| Message ID | 20200601142754.26139-6-l.stelmach@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kexec_file_load() for arm | expand |
On Mon, Jun 01, 2020 at 04:27:54PM +0200, Łukasz Stelmach wrote: > This is kexec_file_load implementation for ARM. It loads zImage and > initrd from file descripters and resuses DTB. > > Most code is derived from arm64 kexec_file_load implementation > and from kexec-tools. Please make the uImage loader able to be configured out of the kernel; it's a legacy image format now, and some of us just don't use it anymore. That way, those who wish to have it can, and those who wish not to can have a smaller kernel. > Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> > Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com> > --- > arch/arm/Kconfig | 15 ++ > arch/arm/include/asm/image.h | 26 ++++ > arch/arm/include/asm/kexec.h | 14 ++ > arch/arm/kernel/Makefile | 5 +- > arch/arm/kernel/kexec_uimage.c | 80 ++++++++++ > arch/arm/kernel/kexec_zimage.c | 199 +++++++++++++++++++++++++ > arch/arm/kernel/machine_kexec.c | 11 +- > arch/arm/kernel/machine_kexec_file.c | 209 +++++++++++++++++++++++++++ > 8 files changed, 554 insertions(+), 5 deletions(-) > create mode 100644 arch/arm/kernel/kexec_uimage.c > create mode 100644 arch/arm/kernel/kexec_zimage.c > create mode 100644 arch/arm/kernel/machine_kexec_file.c > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index c77c93c485a0..6adb849cb304 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -1917,6 +1917,21 @@ config KEXEC > is properly shutdown, so do not be surprised if this code does not > initially work for you. > > +config KEXEC_FILE > + bool "Kexec file based system call (EXPERIMENTAL)" > + depends on (!SMP || PM_SLEEP_SMP) > + depends on USE_OF > + select KEXEC_CORE > + select CRC32 > + help > + This is new version of kexec system call. This system call is > + file based and takes file descriptors as system call argument > + for kernel and initramfs as opposed to list of segments as > + accepted by previous system call. > + > + The kernel to be loaded MUST support Flattened Device Tree > + (selected with CONFIG_USE_OF). > + > config ATAGS_PROC > bool "Export atags in procfs" > depends on ATAGS && KEXEC > diff --git a/arch/arm/include/asm/image.h b/arch/arm/include/asm/image.h > index 624438740f23..95f23837b04f 100644 > --- a/arch/arm/include/asm/image.h > +++ b/arch/arm/include/asm/image.h > @@ -8,8 +8,13 @@ > (((x) >> 8) & 0x0000ff00) | \ > (((x) << 8) & 0x00ff0000) | \ > (((x) << 24) & 0xff000000)) > +#define UIMAGE_MAGIC(x) (x) > #else > #define ZIMAGE_MAGIC(x) (x) > +#define UIMAGE_MAGIC(x) ((((x) >> 24) & 0x000000ff) | \ > + (((x) >> 8) & 0x0000ff00) | \ > + (((x) << 8) & 0x00ff0000) | \ > + (((x) << 24) & 0xff000000)) > #endif > > #define ARM_ZIMAGE_MAGIC1 ZIMAGE_MAGIC(0x016f2818) > @@ -17,6 +22,12 @@ > #define ARM_ZIMAGE_MAGIC3 ZIMAGE_MAGIC(0x5a534c4b) > #define ARM_ZIMAGE_MAGIC4 ZIMAGE_MAGIC(0x5a534344) > > +#define ARM_UIMAGE_MAGIC UIMAGE_MAGIC(0x27051956) > +#define ARM_UIMAGE_NAME_LEN 32 > +#define ARM_UIMAGE_TYPE_KERNEL 2 > +#define ARM_UIMAGE_TYPE_KERNEL_NOLOAD 14 > +#define ARM_UIMAGE_ARCH_ARM 2 > + > #ifndef __ASSEMBLY__ > > #include <linux/types.h> > @@ -33,6 +44,21 @@ struct arm_zimage_header { > __le32 extension_tag_offset; > }; > > +struct arm_uimage_header { > + __be32 magic; > + __be32 hdr_crc; > + __be32 time; > + __be32 size; > + __be32 load; > + __be32 entry; > + __be32 crc; > + __u8 os; > + __u8 arch; > + __u8 type; > + __u8 comp; > + __u8 name[ARM_UIMAGE_NAME_LEN]; > +}; > + > struct arm_zimage_tag { > struct tag_header hdr; > union { > diff --git a/arch/arm/include/asm/kexec.h b/arch/arm/include/asm/kexec.h > index 22751b5b5735..fda35afa7195 100644 > --- a/arch/arm/include/asm/kexec.h > +++ b/arch/arm/include/asm/kexec.h > @@ -83,6 +83,20 @@ static inline struct page *boot_pfn_to_page(unsigned long boot_pfn) > } > #define boot_pfn_to_page boot_pfn_to_page > > +#ifdef CONFIG_KEXEC_FILE > + > +extern const struct kexec_file_ops kexec_zimage_ops; > +extern const struct kexec_file_ops kexec_uimage_ops; > + > +struct kimage; > + > +extern int load_other_segments(struct kimage *image, > + unsigned long kernel_load_addr, unsigned long kernel_size, > + char *initrd, unsigned long initrd_len, > + unsigned long initrd_offset, char *cmdline); > + > +#endif /* CONFIG_KEXEC_FILE */ > + > #endif /* __ASSEMBLY__ */ > > #endif /* CONFIG_KEXEC */ > diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile > index 89e5d864e923..466c683bb551 100644 > --- a/arch/arm/kernel/Makefile > +++ b/arch/arm/kernel/Makefile > @@ -3,6 +3,7 @@ > # Makefile for the linux kernel. > # > > +CFLAGS_kexec_zimage.o := -DTEXT_OFFSET=$(TEXT_OFFSET) > CPPFLAGS_vmlinux.lds := -DTEXT_OFFSET=$(TEXT_OFFSET) > AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET) > > @@ -56,7 +57,9 @@ obj-$(CONFIG_FUNCTION_TRACER) += entry-ftrace.o > obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o insn.o patch.o > obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o insn.o patch.o > obj-$(CONFIG_JUMP_LABEL) += jump_label.o insn.o patch.o > -obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o > +obj-$(CONFIG_KEXEC_CORE) += machine_kexec.o relocate_kernel.o > +obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file.o kexec_zimage.o \ > + kexec_uimage.o > # Main staffs in KPROBES are in arch/arm/probes/ . > obj-$(CONFIG_KPROBES) += patch.o insn.o > obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o > diff --git a/arch/arm/kernel/kexec_uimage.c b/arch/arm/kernel/kexec_uimage.c > new file mode 100644 > index 000000000000..47033574e24e > --- /dev/null > +++ b/arch/arm/kernel/kexec_uimage.c > @@ -0,0 +1,80 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Kexec uImage loader > + * > + * Copyright (C) 2020 Samsung Electronics > + * Author: Łukasz Stelmach <l.stelmach@samsung.com> > + */ > + > +#define pr_fmt(fmt) "kexec_file(uImage): " fmt > + > +#include <asm/image.h> > +#include <linux/crc32.h> > +#include <linux/err.h> > +#include <linux/kexec.h> > + > +#define crc32_ones(crc, buf, len) \ > + (crc32(crc ^ 0xffffffff, buf, len) ^ 0xffffffff) > + > +static int uimage_probe(const char *uimage_buf, unsigned long uimage_len) > +{ > + const struct arm_uimage_header *h = > + (struct arm_uimage_header *) uimage_buf; > + struct arm_uimage_header uhdr; > + unsigned long zoff = sizeof(struct arm_uimage_header); > + uint32_t crc; > + > + if (h->magic != ARM_UIMAGE_MAGIC) > + return -EINVAL; > + > + if (h->type != ARM_UIMAGE_TYPE_KERNEL && > + h->type != ARM_UIMAGE_TYPE_KERNEL_NOLOAD){ > + pr_debug("Invalid image type: %d\n", h->type); > + return -EINVAL; > + } > + > + if (h->arch != ARM_UIMAGE_ARCH_ARM) { > + pr_debug("Invalidy image arch: %d\n", h->arch); > + return -EINVAL; > + } > + > + memcpy((char *)&uhdr, h, sizeof(uhdr)); > + crc = be32_to_cpu(uhdr.hdr_crc); > + uhdr.hdr_crc = 0; > + > + if (crc32_ones(0, (char *)&uhdr, sizeof(uhdr)) != crc) { > + pr_debug("Corrupt header, CRC do not match\n"); > + return -EINVAL; > + } > + > + crc = be32_to_cpu(uhdr.crc); > + if (crc32_ones(0, uimage_buf + zoff, uimage_len - zoff) != crc) { > + pr_debug("Corrupt zImage, CRC do not match\n"); > + return -EINVAL; > + } > + > + return kexec_zimage_ops.probe(uimage_buf + zoff, > + uimage_len - zoff); > +} > + > +static void *uimage_load(struct kimage *image, > + char *uimage, unsigned long uimage_len, > + char *initrd, unsigned long initrd_len, > + char *cmdline, unsigned long cmdline_len) > +{ > + const struct arm_uimage_header *h = > + (struct arm_uimage_header *) uimage; > + unsigned long zimage_offset = sizeof(struct arm_uimage_header); > + > + pr_debug("Loading uImage"); > + return kexec_zimage_ops.load(image, > + uimage + zimage_offset, > + uimage_len - zimage_offset, > + initrd, initrd_len, > + cmdline, cmdline_len); > +} > + > +const struct kexec_file_ops kexec_uimage_ops = { > + .probe = uimage_probe, > + .load = uimage_load, > +}; > diff --git a/arch/arm/kernel/kexec_zimage.c b/arch/arm/kernel/kexec_zimage.c > new file mode 100644 > index 000000000000..d09795fc9072 > --- /dev/null > +++ b/arch/arm/kernel/kexec_zimage.c > @@ -0,0 +1,199 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Kexec zImage loader > + * > + * Copyright (C) 2020 Samsung Electronics > + * Author: Łukasz Stelmach <l.stelmach@samsung.com> Please credit me as part author of this - you have taken some of my code from the userspace kexec tool (such as the contents of find_extension_tag()) and copied it in here, so this is not all your own work. > + */ > + > +#define pr_fmt(fmt) "kexec_file(zImage): " fmt > + > +#include <asm/image.h> > +#include <asm/unaligned.h> > +#include <linux/err.h> > +#include <linux/kexec.h> > +#include <linux/memblock.h> > + > +#define byte_size(t) ((t)->hdr.size << 2) > + > +static const void *find_extension_tag(const char *buf, > + unsigned long len, > + uint32_t tag_id) > +{ > + const struct arm_zimage_header *h = (const struct arm_zimage_header *)buf; > + const struct arm_zimage_tag *tag; > + uint32_t offset, size; > + uint32_t max = len - sizeof(struct tag_header); > + > + if (len < sizeof(*h) || > + h->magic != ARM_ZIMAGE_MAGIC1 || > + h->magic2 != ARM_ZIMAGE_MAGIC2) > + return NULL; > + > + for (offset = h->extension_tag_offset; > + (tag = (void *)(buf + offset)) != NULL && > + offset < max && > + (size = le32_to_cpu(byte_size(tag))) != 0 && > + offset + size < len; > + offset += size) { > + pr_debug(" offset 0x%08x tag 0x%08x size %u\n", > + offset, le32_to_cpu(tag->hdr.tag), size); > + if (tag->hdr.tag == tag_id) > + return tag; > + } > + > + return NULL; > +} > + > +static int zimage_probe(const char *kernel_buf, unsigned long kernel_len) > +{ > + const struct arm_zimage_header *h = > + (struct arm_zimage_header *)(kernel_buf); > + > + if (!h || (kernel_len < sizeof(*h))) > + return -EINVAL; > + > + if ((h->magic != ARM_ZIMAGE_MAGIC1) || > + (h->magic2 != ARM_ZIMAGE_MAGIC2)) > + return -EINVAL; > + > + return 0; > +} > + > + > +#if defined(DEBUG) > +#define debug_offsets() ({ \ > + pr_debug("Image offsets:\n"); \ > + pr_debug(" kernel 0x%08lx 0x%08lx\n", kernel_offset, kernel_len); \ > + pr_debug(" zimage 0x%08lx 0x%08lx\n", zimage_offset, zimage_len); \ > + pr_debug(" initrd 0x%08lx 0x%08lx\n", initrd_offset, initrd_len); \ > +}) > +#else > +#define debug_offsets() > +#endif > + > +static void *zimage_load(struct kimage *image, > + char *zimage, unsigned long zimage_len, > + char *initrd, unsigned long initrd_len, > + char *cmdline, unsigned long cmdline_len) > +{ > + struct arm_zimage_header *h; > + struct kexec_buf kbuf; > + struct kexec_segment *zimage_segment; > + const struct arm_zimage_tag *klsz_tag; > + const struct arm_zimage_tag_dc *dcsz_tag; > + int ret = -EINVAL; > + > + unsigned long zimage_mem = 0x20000; /* malloc 64kB + stack 4 kB + some bss */ > + unsigned long kernel_len = zimage_len * 4; /* 4:1 compression */ This has been proven wrong. > + unsigned long kernel_offset = memblock_start_of_DRAM() + > + ALIGN(TEXT_OFFSET, PAGE_SIZE); TEXT_OFFSET is actually a property of the loaded kernel, not of the currently running kernel. I have a patch to add that into the zImage tag. > + unsigned long zimage_offset = kernel_offset + > + ALIGN(kernel_len, PAGE_SIZE); > + unsigned long initrd_offset = zimage_offset + > + ALIGN(zimage_len + zimage_mem, PAGE_SIZE); Since kernel_len is wrong, these will be wrong... please only fall back to this if you don't find the extension tag - in other words, declare the variables here, but don't initialise them, set them lower down in the file if we fail to find the extension tag. > + > + if (image->type == KEXEC_TYPE_CRASH) { > + kernel_offset += crashk_res.start; > + zimage_offset += crashk_res.start; > + initrd_offset += crashk_res.start; > + } > + debug_offsets(); > + > + h = (struct arm_zimage_header *)zimage; > + > + klsz_tag = find_extension_tag(zimage, zimage_len, ZIMAGE_TAG_KRNL_SIZE); > + if (klsz_tag) { > + uint32_t *p = (void *)zimage + > + le32_to_cpu(klsz_tag->u.krnl_size.size_ptr); > + uint32_t edata_size = le32_to_cpu(get_unaligned(p)); > + uint32_t bss_size = le32_to_cpu(klsz_tag->u.krnl_size.bss_size); > + > + kernel_len = edata_size + bss_size; > + > + pr_debug("Decompressed kernel sizes:\n"); > + pr_debug(" text+data 0x%08lx bss 0x%08lx total 0x%08lx\n", > + (unsigned long)edata_size, > + (unsigned long)bss_size, > + (unsigned long)kernel_len); > + > + zimage_offset = kernel_offset + ALIGN(edata_size, PAGE_SIZE); > + initrd_offset = zimage_offset + > + max(ALIGN(zimage_len + 0x20000, PAGE_SIZE), > + ALIGN((unsigned long)bss_size, PAGE_SIZE)); > + debug_offsets(); This looks incorrect to me. Please see the kexec tool - what its doing in its corresponding section that you copied some of this code from is carefully thought out and can't be simplified. Ergo, I think this is wrong. > + } > + > + dcsz_tag = find_extension_tag(zimage, zimage_len, > + ZIMAGE_TAG_DECOMP_SIZE); > + if (dcsz_tag) { > + uint32_t bss_size = le32_to_cpu(dcsz_tag->u.decomp_size.bss_size); > + uint32_t stack_size = le32_to_cpu(dcsz_tag->u.decomp_size.stack_size); > + uint32_t malloc_size = le32_to_cpu(dcsz_tag->u.decomp_size.malloc_size); > + > + zimage_mem = bss_size + stack_size + malloc_size; > + > + pr_debug("Decompressor memory requirements:\n"); > + pr_debug(" bss 0x%08lx stack 0x%08lx malloc 0x%08lx total 0x%08lx\n", > + (unsigned long)bss_size, > + (unsigned long)stack_size, > + (unsigned long)malloc_size, > + zimage_mem); > + > + initrd_offset = max(ALIGN(zimage_offset + zimage_len + > + bss_size + stack_size + > + malloc_size, PAGE_SIZE), > + ALIGN(kernel_offset + kernel_len, PAGE_SIZE)); > + debug_offsets(); > + } > + > + /* > + * zImage MUST be loaded into the first 128 MiB of physical > + * memory for proper memory detection. Should the uncompressed > + * kernel be larger than 128 MiB, zImage