv.c, heavily modified
- * for kernel.
- */
-
-#define pr_fmt(fmt) "kexec_image: " fmt
-
-#include <linux/elf.h>
-#include <linux/kexec.h>
-#include <linux/slab.h>
-#include <linux/of.h>
-#include <linux/libfdt.h>
-#include <linux/types.h>
-#include <linux/memblock.h>
-#include <linux/vmalloc.h>
-#include <asm/setup.h>
-
-int arch_kimage_file_post_load_cleanup(struct kimage *image)
-{
- kvfree(image->arch.fdt);
- image->arch.fdt = NULL;
-
- vfree(image->elf_headers);
- image->elf_headers = NULL;
- image->elf_headers_sz = 0;
-
- return kexec_image_post_load_cleanup_default(image);
-}
-
-static int riscv_kexec_elf_load(struct kimage *image, struct elfhdr *ehdr,
- struct kexec_elf_info *elf_info, unsigned long old_pbase,
- unsigned long new_pbase)
-{
- int i;
- int ret = 0;
- size_t size;
- struct kexec_buf kbuf;
- const struct elf_phdr *phdr;
-
- kbuf.image = image;
-
- for (i = 0; i < ehdr->e_phnum; i++) {
- phdr = &elf_info->proghdrs[i];
- if (phdr->p_type != PT_LOAD)
- continue;
-
- size = phdr->p_filesz;
- if (size > phdr->p_memsz)
- size = phdr->p_memsz;
-
- kbuf.buffer = (void *) elf_info->buffer + phdr->p_offset;
- kbuf.bufsz = size;
- kbuf.buf_align = phdr->p_align;
- kbuf.mem = phdr->p_paddr - old_pbase + new_pbase;
- kbuf.memsz = phdr->p_memsz;
- kbuf.top_down = false;
- ret = kexec_add_buffer(&kbuf);
- if (ret)
- break;
- }
-
- return ret;
-}
-
-/*
- * Go through the available phsyical memory regions and find one that hold
- * an image of the specified size.
- */
-static int elf_find_pbase(struct kimage *image, unsigned long kernel_len,
- struct elfhdr *ehdr, struct kexec_elf_info *elf_info,
- unsigned long *old_pbase, unsigned long *new_pbase)
-{
- int i;
- int ret;
- struct kexec_buf kbuf;
- const struct elf_phdr *phdr;
- unsigned long lowest_paddr = ULONG_MAX;
- unsigned long lowest_vaddr = ULONG_MAX;
-
- for (i = 0; i < ehdr->e_phnum; i++) {
- phdr = &elf_info->proghdrs[i];
- if (phdr->p_type != PT_LOAD)
- continue;
-
- if (lowest_paddr > phdr->p_paddr)
- lowest_paddr = phdr->p_paddr;
-
- if (lowest_vaddr > phdr->p_vaddr)
- lowest_vaddr = phdr->p_vaddr;
- }
-
- kbuf.image = image;
- kbuf.buf_min = lowest_paddr;
- kbuf.buf_max = ULONG_MAX;
-
- /*
- * Current riscv boot protocol requires 2MB alignment for
- * RV64 and 4MB alignment for RV32
- *
- */
- kbuf.buf_align = PMD_SIZE;
- kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
- kbuf.memsz = ALIGN(kernel_len, PAGE_SIZE);
- kbuf.top_down = false;
- ret = arch_kexec_locate_mem_hole(&kbuf);
- if (!ret) {
- *old_pbase = lowest_paddr;
- *new_pbase = kbuf.mem;
- image->start = ehdr->e_entry - lowest_vaddr + kbuf.mem;
- }
- return ret;
-}
-
-#ifdef CONFIG_CRASH_DUMP
-static int get_nr_ram_ranges_callback(struct resource *res, void *arg)
-{
- unsigned int *nr_ranges = arg;
-
- (*nr_ranges)++;
- return 0;
-}
-
-static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
-{
- struct crash_mem *cmem = arg;
-
- cmem->ranges[cmem->nr_ranges].start = res->start;
- cmem->ranges[cmem->nr_ranges].end = res->end;
- cmem->nr_ranges++;
-
- return 0;
-}
-
-static int prepare_elf_headers(void **addr, unsigned long *sz)
-{
- struct crash_mem *cmem;
- unsigned int nr_ranges;
- int ret;
