[PATCH 0/2] riscv: kexec_file: Support loading Image binary file

[PATCH 0/2] riscv: kexec_file: Support loading Image binary file

[Song Shuai]

Hi,

This series makes the kexec_file_load() syscall support to load Image binary file.
At the same time, corresponding support for kexec-tools had been pushed to my repo[1].

Now, we can leverage that kexec-tools and this series to use the
kexec_load() or kexec_file_load() syscall to boot both vmlinux 
and Image file, as seen in these combo tests:

```
1. kexec -l vmlinux [other options] // or boot paniced kernel with -p
2. kexec -l Image
3. kexec -s -l vmlinux
4. kexec -s -l Image
```

Though all of the aforementioned tests had been passed in my RV64 Qemu-virt, 
it should be noted that tests 3 and 4 should be the emphasis for the current series.

[1]: https://github.com/sugarfillet/kexec-tools/commits/rv-Image

Song Shuai (2):
  riscv: kexec_file: Split the loading of kernel and others
  riscv: kexec_file: Support loading Image binary file

 arch/riscv/include/asm/image.h         |   2 +
 arch/riscv/include/asm/kexec.h         |   6 +
 arch/riscv/kernel/Makefile             |   2 +-
 arch/riscv/kernel/elf_kexec.c          | 469 -------------------------
 arch/riscv/kernel/kexec_elf.c          | 147 ++++++++
 arch/riscv/kernel/kexec_image.c        |  97 +++++
 arch/riscv/kernel/machine_kexec_file.c |   8 +
 7 files changed, 261 insertions(+), 470 deletions(-)
 delete mode 100644 arch/riscv/kernel/elf_kexec.c
 create mode 100644 arch/riscv/kernel/kexec_elf.c
 create mode 100644 arch/riscv/kernel/kexec_image.c

-- 
2.20.1


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[PATCH 1/2] riscv: kexec_file: Split the loading of kernel and others

[Song Shuai]

This is the preparative patch for kexec_file_load Image support.

It separates the elf_kexec_load() as two parts:
- the first part loads the vmlinux (or Image)
- the second part loads other segments (e.g. initrd,fdt,purgatory)

And the second part is exported as the load_extra_segments() function
which would be used in both kexec-elf.c and kexec-image.c.

Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
---
 arch/riscv/include/asm/kexec.h         |   5 +
 arch/riscv/kernel/Makefile             |   2 +-
 arch/riscv/kernel/elf_kexec.c          | 469 -------------------------
 arch/riscv/kernel/kexec_elf.c          | 147 ++++++++
 arch/riscv/kernel/machine_kexec_file.c |   7 +
 5 files changed, 160 insertions(+), 470 deletions(-)
 delete mode 100644 arch/riscv/kernel/elf_kexec.c
 create mode 100644 arch/riscv/kernel/kexec_elf.c

diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
index 2b56769cb530..518825fe4160 100644
--- a/arch/riscv/include/asm/kexec.h
+++ b/arch/riscv/include/asm/kexec.h
@@ -67,6 +67,11 @@ int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
 struct kimage;
 int arch_kimage_file_post_load_cleanup(struct kimage *image);
 #define arch_kimage_file_post_load_cleanup arch_kimage_file_post_load_cleanup
+
+int load_extra_segments(struct kimage *image, unsigned long kernel_start,
+			unsigned long kernel_len, char *initrd,
+			unsigned long initrd_len, char *cmdline,
+			unsigned long cmdline_len);
 #endif
 
 #endif
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 95cf25d48405..1c62c639e875 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -86,7 +86,7 @@ endif
 obj-$(CONFIG_HOTPLUG_CPU)	+= cpu-hotplug.o
 obj-$(CONFIG_KGDB)		+= kgdb.o
 obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate.o crash_save_regs.o machine_kexec.o
-obj-$(CONFIG_KEXEC_FILE)	+= elf_kexec.o machine_kexec_file.o
+obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o machine_kexec_file.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
 obj-$(CONFIG_CRASH_CORE)	+= crash_core.o
 
diff --git a/arch/riscv/kernel/elf_kexec.c b/arch/riscv/kernel/elf_kexec.c
deleted file mode 100644
index e60fbd8660c4..000000000000
--- a/arch/riscv/kernel/elf_kexec.c
+++ /dev/null
@@ -1,469 +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 <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;
-}
-
-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;
-}
-
-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;
-	unsigned long old_kernel_pbase = ULONG_MAX;
-	unsigned long new_kernel_pbase = 0UL;
-	unsigned long initrd_pbase = 0UL;
-	unsigned long headers_sz;
-	unsigned long kernel_start;
-	void *fdt, *headers;
-	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;
-	pr_notice("The entry point of kernel at 0x%lx\n", 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;
-
-	/* Add elfcorehdr */
-	if (image->type == KEXEC_TYPE_CRASH) {
-		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;
-
-		pr_debug("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;
-	}
-
-#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;
-	}
-	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;
-		pr_notice("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;
-	pr_notice("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_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;
-		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,
-};
diff --git a/arch/riscv/kernel/kexec_elf.c b/arch/riscv/kernel/kexec_elf.c
new file mode 100644
index 000000000000..f41272da6b2f
--- /dev/null
+++ b/arch/riscv/kernel/kexec_elf.c
@@ -0,0 +1,147 @@
+// 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 <asm/setup.h>
+
+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;
+}
+
+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;
+	unsigned long old_kernel_pbase = ULONG_MAX;
+	unsigned long new_kernel_pbase = 0UL;
+	struct elfhdr ehdr;
+	struct kexec_elf_info elf_info;
+
+	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;
+
+	pr_notice("The entry point of kernel at 0x%lx\n", 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;
+
+	ret = load_extra_segments(image, image->start, kernel_len,
+				  initrd, initrd_len, cmdline, cmdline_len);
+out:
+	kexec_free_elf_info(&elf_info);
+	return ret ? ERR_PTR(ret) : NULL;
+}
+
+
+const struct kexec_file_ops elf_kexec_ops = {
+	.probe = kexec_elf_probe,
+	.load  = elf_kexec_load,
+};
diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
index 6ebd3ab5a9eb..aedb8c16a283 100644
--- a/arch/riscv/kernel/machine_kexec_file.c
+++ b/arch/riscv/kernel/machine_kexec_file.c
@@ -7,6 +7,13 @@
  * Author: Liao Chang (liaochang1@huawei.com)
  */
 #include <linux/kexec.h>
+#include <linux/elf.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/libfdt.h>
+#include <linux/types.h>
+#include <linux/memblock.h>
+#include <asm/setup.h>
 
 const struct kexec_file_ops * const kexec_file_loaders[] = {
 	&elf_kexec_ops,
-- 
2.20.1


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Re: [External] [PATCH 1/2] riscv: kexec_file: Split the loading of kernel and others

[yunhui cui]

Hi Shuai,

Why rename elf_kexec.c to kexec_elf.c ？

On Thu, Sep 14, 2023 at 10:08 AM Song Shuai <songshuaishuai@tinylab.org> wrote:
>
> This is the preparative patch for kexec_file_load Image support.
>
> It separates the elf_kexec_load() as two parts:
> - the first part loads the vmlinux (or Image)
> - the second part loads other segments (e.g. initrd,fdt,purgatory)
>
> And the second part is exported as the load_extra_segments() function
> which would be used in both kexec-elf.c and kexec-image.c.
>
> Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
> ---
>  arch/riscv/include/asm/kexec.h         |   5 +
>  arch/riscv/kernel/Makefile             |   2 +-
>  arch/riscv/kernel/elf_kexec.c          | 469 -------------------------
>  arch/riscv/kernel/kexec_elf.c          | 147 ++++++++
>  arch/riscv/kernel/machine_kexec_file.c |   7 +
>  5 files changed, 160 insertions(+), 470 deletions(-)
>  delete mode 100644 arch/riscv/kernel/elf_kexec.c
>  create mode 100644 arch/riscv/kernel/kexec_elf.c
>
> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
> index 2b56769cb530..518825fe4160 100644
> --- a/arch/riscv/include/asm/kexec.h
> +++ b/arch/riscv/include/asm/kexec.h
> @@ -67,6 +67,11 @@ int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
>  struct kimage;
>  int arch_kimage_file_post_load_cleanup(struct kimage *image);
>  #define arch_kimage_file_post_load_cleanup arch_kimage_file_post_load_cleanup
> +
> +int load_extra_segments(struct kimage *image, unsigned long kernel_start,
> +                       unsigned long kernel_len, char *initrd,
> +                       unsigned long initrd_len, char *cmdline,
> +                       unsigned long cmdline_len);
>  #endif
>
>  #endif
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index 95cf25d48405..1c62c639e875 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -86,7 +86,7 @@ endif
>  obj-$(CONFIG_HOTPLUG_CPU)      += cpu-hotplug.o
>  obj-$(CONFIG_KGDB)             += kgdb.o
>  obj-$(CONFIG_KEXEC_CORE)       += kexec_relocate.o crash_save_regs.o machine_kexec.o
> -obj-$(CONFIG_KEXEC_FILE)       += elf_kexec.o machine_kexec_file.o
> +obj-$(CONFIG_KEXEC_FILE)       += kexec_elf.o machine_kexec_file.o
>  obj-$(CONFIG_CRASH_DUMP)       += crash_dump.o
>  obj-$(CONFIG_CRASH_CORE)       += crash_core.o
>
> diff --git a/arch/riscv/kernel/elf_kexec.c b/arch/riscv/kernel/elf_kexec.c
> deleted file mode 100644
> index e60fbd8660c4..000000000000
> --- a/arch/riscv/kernel/elf_kexec.c
> +++ /dev/null
> @@ -1,469 +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 <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;
> -}
> -
> -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;
> -}
> -
> -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;
> -       unsigned long old_kernel_pbase = ULONG_MAX;
> -       unsigned long new_kernel_pbase = 0UL;
> -       unsigned long initrd_pbase = 0UL;
> -       unsigned long headers_sz;
> -       unsigned long kernel_start;
> -       void *fdt, *headers;
> -       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;
> -       pr_notice("The entry point of kernel at 0x%lx\n", 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;
> -
> -       /* Add elfcorehdr */
> -       if (image->type == KEXEC_TYPE_CRASH) {
> -               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;
> -
> -               pr_debug("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;
> -       }
> -
> -#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;
> -       }
> -       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;
> -               pr_notice("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;
> -       pr_notice("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_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;
> -               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,
> -};
> diff --git a/arch/riscv/kernel/kexec_elf.c b/arch/riscv/kernel/kexec_elf.c
> new file mode 100644
> index 000000000000..f41272da6b2f
> --- /dev/null
> +++ b/arch/riscv/kernel/kexec_elf.c
> @@ -0,0 +1,147 @@
> +// 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 <asm/setup.h>
> +
> +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;
> +}
> +
> +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;
> +       unsigned long old_kernel_pbase = ULONG_MAX;
> +       unsigned long new_kernel_pbase = 0UL;
> +       struct elfhdr ehdr;
> +       struct kexec_elf_info elf_info;
> +
> +       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;
> +
> +       pr_notice("The entry point of kernel at 0x%lx\n", 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;
> +
> +       ret = load_extra_segments(image, image->start, kernel_len,
> +                                 initrd, initrd_len, cmdline, cmdline_len);
> +out:
> +       kexec_free_elf_info(&elf_info);
> +       return ret ? ERR_PTR(ret) : NULL;
> +}
> +
> +

Remove extra blank lines.

