Messages in this thread | | | Date | Wed, 11 Oct 2023 14:03:59 +0800 | Subject | Re: [PATCH 2/2] riscv: kexec_file: Support loading Image binary file | From | Song Shuai <> |
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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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