Message-Id: <20170824081811.19299-11-takahiro.akashi@linaro.org>
Date:   Thu, 24 Aug 2017 17:18:07 +0900
From:   AKASHI Takahiro <takahiro.akashi@...aro.org>
To:     catalin.marinas@....com, will.deacon@....com,
        bauerman@...ux.vnet.ibm.com, dhowells@...hat.com,
        vgoyal@...hat.com, herbert@...dor.apana.org.au,
        davem@...emloft.net, akpm@...ux-foundation.org, mpe@...erman.id.au,
        dyoung@...hat.com, bhe@...hat.com, arnd@...db.de,
        ard.biesheuvel@...aro.org
Cc:     kexec@...ts.infradead.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org,
        AKASHI Takahiro <takahiro.akashi@...aro.org>
Subject: [PATCH 10/14] arm64: kexec_file: load initrd, device-tree and purgatory segments

load_other_segments() sets up and adds all the memory segments necessary
other than kernel, including initrd, device-tree blob and purgatory.
Most of the code was borrowed from kexec-tools' counterpart.

In addition, arch_kexec_image_probe(), arch_kexec_image_load() and
arch_kexec_kernel_verify_sig() are stubs for supporting multiple types
of kernel image formats.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@...aro.org>
Cc: Catalin Marinas <catalin.marinas@....com>
Cc: Will Deacon <will.deacon@....com>
---
 arch/arm64/include/asm/kexec.h         |  18 +++
 arch/arm64/kernel/machine_kexec_file.c | 255 +++++++++++++++++++++++++++++++++
 2 files changed, 273 insertions(+)

diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
index e17f0529a882..ebc4aaa707ae 100644
--- a/arch/arm64/include/asm/kexec.h
+++ b/arch/arm64/include/asm/kexec.h
@@ -93,6 +93,24 @@ static inline void crash_prepare_suspend(void) {}
 static inline void crash_post_resume(void) {}
 #endif
 
+#ifdef CONFIG_KEXEC_FILE
+#define ARCH_HAS_KIMAGE_ARCH
+
+struct kimage_arch {
+	void *dtb_buf;
+};
+
+struct kimage;
+extern int setup_dtb(struct kimage *image,
+		unsigned long initrd_load_addr, unsigned long initrd_len,
+		char *cmdline, unsigned long cmdline_len,
+		char **dtb_buf, size_t *dtb_buf_len);
+extern int load_other_segments(struct kimage *image,
+		unsigned long kernel_load_addr,
+		char *initrd, unsigned long initrd_len,
+		char *cmdline, unsigned long cmdline_len);
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 #endif
diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index 183f7776d6dd..cd12e451e474 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -16,8 +16,78 @@
 #include <linux/elf.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/libfdt.h>
+#include <linux/memblock.h>
+#include <linux/of_fdt.h>
 #include <linux/types.h>
 #include <asm/byteorder.h>
+#include <asm/kexec_file.h>
+
+static int __dt_root_addr_cells;
+static int __dt_root_size_cells;
+
+static struct kexec_file_ops *kexec_file_loaders[0];
+
+int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
+				  unsigned long buf_len)
+{
+	struct kexec_file_ops *fops;
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) {
+		fops = kexec_file_loaders[i];
+		if (!fops || !fops->probe)
+			continue;
+
+		ret = fops->probe(buf, buf_len);
+		if (!ret) {
+			image->fops = fops;
+			return 0;
+		}
+	}
+
+	return -ENOEXEC;
+}
+
+void *arch_kexec_kernel_image_load(struct kimage *image)
+{
+	if (!image->fops || !image->fops->load)
+		return ERR_PTR(-ENOEXEC);
+
+	return image->fops->load(image, image->kernel_buf,
+				 image->kernel_buf_len, image->initrd_buf,
+				 image->initrd_buf_len, image->cmdline_buf,
+				 image->cmdline_buf_len);
+}
+
+int arch_kimage_file_post_load_cleanup(struct kimage *image)
+{
+	vfree(image->arch.dtb_buf);
+	image->arch.dtb_buf = NULL;
+
+	vfree(image->arch.elf_headers);
+	image->arch.elf_headers = NULL;
+	image->arch.elf_headers_sz = 0;
+
+	if (!image->fops || !image->fops->cleanup)
+		return 0;
+
+	return image->fops->cleanup(image->image_loader_data);
+}
+
+#ifdef CONFIG_KEXEC_VERIFY_SIG
+int arch_kexec_kernel_verify_sig(struct kimage *image, void *kernel,
+				 unsigned long kernel_len)
+{
+	if (!image->fops || !image->fops->verify_sig) {
+		pr_debug("kernel loader does not support signature verification.\n");
+		return -EKEYREJECTED;
+	}
+
+	return image->fops->verify_sig(kernel, kernel_len);
+}
+#endif
 
 /*
  * Apply purgatory relocations.
@@ -197,3 +267,188 @@ int arch_kexec_apply_relocations_add(const Elf64_Ehdr *ehdr,
 