> +const struct kexec_file_ops elf_kexec_ops = {
> +       .probe = kexec_elf_probe,
> +       .load  = elf_kexec_load,
> +};
> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> index 6ebd3ab5a9eb..aedb8c16a283 100644
> --- a/arch/riscv/kernel/machine_kexec_file.c
> +++ b/arch/riscv/kernel/machine_kexec_file.c
> @@ -7,6 +7,13 @@
>   * Author: Liao Chang (liaochang1@huawei.com)
>   */
>  #include <linux/kexec.h>
> +#include <linux/elf.h>
> +#include <linux/slab.h>
> +#include <linux/of.h>
> +#include <linux/libfdt.h>
> +#include <linux/types.h>
> +#include <linux/memblock.h>
> +#include <asm/setup.h>
>
>  const struct kexec_file_ops * const kexec_file_loaders[] = {
>         &elf_kexec_ops,
> --
> 2.20.1
>

Thanks,
Yunhui

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[PATCH 2/2] riscv: kexec_file: Support loading Image binary file

[Song Shuai]

This patch creates image_kexec_ops to load Image binary file
for kexec_file_load() syscall.

Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
---
 arch/riscv/include/asm/image.h         |  2 +
 arch/riscv/include/asm/kexec.h         |  1 +
 arch/riscv/kernel/Makefile             |  2 +-
 arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
 arch/riscv/kernel/machine_kexec_file.c |  1 +
 5 files changed, 102 insertions(+), 1 deletion(-)
 create mode 100644 arch/riscv/kernel/kexec_image.c

diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
index e0b319af3681..8927a6ea1127 100644
--- a/arch/riscv/include/asm/image.h
+++ b/arch/riscv/include/asm/image.h
@@ -30,6 +30,8 @@
 			      RISCV_HEADER_VERSION_MINOR)
 
 #ifndef __ASSEMBLY__
+#define riscv_image_flag_field(flags, field)\
+			       (((flags) >> field##_SHIFT) & field##_MASK)
 /**
  * struct riscv_image_header - riscv kernel image header
  * @code0:		Executable code
diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
index 518825fe4160..b9ee8346cc8c 100644
--- a/arch/riscv/include/asm/kexec.h
+++ b/arch/riscv/include/asm/kexec.h
@@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
 
 #ifdef CONFIG_KEXEC_FILE
 extern const struct kexec_file_ops elf_kexec_ops;
+extern const struct kexec_file_ops image_kexec_ops;
 
 struct purgatory_info;
 int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 1c62c639e875..9ecba3231a36 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -86,7 +86,7 @@ endif
 obj-$(CONFIG_HOTPLUG_CPU)	+= cpu-hotplug.o
 obj-$(CONFIG_KGDB)		+= kgdb.o
 obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate.o crash_save_regs.o machine_kexec.o
-obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o machine_kexec_file.o
+obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o kexec_image.o machine_kexec_file.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
 obj-$(CONFIG_CRASH_CORE)	+= crash_core.o
 
diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
new file mode 100644
index 000000000000..b6aa7f59bd53
--- /dev/null
+++ b/arch/riscv/kernel/kexec_image.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RISC-V Kexec image loader
+ *
+ */
+
+#define pr_fmt(fmt)	"kexec_file(Image): " fmt
+
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/pe.h>
+#include <linux/string.h>
+#include <asm/byteorder.h>
+#include <asm/image.h>
+
+static int image_probe(const char *kernel_buf, unsigned long kernel_len)
+{
+	const struct riscv_image_header *h =
+		(const struct riscv_image_header *)(kernel_buf);
+
+	if (!h || (kernel_len < sizeof(*h)))
+		return -EINVAL;
+
+	/* According to Documentation/riscv/boot-image-header.rst,
+	 * use "magic2" field to check when version >= 0.2.
+	 */
+
+	if (h->version >= RISCV_HEADER_VERSION &&
+	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
+		return -EINVAL;
+
+	return 0;
+}
+
+static void *image_load(struct kimage *image,
+				char *kernel, unsigned long kernel_len,
+				char *initrd, unsigned long initrd_len,
+				char *cmdline, unsigned long cmdline_len)
+{
+	struct riscv_image_header *h;
+	u64 flags;
+	bool be_image, be_kernel;
+	struct kexec_buf kbuf;
+	int ret;
+
+	/* Check Image header */
+	h = (struct riscv_image_header *)kernel;
+	if (!h->image_size) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Check endianness */
+	flags = le64_to_cpu(h->flags);
+	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
+	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
+	if (be_image != be_kernel) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Load the kernel image */
+	kbuf.image = image;
+	kbuf.buf_min = 0;
+	kbuf.buf_max = ULONG_MAX;
+	kbuf.top_down = false;
+
+	kbuf.buffer = kernel;
+	kbuf.bufsz = kernel_len;
+	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
+	kbuf.memsz = le64_to_cpu(h->image_size);
+	kbuf.buf_align = le64_to_cpu(h->text_offset);
+
+	ret = kexec_add_buffer(&kbuf);
+	if (ret) {
+		pr_err("Error add kernel image ret=%d\n", ret);
+		goto out;
+	}
+
+	image->start = kbuf.mem;
+
+	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
+				kbuf.mem, kbuf.bufsz, kbuf.memsz);
+
+	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
+				  initrd, initrd_len, cmdline, cmdline_len);
+
+out:
+	return ret ? ERR_PTR(ret) : NULL;
+}
+
+const struct kexec_file_ops image_kexec_ops = {
+	.probe = image_probe,
+	.load = image_load,
+};
diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
index aedb8c16a283..5dc700834f1e 100644
--- a/arch/riscv/kernel/machine_kexec_file.c
+++ b/arch/riscv/kernel/machine_kexec_file.c
@@ -17,6 +17,7 @@
 
 const struct kexec_file_ops * const kexec_file_loaders[] = {
 	&elf_kexec_ops,
+	&image_kexec_ops,
 	NULL
 };
 
-- 
2.20.1


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Re: [PATCH 2/2] riscv: kexec_file: Support loading Image binary file

[Emil Renner Berthing]

Song Shuai wrote:
> This patch creates image_kexec_ops to load Image binary file
> for kexec_file_load() syscall.
>
> Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
> ---
>  arch/riscv/include/asm/image.h         |  2 +
>  arch/riscv/include/asm/kexec.h         |  1 +
>  arch/riscv/kernel/Makefile             |  2 +-
>  arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
>  arch/riscv/kernel/machine_kexec_file.c |  1 +
>  5 files changed, 102 insertions(+), 1 deletion(-)
>  create mode 100644 arch/riscv/kernel/kexec_image.c
>
> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
> index e0b319af3681..8927a6ea1127 100644
> --- a/arch/riscv/include/asm/image.h
> +++ b/arch/riscv/include/asm/image.h
> @@ -30,6 +30,8 @@
>  			      RISCV_HEADER_VERSION_MINOR)
>
>  #ifndef __ASSEMBLY__
> +#define riscv_image_flag_field(flags, field)\
> +			       (((flags) >> field##_SHIFT) & field##_MASK)

Hi Song,

This macro is almost FIELD_GET from linux/bitfield.h ..

>  /**
>   * struct riscv_image_header - riscv kernel image header
>   * @code0:		Executable code
> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
> index 518825fe4160..b9ee8346cc8c 100644
> --- a/arch/riscv/include/asm/kexec.h
> +++ b/arch/riscv/include/asm/kexec.h
> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
>
>  #ifdef CONFIG_KEXEC_FILE
>  extern const struct kexec_file_ops elf_kexec_ops;
> +extern const struct kexec_file_ops image_kexec_ops;
>
>  struct purgatory_info;
>  int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index 1c62c639e875..9ecba3231a36 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -86,7 +86,7 @@ endif
>  obj-$(CONFIG_HOTPLUG_CPU)	+= cpu-hotplug.o
>  obj-$(CONFIG_KGDB)		+= kgdb.o
>  obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate.o crash_save_regs.o machine_kexec.o
> -obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o machine_kexec_file.o
> +obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o kexec_image.o machine_kexec_file.o
>  obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
>  obj-$(CONFIG_CRASH_CORE)	+= crash_core.o
>
> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
> new file mode 100644
> index 000000000000..b6aa7f59bd53
> --- /dev/null
> +++ b/arch/riscv/kernel/kexec_image.c
> @@ -0,0 +1,97 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * RISC-V Kexec image loader
> + *
> + */
> +
> +#define pr_fmt(fmt)	"kexec_file(Image): " fmt
> +
> +#include <linux/err.h>
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/kexec.h>
> +#include <linux/pe.h>
> +#include <linux/string.h>
> +#include <asm/byteorder.h>
> +#include <asm/image.h>
> +
> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
> +{
> +	const struct riscv_image_header *h =
> +		(const struct riscv_image_header *)(kernel_buf);
> +
> +	if (!h || (kernel_len < sizeof(*h)))
> +		return -EINVAL;
> +
> +	/* According to Documentation/riscv/boot-image-header.rst,
> +	 * use "magic2" field to check when version >= 0.2.
> +	 */
> +
> +	if (h->version >= RISCV_HEADER_VERSION &&
> +	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static void *image_load(struct kimage *image,
> +				char *kernel, unsigned long kernel_len,
> +				char *initrd, unsigned long initrd_len,
> +				char *cmdline, unsigned long cmdline_len)
> +{
> +	struct riscv_image_header *h;
> +	u64 flags;
> +	bool be_image, be_kernel;
> +	struct kexec_buf kbuf;
> +	int ret;
> +
> +	/* Check Image header */
> +	h = (struct riscv_image_header *)kernel;
> +	if (!h->image_size) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	/* Check endianness */
> +	flags = le64_to_cpu(h->flags);
> +	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);

