| Message ID | 20250409193004.643839-3-bjorn@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | riscv: kexec_file: Support loading Image binary file | expand |
| Context | Check | Description |
|---|---|---|
| bjorn/pre-ci_am | success | Success |
| bjorn/build-rv32-defconfig | success | build-rv32-defconfig |
| bjorn/build-rv64-clang-allmodconfig | success | build-rv64-clang-allmodconfig |
| bjorn/build-rv64-gcc-allmodconfig | success | build-rv64-gcc-allmodconfig |
| bjorn/build-rv64-nommu-k210-defconfig | success | build-rv64-nommu-k210-defconfig |
| bjorn/build-rv64-nommu-k210-virt | success | build-rv64-nommu-k210-virt |
| bjorn/checkpatch | warning | checkpatch |
| bjorn/dtb-warn-rv64 | success | dtb-warn-rv64 |
| bjorn/header-inline | success | header-inline |
| bjorn/kdoc | success | kdoc |
| bjorn/module-param | success | module-param |
| bjorn/verify-fixes | success | verify-fixes |
| bjorn/verify-signedoff | success | verify-signedoff |
Hi Björn, On Thu, Apr 10, 2025 at 3:31 AM Björn Töpel <bjorn@kernel.org> wrote: > > From: Song Shuai <songshuaishuai@tinylab.org> > > This patch creates image_kexec_ops to load Image binary file > for kexec_file_load() syscall. > > Signed-off-by: Song Shuai <songshuaishuai@tinylab.org> > Signed-off-by: Björn Töpel <bjorn@rivosinc.com> > --- > 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 | 96 ++++++++++++++++++++++++++ > arch/riscv/kernel/machine_kexec_file.c | 1 + > 5 files changed, 101 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 d56305c8e631..0ead29826419 100644 > --- a/arch/riscv/kernel/Makefile > +++ b/arch/riscv/kernel/Makefile > @@ -107,7 +107,7 @@ obj-$(CONFIG_HOTPLUG_CPU) += cpu-hotplug.o > obj-$(CONFIG_PARAVIRT) += paravirt.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_VMCORE_INFO) += vmcore_info.o > > diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c > new file mode 100644 > index 000000000000..26a81774a78a > --- /dev/null > +++ b/arch/riscv/kernel/kexec_image.c > @@ -0,0 +1,96 @@ > +// 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); It is necessary to ensure that the kernel entry is aligned to PMD_SIZE; otherwise, BUG_ON() in setup_vm() will be triggered. > + > + 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 99bd5a5f4234..e36104af2e24 100644 > --- a/arch/riscv/kernel/machine_kexec_file.c > +++ b/arch/riscv/kernel/machine_kexec_file.c > @@ -18,6 +18,7 @@ > > const struct kexec_file_ops * const kexec_file_loaders[] = { > &elf_kexec_ops, > + &image_kexec_ops, > NULL > }; > > -- > 2.45.2 > > Thanks, Yunhui
Hey Yunhui! yunhui cui <cuiyunhui@bytedance.com> writes: > Hi Björn, > > On Thu, Apr 10, 2025 at 3:31 AM Björn Töpel <bjorn@kernel.org> wrote: ... >> + 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); > > It is necessary to ensure that the kernel entry is aligned to > PMD_SIZE; otherwise, BUG_ON() in setup_vm() will be triggered. Indeed, and text_offset is that [1]. FWIW, the text_offset name in the Image has always weird/confusing to me. Björn [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/riscv/kernel/head.S#n47
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 d56305c8e631..0ead29826419 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -107,7 +107,7 @@ obj-$(CONFIG_HOTPLUG_CPU) += cpu-hotplug.o obj-$(CONFIG_PARAVIRT) += paravirt.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_VMCORE_INFO) += vmcore_info.o diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c new file mode 100644 index 000000000000..26a81774a78a --- /dev/null +++ b/arch/riscv/kernel/kexec_image.c @@ -0,0 +1,96 @@ +// 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 99bd5a5f4234..e36104af2e24 100644 --- a/arch/riscv/kernel/machine_kexec_file.c +++ b/arch/riscv/kernel/machine_kexec_file.c @@ -18,6 +18,7 @@ const struct kexec_file_ops * const kexec_file_loaders[] = { &elf_kexec_ops, + &image_kexec_ops, NULL };