-
- nr_ranges = 1; /* For exclusion of crashkernel region */
- walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
-
- cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL);
- if (!cmem)
- return -ENOMEM;
-
- cmem->max_nr_ranges = nr_ranges;
- cmem->nr_ranges = 0;
- ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
- if (ret)
- goto out;
-
- /* Exclude crashkernel region */
- ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
- if (!ret)
- ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
-
-out:
- kfree(cmem);
- return ret;
-}
-
-static char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
- unsigned long cmdline_len)
-{
- int elfcorehdr_strlen;
- char *cmdline_ptr;
-
- cmdline_ptr = kzalloc(COMMAND_LINE_SIZE, GFP_KERNEL);
- if (!cmdline_ptr)
- return NULL;
-
- elfcorehdr_strlen = sprintf(cmdline_ptr, "elfcorehdr=0x%lx ",
- image->elf_load_addr);
-
- if (elfcorehdr_strlen + cmdline_len > COMMAND_LINE_SIZE) {
- pr_err("Appending elfcorehdr=<addr> exceeds cmdline size\n");
- kfree(cmdline_ptr);
- return NULL;
- }
-
- memcpy(cmdline_ptr + elfcorehdr_strlen, cmdline, cmdline_len);
- /* Ensure it's nul terminated */
- cmdline_ptr[COMMAND_LINE_SIZE - 1] = '\0';
- return cmdline_ptr;
-}
-#endif
-
-static void *elf_kexec_load(struct kimage *image, char *kernel_buf,
- unsigned long kernel_len, char *initrd,
- unsigned long initrd_len, char *cmdline,
- unsigned long cmdline_len)
-{
- int ret;
- void *fdt;
- unsigned long old_kernel_pbase = ULONG_MAX;
- unsigned long new_kernel_pbase = 0UL;
- unsigned long initrd_pbase = 0UL;
- unsigned long kernel_start;
- struct elfhdr ehdr;
- struct kexec_buf kbuf;
- struct kexec_elf_info elf_info;
- char *modified_cmdline = NULL;
-
- ret = kexec_build_elf_info(kernel_buf, kernel_len, &ehdr, &elf_info);
- if (ret)
- return ERR_PTR(ret);
-
- ret = elf_find_pbase(image, kernel_len, &ehdr, &elf_info,
- &old_kernel_pbase, &new_kernel_pbase);
- if (ret)
- goto out;
- kernel_start = image->start;
-
- /* Add the kernel binary to the image */
- ret = riscv_kexec_elf_load(image, &ehdr, &elf_info,
- old_kernel_pbase, new_kernel_pbase);
- if (ret)
- goto out;
-
- kbuf.image = image;
- kbuf.buf_min = new_kernel_pbase + kernel_len;
- kbuf.buf_max = ULONG_MAX;
-
-#ifdef CONFIG_CRASH_DUMP
- /* Add elfcorehdr */
- if (image->type == KEXEC_TYPE_CRASH) {
- void *headers;
- unsigned long headers_sz;
- ret = prepare_elf_headers(&headers, &headers_sz);
- if (ret) {
- pr_err("Preparing elf core header failed\n");
- goto out;
- }
-
- kbuf.buffer = headers;
- kbuf.bufsz = headers_sz;
- kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
- kbuf.memsz = headers_sz;
- kbuf.buf_align = ELF_CORE_HEADER_ALIGN;
- kbuf.top_down = true;
-
- ret = kexec_add_buffer(&kbuf);
- if (ret) {
- vfree(headers);
- goto out;
- }
- image->elf_headers = headers;
- image->elf_load_addr = kbuf.mem;
- image->elf_headers_sz = headers_sz;
-
- kexec_dprintk("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
- image->elf_load_addr, kbuf.bufsz, kbuf.memsz);
-
- /* Setup cmdline for kdump kernel case */
- modified_cmdline = setup_kdump_cmdline(image, cmdline,
- cmdline_len);
- if (!modified_cmdline) {