..but here you're just testing a single bit, so since be_image is a bool it
could just be
	be_image = flags & RISCV_IMAGE_FLAG_BE_MASK;

/Emil

> +	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
> +	if (be_image != be_kernel) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	/* Load the kernel image */
> +	kbuf.image = image;
> +	kbuf.buf_min = 0;
> +	kbuf.buf_max = ULONG_MAX;
> +	kbuf.top_down = false;
> +
> +	kbuf.buffer = kernel;
> +	kbuf.bufsz = kernel_len;
> +	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
> +	kbuf.memsz = le64_to_cpu(h->image_size);
> +	kbuf.buf_align = le64_to_cpu(h->text_offset);
> +
> +	ret = kexec_add_buffer(&kbuf);
> +	if (ret) {
> +		pr_err("Error add kernel image ret=%d\n", ret);
> +		goto out;
> +	}
> +
> +	image->start = kbuf.mem;
> +
> +	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
> +				kbuf.mem, kbuf.bufsz, kbuf.memsz);
> +
> +	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
> +				  initrd, initrd_len, cmdline, cmdline_len);
> +
> +out:
> +	return ret ? ERR_PTR(ret) : NULL;
> +}
> +
> +const struct kexec_file_ops image_kexec_ops = {
> +	.probe = image_probe,
> +	.load = image_load,
> +};
> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> index aedb8c16a283..5dc700834f1e 100644
> --- a/arch/riscv/kernel/machine_kexec_file.c
> +++ b/arch/riscv/kernel/machine_kexec_file.c
> @@ -17,6 +17,7 @@
>
>  const struct kexec_file_ops * const kexec_file_loaders[] = {
>  	&elf_kexec_ops,
> +	&image_kexec_ops,
>  	NULL
>  };
>
> --
> 2.20.1
>
>
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

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Re: [PATCH 2/2] riscv: kexec_file: Support loading Image binary file

[Song Shuai]

在 2023/9/14 16:37, Emil Renner Berthing 写道:
> Song Shuai wrote:
>> This patch creates image_kexec_ops to load Image binary file
>> for kexec_file_load() syscall.
>>
>> Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
>> ---
>>   arch/riscv/include/asm/image.h         |  2 +
>>   arch/riscv/include/asm/kexec.h         |  1 +
>>   arch/riscv/kernel/Makefile             |  2 +-
>>   arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
>>   arch/riscv/kernel/machine_kexec_file.c |  1 +
>>   5 files changed, 102 insertions(+), 1 deletion(-)
>>   create mode 100644 arch/riscv/kernel/kexec_image.c
>>
>> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
>> index e0b319af3681..8927a6ea1127 100644
>> --- a/arch/riscv/include/asm/image.h
>> +++ b/arch/riscv/include/asm/image.h
>> @@ -30,6 +30,8 @@
>>   			      RISCV_HEADER_VERSION_MINOR)
>>
>>   #ifndef __ASSEMBLY__
>> +#define riscv_image_flag_field(flags, field)\
>> +			       (((flags) >> field##_SHIFT) & field##_MASK)
> 
> Hi Song,
> 
> This macro is almost FIELD_GET from linux/bitfield.h ..
> 
>>   /**
>>    * struct riscv_image_header - riscv kernel image header
>>    * @code0:		Executable code
>> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
>> index 518825fe4160..b9ee8346cc8c 100644
>> --- a/arch/riscv/include/asm/kexec.h
>> +++ b/arch/riscv/include/asm/kexec.h
>> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
>>
>>   #ifdef CONFIG_KEXEC_FILE
>>   extern const struct kexec_file_ops elf_kexec_ops;
>> +extern const struct kexec_file_ops image_kexec_ops;
>>
>>   struct purgatory_info;
>>   int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
>> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
>> index 1c62c639e875..9ecba3231a36 100644
>> --- a/arch/riscv/kernel/Makefile
>> +++ b/arch/riscv/kernel/Makefile
>> @@ -86,7 +86,7 @@ endif
>>   obj-$(CONFIG_HOTPLUG_CPU)	+= cpu-hotplug.o
>>   obj-$(CONFIG_KGDB)		+= kgdb.o
>>   obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate.o crash_save_regs.o machine_kexec.o
>> -obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o machine_kexec_file.o
>> +obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o kexec_image.o machine_kexec_file.o
>>   obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
>>   obj-$(CONFIG_CRASH_CORE)	+= crash_core.o
>>
>> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
>> new file mode 100644
>> index 000000000000..b6aa7f59bd53
>> --- /dev/null
>> +++ b/arch/riscv/kernel/kexec_image.c
>> @@ -0,0 +1,97 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * RISC-V Kexec image loader
>> + *
>> + */
>> +
>> +#define pr_fmt(fmt)	"kexec_file(Image): " fmt
>> +
>> +#include <linux/err.h>
>> +#include <linux/errno.h>
>> +#include <linux/kernel.h>
>> +#include <linux/kexec.h>
>> +#include <linux/pe.h>
>> +#include <linux/string.h>
>> +#include <asm/byteorder.h>
>> +#include <asm/image.h>
>> +
>> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
>> +{
>> +	const struct riscv_image_header *h =
>> +		(const struct riscv_image_header *)(kernel_buf);
>> +
>> +	if (!h || (kernel_len < sizeof(*h)))
>> +		return -EINVAL;
>> +
>> +	/* According to Documentation/riscv/boot-image-header.rst,
>> +	 * use "magic2" field to check when version >= 0.2.
>> +	 */
>> +
>> +	if (h->version >= RISCV_HEADER_VERSION &&
>> +	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
>> +		return -EINVAL;
>> +
>> +	return 0;
>> +}
>> +
>> +static void *image_load(struct kimage *image,
>> +				char *kernel, unsigned long kernel_len,
>> +				char *initrd, unsigned long initrd_len,
>> +				char *cmdline, unsigned long cmdline_len)
>> +{
>> +	struct riscv_image_header *h;
>> +	u64 flags;
>> +	bool be_image, be_kernel;
>> +	struct kexec_buf kbuf;
>> +	int ret;
>> +
>> +	/* Check Image header */
>> +	h = (struct riscv_image_header *)kernel;
>> +	if (!h->image_size) {
>> +		ret = -EINVAL;
>> +		goto out;
>> +	}
>> +
>> +	/* Check endianness */
>> +	flags = le64_to_cpu(h->flags);
>> +	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
> 
> ..but here you're just testing a single bit, so since be_image is a bool it
> could just be
> 	be_image = flags & RISCV_IMAGE_FLAG_BE_MASK;
> 
> /Emil
Hi Emil,

Sorry for the delayed response,

The `flags` field currently only has bit-0 to indicate the kenrel 
endianness, your comment looks good in this case.

While considering the future extension of the `flags` feild, the 
riscv_image_flag_field() is neccessiry to make callers to require the 
bits they want.

So I prefer to keep this snippet.
> 
>> +	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
>> +	if (be_image != be_kernel) {
>> +		ret = -EINVAL;
>> +		goto out;
>> +	}
>> +
>> +	/* Load the kernel image */
>> +	kbuf.image = image;
>> +	kbuf.buf_min = 0;
>> +	kbuf.buf_max = ULONG_MAX;
>> +	kbuf.top_down = false;
>> +
>> +	kbuf.buffer = kernel;
>> +	kbuf.bufsz = kernel_len;
>> +	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
>> +	kbuf.memsz = le64_to_cpu(h->image_size);
>> +	kbuf.buf_align = le64_to_cpu(h->text_offset);
>> +
>> +	ret = kexec_add_buffer(&kbuf);
>> +	if (ret) {
>> +		pr_err("Error add kernel image ret=%d\n", ret);
>> +		goto out;
>> +	}
>> +
>> +	image->start = kbuf.mem;
>> +
>> +	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
>> +				kbuf.mem, kbuf.bufsz, kbuf.memsz);
>> +
>> +	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
>> +				  initrd, initrd_len, cmdline, cmdline_len);
>> +
>> +out:
>> +	return ret ? ERR_PTR(ret) : NULL;
>> +}
>> +
>> +const struct kexec_file_ops image_kexec_ops = {
>> +	.probe = image_probe,
>> +	.load = image_load,
>> +};
>> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
>> index aedb8c16a283..5dc700834f1e 100644
>> --- a/arch/riscv/kernel/machine_kexec_file.c
>> +++ b/arch/riscv/kernel/machine_kexec_file.c
>> @@ -17,6 +17,7 @@
>>
>>   const struct kexec_file_ops * const kexec_file_loaders[] = {
>>   	&elf_kexec_ops,
>> +	&image_kexec_ops,
>>   	NULL
>>   };
>>
>> --
>> 2.20.1
>>
>>
>> _______________________________________________
>> linux-riscv mailing list
>> linux-riscv@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-riscv
> 

-- 
Thanks
Song Shuai


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Re: [PATCH 2/2] riscv: kexec_file: Support loading Image binary file

[Emil Renner Berthing]

