On 1/9/23 01:36, Baoquan He wrote:
On 01/05/23 at 10:17am, Eric DeVolder wrote: ......@@ -394,10 +409,37 @@ int crash_load_segments(struct kimage *image) if (ret) return ret;- image->elf_headers = kbuf.buffer;- image->elf_headers_sz = kbuf.bufsz; + image->elf_headers = kbuf.buffer; + image->elf_headers_sz = kbuf.bufsz; + kbuf.memsz = kbuf.bufsz; + + if (IS_ENABLED(CONFIG_CRASH_HOTPLUG)) { + /* + * Ensure the elfcorehdr segment large enough for hotplug changes. + * Start with VMCOREINFO and kernel_map. + */ + unsigned long pnum = 2; + + if (IS_ENABLED(CONFIG_HOTPLUG_CPU)) + pnum += CONFIG_NR_CPUS_DEFAULT; + + if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG)) + pnum += CRASH_MAX_MEMORY_RANGES;Logic of pnum calculating is a little confusing to me. If I only enable one of CONFIG_HOTPLUG_CPU and CONFIG_MEMORY_HOTPLUG, is it OK? Say I only enable CONFIG_HOTPLUG_CPU and CONFIG_SMP, on x86_64, CONFIG_NR_CPUS_DEFAULT will be 64. pnum will be 64, is it OK. Am I miss anything?
Ah, your understanding is correct, and the issue you point out I need to fix. Specifically is only one of HOTPLUG_CPU or MEMORY_HOTPLUG is set, then I need to allow a default for the other. Using the example you have above, there would not be room for a single memory region, so I need to allow for a default number of memory regions. Good find! eric
+ + if (pnum < (unsigned long)PN_XNUM) { + kbuf.memsz = pnum * sizeof(Elf64_Phdr); + kbuf.memsz += sizeof(Elf64_Ehdr); + + image->elfcorehdr_index = image->nr_segments; + image->elfcorehdr_index_valid = true; + + /* Mark as usable to crash kernel, else crash kernel fails on boot */ + image->elf_headers_sz = kbuf.memsz; + } else { + pr_err("number of Phdrs %lu exceeds max\n", pnum); + } + }- kbuf.memsz = kbuf.bufsz;kbuf.buf_align = ELF_CORE_HEADER_ALIGN; kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; ret = kexec_add_buffer(&kbuf); @@ -412,3 +454,67 @@ int crash_load_segments(struct kimage *image) return ret; } #endif /* CONFIG_KEXEC_FILE */
_______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