- pr_err("Setting up cmdline for kdump kernel failed\n");
- ret = -EINVAL;
- goto out;
- }
- cmdline = modified_cmdline;
- }
-#endif
-
-#ifdef CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY
- /* Add purgatory to the image */
- kbuf.top_down = true;
- kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
- ret = kexec_load_purgatory(image, &kbuf);
- if (ret) {
- pr_err("Error loading purgatory ret=%d\n", ret);
- goto out;
- }
- kexec_dprintk("Loaded purgatory at 0x%lx\n", kbuf.mem);
-
- ret = kexec_purgatory_get_set_symbol(image, "riscv_kernel_entry",
- &kernel_start,
- sizeof(kernel_start), 0);
- if (ret)
- pr_err("Error update purgatory ret=%d\n", ret);
-#endif /* CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY */
-
- /* Add the initrd to the image */
- if (initrd != NULL) {
- kbuf.buffer = initrd;
- kbuf.bufsz = kbuf.memsz = initrd_len;
- kbuf.buf_align = PAGE_SIZE;
- kbuf.top_down = true;
- kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
- ret = kexec_add_buffer(&kbuf);
- if (ret)
- goto out;
- initrd_pbase = kbuf.mem;
- kexec_dprintk("Loaded initrd at 0x%lx\n", initrd_pbase);
- }
-
- /* Add the DTB to the image */
- fdt = of_kexec_alloc_and_setup_fdt(image, initrd_pbase,
- initrd_len, cmdline, 0);
- if (!fdt) {
- pr_err("Error setting up the new device tree.\n");
- ret = -EINVAL;
- goto out;
- }
-
- fdt_pack(fdt);
- kbuf.buffer = fdt;
- kbuf.bufsz = kbuf.memsz = fdt_totalsize(fdt);
- kbuf.buf_align = PAGE_SIZE;
- kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
- kbuf.top_down = true;
- ret = kexec_add_buffer(&kbuf);
- if (ret) {
- pr_err("Error add DTB kbuf ret=%d\n", ret);
- goto out_free_fdt;
- }
- /* Cache the fdt buffer address for memory cleanup */
- image->arch.fdt = fdt;
- kexec_dprintk("Loaded device tree at 0x%lx\n", kbuf.mem);
- goto out;
-
-out_free_fdt:
- kvfree(fdt);
-out:
- kfree(modified_cmdline);
- kexec_free_elf_info(&elf_info);
- return ret ? ERR_PTR(ret) : NULL;
-}
-
-#define RV_X(x, s, n) (((x) >> (s)) & ((1 << (n)) - 1))
-#define RISCV_IMM_BITS 12
-#define RISCV_IMM_REACH (1LL << RISCV_IMM_BITS)
-#define RISCV_CONST_HIGH_PART(x) \
- (((x) + (RISCV_IMM_REACH >> 1)) & ~(RISCV_IMM_REACH - 1))
-#define RISCV_CONST_LOW_PART(x) ((x) - RISCV_CONST_HIGH_PART(x))
-
-#define ENCODE_ITYPE_IMM(x) \
- (RV_X(x, 0, 12) << 20)
-#define ENCODE_BTYPE_IMM(x) \
- ((RV_X(x, 1, 4) << 8) | (RV_X(x, 5, 6) << 25) | \
- (RV_X(x, 11, 1) << 7) | (RV_X(x, 12, 1) << 31))
-#define ENCODE_UTYPE_IMM(x) \
- (RV_X(x, 12, 20) << 12)
-#define ENCODE_JTYPE_IMM(x) \
- ((RV_X(x, 1, 10) << 21) | (RV_X(x, 11, 1) << 20) | \
- (RV_X(x, 12, 8) << 12) | (RV_X(x, 20, 1) << 31))
-#define ENCODE_CBTYPE_IMM(x) \
- ((RV_X(x, 1, 2) << 3) | (RV_X(x, 3, 2) << 10) | (RV_X(x, 5, 1) << 2) | \
- (RV_X(x, 6, 2) << 5) | (RV_X(x, 8, 1) << 12))
-#define ENCODE_CJTYPE_IMM(x) \
- ((RV_X(x, 1, 3) << 3) | (RV_X(x, 4, 1) << 11) | (RV_X(x, 5, 1) << 2) | \
- (RV_X(x, 6, 1) << 7) | (RV_X(x, 7, 1) << 6) | (RV_X(x, 8, 2) << 9) | \
- (RV_X(x, 10, 1) << 8) | (RV_X(x, 11, 1) << 12))
-#define ENCODE_UJTYPE_IMM(x) \
- (ENCODE_UTYPE_IMM(RISCV_CONST_HIGH_PART(x)) | \
- (ENCODE_ITYPE_IMM(RISCV_CONST_LOW_PART(x)) << 32))
-#define ENCODE_UITYPE_IMM(x) \