Song Shuai wrote:
>
>
> 在 2023/9/14 16:37, Emil Renner Berthing 写道:
> > Song Shuai wrote:
> >> This patch creates image_kexec_ops to load Image binary file
> >> for kexec_file_load() syscall.
> >>
> >> Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
> >> ---
> >>   arch/riscv/include/asm/image.h         |  2 +
> >>   arch/riscv/include/asm/kexec.h         |  1 +
> >>   arch/riscv/kernel/Makefile             |  2 +-
> >>   arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
> >>   arch/riscv/kernel/machine_kexec_file.c |  1 +
> >>   5 files changed, 102 insertions(+), 1 deletion(-)
> >>   create mode 100644 arch/riscv/kernel/kexec_image.c
> >>
> >> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
> >> index e0b319af3681..8927a6ea1127 100644
> >> --- a/arch/riscv/include/asm/image.h
> >> +++ b/arch/riscv/include/asm/image.h
> >> @@ -30,6 +30,8 @@
> >>   			      RISCV_HEADER_VERSION_MINOR)
> >>
> >>   #ifndef __ASSEMBLY__
> >> +#define riscv_image_flag_field(flags, field)\
> >> +			       (((flags) >> field##_SHIFT) & field##_MASK)
> >
> > Hi Song,
> >
> > This macro is almost FIELD_GET from linux/bitfield.h ..
> >
> >>   /**
> >>    * struct riscv_image_header - riscv kernel image header
> >>    * @code0:		Executable code
> >> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
> >> index 518825fe4160..b9ee8346cc8c 100644
> >> --- a/arch/riscv/include/asm/kexec.h
> >> +++ b/arch/riscv/include/asm/kexec.h
> >> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
> >>
> >>   #ifdef CONFIG_KEXEC_FILE
> >>   extern const struct kexec_file_ops elf_kexec_ops;
> >> +extern const struct kexec_file_ops image_kexec_ops;
> >>
> >>   struct purgatory_info;
> >>   int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
> >> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> >> index 1c62c639e875..9ecba3231a36 100644
> >> --- a/arch/riscv/kernel/Makefile
> >> +++ b/arch/riscv/kernel/Makefile
> >> @@ -86,7 +86,7 @@ endif
> >>   obj-$(CONFIG_HOTPLUG_CPU)	+= cpu-hotplug.o
> >>   obj-$(CONFIG_KGDB)		+= kgdb.o
> >>   obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate.o crash_save_regs.o machine_kexec.o
> >> -obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o machine_kexec_file.o
> >> +obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o kexec_image.o machine_kexec_file.o
> >>   obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
> >>   obj-$(CONFIG_CRASH_CORE)	+= crash_core.o
> >>
> >> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
> >> new file mode 100644
> >> index 000000000000..b6aa7f59bd53
> >> --- /dev/null
> >> +++ b/arch/riscv/kernel/kexec_image.c
> >> @@ -0,0 +1,97 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * RISC-V Kexec image loader
> >> + *
> >> + */
> >> +
> >> +#define pr_fmt(fmt)	"kexec_file(Image): " fmt
> >> +
> >> +#include <linux/err.h>
> >> +#include <linux/errno.h>
> >> +#include <linux/kernel.h>
> >> +#include <linux/kexec.h>
> >> +#include <linux/pe.h>
> >> +#include <linux/string.h>
> >> +#include <asm/byteorder.h>
> >> +#include <asm/image.h>
> >> +
> >> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
> >> +{
> >> +	const struct riscv_image_header *h =
> >> +		(const struct riscv_image_header *)(kernel_buf);
> >> +
> >> +	if (!h || (kernel_len < sizeof(*h)))
> >> +		return -EINVAL;
> >> +
> >> +	/* According to Documentation/riscv/boot-image-header.rst,
> >> +	 * use "magic2" field to check when version >= 0.2.
> >> +	 */
> >> +
> >> +	if (h->version >= RISCV_HEADER_VERSION &&
> >> +	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
> >> +		return -EINVAL;
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static void *image_load(struct kimage *image,
> >> +				char *kernel, unsigned long kernel_len,
> >> +				char *initrd, unsigned long initrd_len,
> >> +				char *cmdline, unsigned long cmdline_len)
> >> +{
> >> +	struct riscv_image_header *h;
> >> +	u64 flags;
> >> +	bool be_image, be_kernel;
> >> +	struct kexec_buf kbuf;
> >> +	int ret;
> >> +
> >> +	/* Check Image header */
> >> +	h = (struct riscv_image_header *)kernel;
> >> +	if (!h->image_size) {
> >> +		ret = -EINVAL;
> >> +		goto out;
> >> +	}
> >> +
> >> +	/* Check endianness */
> >> +	flags = le64_to_cpu(h->flags);
> >> +	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
> >
> > ..but here you're just testing a single bit, so since be_image is a bool it
> > could just be
> > 	be_image = flags & RISCV_IMAGE_FLAG_BE_MASK;
> >
> > /Emil
> Hi Emil,
>
> Sorry for the delayed response,
>
> The `flags` field currently only has bit-0 to indicate the kenrel
> endianness, your comment looks good in this case.
>
> While considering the future extension of the `flags` feild, the
> riscv_image_flag_field() is neccessiry to make callers to require the
> bits they want.

Right, but please don't invent your own FIELD_GET then.

>
> So I prefer to keep this snippet.
> >
> >> +	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
> >> +	if (be_image != be_kernel) {
> >> +		ret = -EINVAL;
> >> +		goto out;
> >> +	}
> >> +
> >> +	/* Load the kernel image */
> >> +	kbuf.image = image;
> >> +	kbuf.buf_min = 0;
> >> +	kbuf.buf_max = ULONG_MAX;
> >> +	kbuf.top_down = false;
> >> +
> >> +	kbuf.buffer = kernel;
> >> +	kbuf.bufsz = kernel_len;
> >> +	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
> >> +	kbuf.memsz = le64_to_cpu(h->image_size);
> >> +	kbuf.buf_align = le64_to_cpu(h->text_offset);
> >> +
> >> +	ret = kexec_add_buffer(&kbuf);
> >> +	if (ret) {
> >> +		pr_err("Error add kernel image ret=%d\n", ret);
> >> +		goto out;
> >> +	}
> >> +
> >> +	image->start = kbuf.mem;
> >> +
> >> +	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
> >> +				kbuf.mem, kbuf.bufsz, kbuf.memsz);
> >> +
> >> +	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
> >> +				  initrd, initrd_len, cmdline, cmdline_len);
> >> +
> >> +out:
> >> +	return ret ? ERR_PTR(ret) : NULL;
> >> +}
> >> +
> >> +const struct kexec_file_ops image_kexec_ops = {
> >> +	.probe = image_probe,
> >> +	.load = image_load,
> >> +};
> >> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> >> index aedb8c16a283..5dc700834f1e 100644
> >> --- a/arch/riscv/kernel/machine_kexec_file.c
> >> +++ b/arch/riscv/kernel/machine_kexec_file.c
> >> @@ -17,6 +17,7 @@
> >>
> >>   const struct kexec_file_ops * const kexec_file_loaders[] = {
> >>   	&elf_kexec_ops,
> >> +	&image_kexec_ops,
> >>   	NULL
> >>   };
> >>
> >> --
> >> 2.20.1
> >>
> >>
> >> _______________________________________________
> >> linux-riscv mailing list
> >> linux-riscv@lists.infradead.org
> >> http://lists.infradead.org/mailman/listinfo/linux-riscv
> >
>
> --
> Thanks
> Song Shuai
>
>
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

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Re: [PATCH 2/2] riscv: kexec_file: Support loading Image binary file

[Song Shuai]