relocation becomes > + * unavoidable and it is best to rely on the relocation code. > + */ > + if (((zimage_offset - kernel_offset) + PAGE_SIZE + 0x8000) >= SZ_128M) { > + pr_debug("The kernel is too big (%ld MiB) to avoid " > + "zImage relocation. Loading zimage at 0x%08lx\n", > + ((zimage_offset - kernel_offset) >> 20), > + kernel_offset); > + zimage_offset = kernel_offset; > + } > + > + kbuf.image = image; > + kbuf.top_down = false; > + > + kbuf.buf_min = zimage_offset; > + kbuf.buf_max = ULONG_MAX; > + kbuf.buffer = zimage; > + kbuf.bufsz = zimage_len; > + kbuf.buf_align = PAGE_SIZE; > + > + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; > + kbuf.memsz = zimage_len; > + > + ret = kexec_add_buffer(&kbuf); > + if (ret) > + return ERR_PTR(ret); > + > + pr_debug("Loaded zImage at 0x%lx bufsz=0x%lx memsz=0x%lx\n", > + kbuf.mem, kbuf.bufsz, kbuf.memsz); > + > + initrd_offset += kbuf.mem - zimage_offset; > + debug_offsets(); > + > + zimage_segment = &image->segment[image->nr_segments - 1]; > + image->start = zimage_segment->mem; > + > + ret = load_other_segments(image, > + zimage_segment->mem, zimage_segment->memsz, > + initrd, initrd_len, initrd_offset, > + cmdline); > + return ERR_PTR(ret); > +} > + > +const struct kexec_file_ops kexec_zimage_ops = { > + .probe = zimage_probe, > + .load = zimage_load, > +}; > diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c > index c10a2dfd53d1..2e4780efabb4 100644 > --- a/arch/arm/kernel/machine_kexec.c > +++ b/arch/arm/kernel/machine_kexec.c > @@ -93,10 +93,13 @@ int machine_kexec_prepare(struct kimage *image) > current_segment->memsz)) > return -EINVAL; > > - err = get_user(header, (__be32*)current_segment->buf); > - if (err) > - return err; > - > + if (image->file_mode) { > + header = *(__be32 *)current_segment->buf; > + } else { > + err = get_user(header, (__be32 *)current_segment->buf); > + if (err) > + return err; > + } > if (header == cpu_to_be32(OF_DT_HEADER)) > image->arch.kernel_r2 = current_segment->mem; > } > diff --git a/arch/arm/kernel/machine_kexec_file.c b/arch/arm/kernel/machine_kexec_file.c > new file mode 100644 > index 000000000000..ead680f1e795 > --- /dev/null > +++ b/arch/arm/kernel/machine_kexec_file.c > @@ -0,0 +1,209 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * kexec_file for arm > + * > + * Copyright (C) 2018 Linaro Limited > + * Copyright (C) 2020 Samsung Electronics > + * Authors: > + * AKASHI Takahiro <takahiro.akashi@linaro.org> > + * Łukasz Stelmach <l.stelmach@samsung.com> > + * > + */ > + > +#define pr_fmt(fmt) "kexec_file: " fmt > + > +#include <linux/kexec.h> > +#include <linux/libfdt.h> > +#include <linux/of_fdt.h> > +#include <linux/random.h> > + > +/* relevant device tree properties */ > +#define FDT_PROP_INITRD_START "linux,initrd-start" > +#define FDT_PROP_INITRD_END "linux,initrd-end" > +#define FDT_PROP_BOOTARGS "bootargs" > +#define FDT_PROP_RNG_SEED "rng-seed" > + > +static int setup_dtb(struct kimage *image, > + unsigned long initrd_load_addr, unsigned long initrd_len, > + char *cmdline, void *dtb) > +{ > + int off, ret; > + > + ret = fdt_path_offset(dtb, "/chosen"); > + if (ret < 0) > + goto out; > + > + off = ret; > + > + /* add bootargs */ > + if (cmdline) { > + ret = fdt_setprop_string(dtb, off, FDT_PROP_BOOTARGS, cmdline); > + if (ret) > + goto out; > + } else { > + ret = fdt_delprop(dtb, off, FDT_PROP_BOOTARGS); > + if (ret && (ret != -FDT_ERR_NOTFOUND)) > + goto out; > + } > + > + /* add initrd-* */ > + if (initrd_load_addr) { > + ret = fdt_setprop_u64(dtb, off, FDT_PROP_INITRD_START, > + initrd_load_addr); > + if (ret) > + goto out; > + > + ret = fdt_setprop_u64(dtb, off, FDT_PROP_INITRD_END, > + initrd_load_addr + initrd_len); > + if (ret) > + goto out; > + } else { > + ret = fdt_delprop(dtb, off, FDT_PROP_INITRD_START); > + if (ret && (ret != -FDT_ERR_NOTFOUND)) > + goto out; > + > + ret = fdt_delprop(dtb, off, FDT_PROP_INITRD_END); > + if (ret && (ret != -FDT_ERR_NOTFOUND)) > + goto out; > + } > + > + /* add rng-seed */ > + if (rng_is_initialized()) { > + char seed[128]; > + get_random_bytes(seed, sizeof(seed)); > + > + ret = fdt_setprop(dtb, off, FDT_PROP_RNG_SEED, > + seed, sizeof(seed)); > + if (ret) > + goto out; > + } else { > + pr_notice("RNG is not initialised: omitting \"%s\" property\n", > + FDT_PROP_RNG_SEED); > + ret = 0; > + } > + > +out: > + if (ret) > + return (ret == -FDT_ERR_NOSPACE) ? -ENOMEM : -EINVAL; > + > + return 0; > +} > +/* > + * More space needed so that we can add initrd, bootargs and kaslr-seed. > + */ > +#define DTB_EXTRA_SPACE 0x1000 > + > +static int create_dtb(struct kimage *image, > + unsigned long initrd_load_addr, unsigned long initrd_len, > + char *cmdline, void **dtb) > +{ > + void *buf; > + size_t buf_size; > + size_t cmdline_len; > + int ret; > + > + cmdline_len = cmdline ? strlen(cmdline) : 0; > + buf_size = fdt_totalsize(initial_boot_params) > + + cmdline_len + DTB_EXTRA_SPACE; > + > + for (;;) { > + buf = vmalloc(buf_size); > + if (!buf) > + return -ENOMEM; > + > + /* duplicate a device tree blob */ > + ret = fdt_open_into(initial_boot_params, buf, buf_size); > + if (ret) > + return -EINVAL; > + > + ret = setup_dtb(image, initrd_load_addr, initrd_len, > + cmdline, buf); > + if (ret) { > + vfree(buf); > + if (ret == -ENOMEM) { > + /* unlikely, but just in case */ > + buf_size += DTB_EXTRA_SPACE; > + continue; > + } else { > + return ret; > + } > + } > + > + /* trim it */ > + fdt_pack(buf); > + *dtb = buf; > + > + return 0; > + } > +} > + > +int load_other_segments(struct kimage *image, > + unsigned long zimage_load_addr, > + unsigned long zimage_len, > + char *initrd, > + unsigned long initrd_len, > + unsigned long initrd_offset, > + char *cmdline) > +{ > + struct kexec_buf kbuf; > + void *dtb = NULL; > + unsigned long initrd_load_addr = 0; > + unsigned long dtb_len; > + int ret = 0; > + > + kbuf.image = image; > + /* not allocate anything below the kernel */ > + kbuf.buf_min = initrd_offset; > + if (initrd) { > + kbuf.buffer = initrd; > + kbuf.bufsz = initrd_len; > + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; > + kbuf.memsz = initrd_len; > + kbuf.buf_align = PAGE_SIZE; > + kbuf.buf_max = ULONG_MAX; > + kbuf.top_down = false; > + > + ret = kexec_add_buffer(&kbuf); > + if (ret) > + goto out_err; > + > + pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n", > + kbuf.mem, kbuf.bufsz, kbuf.memsz); > + > + initrd_load_addr = kbuf.mem; > + kbuf.buf_min = initrd_load_addr + kbuf.memsz; > + } > + > + /* load dtb */ > + ret = create_dtb(image, initrd_load_addr, initrd_len, cmdline, &dtb); > + if (ret) { > + pr_err("Preparing for new dtb failed\n"); > + goto out_err; > + } > + > + dtb_len = fdt_totalsize(dtb); > + kbuf.buffer = dtb; > + kbuf.bufsz = dtb_len; > + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; > + kbuf.memsz = dtb_len; > + kbuf.buf_align = PAGE_SIZE; > + kbuf.buf_max = ULONG_MAX; > + kbuf.top_down = false; > + > + ret = kexec_add_buffer(&kbuf); > + if (ret) > + goto out_err; > + > + pr_debug("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n", > + kbuf.mem, kbuf.bufsz, kbuf.memsz); > + return 0; > +out_err: > + vfree(dtb); > + return ret; > +} > + > +const struct kexec_file_ops * const kexec_file_loaders[] = { > + &kexec_uimage_ops, > + &kexec_zimage_ops, > + NULL > +}; > -- > 2.26.2 > >
