linux-stable/arch/arm64/kernel/kexec_image.c
Will Deacon 85f0b2fc91 arm64: kexec_file: Fix sparse warning
Sparse gets cross about us returning 0 from image_load(), which has a
return type of 'void *':

>> arch/arm64/kernel/kexec_image.c:130:16: sparse: sparse: Using plain integer as NULL pointer

Return NULL instead, as we don't use the return value for anything if it
does not indicate an error.

Cc: Benjamin Gwin <bgwin@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 108aa50365 ("arm64: kexec_file: try more regions if loading segments fails")
Link: https://lore.kernel.org/r/202011091736.T0zH8kaC-lkp@intel.com
Signed-off-by: Will Deacon <will@kernel.org>
2020-11-10 13:11:44 +00:00

147 lines
4 KiB
C

// 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 <linux/verification.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;
}
#ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG
static int image_verify_sig(const char *kernel, unsigned long kernel_len)
{
return verify_pefile_signature(kernel, kernel_len, NULL,
VERIFYING_KEXEC_PE_SIGNATURE);
}
#endif
const struct kexec_file_ops kexec_image_ops = {
.probe = image_probe,
.load = image_load,
#ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG
.verify_sig = image_verify_sig,
#endif
};