在 2023/10/11 18:48, Emil Renner Berthing 写道:
> Song Shuai wrote:
>>
>>
>> 在 2023/9/14 16:37, Emil Renner Berthing 写道:
>>> Song Shuai wrote:
>>>> This patch creates image_kexec_ops to load Image binary file
>>>> for kexec_file_load() syscall.
>>>>
>>>> Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
>>>> ---
>>>>    arch/riscv/include/asm/image.h         |  2 +
>>>>    arch/riscv/include/asm/kexec.h         |  1 +
>>>>    arch/riscv/kernel/Makefile             |  2 +-
>>>>    arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
>>>>    arch/riscv/kernel/machine_kexec_file.c |  1 +
>>>>    5 files changed, 102 insertions(+), 1 deletion(-)
>>>>    create mode 100644 arch/riscv/kernel/kexec_image.c
>>>>
>>>> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
>>>> index e0b319af3681..8927a6ea1127 100644
>>>> --- a/arch/riscv/include/asm/image.h
>>>> +++ b/arch/riscv/include/asm/image.h
>>>> @@ -30,6 +30,8 @@
>>>>    			      RISCV_HEADER_VERSION_MINOR)
>>>>
>>>>    #ifndef __ASSEMBLY__
>>>> +#define riscv_image_flag_field(flags, field)\
>>>> +			       (((flags) >> field##_SHIFT) & field##_MASK)
>>>
>>> Hi Song,
>>>
>>> This macro is almost FIELD_GET from linux/bitfield.h ..
>>>
>>>>    /**
>>>>     * struct riscv_image_header - riscv kernel image header
>>>>     * @code0:		Executable code
>>>> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
>>>> index 518825fe4160..b9ee8346cc8c 100644
>>>> --- a/arch/riscv/include/asm/kexec.h
>>>> +++ b/arch/riscv/include/asm/kexec.h
>>>> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
>>>>
>>>>    #ifdef CONFIG_KEXEC_FILE
>>>>    extern const struct kexec_file_ops elf_kexec_ops;
>>>> +extern const struct kexec_file_ops image_kexec_ops;
>>>>
>>>>    struct purgatory_info;
>>>>    int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
>>>> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
>>>> index 1c62c639e875..9ecba3231a36 100644
>>>> --- a/arch/riscv/kernel/Makefile
>>>> +++ b/arch/riscv/kernel/Makefile
>>>> @@ -86,7 +86,7 @@ endif
>>>>    obj-$(CONFIG_HOTPLUG_CPU)	+= cpu-hotplug.o
>>>>    obj-$(CONFIG_KGDB)		+= kgdb.o
>>>>    obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate.o crash_save_regs.o machine_kexec.o
>>>> -obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o machine_kexec_file.o
>>>> +obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o kexec_image.o machine_kexec_file.o
>>>>    obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
>>>>    obj-$(CONFIG_CRASH_CORE)	+= crash_core.o
>>>>
>>>> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
>>>> new file mode 100644
>>>> index 000000000000..b6aa7f59bd53
>>>> --- /dev/null
>>>> +++ b/arch/riscv/kernel/kexec_image.c
>>>> @@ -0,0 +1,97 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +/*
>>>> + * RISC-V Kexec image loader
>>>> + *
>>>> + */
>>>> +
>>>> +#define pr_fmt(fmt)	"kexec_file(Image): " fmt
>>>> +
>>>> +#include <linux/err.h>
>>>> +#include <linux/errno.h>
>>>> +#include <linux/kernel.h>
>>>> +#include <linux/kexec.h>
>>>> +#include <linux/pe.h>
>>>> +#include <linux/string.h>
>>>> +#include <asm/byteorder.h>
>>>> +#include <asm/image.h>
>>>> +
>>>> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
>>>> +{
>>>> +	const struct riscv_image_header *h =
>>>> +		(const struct riscv_image_header *)(kernel_buf);
>>>> +
>>>> +	if (!h || (kernel_len < sizeof(*h)))
>>>> +		return -EINVAL;
>>>> +
>>>> +	/* According to Documentation/riscv/boot-image-header.rst,
>>>> +	 * use "magic2" field to check when version >= 0.2.
>>>> +	 */
>>>> +
>>>> +	if (h->version >= RISCV_HEADER_VERSION &&
>>>> +	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
>>>> +		return -EINVAL;
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>> +static void *image_load(struct kimage *image,
>>>> +				char *kernel, unsigned long kernel_len,
>>>> +				char *initrd, unsigned long initrd_len,
>>>> +				char *cmdline, unsigned long cmdline_len)
>>>> +{
>>>> +	struct riscv_image_header *h;
>>>> +	u64 flags;
>>>> +	bool be_image, be_kernel;
>>>> +	struct kexec_buf kbuf;
>>>> +	int ret;
>>>> +
>>>> +	/* Check Image header */
>>>> +	h = (struct riscv_image_header *)kernel;
>>>> +	if (!h->image_size) {
>>>> +		ret = -EINVAL;
>>>> +		goto out;
>>>> +	}
>>>> +
>>>> +	/* Check endianness */
>>>> +	flags = le64_to_cpu(h->flags);
>>>> +	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
>>>
>>> ..but here you're just testing a single bit, so since be_image is a bool it
>>> could just be
>>> 	be_image = flags & RISCV_IMAGE_FLAG_BE_MASK;
>>>
>>> /Emil
>> Hi Emil,
>>
>> Sorry for the delayed response,
>>
>> The `flags` field currently only has bit-0 to indicate the kenrel
>> endianness, your comment looks good in this case.
>>
>> While considering the future extension of the `flags` feild, the
>> riscv_image_flag_field() is neccessiry to make callers to require the
>> bits they want.
> 
> Right, but please don't invent your own FIELD_GET then.

Hi Emil,

I tried to use FIELD_PREP/FIELD_GET to set/get the RISCV_IMAGE_FLAG_BE,
but using FIELD_PREP to define the __HEAD_FLAGS (used in head.S) emitted 
AS build error and the final .s file looked like:

  883  .dword _end - _start
  884  .dword (({ ({ do { } while (0); do { } while (0); do { } while 
(0); do { } while (0); do { } while (0); }); ((typeof((((1)) << 
(0))))(0) << (__builtin_ffsll((((1)) << (0))) - 1)) & ((((1)) << (0))); }))

IIUC the FIELD_PREP can't work well in this asm context, and using 
FILED_GET without FIELD_PREP paired looks not good to me.

The original riscv/*/image.h and the riscv_image_flag_filed() of this 
patch just do what arm64 does, so I still like to keep them.

I also found that Patch1 has a build issue due to my previous uncareful 
cherry-picking,
V2 will be sent to fix it if you're ok this patch without bitfield armed.

I would like to listen to your advice.

> 
>>
>> So I prefer to keep this snippet.
>>>
>>>> +	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
>>>> +	if (be_image != be_kernel) {
>>>> +		ret = -EINVAL;
>>>> +		goto out;
>>>> +	}
>>>> +
>>>> +	/* Load the kernel image */
>>>> +	kbuf.image = image;
>>>> +	kbuf.buf_min = 0;
>>>> +	kbuf.buf_max = ULONG_MAX;
>>>> +	kbuf.top_down = false;
>>>> +
>>>> +	kbuf.buffer = kernel;
>>>> +	kbuf.bufsz = kernel_len;
>>>> +	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
>>>> +	kbuf.memsz = le64_to_cpu(h->image_size);
>>>> +	kbuf.buf_align = le64_to_cpu(h->text_offset);
>>>> +
>>>> +	ret = kexec_add_buffer(&kbuf);
>>>> +	if (ret) {
>>>> +		pr_err("Error add kernel image ret=%d\n", ret);
>>>> +		goto out;
>>>> +	}
>>>> +
>>>> +	image->start = kbuf.mem;
>>>> +
>>>> +	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
>>>> +				kbuf.mem, kbuf.bufsz, kbuf.memsz);
>>>> +
>>>> +	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
>>>> +				  initrd, initrd_len, cmdline, cmdline_len);
>>>> +
>>>> +out:
>>>> +	return ret ? ERR_PTR(ret) : NULL;
>>>> +}
>>>> +
>>>> +const struct kexec_file_ops image_kexec_ops = {
>>>> +	.probe = image_probe,
>>>> +	.load = image_load,
>>>> +};
>>>> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
>>>> index aedb8c16a283..5dc700834f1e 100644
>>>> --- a/arch/riscv/kernel/machine_kexec_file.c
>>>> +++ b/arch/riscv/kernel/machine_kexec_file.c
>>>> @@ -17,6 +17,7 @@
>>>>
>>>>    const struct kexec_file_ops * const kexec_file_loaders[] = {
>>>>    	&elf_kexec_ops,
>>>> +	&image_kexec_ops,
>>>>    	NULL
>>>>    };
>>>>
>>>> --
>>>> 2.20.1
>>>>
>>>>
>>>> _______________________________________________
>>>> linux-riscv mailing list
>>>> linux-riscv@lists.infradead.org
>>>> http://lists.infradead.org/mailman/listinfo/linux-riscv
>>>
>>
>> --
>> Thanks
>> Song Shuai
>>
>>
>> _______________________________________________
>> linux-riscv mailing list
>> linux-riscv@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-riscv
> 

-- 
Thanks
Song Shuai


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Re: [PATCH 2/2] riscv: kexec_file: Support loading Image binary file

[Emil Renner Berthing]