On Mon, Jun 01, 2020 at 04:07:45PM +0100, Russell King - ARM Linux admin wrote: > On Mon, Jun 01, 2020 at 04:27:54PM +0200, Łukasz Stelmach wrote: > > diff --git a/arch/arm/kernel/kexec_zimage.c b/arch/arm/kernel/kexec_zimage.c > > new file mode 100644 > > index 000000000000..d09795fc9072 > > --- /dev/null > > +++ b/arch/arm/kernel/kexec_zimage.c > > @@ -0,0 +1,199 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * Kexec zImage loader > > + * > > + * Copyright (C) 2020 Samsung Electronics > > + * Author: Łukasz Stelmach <l.stelmach@samsung.com> > > Please credit me as part author of this - you have taken some of my > code from the userspace kexec tool (such as the contents of > find_extension_tag()) and copied it in here, so this is not all your > own work. It would also be a very good idea to indicate _where_ you copied some of this code from.
It was <2020-06-01 pon 16:14>, when Russell King - ARM Linux admin wrote: > On Mon, Jun 01, 2020 at 04:07:45PM +0100, Russell King - ARM Linux admin wrote: >> On Mon, Jun 01, 2020 at 04:27:54PM +0200, Łukasz Stelmach wrote: >> > diff --git a/arch/arm/kernel/kexec_zimage.c b/arch/arm/kernel/kexec_zimage.c >> > new file mode 100644 >> > index 000000000000..d09795fc9072 >> > --- /dev/null >> > +++ b/arch/arm/kernel/kexec_zimage.c >> > @@ -0,0 +1,199 @@ >> > +// SPDX-License-Identifier: GPL-2.0 >> > +/* >> > + * Kexec zImage loader >> > + * >> > + * Copyright (C) 2020 Samsung Electronics >> > + * Author: Łukasz Stelmach <l.stelmach@samsung.com> >> >> Please credit me as part author of this - you have taken some of my >> code from the userspace kexec tool (such as the contents of >> find_extension_tag()) and copied it in here, so this is not all your >> own work. > > It would also be a very good idea to indicate _where_ you copied some > of this code from. Sure thing. Done.
It was <2020-06-01 pon 16:07>, when Russell King - ARM Linux admin wrote: > On Mon, Jun 01, 2020 at 04:27:54PM +0200, Łukasz Stelmach wrote: >> This is kexec_file_load implementation for ARM. It loads zImage and >> initrd from file descripters and resuses DTB. >> >> Most code is derived from arm64 kexec_file_load implementation >> and from kexec-tools. > > Please make the uImage loader able to be configured out of the > kernel; it's a legacy image format now, and some of us just don't > use it anymore. That way, those who wish to have it can, and > those who wish not to can have a smaller kernel. The difference in size of arch/arm/boot/Image is 160 bytes, but OK. Done. >> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> >> Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com> >> --- >> arch/arm/Kconfig | 15 ++ >> arch/arm/include/asm/image.h | 26 ++++ >> arch/arm/include/asm/kexec.h | 14 ++ >> arch/arm/kernel/Makefile | 5 +- >> arch/arm/kernel/kexec_uimage.c | 80 ++++++++++ >> arch/arm/kernel/kexec_zimage.c | 199 +++++++++++++++++++++++++ >> arch/arm/kernel/machine_kexec.c | 11 +- >> arch/arm/kernel/machine_kexec_file.c | 209 +++++++++++++++++++++++++++ >> 8 files changed, 554 insertions(+), 5 deletions(-) >> create mode 100644 arch/arm/kernel/kexec_uimage.c >> create mode 100644 arch/arm/kernel/kexec_zimage.c >> create mode 100644 arch/arm/kernel/machine_kexec_file.c >> >> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig >> index c77c93c485a0..6adb849cb304 100644 >> --- a/arch/arm/Kconfig >> +++ b/arch/arm/Kconfig >> @@ -1917,6 +1917,21 @@ config KEXEC >> is properly shutdown, so do not be surprised if this code does not >> initially work for you. >> >> +config KEXEC_FILE >> + bool "Kexec file based system call (EXPERIMENTAL)" >> + depends on (!SMP || PM_SLEEP_SMP) >> + depends on USE_OF >> + select KEXEC_CORE >> + select CRC32 >> + help >> + This is new version of kexec system call. This system call is >> + file based and takes file descriptors as system call argument >> + for kernel and initramfs as opposed to list of segments as >> + accepted by previous system call. >> + >> + The kernel to be loaded MUST support Flattened Device Tree >> + (selected with CONFIG_USE_OF). >> + >> config ATAGS_PROC >> bool "Export atags in procfs" >> depends on ATAGS && KEXEC >> diff --git a/arch/arm/include/asm/image.h b/arch/arm/include/asm/image.h >> index 624438740f23..95f23837b04f 100644 >> --- a/arch/arm/include/asm/image.h >> +++ b/arch/arm/include/asm/image.h >> @@ -8,8 +8,13 @@ >> (((x) >> 8) & 0x0000ff00) | \ >> (((x) << 8) & 0x00ff0000) | \ >> (((x) << 24) & 0xff000000)) >> +#define UIMAGE_MAGIC(x) (x) >> #else >> #define ZIMAGE_MAGIC(x) (x) >> +#define UIMAGE_MAGIC(x) ((((x) >> 24) & 0x000000ff) | \ >> + (((x) >> 8) & 0x0000ff00) | \ >> + (((x) << 8) & 0x00ff0000) | \ >> + (((x) << 24) & 0xff000000)) >> #endif >> >> #define ARM_ZIMAGE_MAGIC1 ZIMAGE_MAGIC(0x016f2818) >> @@ -17,6 +22,12 @@ >> #define ARM_ZIMAGE_MAGIC3 ZIMAGE_MAGIC(0x5a534c4b) >> #define ARM_ZIMAGE_MAGIC4 ZIMAGE_MAGIC(0x5a534344) >> >> +#define ARM_UIMAGE_MAGIC UIMAGE_MAGIC(0x27051956) >> +#define ARM_UIMAGE_NAME_LEN 32 >> +#define ARM_UIMAGE_TYPE_KERNEL 2 >> +#define ARM_UIMAGE_TYPE_KERNEL_NOLOAD 14 >> +#define ARM_UIMAGE_ARCH_ARM 2 >> + >> #ifndef __ASSEMBLY__ >> >> #include <linux/types.h> >> @@ -33,6 +44,21 @@ struct arm_zimage_header { >> __le32 extension_tag_offset; >> }; >> >> +struct arm_uimage_header { >> + __be32 magic; >> + __be32 hdr_crc; >> + __be32 time; >> + __be32 size; >> + __be32 load; >> + __be32 entry; >> + __be32 crc; >> + __u8 os; >> + __u8 arch; >> + __u8 type; >> + __u8 comp; >> + __u8 name[ARM_UIMAGE_NAME_LEN]; >> +}; >> + >> struct arm_zimage_tag { >> struct tag_header hdr; >> union { >> diff --git a/arch/arm/include/asm/kexec.h b/arch/arm/include/asm/kexec.h >> index 22751b5b5735..fda35afa7195 100644 >> --- a/arch/arm/include/asm/kexec.h >> +++ b/arch/arm/include/asm/kexec.h >> @@ -83,6 +83,20 @@ static inline struct page *boot_pfn_to_page(unsigned long boot_pfn) >> } >> #define boot_pfn_to_page boot_pfn_to_page >> >> +#ifdef CONFIG_KEXEC_FILE >> + >> +extern const struct kexec_file_ops kexec_zimage_ops; >> +extern const struct kexec_file_ops kexec_uimage_ops; >> + >> +struct kimage; >> + >> +extern int load_other_segments(struct kimage *image, >> + unsigned long kernel_load_addr, unsigned long kernel_size, >> + char *initrd, unsigned long initrd_len, >> + unsigned long initrd_offset, char *cmdline); >> + >> +#endif /* CONFIG_KEXEC_FILE */ >> + >> #endif /* __ASSEMBLY__ */ >> >> #endif /* CONFIG_KEXEC */ >> diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile >> index 89e5d864e923..466c683bb551 100644 >> --- a/arch/arm/kernel/Makefile >> +++ b/arch/arm/kernel/Makefile >> @@ -3,6 +3,7 @@ >> # Makefile for the linux kernel. >> # >> >> +CFLAGS_kexec_zimage.o := -DTEXT_OFFSET=$(TEXT_OFFSET) >> CPPFLAGS_vmlinux.lds := -DTEXT_OFFSET=$(TEXT_OFFSET) >> AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET) >> >> @@ -56,7 +57,9 @@ obj-$(CONFIG_FUNCTION_TRACER) += entry-ftrace.o >> obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o insn.o patch.o >> obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o insn.o patch.o >> obj-$(CONFIG_JUMP_LABEL) += jump_label.o insn.o patch.o >> -obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o >> +obj-$(CONFIG_KEXEC_CORE) += machine_kexec.o relocate_kernel.o >> +obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file.o kexec_zimage.o \ >> + kexec_uimage.o >> # Main staffs in KPROBES are in arch/arm/probes/ . >> obj-$(CONFIG_KPROBES) += patch.o insn.o >> obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o >> diff --git a/arch/arm/kernel/kexec_uimage.c b/arch/arm/kernel/kexec_uimage.c >> new file mode 100644 >> index 000000000000..47033574e24e >> --- /dev/null >> +++ b/arch/arm/kernel/kexec_uimage.c >> @@ -0,0 +1,80 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Kexec uImage loader >> + * >> + * Copyright (C) 2020 Samsung Electronics >> + * Author: Łukasz Stelmach <l.stelmach@samsung.com> >> + */ >> + >> +#define pr_fmt(fmt) "kexec_file(uImage): " fmt >> + >> +#include <asm/image.h> >> +#include <linux/crc32.h> >> +#include <linux/err.h> >> +#include <linux/kexec.h> >> + >> +#define crc32_ones(crc, buf, len) \ >> + (crc32(crc ^ 0xffffffff, buf, len) ^ 0xffffffff) >> + >> +static int uimage_probe(const char *uimage_buf, unsigned long uimage_len) >> +{ >> + const struct arm_uimage_header *h = >> + (struct arm_uimage_header *) uimage_buf; >> + struct arm_uimage_header uhdr; >> + unsigned long zoff = sizeof(struct arm_uimage_header); >> + uint32_t crc; >> + >> + if (h->magic != ARM_UIMAGE_MAGIC) >> + return -EINVAL; >> + >> + if (h->type != ARM_UIMAGE_TYPE_KERNEL && >> + h->type != ARM_UIMAGE_TYPE_KERNEL_NOLOAD){ >> + pr_debug("Invalid image type: %d\n", h->type); >> + return -EINVAL; >> + } >> + >> + if (h->arch != ARM_UIMAGE_ARCH_ARM) { >> + pr_debug("Invalidy image arch: %d\n", h->arch); >> + return -EINVAL; >> + } >> + >> + memcpy((char *)&uhdr, h, sizeof(uhdr)); >> + crc = be32_to_cpu(uhdr.hdr_crc); >> + uhdr.hdr_crc = 0; >> + >> + if (crc32_ones(0, (char *)&uhdr, sizeof(uhdr)) != crc) { >> + pr_debug("Corrupt header, CRC do not match\n"); >> + return -EINVAL; >> + } >> + >> + crc = be32_to_cpu(uhdr.crc); >> + if (crc32_ones(0, uimage_buf + zoff, uimage_len - zoff) != crc) { >> + pr_debug("Corrupt zImage, CRC do not match\n"); >> + return -EINVAL; >> + } >> + >> + return kexec_zimage_ops.probe(uimage_buf + zoff, >> + uimage_len - zoff); >> +} >> + >> +static void *uimage_load(struct kimage *image, >> + char *uimage, unsigned long uimage_len, >> + char *initrd, unsigned long initrd_len, >> + char *cmdline, unsigned long cmdline_len) >> +{ >> + const struct arm_uimage_header *h = >> + (struct arm_uimage_header *) uimage; >> + unsigned long zimage_offset = sizeof(struct arm_uimage_header); >> + >> + pr_debug("Loading uImage"); >> + return kexec_zimage_ops.load(image, >> + uimage + zimage_offset, >> + uimage_len - zimage_offset, >> + initrd, initrd_len, >> + cmdline, cmdline_len); >> +} >> + >> +const struct kexec_file_ops kexec_uimage_ops = { >> + .probe = uimage_probe, >> + .load = uimage_load, >> +}; >> diff --git a/arch/arm/kernel/kexec_zimage.c b/arch/arm/kernel/kexec_zimage.c >> new file mode 100644 >> index 000000000000..d09795fc9072 >> --- /dev/null >> +++ b/arch/arm/kernel/kexec_zimage.c >> @@ -0,0 +1,199 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Kexec zImage loader >> + * >> + * Copyright (C) 2020 Samsung Electronics >> + * Author: Łukasz Stelmach <l.stelmach@samsung.com> > > Please credit me as part author of this - you have taken some of my > code from the userspace kexec tool (such as the contents of > find_extension_tag()) and copied it in here, so this is not all your > own work. Done. >> + */ >> + >> +#define pr_fmt(fmt) "kexec_file(zImage): " fmt >> + >> +#include <asm/image.h> >> +#include <asm/unaligned.h> >> +#include <linux/err.h> >> +#include <linux/kexec.h> >> +#include <linux/memblock.h> >> + >> +#define byte_size(t) ((t)->hdr.size << 2) >> + >> +static const void *find_extension_tag(const char *buf, >> + unsigned long len, >> + uint32_t tag_id) >> +{ >> + const struct arm_zimage_header *h = (const struct arm_zimage_header *)buf; >> + const struct arm_zimage_tag *tag; >> + uint32_t offset, size; >> + uint32_t max = len - sizeof(struct tag_header); >> + >> + if (len < sizeof(*h) || >> + h->magic != ARM_ZIMAGE_MAGIC1 || >> + h->magic2 != ARM_ZIMAGE_MAGIC2) >> + return NULL; >> + >> + for (offset = h->extension_tag_offset; >> + (tag = (void *)(buf + offset)) != NULL && >> + offset < max && >> + (size = le32_to_cpu(byte_size(tag))) != 0 && >> + offset + size < len; >> + offset += size) { >> + pr_debug(" offset 0x%08x tag 0x%08x size %u\n", >> + offset, le32_to_cpu(tag->hdr.tag), size); >> + if (tag->hdr.tag == tag_id) >> + return tag; >> + } >> + >> + return NULL; >> +} >> + >> +static int zimage_probe(const char *kernel_buf, unsigned long kernel_len) >> +{ >> + const struct arm_zimage_header *h = >> + (struct arm_zimage_header *)(kernel_buf); >> + >> + if (!h || (kernel_len < sizeof(*h))) >> + return -EINVAL; >> + >> + if ((h->magic != ARM_ZIMAGE_MAGIC1) || >> + (h->magic2 != ARM_ZIMAGE_MAGIC2)) >> + return -EINVAL; >> + >> + return 0; >> +} >> + >> + >> +#if defined(DEBUG) >> +#define debug_offsets() ({ \ >> + pr_debug("Image offsets:\n"); \ >> + pr_debug(" kernel 0x%08lx 0x%08lx\n", kernel_offset, kernel_len); \ >> + pr_debug(" zimage 0x%08lx 0x%08lx\n", zimage_offset, zimage_len); \ >> + pr_debug(" initrd 0x%08lx 0x%08lx\n", initrd_offset, initrd_len); \ >> +}) >> +#else >> +#define debug_offsets() >> +#endif >> + >> +static void *zimage_load(struct kimage *image, >> + char *zimage, unsigned long zimage_len, >> + char *initrd, unsigned long initrd_len, >> + char *cmdline, unsigned long cmdline_len) >> +{ >> + struct arm_zimage_header *h; >> + struct kexec_buf kbuf; >> + struct kexec_segment *zimage_segment; >> + const struct arm_zimage_tag *klsz_tag; >> + const struct arm_zimage_tag_dc *dcsz_tag; >> + int ret = -EINVAL; >> + >> + unsigned long zimage_mem = 0x20000; /* malloc 64kB + stack 4 kB + some bss */ >> + unsigned long kernel_len = zimage_len * 4; /* 4:1 compression */ > > This has been proven wrong. 