In contrast to kexec_add_buffer(), this function assumes that kbuf->mem is already assigned by caller. This type of allocation is commonly used in kexec-tools. This function will be used on arm64 in loading vmlinux(elf) binary. Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org> Cc: Dave Young <dyoung at redhat.com> Cc: Vivek Goyal <vgoyal at redhat.com> Cc: Baoquan He <bhe at redhat.com> --- include/linux/kexec.h | 1 + kernel/kexec_file.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 48 insertions(+) diff --git a/include/linux/kexec.h b/include/linux/kexec.h index acaecd72b134..be5e99afaf77 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -162,6 +162,7 @@ struct kexec_buf { int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf, int (*func)(u64, u64, void *)); extern int kexec_add_buffer(struct kexec_buf *kbuf); +extern int kexec_add_segment(struct kexec_buf *kbuf); int kexec_locate_mem_hole(struct kexec_buf *kbuf); #ifdef CONFIG_CRASH_CORE extern int prepare_elf_headers(struct kimage *image, void **addr, diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 9f48f4412297..d898dec37816 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -519,6 +519,53 @@ int kexec_add_buffer(struct kexec_buf *kbuf) return 0; } +/** + * kexec_add_segment - place a buffer in a kexec segment + * @kbuf: Buffer contents and memory parameters. + * + * In contrast to kexec_add_buffer(), this function assumes + * that kbuf->mem is already assigned by caller. + * + * Return: 0 on success, negative errno on error. + */ +int kexec_add_segment(struct kexec_buf *kbuf) +{ + + struct kexec_segment *ksegment; + + /* Currently adding segment this way is allowed only in file mode */ + if (!kbuf->image->file_mode) + return -EINVAL; + + if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX) + return -EINVAL; + + /* + * Make sure we are not trying to add buffer after allocating + * control pages. All segments need to be placed first before + * any control pages are allocated. As control page allocation + * logic goes through list of segments to make sure there are + * no destination overlaps. + */ + if (!list_empty(&kbuf->image->control_pages)) { + WARN_ON(1); + return -EINVAL; + } + + /* Ensure minimum alignment needed for segments. */ + kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE); + + /* Found a suitable memory range */ + ksegment = &kbuf->image->segment[kbuf->image->nr_segments]; + ksegment->kbuf = kbuf->buffer; + ksegment->bufsz = kbuf->bufsz; + ksegment->mem = kbuf->mem; + ksegment->memsz = kbuf->memsz; + kbuf->image->nr_segments++; + + return 0; +} + /* Calculate and store the digest of segments */ static int kexec_calculate_store_digests(struct kimage *image) { -- 2.14.1