Song Shuai wrote:
>
>
> 在 2023/10/11 18:48, Emil Renner Berthing 写道:
> > Song Shuai wrote:
> >>
> >>
> >> 在 2023/9/14 16:37, Emil Renner Berthing 写道:
> >>> Song Shuai wrote:
> >>>> This patch creates image_kexec_ops to load Image binary file
> >>>> for kexec_file_load() syscall.
> >>>>
> >>>> Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
> >>>> ---
> >>>>    arch/riscv/include/asm/image.h         |  2 +
> >>>>    arch/riscv/include/asm/kexec.h         |  1 +
> >>>>    arch/riscv/kernel/Makefile             |  2 +-
> >>>>    arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
> >>>>    arch/riscv/kernel/machine_kexec_file.c |  1 +
> >>>>    5 files changed, 102 insertions(+), 1 deletion(-)
> >>>>    create mode 100644 arch/riscv/kernel/kexec_image.c
> >>>>
> >>>> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
> >>>> index e0b319af3681..8927a6ea1127 100644
> >>>> --- a/arch/riscv/include/asm/image.h
> >>>> +++ b/arch/riscv/include/asm/image.h
> >>>> @@ -30,6 +30,8 @@
> >>>>    			      RISCV_HEADER_VERSION_MINOR)
> >>>>
> >>>>    #ifndef __ASSEMBLY__
> >>>> +#define riscv_image_flag_field(flags, field)\
> >>>> +			       (((flags) >> field##_SHIFT) & field##_MASK)
> >>>
> >>> Hi Song,
> >>>
> >>> This macro is almost FIELD_GET from linux/bitfield.h ..
> >>>
> >>>>    /**
> >>>>     * struct riscv_image_header - riscv kernel image header
> >>>>     * @code0:		Executable code
> >>>> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
> >>>> index 518825fe4160..b9ee8346cc8c 100644
> >>>> --- a/arch/riscv/include/asm/kexec.h
> >>>> +++ b/arch/riscv/include/asm/kexec.h
> >>>> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
> >>>>
> >>>>    #ifdef CONFIG_KEXEC_FILE
> >>>>    extern const struct kexec_file_ops elf_kexec_ops;
> >>>> +extern const struct kexec_file_ops image_kexec_ops;
> >>>>
> >>>>    struct purgatory_info;
> >>>>    int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
> >>>> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> >>>> index 1c62c639e875..9ecba3231a36 100644
> >>>> --- a/arch/riscv/kernel/Makefile
> >>>> +++ b/arch/riscv/kernel/Makefile
> >>>> @@ -86,7 +86,7 @@ endif
> >>>>    obj-$(CONFIG_HOTPLUG_CPU)	+= cpu-hotplug.o
> >>>>    obj-$(CONFIG_KGDB)		+= kgdb.o
> >>>>    obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate.o crash_save_regs.o machine_kexec.o
> >>>> -obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o machine_kexec_file.o
> >>>> +obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o kexec_image.o machine_kexec_file.o
> >>>>    obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
> >>>>    obj-$(CONFIG_CRASH_CORE)	+= crash_core.o
> >>>>
> >>>> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
> >>>> new file mode 100644
> >>>> index 000000000000..b6aa7f59bd53
> >>>> --- /dev/null
> >>>> +++ b/arch/riscv/kernel/kexec_image.c
> >>>> @@ -0,0 +1,97 @@
> >>>> +// SPDX-License-Identifier: GPL-2.0
> >>>> +/*
> >>>> + * RISC-V Kexec image loader
> >>>> + *
> >>>> + */
> >>>> +
> >>>> +#define pr_fmt(fmt)	"kexec_file(Image): " fmt
> >>>> +
> >>>> +#include <linux/err.h>
> >>>> +#include <linux/errno.h>
> >>>> +#include <linux/kernel.h>
> >>>> +#include <linux/kexec.h>
> >>>> +#include <linux/pe.h>
> >>>> +#include <linux/string.h>
> >>>> +#include <asm/byteorder.h>
> >>>> +#include <asm/image.h>
> >>>> +
> >>>> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
> >>>> +{
> >>>> +	const struct riscv_image_header *h =
> >>>> +		(const struct riscv_image_header *)(kernel_buf);
> >>>> +
> >>>> +	if (!h || (kernel_len < sizeof(*h)))
> >>>> +		return -EINVAL;
> >>>> +
> >>>> +	/* According to Documentation/riscv/boot-image-header.rst,
> >>>> +	 * use "magic2" field to check when version >= 0.2.
> >>>> +	 */
> >>>> +
> >>>> +	if (h->version >= RISCV_HEADER_VERSION &&
> >>>> +	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
> >>>> +		return -EINVAL;
> >>>> +
> >>>> +	return 0;
> >>>> +}
> >>>> +
> >>>> +static void *image_load(struct kimage *image,
> >>>> +				char *kernel, unsigned long kernel_len,
> >>>> +				char *initrd, unsigned long initrd_len,
> >>>> +				char *cmdline, unsigned long cmdline_len)
> >>>> +{
> >>>> +	struct riscv_image_header *h;
> >>>> +	u64 flags;
> >>>> +	bool be_image, be_kernel;
> >>>> +	struct kexec_buf kbuf;
> >>>> +	int ret;
> >>>> +
> >>>> +	/* Check Image header */
> >>>> +	h = (struct riscv_image_header *)kernel;
> >>>> +	if (!h->image_size) {
> >>>> +		ret = -EINVAL;
> >>>> +		goto out;
> >>>> +	}
> >>>> +
> >>>> +	/* Check endianness */
> >>>> +	flags = le64_to_cpu(h->flags);
> >>>> +	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
> >>>
> >>> ..but here you're just testing a single bit, so since be_image is a bool it
> >>> could just be
> >>> 	be_image = flags & RISCV_IMAGE_FLAG_BE_MASK;
> >>>
> >>> /Emil
> >> Hi Emil,
> >>
> >> Sorry for the delayed response,
> >>
> >> The `flags` field currently only has bit-0 to indicate the kenrel
> >> endianness, your comment looks good in this case.
> >>
> >> While considering the future extension of the `flags` feild, the
> >> riscv_image_flag_field() is neccessiry to make callers to require the
> >> bits they want.
> >
> > Right, but please don't invent your own FIELD_GET then.
>
> Hi Emil,
>
> I tried to use FIELD_PREP/FIELD_GET to set/get the RISCV_IMAGE_FLAG_BE,
> but using FIELD_PREP to define the __HEAD_FLAGS (used in head.S) emitted
> AS build error and the final .s file looked like:
>
>   883  .dword _end - _start
>   884  .dword (({ ({ do { } while (0); do { } while (0); do { } while
> (0); do { } while (0); do { } while (0); }); ((typeof((((1)) <<
> (0))))(0) << (__builtin_ffsll((((1)) << (0))) - 1)) & ((((1)) << (0))); }))
>
> IIUC the FIELD_PREP can't work well in this asm context, and using
> FILED_GET without FIELD_PREP paired looks not good to me.
>
> The original riscv/*/image.h and the riscv_image_flag_filed() of this
> patch just do what arm64 does, so I still like to keep them.

Hi Song,

Your riscv_image_flag_field macro is already guarded by a #ifndef __ASSEMBLY__
and your patches above doesn't touch any __HEAD_FLAGS macro, so I don't know
what you're trying to do with FIELD_PREP.

What I'm saying is that instead of defining the riscv_image_flag_field macro
you can just do

-be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
+be_image = FIELD_GET(RISCV_IMAGE_FLAG_BE, flags);

/Emil

> I also found that Patch1 has a build issue due to my previous uncareful
> cherry-picking,
> V2 will be sent to fix it if you're ok this patch without bitfield armed.
>
> I would like to listen to your advice.
>
> >
> >>
> >> So I prefer to keep this snippet.
> >>>
> >>>> +	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
> >>>> +	if (be_image != be_kernel) {
> >>>> +		ret = -EINVAL;
> >>>> +		goto out;
> >>>> +	}
> >>>> +
> >>>> +	/* Load the kernel image */
> >>>> +	kbuf.image = image;
> >>>> +	kbuf.buf_min = 0;
> >>>> +	kbuf.buf_max = ULONG_MAX;
> >>>> +	kbuf.top_down = false;
> >>>> +
> >>>> +	kbuf.buffer = kernel;
> >>>> +	kbuf.bufsz = kernel_len;
> >>>> +	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
> >>>> +	kbuf.memsz = le64_to_cpu(h->image_size);
> >>>> +	kbuf.buf_align = le64_to_cpu(h->text_offset);
> >>>> +
> >>>> +	ret = kexec_add_buffer(&kbuf);
> >>>> +	if (ret) {
> >>>> +		pr_err("Error add kernel image ret=%d\n", ret);
> >>>> +		goto out;
> >>>> +	}
> >>>> +
> >>>> +	image->start = kbuf.mem;
> >>>> +
> >>>> +	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
> >>>> +				kbuf.mem, kbuf.bufsz, kbuf.memsz);
> >>>> +
> >>>> +	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
> >>>> +				  initrd, initrd_len, cmdline, cmdline_len);
> >>>> +
> >>>> +out:
> >>>> +	return ret ? ERR_PTR(ret) : NULL;
> >>>> +}
> >>>> +
> >>>> +const struct kexec_file_ops image_kexec_ops = {
> >>>> +	.probe = image_probe,
> >>>> +	.load = image_load,
> >>>> +};
> >>>> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> >>>> index aedb8c16a283..5dc700834f1e 100644
> >>>> --- a/arch/riscv/kernel/machine_kexec_file.c
> >>>> +++ b/arch/riscv/kernel/machine_kexec_file.c
> >>>> @@ -17,6 +17,7 @@
> >>>>
> >>>>    const struct kexec_file_ops * const kexec_file_loaders[] = {
> >>>>    	&elf_kexec_ops,
> >>>> +	&image_kexec_ops,
> >>>>    	NULL
> >>>>    };
> >>>>
> >>>> --
> >>>> 2.20.1

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Re: [External] [PATCH 2/2] riscv: kexec_file: Support loading Image binary file

[yunhui cui]

Hi Shuai,

On Thu, Sep 14, 2023 at 10:09 AM Song Shuai <songshuaishuai@tinylab.org> wrote:
>
> This patch creates image_kexec_ops to load Image binary file
> for kexec_file_load() syscall.
>
> Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
> ---
>  arch/riscv/include/asm/image.h         |  2 +
>  arch/riscv/include/asm/kexec.h         |  1 +
>  arch/riscv/kernel/Makefile             |  2 +-
>  arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
>  arch/riscv/kernel/machine_kexec_file.c |  1 +
>  5 files changed, 102 insertions(+), 1 deletion(-)
>  create mode 100644 arch/riscv/kernel/kexec_image.c
>
> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
> index e0b319af3681..8927a6ea1127 100644
> --- a/arch/riscv/include/asm/image.h
> +++ b/arch/riscv/include/asm/image.h
> @@ -30,6 +30,8 @@
>                               RISCV_HEADER_VERSION_MINOR)
>
>  #ifndef __ASSEMBLY__
> +#define riscv_image_flag_field(flags, field)\
> +                              (((flags) >> field##_SHIFT) & field##_MASK)
>  /**
>   * struct riscv_image_header - riscv kernel image header
>   * @code0:             Executable code
> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
> index 518825fe4160..b9ee8346cc8c 100644
> --- a/arch/riscv/include/asm/kexec.h
> +++ b/arch/riscv/include/asm/kexec.h
> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
>
>  #ifdef CONFIG_KEXEC_FILE
>  extern const struct kexec_file_ops elf_kexec_ops;
> +extern const struct kexec_file_ops image_kexec_ops;
>
>  struct purgatory_info;
>  int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index 1c62c639e875..9ecba3231a36 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -86,7 +86,7 @@ endif
>  obj-$(CONFIG_HOTPLUG_CPU)      += cpu-hotplug.o
>  obj-$(CONFIG_KGDB)             += kgdb.o
>  obj-$(CONFIG_KEXEC_CORE)       += kexec_relocate.o crash_save_regs.o machine_kexec.o
> -obj-$(CONFIG_KEXEC_FILE)       += kexec_elf.o machine_kexec_file.o
> +obj-$(CONFIG_KEXEC_FILE)       += kexec_elf.o kexec_image.o machine_kexec_file.o
>  obj-$(CONFIG_CRASH_DUMP)       += crash_dump.o
>  obj-$(CONFIG_CRASH_CORE)       += crash_core.o
>
> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
> new file mode 100644
> index 000000000000..b6aa7f59bd53
> --- /dev/null
> +++ b/arch/riscv/kernel/kexec_image.c
> @@ -0,0 +1,97 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * RISC-V Kexec image loader
> + *
> + */
> +
> +#define pr_fmt(fmt)    "kexec_file(Image): " fmt
> +
> +#include <linux/err.h>
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/kexec.h>
> +#include <linux/pe.h>
> +#include <linux/string.h>
> +#include <asm/byteorder.h>
> +#include <asm/image.h>
> +
> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
> +{
> +       const struct riscv_image_header *h =
> +               (const struct riscv_image_header *)(kernel_buf);
> +
> +       if (!h || (kernel_len < sizeof(*h)))
> +               return -EINVAL;
> +
> +       /* According to Documentation/riscv/boot-image-header.rst,
> +        * use "magic2" field to check when version >= 0.2.
> +        */
> +
> +       if (h->version >= RISCV_HEADER_VERSION &&
> +           memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
> +               return -EINVAL;
> +
> +       return 0;
> +}
> +
> +static void *image_load(struct kimage *image,
> +                               char *kernel, unsigned long kernel_len,
> +                               char *initrd, unsigned long initrd_len,
> +                               char *cmdline, unsigned long cmdline_len)
> +{
> +       struct riscv_image_header *h;
> +       u64 flags;
> +       bool be_image, be_kernel;
> +       struct kexec_buf kbuf;
> +       int ret;
> +
> +       /* Check Image header */
> +       h = (struct riscv_image_header *)kernel;
> +       if (!h->image_size) {
> +               ret = -EINVAL;
> +               goto out;
> +       }
> +
> +       /* Check endianness */
> +       flags = le64_to_cpu(h->flags);
> +       be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
> +       be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
> +       if (be_image != be_kernel) {
> +               ret = -EINVAL;
> +               goto out;
> +       }
> +
> +       /* Load the kernel image */
> +       kbuf.image = image;
> +       kbuf.buf_min = 0;
> +       kbuf.buf_max = ULONG_MAX;
> +       kbuf.top_down = false;
> +
> +       kbuf.buffer = kernel;
> +       kbuf.bufsz = kernel_len;
> +       kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
> +       kbuf.memsz = le64_to_cpu(h->image_size);
> +       kbuf.buf_align = le64_to_cpu(h->text_offset);
> +
> +       ret = kexec_add_buffer(&kbuf);
> +       if (ret) {
> +               pr_err("Error add kernel image ret=%d\n", ret);
> +               goto out;
> +       }
> +
> +       image->start = kbuf.mem;
> +
> +       pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
> +                               kbuf.mem, kbuf.bufsz, kbuf.memsz);