5:1? The comment and the code in kexec-tools are inconsisten in this regard. The comment says 4:1, but the code multiplies by 5. Your recommendation? This value is used as a fallback anyway in a very unlikely case, when tags are missing (see below). >> + unsigned long kernel_offset = memblock_start_of_DRAM() + >> + ALIGN(TEXT_OFFSET, PAGE_SIZE); > > TEXT_OFFSET is actually a property of the loaded kernel, not of the > currently running kernel. Indeed. > I have a patch to add that into the zImage tag. I am afraid, I haven't seen it before. Where can I find it? >> + unsigned long zimage_offset = kernel_offset + >> + ALIGN(kernel_len, PAGE_SIZE); >> + unsigned long initrd_offset = zimage_offset + >> + ALIGN(zimage_len + zimage_mem, PAGE_SIZE); > > Since kernel_len is wrong, these will be wrong... please only fall > back to this if you don't find the extension tag - in other words, > declare the variables here, but don't initialise them, set them > lower down in the file if we fail to find the extension tag. That is how it works now. This is the structure I have taken from kexec-tools: initialize and change if additional information is available. If the tags are not available use these values as a fallback. >> + >> + if (image->type == KEXEC_TYPE_CRASH) { >> + kernel_offset += crashk_res.start; >> + zimage_offset += crashk_res.start; >> + initrd_offset += crashk_res.start; >> + } >> + debug_offsets(); >> + >> + h = (struct arm_zimage_header *)zimage; >> + >> + klsz_tag = find_extension_tag(zimage, zimage_len, ZIMAGE_TAG_KRNL_SIZE); >> + if (klsz_tag) { >> + uint32_t *p = (void *)zimage + >> + le32_to_cpu(klsz_tag->u.krnl_size.size_ptr); >> + uint32_t edata_size = le32_to_cpu(get_unaligned(p)); >> + uint32_t bss_size = le32_to_cpu(klsz_tag->u.krnl_size.bss_size); >> + >> + kernel_len = edata_size + bss_size; >> + >> + pr_debug("Decompressed kernel sizes:\n"); >> + pr_debug(" text+data 0x%08lx bss 0x%08lx total 0x%08lx\n", >> + (unsigned long)edata_size, >> + (unsigned long)bss_size, >> + (unsigned long)kernel_len); >> + >> + zimage_offset = kernel_offset + ALIGN(edata_size, PAGE_SIZE); >> + initrd_offset = zimage_offset + >> + max(ALIGN(zimage_len + 0x20000, PAGE_SIZE), >> + ALIGN((unsigned long)bss_size, PAGE_SIZE)); >> + debug_offsets(); > > This looks incorrect to me. Please see the kexec tool - what its doing > in its corresponding section that you copied some of this code from is > carefully thought out and can't be simplified. Ergo, I think this is > wrong. As I explained in <dleftjwo4qsqqf.fsf%l.stelmach@samsung.com> my approach is slightly different. I am trying to avoid copying zImage by putting it hight enough in the first place. Kind regards,
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index c77c93c485a0..6adb849cb304 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1917,6 +1917,21 @@ config KEXEC is properly shutdown, so do not be surprised if this code does not initially work for you. +config KEXEC_FILE + bool "Kexec file based system call (EXPERIMENTAL)" + depends on (!SMP || PM_SLEEP_SMP) + depends on USE_OF + select KEXEC_CORE + select CRC32 + help + This is new version of kexec system call. This system call is + file based and takes file descriptors as system call argument + for kernel and initramfs as opposed to list of segments as + accepted by previous system call. + + The kernel to be loaded MUST support Flattened Device Tree + (selected with CONFIG_USE_OF). + config ATAGS_PROC bool "Export atags in procfs" depends on ATAGS && KEXEC diff --git a/arch/arm/include/asm/image.h b/arch/arm/include/asm/image.h index 624438740f23..95f23837b04f 100644 --- a/arch/arm/include/asm/image.h +++ b/arch/arm/include/asm/image.h @@ -8,8 +8,13 @@ (((x) >> 8) & 0x0000ff00) | \ (((x) << 8) & 0x00ff0000) | \ (((x) << 24) & 0xff000000)) +#define UIMAGE_MAGIC(x) (x) #else #define ZIMAGE_MAGIC(x) (x) +#define UIMAGE_MAGIC(x) ((((x) >> 24) & 0x000000ff) | \ + (((x) >> 8) & 0x0000ff00) | \ + (((x) << 8) & 0x00ff0000) | \ + (((x) << 24) & 0xff000000)) #endif #define ARM_ZIMAGE_MAGIC1 ZIMAGE_MAGIC(0x016f2818) @@ -17,6 +22,12 @@ #define ARM_ZIMAGE_MAGIC3 ZIMAGE_MAGIC(0x5a534c4b) #define ARM_ZIMAGE_MAGIC4 ZIMAGE_MAGIC(0x5a534344) +#define ARM_UIMAGE_MAGIC UIMAGE_MAGIC(0x27051956) +#define ARM_UIMAGE_NAME_LEN 32 +#define ARM_UIMAGE_TYPE_KERNEL 2 +#define ARM_UIMAGE_TYPE_KERNEL_NOLOAD 14 +#define ARM_UIMAGE_ARCH_ARM 2 + #ifndef __ASSEMBLY__ #include <linux/types.h> @@ -33,6 +44,21 @@ struct arm_zimage_header { __le32 extension_tag_offset; }; +struct arm_uimage_header { + __be32 magic; + __be32 hdr_crc; + __be32 time; + __be32 size; + __be32 load; + __be32 entry; + __be32 crc; + __u8 os; + __u8 arch; + __u8 type; + __u8 comp; + __u8 name[ARM_UIMAGE_NAME_LEN]; +}; + struct arm_zimage_tag { struct tag_header hdr; union { diff --git a/arch/arm/include/asm/kexec.h b/arch/arm/include/asm/kexec.h index 22751b5b5735..fda35afa7195 100644 --- a/arch/arm/include/asm/kexec.h +++ b/arch/arm/include/asm/kexec.h @@ -83,6 +83,20 @@ static inline struct page *boot_pfn_to_page(unsigned long boot_pfn) } #define boot_pfn_to_page boot_pfn_to_page +#ifdef CONFIG_KEXEC_FILE + +extern const struct kexec_file_ops kexec_zimage_ops; +extern const struct kexec_file_ops kexec_uimage_ops; + +struct kimage; + +extern int load_other_segments(struct kimage *image, + unsigned long kernel_load_addr, unsigned long kernel_size, + char *initrd, unsigned long initrd_len, + unsigned long initrd_offset, char *cmdline); + +#endif /* CONFIG_KEXEC_FILE */ + #endif /* __ASSEMBLY__ */ #endif /* CONFIG_KEXEC */ diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 89e5d864e923..466c683bb551 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -3,6 +3,7 @@ # Makefile for the linux kernel. # +CFLAGS_kexec_zimage.o := -DTEXT_OFFSET=$(TEXT_OFFSET) CPPFLAGS_vmlinux.lds := -DTEXT_OFFSET=$(TEXT_OFFSET) AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET) @@ -56,7 +57,9 @@ obj-$(CONFIG_FUNCTION_TRACER) += entry-ftrace.o obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o insn.o patch.o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o insn.o patch.o obj-$(CONFIG_JUMP_LABEL) += jump_label.o insn.o patch.o -obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o +obj-$(CONFIG_KEXEC_CORE) += machine_kexec.o relocate_kernel.o +obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file.o kexec_zimage.o \ + kexec_uimage.o # Main staffs in KPROBES are in arch/arm/probes/ . obj-$(CONFIG_KPROBES) += patch.o insn.o obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o diff --git a/arch/arm/kernel/kexec_uimage.c b/arch/arm/kernel/kexec_uimage.c new file mode 100644 index 000000000000..47033574e24e --- /dev/null +++ b/arch/arm/kernel/kexec_uimage.