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);
+
+ 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
Hi Björn, kernel test robot noticed the following build warnings: [auto build test WARNING on a24588245776dafc227243a01bfbeb8a59bafba9] url: https://github.com/intel-lab-lkp/linux/commits/Bj-rn-T-pel/riscv-kexec_file-Split-the-loading-of-kernel-and-others/20250410-033243 base: a24588245776dafc227243a01bfbeb8a59bafba9 patch link: https://lore.kernel.org/r/20250409193004.643839-3-bjorn%40kernel.org patch subject: [PATCH v3 2/2] riscv: kexec_file: Support loading Image binary file reproduce: (https://download.01.org/0day-ci/archive/20250416/202504162100.DHKsuYS1-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202504162100.DHKsuYS1-lkp@intel.com/ All warnings (new ones prefixed by >>): Warning: Documentation/translations/zh_CN/admin-guide/README.rst references a file that doesn't exist: Documentation/dev-tools/kgdb.rst Warning: Documentation/translations/zh_CN/dev-tools/gdb-kernel-debugging.rst references a file that doesn't exist: Documentation/dev-tools/gdb-kernel-debugging.rst Warning: Documentation/translations/zh_TW/admin-guide/README.rst references a file that doesn't exist: Documentation/dev-tools/kgdb.rst Warning: Documentation/translations/zh_TW/dev-tools/gdb-kernel-debugging.rst references a file that doesn't exist: Documentation/dev-tools/gdb-kernel-debugging.rst Warning: MAINTAINERS references a file that doesn't exist: Documentation/devicetree/bindings/leds/backlight/ti,lp8864.yaml >> Warning: arch/riscv/kernel/kexec_image.c references a file that doesn't exist: Documentation/riscv/boot-image-header.rst Can't build as 1 mandatory dependency is missing at ./scripts/sphinx-pre-install line 984. make[2]: *** [Documentation/Makefile:121: htmldocs] Error 255 make[1]: *** [Makefile:1804: htmldocs] Error 2 make: *** [Makefile:248: __sub-make] Error 2 make: Target 'htmldocs' not remade because of errors. -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
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
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