pr_info() or pr_debug()?


> +
> +       ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
> +                                 initrd, initrd_len, cmdline, cmdline_len);
> +
> +out:
> +       return ret ? ERR_PTR(ret) : NULL;
> +}
> +
> +const struct kexec_file_ops image_kexec_ops = {
> +       .probe = image_probe,
> +       .load = image_load,
> +};
> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> index aedb8c16a283..5dc700834f1e 100644
> --- a/arch/riscv/kernel/machine_kexec_file.c
> +++ b/arch/riscv/kernel/machine_kexec_file.c
> @@ -17,6 +17,7 @@
>
>  const struct kexec_file_ops * const kexec_file_loaders[] = {
>         &elf_kexec_ops,
> +       &image_kexec_ops,
>         NULL
>  };
>
> --
> 2.20.1
>

I tested these two patches. It works when
CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY is not enabled. When
CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY is enabled, the error is as
follows:

[45.712019] Unknown rela relocation: 34
[45.712258] Error loading purgatory ret=-8

How to fix it?

Thanks，
Yunhui

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Re: [External] [PATCH 2/2] riscv: kexec_file: Support loading Image binary file

[Song Shuai]

Hi, yunhui:

在 2024/2/16 16:54, yunhui cui 写道:
> Hi Shuai,
> 
> On Thu, Sep 14, 2023 at 10:09 AM Song Shuai <songshuaishuai@tinylab.org> wrote:
>>
>> This patch creates image_kexec_ops to load Image binary file
>> for kexec_file_load() syscall.
>>
>> Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
>> ---
>>   arch/riscv/include/asm/image.h         |  2 +
>>   arch/riscv/include/asm/kexec.h         |  1 +
>>   arch/riscv/kernel/Makefile             |  2 +-
>>   arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
>>   arch/riscv/kernel/machine_kexec_file.c |  1 +
>>   5 files changed, 102 insertions(+), 1 deletion(-)
>>   create mode 100644 arch/riscv/kernel/kexec_image.c
>>
>> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
>> index e0b319af3681..8927a6ea1127 100644
>> --- a/arch/riscv/include/asm/image.h
>> +++ b/arch/riscv/include/asm/image.h
>> @@ -30,6 +30,8 @@
>>                                RISCV_HEADER_VERSION_MINOR)
>>
>>   #ifndef __ASSEMBLY__
>> +#define riscv_image_flag_field(flags, field)\
>> +                              (((flags) >> field##_SHIFT) & field##_MASK)
>>   /**
>>    * struct riscv_image_header - riscv kernel image header
>>    * @code0:             Executable code
>> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
>> index 518825fe4160..b9ee8346cc8c 100644
>> --- a/arch/riscv/include/asm/kexec.h
>> +++ b/arch/riscv/include/asm/kexec.h
>> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
>>
>>   #ifdef CONFIG_KEXEC_FILE
>>   extern const struct kexec_file_ops elf_kexec_ops;
>> +extern const struct kexec_file_ops image_kexec_ops;
>>
>>   struct purgatory_info;
>>   int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
>> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
>> index 1c62c639e875..9ecba3231a36 100644
>> --- a/arch/riscv/kernel/Makefile
>> +++ b/arch/riscv/kernel/Makefile
>> @@ -86,7 +86,7 @@ endif
>>   obj-$(CONFIG_HOTPLUG_CPU)      += cpu-hotplug.o
>>   obj-$(CONFIG_KGDB)             += kgdb.o
>>   obj-$(CONFIG_KEXEC_CORE)       += kexec_relocate.o crash_save_regs.o machine_kexec.o
>> -obj-$(CONFIG_KEXEC_FILE)       += kexec_elf.o machine_kexec_file.o
>> +obj-$(CONFIG_KEXEC_FILE)       += kexec_elf.o kexec_image.o machine_kexec_file.o
>>   obj-$(CONFIG_CRASH_DUMP)       += crash_dump.o
>>   obj-$(CONFIG_CRASH_CORE)       += crash_core.o
>>
>> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
>> new file mode 100644
>> index 000000000000..b6aa7f59bd53
>> --- /dev/null
>> +++ b/arch/riscv/kernel/kexec_image.c
>> @@ -0,0 +1,97 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * RISC-V Kexec image loader
>> + *
>> + */
>> +
>> +#define pr_fmt(fmt)    "kexec_file(Image): " fmt
>> +
>> +#include <linux/err.h>
>> +#include <linux/errno.h>
>> +#include <linux/kernel.h>
>> +#include <linux/kexec.h>
>> +#include <linux/pe.h>
>> +#include <linux/string.h>
>> +#include <asm/byteorder.h>
>> +#include <asm/image.h>
>> +
>> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
>> +{
>> +       const struct riscv_image_header *h =
>> +               (const struct riscv_image_header *)(kernel_buf);
>> +
>> +       if (!h || (kernel_len < sizeof(*h)))
>> +               return -EINVAL;
>> +
>> +       /* According to Documentation/riscv/boot-image-header.rst,
>> +        * use "magic2" field to check when version >= 0.2.
>> +        */
>> +
>> +       if (h->version >= RISCV_HEADER_VERSION &&
>> +           memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
>> +               return -EINVAL;
>> +
>> +       return 0;
>> +}
>> +
>> +static void *image_load(struct kimage *image,
>> +                               char *kernel, unsigned long kernel_len,
>> +                               char *initrd, unsigned long initrd_len,
>> +                               char *cmdline, unsigned long cmdline_len)
>> +{
>> +       struct riscv_image_header *h;
>> +       u64 flags;
>> +       bool be_image, be_kernel;
>> +       struct kexec_buf kbuf;
>> +       int ret;
>> +
>> +       /* Check Image header */
>> +       h = (struct riscv_image_header *)kernel;
>> +       if (!h->image_size) {
>> +               ret = -EINVAL;
>> +               goto out;
>> +       }
>> +
>> +       /* Check endianness */
>> +       flags = le64_to_cpu(h->flags);
>> +       be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
>> +       be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
>> +       if (be_image != be_kernel) {
>> +               ret = -EINVAL;
>> +               goto out;
>> +       }
>> +
>> +       /* Load the kernel image */
>> +       kbuf.image = image;
>> +       kbuf.buf_min = 0;
>> +       kbuf.buf_max = ULONG_MAX;
>> +       kbuf.top_down = false;
>> +
>> +       kbuf.buffer = kernel;
>> +       kbuf.bufsz = kernel_len;
>> +       kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
>> +       kbuf.memsz = le64_to_cpu(h->image_size);
>> +       kbuf.buf_align = le64_to_cpu(h->text_offset);
>> +
>> +       ret = kexec_add_buffer(&kbuf);
>> +       if (ret) {
>> +               pr_err("Error add kernel image ret=%d\n", ret);
>> +               goto out;
>> +       }
>> +
>> +       image->start = kbuf.mem;
>> +
>> +       pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
>> +                               kbuf.mem, kbuf.bufsz, kbuf.memsz);
> 
> pr_info() or pr_debug()? >
> 
>> +
>> +       ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
>> +                                 initrd, initrd_len, cmdline, cmdline_len);
>> +
>> +out:
>> +       return ret ? ERR_PTR(ret) : NULL;
>> +}
>> +
>> +const struct kexec_file_ops image_kexec_ops = {
>> +       .probe = image_probe,
>> +       .load = image_load,
>> +};
>> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
>> index aedb8c16a283..5dc700834f1e 100644
>> --- a/arch/riscv/kernel/machine_kexec_file.c
>> +++ b/arch/riscv/kernel/machine_kexec_file.c
>> @@ -17,6 +17,7 @@
>>
>>   const struct kexec_file_ops * const kexec_file_loaders[] = {
>>          &elf_kexec_ops,
>> +       &image_kexec_ops,
>>          NULL
>>   };
>>
>> --
>> 2.20.1
>>
> 
> I tested these two patches. It works when
> CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY is not enabled. When
> CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY is enabled, the error is as
> follows:
> 
> [45.712019] Unknown rela relocation: 34
> [45.712258] Error loading purgatory ret=-8
> 
> How to fix it? >
> Thanks，
> Yunhui
> 
Thanks for your attention to this series and RV kdump/kexec stack.

As you noticed, this series and the kexec-tools RV support patches[1] 
didn't get any positive responses and have been suspended for a few 
months. And I'm now struggling in my own job, so really sorry that I 
have no time to continue these works.