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Kexec uImage loader + * + * Copyright (C) 2020 Samsung Electronics + * Author: Łukasz Stelmach <l.stelmach@samsung.com> + */ + +#define pr_fmt(fmt) "kexec_file(uImage): " fmt + +#include <asm/image.h> +#include <linux/crc32.h> +#include <linux/err.h> +#include <linux/kexec.h> + +#define crc32_ones(crc, buf, len) \ + (crc32(crc ^ 0xffffffff, buf, len) ^ 0xffffffff) + +static int uimage_probe(const char *uimage_buf, unsigned long uimage_len) +{ + const struct arm_uimage_header *h = + (struct arm_uimage_header *) uimage_buf; + struct arm_uimage_header uhdr; + unsigned long zoff = sizeof(struct arm_uimage_header); + uint32_t crc; + + if (h->magic != ARM_UIMAGE_MAGIC) + return -EINVAL; + + if (h->type != ARM_UIMAGE_TYPE_KERNEL && + h->type != ARM_UIMAGE_TYPE_KERNEL_NOLOAD){ + pr_debug("Invalid image type: %d\n", h->type); + return -EINVAL; + } + + if (h->arch != ARM_UIMAGE_ARCH_ARM) { + pr_debug("Invalidy image arch: %d\n", h->arch); + return -EINVAL; + } + + memcpy((char *)&uhdr, h, sizeof(uhdr)); + crc = be32_to_cpu(uhdr.hdr_crc); + uhdr.hdr_crc = 0; + + if (crc32_ones(0, (char *)&uhdr, sizeof(uhdr)) != crc) { + pr_debug("Corrupt header, CRC do not match\n"); + return -EINVAL; + } + + crc = be32_to_cpu(uhdr.crc); + if (crc32_ones(0, uimage_buf + zoff, uimage_len - zoff) != crc) { + pr_debug("Corrupt zImage, CRC do not match\n"); + return -EINVAL; + } + + return kexec_zimage_ops.probe(uimage_buf + zoff, + uimage_len - zoff); +} + +static void *uimage_load(struct kimage *image, + char *uimage, unsigned long uimage_len, + char *initrd, unsigned long initrd_len, + char *cmdline, unsigned long cmdline_len) +{ + const struct arm_uimage_header *h = + (struct arm_uimage_header *) uimage; + unsigned long zimage_offset = sizeof(struct arm_uimage_header); + + pr_debug("Loading uImage"); + return kexec_zimage_ops.load(image, + uimage + zimage_offset, + uimage_len - zimage_offset, + initrd, initrd_len, + cmdline, cmdline_len); +} + +const struct kexec_file_ops kexec_uimage_ops = { + .probe = uimage_probe, + .load = uimage_load, +}; diff --git a/arch/arm/kernel/kexec_zimage.c b/arch/arm/kernel/kexec_zimage.c new file mode 100644 index 000000000000..d09795fc9072 --- /dev/null +++ b/arch/arm/kernel/kexec_zimage.c @@ -0,0 +1,199 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Kexec zImage loader + * + * Copyright (C) 2020 Samsung Electronics + * Author: Łukasz Stelmach <l.stelmach@samsung.com> + */ + +#define pr_fmt(fmt) "kexec_file(zImage): " fmt + +#include <asm/image.h> +#include <asm/unaligned.h> +#include <linux/err.h> +#include <linux/kexec.h> +#include <linux/memblock.h> + +#define byte_size(t) ((t)->hdr.size << 2) + +static const void *find_extension_tag(const char *buf, + unsigned long len, + uint32_t tag_id) +{ + const struct arm_zimage_header *h = (const struct arm_zimage_header *)buf; + const struct arm_zimage_tag *tag; + uint32_t offset, size; + uint32_t max = len - sizeof(struct tag_header); + + if (len < sizeof(*h) || + h->magic != ARM_ZIMAGE_MAGIC1 || + h->magic2 != ARM_ZIMAGE_MAGIC2) + return NULL; + + for (offset = h->extension_tag_offset; + (tag = (void *)(buf + offset)) != NULL && + offset < max && + (size = le32_to_cpu(byte_size(tag))) != 0 && + offset + size < len; + offset += size) { + pr_debug(" offset 0x%08x tag 0x%08x size %u\n", + offset, le32_to_cpu(tag->hdr.tag), size); + if (tag->hdr.tag == tag_id) + return tag; + } + + return NULL; +} + +static int zimage_probe(const char *kernel_buf, unsigned long kernel_len) +{ + const struct arm_zimage_header *h = + (struct arm_zimage_header *)(kernel_buf); + + if (!h || (kernel_len < sizeof(*h))) + return -EINVAL; + + if ((h->magic != ARM_ZIMAGE_MAGIC1) || + (h->magic2 != ARM_ZIMAGE_MAGIC2)) + return -EINVAL; + + return 0; +} + + +#if defined(DEBUG) +#define debug_offsets() ({ \ + pr_debug("Image offsets:\n"); \ + pr_debug(" kernel 0x%08lx 0x%08lx\n", kernel_offset, kernel_len); \ + pr_debug(" zimage 0x%08lx 0x%08lx\n", zimage_offset, zimage_len); \ + pr_debug(" initrd 0x%08lx 0x%08lx\n", initrd_offset, initrd_len); \ +}) +#else +#define debug_offsets() +#endif + +static void *zimage_load(struct kimage *image, + char *zimage, unsigned long zimage_len, + char *initrd, unsigned long initrd_len, + char *cmdline, unsigned long cmdline_len) +{ + struct arm_zimage_header *h; + struct kexec_buf kbuf; + struct kexec_segment *zimage_segment; + const struct arm_zimage_tag *klsz_tag; + const struct arm_zimage_tag_dc *dcsz_tag; + int ret = -EINVAL; + + unsigned long zimage_mem = 0x20000; /* malloc 64kB + stack 4 kB + some bss */ + unsigned long kernel_len = zimage_len * 4; /* 4:1 compression */ + unsigned long kernel_offset = memblock_start_of_DRAM() + + ALIGN(TEXT_OFFSET, PAGE_SIZE); + unsigned long zimage_offset = kernel_offset + + ALIGN(kernel_len, PAGE_SIZE); + unsigned long initrd_offset = zimage_offset + + ALIGN(zimage_len + zimage_mem, PAGE_SIZE); + + if (image->type == KEXEC_TYPE_CRASH) { + kernel_offset += crashk_res.start; + zimage_offset += crashk_res.start; + initrd_offset += crashk_res.start; + } + debug_offsets(); + + h = (struct arm_zimage_header *)zimage; + + klsz_tag = find_extension_tag(zimage, zimage_len, ZIMAGE_TAG_KRNL_SIZE); + if (klsz_tag) { + uint32_t *p = (void *)zimage + + le32_to_cpu(klsz_tag->u.krnl_size.size_ptr); + uint32_t edata_size = le32_to_cpu(get_unaligned(p)); + uint32_t bss_size = le32_to_cpu(klsz_tag->u.krnl_size.bss_size); + + kernel_len = edata_size + bss_size; + + pr_debug("Decompressed kernel sizes:\n"); + pr_debug(" text+data 0x%08lx bss 0x%08lx total 0x%08lx\n", + (unsigned long)edata_size, + (unsigned long)bss_size, + (unsigned long)kernel_len); + + zimage_offset = kernel_offset + ALIGN(edata_size, PAGE_SIZE); + initrd_offset = zimage_offset + + max(ALIGN(zimage_len + 0x20000, PAGE_SIZE), + ALIGN((unsigned long)bss_size, PAGE_SIZE)); + debug_offsets(); + } + + dcsz_tag = find_extension_tag(zimage, zimage_len, + ZIMAGE_TAG_DECOMP_SIZE); + if (dcsz_tag) { + uint32_t bss_size = le32_to_cpu(dcsz_tag->u.decomp_size.bss_size); + uint32_t stack_size = le32_to_cpu(dcsz_tag->u.decomp_size.stack_size); + uint32_t malloc_size = le32_to_cpu(dcsz_tag->u.decomp_size.malloc_size); + + zimage_mem = bss_size + stack_size + malloc_size; + + pr_debug("Decompressor memory requirements:\n"); + pr_debug(" bss 0x%08lx stack 0x%08lx malloc 0x%08lx total 0x%08lx\n", + (unsigned long)bss_size, + (unsigned long)stack_size, + (unsigned long)malloc_size, + zimage_mem); + + initrd_offset = max(ALIGN(zimage_offset + zimage_len + + bss_size + stack_size + + malloc_size, PAGE_SIZE), + ALIGN(kernel_offset + kernel_len, PAGE_SIZE)); + debug_offsets(); + } + + /* + * zImage MUST be loaded into the first 128 MiB of physical + * memory for proper memory detection. Should the uncompressed + * kernel be larger than 128 MiB, zImage relocation becomes + * unavoidable and it is best to rely on the relocation code. + */ + if (((zimage_offset - kernel_offset) + PAGE_SIZE + 0x8000) >= SZ_128M) { + pr_debug("The kernel is too big (%ld MiB) to avoid " + "zImage relocation. Loading zimage at 0x%08lx\n", + ((zimage_offset - kernel_offset) >> 20), + kernel_offset); + zimage_offset = kernel_offset; + } + + kbuf.image = image; + kbuf.top_down = false; + + kbuf.buf_min = zimage_offset; + kbuf.buf_max = ULONG_MAX; + kbuf.buffer = zimage; + kbuf.bufsz = zimage_len; + kbuf.buf_align = PAGE_SIZE; + + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; + kbuf.memsz = zimage_len; + + ret = kexec_add_buffer(&kbuf); + if (ret) + return ERR_PTR(ret); + + pr_debug("Loaded zImage at 0x%lx bufsz=0x%lx memsz=0x%lx\n", + kbuf.mem, kbuf.bufsz, kbuf.memsz); + + initrd_offset += kbuf.mem - zimage_offset; + debug_offsets(); + + zimage_segment = &image->segment[image->nr_segments - 1]; + image->start = zimage_segment->mem; + + ret = load_other_segments(image, + zimage_segment->mem, zimage_segment->memsz, + initrd, initrd_len, initrd_offset, + cmdline); + return ERR_PTR(ret); +} + +const struct kexec_file_ops kexec_zimage_ops = { + .probe = zimage_probe, + .load = zimage_load, +}; diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c index c10a2dfd53d1..2e4780efabb4 100644 --- a/arch/arm/kernel/machine_kexec.c +++ b/arch/arm/kernel/machine_kexec.c @@ -93,10 +93,13 @@ int machine_kexec_prepare(struct kimage *image) current_segment->memsz)) return -EINVAL; - err = get_user(header, (__be32*)current_segment->buf); - if (err) - return err; - + if (image->file_mode) { + header = *(__be32 *)current_segment->buf; + } else { + err = get_user(header, (__be32 *)current_segment->buf); + if (err) + return err; + } if (header == cpu_to_be32(OF_DT_HEADER)) image->arch.kernel_r2 = current_segment->mem; } diff --git a/arch/arm/kernel/machine_kexec_file.c b/arch/arm/kernel/machine_kexec_file.c new file mode 100644 index 000000000000..ead680f1e795 --- /dev/null +++ b/arch/arm/kernel/machine_kexec_file.c @@ -0,0 +1,209 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * kexec_file for arm + * + * Copyright (C) 2018 Linaro Limited + * Copyright (C) 2020 Samsung Electronics + * Authors: + * AKASHI Takahiro <takahiro.akashi@linaro.org> + * Łukasz Stelmach <l.stelmach@samsung.com> + * + */ + +#define pr_fmt(fmt) "kexec_file: " fmt + +#include <linux/kexec.h> +#include <linux/libfdt.h> +#include <linux/of_fdt.h> +#include <linux/random.h> + +/* relevant device tree properties */ +#define FDT_PROP_INITRD_START "linux,initrd-start" +#define FDT_PROP_INITRD_END "linux,initrd-end" +#define FDT_PROP_BOOTARGS "bootargs" +#define FDT_PROP_RNG_SEED "rng-seed" + +static int setup_dtb(struct kimage *image, + unsigned long initrd_load_addr, unsigned long initrd_len, + char *cmdline, void *dtb) +{ + int off, ret; + + ret = fdt_path_offset(dtb, "/chosen"); + if (ret < 0) + goto out; + + off = ret; + + /* add bootargs */ + if (cmdline) { + ret = fdt_setprop_string(dtb, off, FDT_PROP_BOOTARGS, cmdline); + if (ret) + goto out; + } else { + ret = fdt_delprop(dtb, off, FDT_PROP_BOOTARGS); + if (ret && (ret != -FDT_ERR_NOTFOUND)) + goto out; + } + + /* add initrd-* */ + if (initrd_load_addr) { + ret = fdt_setprop_u64(dtb, off, FDT_PROP_INITRD_START, + initrd_load_addr); + if (ret) + goto out; + + ret = fdt_setprop_u64(dtb, off, FDT_PROP_INITRD_END, + initrd_load_addr + initrd_len); + if (ret) + goto out; + } else { + ret = fdt_delprop(dtb, off, FDT_PROP_INITRD_START); + if (ret && (ret != -FDT_ERR_NOTFOUND)) + goto out; + + ret = fdt_delprop(dtb, off, FDT_PROP_INITRD_END); + if (ret && (ret != -FDT_ERR_NOTFOUND)) + goto out; + } + + /* add rng-seed */ + if (rng_is_initialized()) { + char seed[128]; + get_random_bytes(seed, sizeof(seed)); + + ret = fdt_setprop(dtb, off, FDT_PROP_RNG_SEED, + seed, sizeof(seed)); + if (ret) + goto out; + } else { + pr_notice("RNG is not initialised: omitting \"%s\" property\n", + FDT_PROP_RNG_SEED); + ret = 0; + } + +out: + if (ret) + return (ret == -FDT_ERR_NOSPACE) ? -ENOMEM : -EINVAL; + + return 0; +} +/* + * More space needed so that we can add initrd, bootargs and kaslr-seed. + */ +#define DTB_EXTRA_SPACE 0x1000 + +static int create_dtb(struct kimage *image, + unsigned long initrd_load_addr, unsigned long initrd_len, + char *cmdline, void **dtb) +{ + void *buf; + size_t buf_size; + size_t cmdline_len; + int ret; + + cmdline_len = cmdline ? strlen(cmdline) : 0; + buf_size = fdt_totalsize(initial_boot_params) + + cmdline_len + DTB_EXTRA_SPACE; + + for (;;) { + buf = vmalloc(buf_size); + if (!buf) + return -ENOMEM; + + /* duplicate a device tree blob */ + ret = fdt_open_into(initial_boot_params, buf, buf_size); + if (ret) + return -EINVAL; + + ret = setup_dtb(image, initrd_load_addr, initrd_len, + cmdline, buf); + if (ret) { + vfree(buf); + if (ret == -ENOMEM) { + /* unlikely, but just in case */ + buf_size += DTB_EXTRA_SPACE; + continue; + } else { + return ret; + } + } + + /* trim it */ + fdt_pack(buf); + *dtb = buf; + + return 0; + } +} + +int load_other_segments(struct kimage *image, + unsigned long zimage_load_addr, + unsigned long zimage_len, + char *initrd, + unsigned long initrd_len, + unsigned long initrd_offset, + char *cmdline) +{ + struct kexec_buf kbuf; + void *dtb = NULL; + unsigned long initrd_load_addr = 0; + unsigned long dtb_len; + int ret = 0; + + kbuf.image = image; + /* not allocate anything below the kernel */ + kbuf.buf_min = initrd_offset; + if (initrd) { + kbuf.buffer = initrd; + kbuf.bufsz = initrd_len; + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; + kbuf.memsz = initrd_len; + kbuf.buf_align = PAGE_SIZE; + kbuf.buf_max = ULONG_MAX; + kbuf.top_down = false; + + ret = kexec_add_buffer(&kbuf); + if (ret) + goto out_err; + + pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n", + kbuf.mem, kbuf.bufsz, kbuf.memsz); + + initrd_load_addr = kbuf.mem; + kbuf.buf_min = initrd_load_addr + kbuf.memsz; + } + + /* load dtb */ + ret = create_dtb(image, initrd_load_addr, initrd_len, cmdline, &dtb); + if (ret) { + pr_err("Preparing for new dtb failed\n"); + goto out_err; + } + + dtb_len = fdt_totalsize(dtb); + kbuf.buffer = dtb; + kbuf.bufsz = dtb_len; + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; + kbuf.memsz = dtb_len; + kbuf.buf_align = PAGE_SIZE; + kbuf.buf_max = ULONG_MAX; + kbuf.top_down = false; + + ret = kexec_add_buffer(&kbuf); + if (ret) + goto out_err; + + pr_debug("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n", + kbuf.mem, kbuf.bufsz, kbuf.memsz); + return 0; +out_err: + vfree(dtb); + return ret; +} + +const struct kexec_file_ops * const kexec_file_loaders[] = { + &kexec_uimage_ops, + &kexec_zimage_ops, + NULL +};
This is kexec_file_load implementation for ARM. It loads zImage and initrd from file descripters and resuses DTB. Most code is derived from arm64 kexec_file_load implementation and from kexec-tools. Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com> --- arch/arm/Kconfig | 15 ++ arch/arm/include/asm/image.h | 26 ++++ arch/arm/include/asm/kexec.h | 14 ++ arch/arm/kernel/Makefile | 5 +- arch/arm/kernel/kexec_uimage.c | 80 ++++++++++ arch/arm/kernel/kexec_zimage.c | 199 +++++++++++++++++++++++++ arch/arm/kernel/machine_kexec.c | 11 +- arch/arm/kernel/machine_kexec_file.c | 209 +++++++++++++++++++++++++++ 8 files changed, 554 insertions(+), 5 deletions(-) create mode 100644 arch/arm/kernel/kexec_uimage.c create mode 100644 arch/arm/kernel/kexec_zimage.c create mode 100644 arch/arm/kernel/machine_kexec_file.c