- (ENCODE_UTYPE_IMM(x) | (ENCODE_ITYPE_IMM(x) << 32))
-
-#define CLEAN_IMM(type, x) \
- ((~ENCODE_##type##_IMM((uint64_t)(-1))) & (x))
-
-int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
- Elf_Shdr *section,
- const Elf_Shdr *relsec,
- const Elf_Shdr *symtab)
-{
- const char *strtab, *name, *shstrtab;
- const Elf_Shdr *sechdrs;
- Elf64_Rela *relas;
- int i, r_type;
-
- /* String & section header string table */
- sechdrs = (void *)pi->ehdr + pi->ehdr->e_shoff;
- strtab = (char *)pi->ehdr + sechdrs[symtab->sh_link].sh_offset;
- shstrtab = (char *)pi->ehdr + sechdrs[pi->ehdr->e_shstrndx].sh_offset;
-
- relas = (void *)pi->ehdr + relsec->sh_offset;
-
- for (i = 0; i < relsec->sh_size / sizeof(*relas); i++) {
- const Elf_Sym *sym; /* symbol to relocate */
- unsigned long addr; /* final location after relocation */
- unsigned long val; /* relocated symbol value */
- unsigned long sec_base; /* relocated symbol value */
- void *loc; /* tmp location to modify */
-
- sym = (void *)pi->ehdr + symtab->sh_offset;
- sym += ELF64_R_SYM(relas[i].r_info);
-
- if (sym->st_name)
- name = strtab + sym->st_name;
- else
- name = shstrtab + sechdrs[sym->st_shndx].sh_name;
-
- loc = pi->purgatory_buf;
- loc += section->sh_offset;
- loc += relas[i].r_offset;
-
- if (sym->st_shndx == SHN_ABS)
- sec_base = 0;
- else if (sym->st_shndx >= pi->ehdr->e_shnum) {
- pr_err("Invalid section %d for symbol %s\n",
- sym->st_shndx, name);
- return -ENOEXEC;
- } else
- sec_base = pi->sechdrs[sym->st_shndx].sh_addr;
-
- val = sym->st_value;
- val += sec_base;
- val += relas[i].r_addend;
-
- addr = section->sh_addr + relas[i].r_offset;
-
- r_type = ELF64_R_TYPE(relas[i].r_info);
-
- switch (r_type) {
- case R_RISCV_BRANCH:
- *(u32 *)loc = CLEAN_IMM(BTYPE, *(u32 *)loc) |
- ENCODE_BTYPE_IMM(val - addr);
- break;
- case R_RISCV_JAL:
- *(u32 *)loc = CLEAN_IMM(JTYPE, *(u32 *)loc) |
- ENCODE_JTYPE_IMM(val - addr);
- break;
- /*
- * With no R_RISCV_PCREL_LO12_S, R_RISCV_PCREL_LO12_I
- * sym is expected to be next to R_RISCV_PCREL_HI20
- * in purgatory relsec. Handle it like R_RISCV_CALL
- * sym, instead of searching the whole relsec.
- */
- case R_RISCV_PCREL_HI20:
- case R_RISCV_CALL_PLT:
- case R_RISCV_CALL:
- *(u64 *)loc = CLEAN_IMM(UITYPE, *(u64 *)loc) |
- ENCODE_UJTYPE_IMM(val - addr);
- break;
- case R_RISCV_RVC_BRANCH:
- *(u32 *)loc = CLEAN_IMM(CBTYPE, *(u32 *)loc) |
- ENCODE_CBTYPE_IMM(val - addr);
- break;
- case R_RISCV_RVC_JUMP:
- *(u32 *)loc = CLEAN_IMM(CJTYPE, *(u32 *)loc) |
- ENCODE_CJTYPE_IMM(val - addr);
- break;
- case R_RISCV_ADD16:
- *(u16 *)loc += val;
- break;
- case R_RISCV_SUB16:
- *(u16 *)loc -= val;
- break;
- case R_RISCV_ADD32:
- *(u32 *)loc += val;
- break;
- case R_RISCV_SUB32:
- *(u32 *)loc -= val;
- break;
- /* It has been applied by R_RISCV_PCREL_HI20 sym */
- case R_RISCV_PCREL_LO12_I:
- case R_RISCV_ALIGN:
- case R_RISCV_RELAX:
- break;
- case R_RISCV_64:
- *(u64 *)loc = val;
- break;
- default:
- pr_err("Unknown rela relocation: %d\n", r_type);
- return -ENOEXEC;
- }
- }
- return 0;
-}
-
-const struct kexec_file_ops elf_kexec_ops = {
- .probe = kexec_elf_probe,
- .load = elf_kexec_load,
-};
generated by cgit (git 2.34.1) at 2025-06-08 21:20:11 +0000