Messages in this thread | | | From | Emil Renner Berthing <> | Date | Wed, 11 Oct 2023 03:48:35 -0700 | Subject | Re: [PATCH 2/2] riscv: kexec_file: Support loading Image binary file |
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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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