![Jean-Philippe Brucker](/assets/img/avatar_default.png)
Calling strlen() on cmdline == NULL produces a kernel oops. Since having
a NULL cmdline is valid, handle this case explicitly.
Fixes: 52b2a8af74
("arm64: kexec_file: load initrd and device-tree")
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
229 lines
4.9 KiB
C
229 lines
4.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* kexec_file for arm64
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*
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* Copyright (C) 2018 Linaro Limited
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* Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
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*
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* Most code is derived from arm64 port of kexec-tools
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*/
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#define pr_fmt(fmt) "kexec_file: " fmt
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#include <linux/ioport.h>
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#include <linux/kernel.h>
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#include <linux/kexec.h>
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#include <linux/libfdt.h>
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#include <linux/memblock.h>
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#include <linux/of_fdt.h>
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#include <linux/random.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/vmalloc.h>
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#include <asm/byteorder.h>
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/* relevant device tree properties */
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#define FDT_PROP_INITRD_START "linux,initrd-start"
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#define FDT_PROP_INITRD_END "linux,initrd-end"
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#define FDT_PROP_BOOTARGS "bootargs"
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#define FDT_PROP_KASLR_SEED "kaslr-seed"
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const struct kexec_file_ops * const kexec_file_loaders[] = {
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&kexec_image_ops,
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NULL
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};
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int arch_kimage_file_post_load_cleanup(struct kimage *image)
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{
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vfree(image->arch.dtb);
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image->arch.dtb = NULL;
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return kexec_image_post_load_cleanup_default(image);
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}
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static int setup_dtb(struct kimage *image,
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unsigned long initrd_load_addr, unsigned long initrd_len,
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char *cmdline, void *dtb)
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{
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int off, ret;
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ret = fdt_path_offset(dtb, "/chosen");
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if (ret < 0)
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goto out;
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off = ret;
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/* add bootargs */
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if (cmdline) {
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ret = fdt_setprop_string(dtb, off, FDT_PROP_BOOTARGS, cmdline);
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if (ret)
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goto out;
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} else {
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ret = fdt_delprop(dtb, off, FDT_PROP_BOOTARGS);
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if (ret && (ret != -FDT_ERR_NOTFOUND))
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goto out;
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}
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/* add initrd-* */
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if (initrd_load_addr) {
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ret = fdt_setprop_u64(dtb, off, FDT_PROP_INITRD_START,
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initrd_load_addr);
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if (ret)
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goto out;
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ret = fdt_setprop_u64(dtb, off, FDT_PROP_INITRD_END,
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initrd_load_addr + initrd_len);
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if (ret)
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goto out;
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} else {
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ret = fdt_delprop(dtb, off, FDT_PROP_INITRD_START);
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if (ret && (ret != -FDT_ERR_NOTFOUND))
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goto out;
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ret = fdt_delprop(dtb, off, FDT_PROP_INITRD_END);
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if (ret && (ret != -FDT_ERR_NOTFOUND))
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goto out;
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}
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/* add kaslr-seed */
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ret = fdt_delprop(dtb, off, FDT_PROP_KASLR_SEED);
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if (ret == -FDT_ERR_NOTFOUND)
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ret = 0;
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else if (ret)
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goto out;
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if (rng_is_initialized()) {
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u64 seed = get_random_u64();
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ret = fdt_setprop_u64(dtb, off, FDT_PROP_KASLR_SEED, seed);
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if (ret)
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goto out;
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} else {
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pr_notice("RNG is not initialised: omitting \"%s\" property\n",
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FDT_PROP_KASLR_SEED);
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}
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out:
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if (ret)
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return (ret == -FDT_ERR_NOSPACE) ? -ENOMEM : -EINVAL;
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return 0;
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}
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/*
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* More space needed so that we can add initrd, bootargs and kaslr-seed.
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*/
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#define DTB_EXTRA_SPACE 0x1000
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static int create_dtb(struct kimage *image,
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unsigned long initrd_load_addr, unsigned long initrd_len,
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char *cmdline, void **dtb)
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{
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void *buf;
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size_t buf_size;
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size_t cmdline_len;
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int ret;
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cmdline_len = cmdline ? strlen(cmdline) : 0;
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buf_size = fdt_totalsize(initial_boot_params)
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+ cmdline_len + DTB_EXTRA_SPACE;
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for (;;) {
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buf = vmalloc(buf_size);
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if (!buf)
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return -ENOMEM;
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/* duplicate a device tree blob */
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ret = fdt_open_into(initial_boot_params, buf, buf_size);
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if (ret)
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return -EINVAL;
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ret = setup_dtb(image, initrd_load_addr, initrd_len,
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cmdline, buf);
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if (ret) {
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vfree(buf);
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if (ret == -ENOMEM) {
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/* unlikely, but just in case */
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buf_size += DTB_EXTRA_SPACE;
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continue;
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} else {
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return ret;
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}
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}
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/* trim it */
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fdt_pack(buf);
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*dtb = buf;
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return 0;
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}
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}
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int load_other_segments(struct kimage *image,
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unsigned long kernel_load_addr,
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unsigned long kernel_size,
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char *initrd, unsigned long initrd_len,
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char *cmdline)
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{
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struct kexec_buf kbuf;
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void *dtb = NULL;
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unsigned long initrd_load_addr = 0, dtb_len;
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int ret = 0;
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kbuf.image = image;
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/* not allocate anything below the kernel */
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kbuf.buf_min = kernel_load_addr + kernel_size;
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/* load initrd */
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if (initrd) {
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kbuf.buffer = initrd;
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kbuf.bufsz = initrd_len;
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kbuf.mem = 0;
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kbuf.memsz = initrd_len;
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kbuf.buf_align = 0;
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/* within 1GB-aligned window of up to 32GB in size */
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kbuf.buf_max = round_down(kernel_load_addr, SZ_1G)
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+ (unsigned long)SZ_1G * 32;
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kbuf.top_down = false;
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ret = kexec_add_buffer(&kbuf);
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if (ret)
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goto out_err;
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initrd_load_addr = kbuf.mem;
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pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
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initrd_load_addr, initrd_len, initrd_len);
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}
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/* load dtb */
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ret = create_dtb(image, initrd_load_addr, initrd_len, cmdline, &dtb);
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if (ret) {
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pr_err("Preparing for new dtb failed\n");
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goto out_err;
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}
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dtb_len = fdt_totalsize(dtb);
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kbuf.buffer = dtb;
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kbuf.bufsz = dtb_len;
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kbuf.mem = 0;
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kbuf.memsz = dtb_len;
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/* not across 2MB boundary */
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kbuf.buf_align = SZ_2M;
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kbuf.buf_max = ULONG_MAX;
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kbuf.top_down = true;
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ret = kexec_add_buffer(&kbuf);
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if (ret)
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goto out_err;
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image->arch.dtb = dtb;
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image->arch.dtb_mem = kbuf.mem;
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pr_debug("Loaded dtb at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
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kbuf.mem, dtb_len, dtb_len);
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return 0;
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out_err:
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vfree(dtb);
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return ret;
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}
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