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Diffstat (limited to 'arch/arm64/kernel/kexec_image.c')
-rw-r--r--arch/arm64/kernel/kexec_image.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c
new file mode 100644
index 000000000..5ed6a585f
--- /dev/null
+++ b/arch/arm64/kernel/kexec_image.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Kexec image loader
+
+ * Copyright (C) 2018 Linaro Limited
+ * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
+ */
+
+#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/cpufeature.h>
+#include <asm/image.h>
+#include <asm/memory.h>
+
+static int image_probe(const char *kernel_buf, unsigned long kernel_len)
+{
+ const struct arm64_image_header *h =
+ (const struct arm64_image_header *)(kernel_buf);
+
+ if (!h || (kernel_len < sizeof(*h)))
+ return -EINVAL;
+
+ if (memcmp(&h->magic, ARM64_IMAGE_MAGIC, sizeof(h->magic)))
+ 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 arm64_image_header *h;
+ u64 flags, value;
+ bool be_image, be_kernel;
+ struct kexec_buf kbuf;
+ unsigned long text_offset, kernel_segment_number;
+ struct kexec_segment *kernel_segment;
+ int ret;
+
+ /*
+ * We require a kernel with an unambiguous Image header. Per
+ * Documentation/arm64/booting.rst, this is the case when image_size
+ * is non-zero (practically speaking, since v3.17).
+ */
+ h = (struct arm64_image_header *)kernel;
+ if (!h->image_size)
+ return ERR_PTR(-EINVAL);
+
+ /* Check cpu features */
+ flags = le64_to_cpu(h->flags);
+ be_image = arm64_image_flag_field(flags, ARM64_IMAGE_FLAG_BE);
+ be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
+ if ((be_image != be_kernel) && !system_supports_mixed_endian())
+ return ERR_PTR(-EINVAL);
+
+ value = arm64_image_flag_field(flags, ARM64_IMAGE_FLAG_PAGE_SIZE);
+ if (((value == ARM64_IMAGE_FLAG_PAGE_SIZE_4K) &&
+ !system_supports_4kb_granule()) ||
+ ((value == ARM64_IMAGE_FLAG_PAGE_SIZE_64K) &&
+ !system_supports_64kb_granule()) ||
+ ((value == ARM64_IMAGE_FLAG_PAGE_SIZE_16K) &&
+ !system_supports_16kb_granule()))
+ return ERR_PTR(-EINVAL);
+
+ /* Load the kernel */
+ 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);
+ text_offset = le64_to_cpu(h->text_offset);
+ kbuf.buf_align = MIN_KIMG_ALIGN;
+
+ /* Adjust kernel segment with TEXT_OFFSET */
+ kbuf.memsz += text_offset;
+
+ kernel_segment_number = image->nr_segments;
+
+ /*
+ * The location of the kernel segment may make it impossible to satisfy
+ * the other segment requirements, so we try repeatedly to find a
+ * location that will work.
+ */
+ while ((ret = kexec_add_buffer(&kbuf)) == 0) {
+ /* Try to load additional data */
+ kernel_segment = &image->segment[kernel_segment_number];
+ ret = load_other_segments(image, kernel_segment->mem,
+ kernel_segment->memsz, initrd,
+ initrd_len, cmdline);
+ if (!ret)
+ break;
+
+ /*
+ * We couldn't find space for the other segments; erase the
+ * kernel segment and try the next available hole.
+ */
+ image->nr_segments -= 1;
+ kbuf.buf_min = kernel_segment->mem + kernel_segment->memsz;
+ kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
+ }
+
+ if (ret) {
+ pr_err("Could not find any suitable kernel location!");
+ return ERR_PTR(ret);
+ }
+
+ kernel_segment = &image->segment[kernel_segment_number];
+ kernel_segment->mem += text_offset;
+ kernel_segment->memsz -= text_offset;
+ image->start = kernel_segment->mem;
+
+ pr_debug("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
+ kernel_segment->mem, kbuf.bufsz,
+ kernel_segment->memsz);
+
+ return NULL;
+}
+
+const struct kexec_file_ops kexec_image_ops = {
+ .probe = image_probe,
+ .load = image_load,
+#ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG
+ .verify_sig = kexec_kernel_verify_pe_sig,
+#endif
+};