Although that, I would like to reply to your comments in case anyone 
wants to push this series:

Comment1: Why rename elf_kexec.c to kexec_elf.c ？
- s390 uses kexec_{elf,image}.c file names, so I followed it.

Comment2: pr_info() or pr_debug()?
- pr_debug() seems better.

Comment3: Unknown rela relocation: 34

- The CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY was enabled when I posted 
this series, I didn't see this relocation error at that time.

If you want to fix this relocation error, you need to figure out who 
hold the R_RISCV_ADD16 (34), and how it was generated (compiler options 
or other RV kernel configures). This commit 0f5f46a869a5 ("riscv: kexec: 
Remove -fPIE for PURGATORY_CFLAGS") may help.

[1]: 
https://lore.kernel.org/kexec/DA84A55096BADE15+594e239a-ff6a-368f-ae92-b6cfebbf8dc0@tinylab.org/
-- 
Thanks
Song Shuai


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Re: [External] [PATCH 2/2] riscv: kexec_file: Support loading Image binary file

[yunhui cui]

Hi Song Shuai,

On Mon, Feb 19, 2024 at 5:53 PM Song Shuai <songshuaishuai@tinylab.org> wrote:
>
>
> Hi, yunhui:
>
> 在 2024/2/16 16:54, yunhui cui 写道:
> > Hi Shuai,
> >
> > On Thu, Sep 14, 2023 at 10:09 AM Song Shuai <songshuaishuai@tinylab.org> wrote:
> >>
> >> This patch creates image_kexec_ops to load Image binary file
> >> for kexec_file_load() syscall.
> >>
> >> Signed-off-by: Song Shuai <songshuaishuai@tinylab.org>
> >> ---
> >>   arch/riscv/include/asm/image.h         |  2 +
> >>   arch/riscv/include/asm/kexec.h         |  1 +
> >>   arch/riscv/kernel/Makefile             |  2 +-
> >>   arch/riscv/kernel/kexec_image.c        | 97 ++++++++++++++++++++++++++
> >>   arch/riscv/kernel/machine_kexec_file.c |  1 +
> >>   5 files changed, 102 insertions(+), 1 deletion(-)
> >>   create mode 100644 arch/riscv/kernel/kexec_image.c
> >>
> >> diff --git a/arch/riscv/include/asm/image.h b/arch/riscv/include/asm/image.h
> >> index e0b319af3681..8927a6ea1127 100644
> >> --- a/arch/riscv/include/asm/image.h
> >> +++ b/arch/riscv/include/asm/image.h
> >> @@ -30,6 +30,8 @@
> >>                                RISCV_HEADER_VERSION_MINOR)
> >>
> >>   #ifndef __ASSEMBLY__
> >> +#define riscv_image_flag_field(flags, field)\
> >> +                              (((flags) >> field##_SHIFT) & field##_MASK)
> >>   /**
> >>    * struct riscv_image_header - riscv kernel image header
> >>    * @code0:             Executable code
> >> diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h
> >> index 518825fe4160..b9ee8346cc8c 100644
> >> --- a/arch/riscv/include/asm/kexec.h
> >> +++ b/arch/riscv/include/asm/kexec.h
> >> @@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate;
> >>
> >>   #ifdef CONFIG_KEXEC_FILE
> >>   extern const struct kexec_file_ops elf_kexec_ops;
> >> +extern const struct kexec_file_ops image_kexec_ops;
> >>
> >>   struct purgatory_info;
> >>   int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
> >> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> >> index 1c62c639e875..9ecba3231a36 100644
> >> --- a/arch/riscv/kernel/Makefile
> >> +++ b/arch/riscv/kernel/Makefile
> >> @@ -86,7 +86,7 @@ endif
> >>   obj-$(CONFIG_HOTPLUG_CPU)      += cpu-hotplug.o
> >>   obj-$(CONFIG_KGDB)             += kgdb.o
> >>   obj-$(CONFIG_KEXEC_CORE)       += kexec_relocate.o crash_save_regs.o machine_kexec.o
> >> -obj-$(CONFIG_KEXEC_FILE)       += kexec_elf.o machine_kexec_file.o
> >> +obj-$(CONFIG_KEXEC_FILE)       += kexec_elf.o kexec_image.o machine_kexec_file.o
> >>   obj-$(CONFIG_CRASH_DUMP)       += crash_dump.o
> >>   obj-$(CONFIG_CRASH_CORE)       += crash_core.o
> >>
> >> diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
> >> new file mode 100644
> >> index 000000000000..b6aa7f59bd53
> >> --- /dev/null
> >> +++ b/arch/riscv/kernel/kexec_image.c
> >> @@ -0,0 +1,97 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * RISC-V Kexec image loader
> >> + *
> >> + */
> >> +
> >> +#define pr_fmt(fmt)    "kexec_file(Image): " fmt
> >> +
> >> +#include <linux/err.h>
> >> +#include <linux/errno.h>
> >> +#include <linux/kernel.h>
> >> +#include <linux/kexec.h>
> >> +#include <linux/pe.h>
> >> +#include <linux/string.h>
> >> +#include <asm/byteorder.h>
> >> +#include <asm/image.h>
> >> +
> >> +static int image_probe(const char *kernel_buf, unsigned long kernel_len)
> >> +{
> >> +       const struct riscv_image_header *h =
> >> +               (const struct riscv_image_header *)(kernel_buf);
> >> +
> >> +       if (!h || (kernel_len < sizeof(*h)))
> >> +               return -EINVAL;
> >> +
> >> +       /* According to Documentation/riscv/boot-image-header.rst,
> >> +        * use "magic2" field to check when version >= 0.2.
> >> +        */
> >> +
> >> +       if (h->version >= RISCV_HEADER_VERSION &&
> >> +           memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))
> >> +               return -EINVAL;
> >> +
> >> +       return 0;
> >> +}
> >> +
> >> +static void *image_load(struct kimage *image,
> >> +                               char *kernel, unsigned long kernel_len,
> >> +                               char *initrd, unsigned long initrd_len,
> >> +                               char *cmdline, unsigned long cmdline_len)
> >> +{
> >> +       struct riscv_image_header *h;
> >> +       u64 flags;
> >> +       bool be_image, be_kernel;
> >> +       struct kexec_buf kbuf;
> >> +       int ret;
> >> +
> >> +       /* Check Image header */
> >> +       h = (struct riscv_image_header *)kernel;
> >> +       if (!h->image_size) {
> >> +               ret = -EINVAL;
> >> +               goto out;
> >> +       }
> >> +
> >> +       /* Check endianness */
> >> +       flags = le64_to_cpu(h->flags);
> >> +       be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);
> >> +       be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
> >> +       if (be_image != be_kernel) {
> >> +               ret = -EINVAL;
> >> +               goto out;
> >> +       }
> >> +
> >> +       /* Load the kernel image */
> >> +       kbuf.image = image;
> >> +       kbuf.buf_min = 0;
> >> +       kbuf.buf_max = ULONG_MAX;
> >> +       kbuf.top_down = false;
> >> +
> >> +       kbuf.buffer = kernel;
> >> +       kbuf.bufsz = kernel_len;
> >> +       kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
> >> +       kbuf.memsz = le64_to_cpu(h->image_size);
> >> +       kbuf.buf_align = le64_to_cpu(h->text_offset);
> >> +
> >> +       ret = kexec_add_buffer(&kbuf);
> >> +       if (ret) {
> >> +               pr_err("Error add kernel image ret=%d\n", ret);
> >> +               goto out;
> >> +       }
> >> +
> >> +       image->start = kbuf.mem;
> >> +
> >> +       pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
> >> +                               kbuf.mem, kbuf.bufsz, kbuf.memsz);
> >
> > pr_info() or pr_debug()? >
> >
> >> +
> >> +       ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,
> >> +                                 initrd, initrd_len, cmdline, cmdline_len);
> >> +
> >> +out:
> >> +       return ret ? ERR_PTR(ret) : NULL;
> >> +}
> >> +
> >> +const struct kexec_file_ops image_kexec_ops = {
> >> +       .probe = image_probe,
> >> +       .load = image_load,
> >> +};
> >> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> >> index aedb8c16a283..5dc700834f1e 100644
> >> --- a/arch/riscv/kernel/machine_kexec_file.c
> >> +++ b/arch/riscv/kernel/machine_kexec_file.c
> >> @@ -17,6 +17,7 @@
> >>
> >>   const struct kexec_file_ops * const kexec_file_loaders[] = {
> >>          &elf_kexec_ops,
> >> +       &image_kexec_ops,
> >>          NULL
> >>   };
> >>
> >> --
> >> 2.20.1
> >>
> >
> > I tested these two patches. It works when
> > CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY is not enabled. When
> > CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY is enabled, the error is as
> > follows:
> >
> > [45.712019] Unknown rela relocation: 34
> > [45.712258] Error loading purgatory ret=-8
> >
> > How to fix it? >
> > Thanks，
> > Yunhui
> >
> Thanks for your attention to this series and RV kdump/kexec stack.
>
> As you noticed, this series and the kexec-tools RV support patches[1]
> didn't get any positive responses and have been suspended for a few
> months. And I'm now struggling in my own job, so really sorry that I
> have no time to continue these works.
>
> Although that, I would like to reply to your comments in case anyone
> wants to push this series:
>
> Comment1: Why rename elf_kexec.c to kexec_elf.c ？
> - s390 uses kexec_{elf,image}.c file names, so I followed it.
Okay, so are arm64/x86.

> Comment2: pr_info() or pr_debug()?
> - pr_debug() seems better.
>
> Comment3: Unknown rela relocation: 34
>
> - The CONFIG_ARCH_SUPPORTS_KEXEC_PURGATORY was enabled when I posted
> this series, I didn't see this relocation error at that time.
>
> If you want to fix this relocation error, you need to figure out who
> hold the R_RISCV_ADD16 (34), and how it was generated (compiler options
> or other RV kernel configures). This commit 0f5f46a869a5 ("riscv: kexec:
> Remove -fPIE for PURGATORY_CFLAGS") may help.

Have you tested it with the top commit of linux-next? Can you share the .config?

Thanks

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