Hari Bathini <hbath...@linux.ibm.com> writes:
> /**
> + * get_crash_memory_ranges - Get crash memory ranges. This list includes
> + * first/crashing kernel's memory regions that
> + * would be exported via an elfcore.
> + * @mem_ranges: Range list to add the memory ranges to.
> + *
> + * Returns 0 on success, negative errno on error.
> + */
> +static int get_crash_memory_ranges(struct crash_mem **mem_ranges)
> +{
> + struct memblock_region *reg;
> + struct crash_mem *tmem;
> + int ret;
> +
> + for_each_memblock(memory, reg) {
> + u64 base, size;
> +
> + base = (u64)reg->base;
> + size = (u64)reg->size;
> +
> + /* Skip backup memory region, which needs a separate entry */
> + if (base == BACKUP_SRC_START) {
> + if (size > BACKUP_SRC_SIZE) {
> + base = BACKUP_SRC_END + 1;
> + size -= BACKUP_SRC_SIZE;
> + } else
> + continue;
> + }
> +
> + ret = add_mem_range(mem_ranges, base, size);
> + if (ret)
> + goto out;
> +
> + /* Try merging adjacent ranges before reallocation attempt */
> + if ((*mem_ranges)->nr_ranges == (*mem_ranges)->max_nr_ranges)
> + sort_memory_ranges(*mem_ranges, true);
> + }
> +
> + /* Reallocate memory ranges if there is no space to split ranges */
> + tmem = *mem_ranges;
> + if (tmem && (tmem->nr_ranges == tmem->max_nr_ranges)) {
> + tmem = realloc_mem_ranges(mem_ranges);
> + if (!tmem)
> + goto out;
> + }
> +
> + /* Exclude crashkernel region */
> + ret = crash_exclude_mem_range(tmem, crashk_res.start, crashk_res.end);
> + if (ret)
> + goto out;
> +
> + ret = add_rtas_mem_range(mem_ranges);
> + if (ret)
> + goto out;
> +
> + ret = add_opal_mem_range(mem_ranges);
> + if (ret)
> + goto out;
Maybe I'm confused, but don't you add the RTAS and OPAL regions as
usable memory for the crashkernel? In that case they shouldn't show up
in the core file.
> +
> + /* create a separate program header for the backup region */
> + ret = add_mem_range(mem_ranges, BACKUP_SRC_START, BACKUP_SRC_SIZE);
> + if (ret)
> + goto out;
> +
> + sort_memory_ranges(*mem_ranges, false);
> +out:
> + if (ret)
> + pr_err("Failed to setup crash memory ranges\n");
> + return ret;
> +}
<snip>
> +/**
> + * prepare_elf_headers - Prepare headers for the elfcore to be exported as
> + * /proc/vmcore by the kdump kernel.
> + * @image: Kexec image.
> + * @cmem: Crash memory ranges to be exported via elfcore.
> + * @addr: Vmalloc'd memory allocated by
> crash_prepare_elf64_headers
> + * to prepare the elf headers.
> + * @sz: Size of the vmalloc'd memory allocated.
> + *
> + * Returns 0 on success, negative errno on error.
> + */
> +static int prepare_elf_headers(struct kimage *image, struct crash_mem *cmem,
> + void **addr, unsigned long *sz)
> +{
> + int ret;
> +
> + ret = crash_prepare_elf64_headers(cmem, false, addr, sz);
> +
> + /* Fix the offset for backup region in the ELF header */
> + if (!ret)
> + update_backup_region_phdr(image, *addr);
> +
> + return ret;
> +}
The code above can be inlined into its caller, I don't see a need to
have a separate function.
> +
> +/**
> + * load_elfcorehdr_segment - Setup crash memory ranges and initialize
> elfcorehdr
> + * segment needed to load kdump kernel.
> + * @image: Kexec image.
> + * @kbuf: Buffer contents and memory parameters.
> + *
> + * Returns 0 on success, negative errno on error.
> + */
> +static int load_elfcorehdr_segment(struct kimage *image, struct kexec_buf
> *kbuf)
> +{
> + struct crash_mem *cmem = NULL;
> + unsigned long headers_sz;
> + void *headers = NULL;
> + int ret;
> +
> + ret = get_crash_memory_ranges(&cmem);
> + if (ret)
> + goto out;
> +
> + /* Setup elfcorehdr segment */
> + ret = prepare_elf_headers(image, cmem, &headers, &headers_sz);
> + if (ret) {
> + pr_err("Failed to prepare elf headers for the core\n");
> + goto out;
> + }
> +
> + kbuf->buffer = headers;
> + kbuf->mem = KEXEC_BUF_MEM_UNKNOWN;
> + kbuf->bufsz = kbuf->memsz = headers_sz;
> + kbuf->top_down = false;
> +
> + ret = kexec_add_buffer(kbuf);
> + if (ret) {
> + vfree(headers);
> + goto out;
> + }
> +
> + image->arch.elfcorehdr_addr = kbuf->mem;
> + image->arch.elf_headers_sz = headers_sz;
> + image->arch.elf_headers = headers;
> +out:
> + kfree(cmem);
> + return ret;
> +}
--
Thiago Jung Bauermann
IBM Linux Technology Center