 	return 0;
 }
+
+int arch_kexec_walk_mem(struct kexec_buf *kbuf, int (*func)(u64, u64, void *))
+{
+	if (kbuf->image->type == KEXEC_TYPE_CRASH)
+		return walk_iomem_res_desc(crashk_res.desc,
+					IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
+					crashk_res.start, crashk_res.end,
+					kbuf, func);
+	else if (kbuf->top_down)
+		return walk_system_ram_res_rev(0, ULONG_MAX, kbuf, func);
+	else
+		return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
+}
+
+int setup_dtb(struct kimage *image,
+		unsigned long initrd_load_addr, unsigned long initrd_len,
+		char *cmdline, unsigned long cmdline_len,
+		char **dtb_buf, size_t *dtb_buf_len)
+{
+	char *buf = NULL;
+	size_t buf_size;
+	int nodeoffset;
+	u64 value;
+	int range_len;
+	int ret;
+
+	/* duplicate dt blob */
+	buf_size = fdt_totalsize(initial_boot_params);
+	range_len = (__dt_root_addr_cells + __dt_root_size_cells) * sizeof(u32);
+
+	if (initrd_load_addr)
+		buf_size += fdt_prop_len("initrd-start", sizeof(u64))
+				+ fdt_prop_len("initrd-end", sizeof(u64));
+
+	if (cmdline)
+		buf_size += fdt_prop_len("bootargs", cmdline_len + 1);
+
+	buf = vmalloc(buf_size);
+	if (!buf) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	ret = fdt_open_into(initial_boot_params, buf, buf_size);
+	if (ret)
+		goto out_err;
+
+	nodeoffset = fdt_path_offset(buf, "/chosen");
+	if (nodeoffset < 0)
+		goto out_err;
+
+	/* add bootargs */
+	if (cmdline) {
+		ret = fdt_setprop(buf, nodeoffset, "bootargs",
+						cmdline, cmdline_len + 1);
+		if (ret)
+			goto out_err;
+	}
+
+	/* add initrd-* */
+	if (initrd_load_addr) {
+		value = cpu_to_fdt64(initrd_load_addr);
+		ret = fdt_setprop(buf, nodeoffset, "initrd-start",
+				&value, sizeof(value));
+		if (ret)
+			goto out_err;
+
+		value = cpu_to_fdt64(initrd_load_addr + initrd_len);
+		ret = fdt_setprop(buf, nodeoffset, "initrd-end",
+				&value, sizeof(value));
+		if (ret)
+			goto out_err;
+	}
+
+	/* trim a buffer */
+	fdt_pack(buf);
+	*dtb_buf = buf;
+	*dtb_buf_len = fdt_totalsize(buf);
+
+	return 0;
+
+out_err:
+	vfree(buf);
+	return ret;
+}
+
+int load_other_segments(struct kimage *image, unsigned long kernel_load_addr,
+			char *initrd, unsigned long initrd_len,
+			char *cmdline, unsigned long cmdline_len)
+{
+	struct kexec_buf kbuf;
+	unsigned long initrd_load_addr = 0;
+	unsigned long purgatory_load_addr, dtb_load_addr;
+	char *dtb = NULL;
+	unsigned long dtb_len;
+	int ret = 0;
+
+	kbuf.image = image;
+
+	/* Load initrd */
+	if (initrd) {
+		kbuf.buffer = initrd;
+		kbuf.bufsz = initrd_len;
+		kbuf.memsz = initrd_len;
+		kbuf.buf_align = PAGE_SIZE;
+		/* within 1GB-aligned window of up to 32GB in size */
+		kbuf.buf_min = kernel_load_addr;
+		kbuf.buf_max = round_down(kernel_load_addr, SZ_1G)
+						+ (unsigned long)SZ_1G * 31;
+		kbuf.top_down = 0;
+
+		ret = kexec_add_buffer(&kbuf);
+		if (ret)
+			goto out_err;
+		initrd_load_addr = kbuf.mem;
+
+		pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
+				initrd_load_addr, initrd_len, initrd_len);
+	}
+
+	/* Load dtb blob */
+	ret = setup_dtb(image, initrd_load_addr, initrd_len,
+				cmdline, cmdline_len, &dtb, &dtb_len);
+	if (ret) {
+		pr_err("Preparing for new dtb failed\n");
+		goto out_err;
+	}
+
+	kbuf.buffer = dtb;
+	kbuf.bufsz = dtb_len;
+	kbuf.memsz = dtb_len;
+	/* not across 2MB boundary */
+	kbuf.buf_align = SZ_2M;
+	/*
+	 * Note for backporting:
+	 * On kernel prior to v4.2, fdt must reside within 512MB block
+	 * where the kernel also resides. So
+	 *   kbuf.buf_min = round_down(kernel_load_addr, SZ_512M);
+	 *   kbuf.buf_max = round_up(kernel_load_addr, SZ_512M);
+	 * would be required.
+	 */
+	kbuf.buf_min = kernel_load_addr;
+	kbuf.buf_max = ULONG_MAX;
+	kbuf.top_down = 1;
+
+	ret = kexec_add_buffer(&kbuf);
+	if (ret)
+		goto out_err;
+	dtb_load_addr = kbuf.mem;
+	image->arch.dtb_buf = dtb;
+
+	pr_debug("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
+			dtb_load_addr, dtb_len, dtb_len);
+
+	/* Load purgatory  */
+	ret = kexec_load_purgatory(image, kernel_load_addr, ULONG_MAX, 1,
+				   &purgatory_load_addr);
+	if (ret) {
+		pr_err("Loading purgatory failed\n");
+		goto out_err;
+	}
+
+	ret = kexec_purgatory_get_set_symbol(image, "arm64_kernel_entry",
+				&kernel_load_addr, sizeof(kernel_load_addr), 0);
+	if (ret) {
+		pr_err("Relocating symbol (arm64_kernel_entry) failed.\n");
+		goto out_err;
+	}
+
+	ret = kexec_purgatory_get_set_symbol(image, "arm64_dtb_addr",
+				&dtb_load_addr, sizeof(dtb_load_addr), 0);
+	if (ret) {
+		pr_err("Relocating symbol (arm64_dtb_addr) failed.\n");
+		goto out_err;
+	}
+
+	pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr);
+
+	return 0;
+
+out_err:
+	vfree(dtb);
+	image->arch.dtb_buf = NULL;
+	return ret;
+}
-- 
2.14.1

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