From fd59d231f81cb02870b9cf15f456a897f3669b4e Mon Sep 17 00:00:00 2001 From: Ken'ichi Ohmichi Date: Tue, 16 Oct 2007 23:27:27 -0700 Subject: Add vmcoreinfo This patch set frees the restriction that makedumpfile users should install a vmlinux file (including the debugging information) into each system. makedumpfile command is the dump filtering feature for kdump. It creates a small dumpfile by filtering unnecessary pages for the analysis. To distinguish unnecessary pages, it needs a vmlinux file including the debugging information. These days, the debugging package becomes a huge file, and it is hard to install it into each system. To solve the problem, kdump developers discussed it at lkml and kexec-ml. As the result, we reached the conclusion that necessary information for dump filtering (called "vmcoreinfo") should be embedded into the first kernel file and it should be accessed through /proc/vmcore during the second kernel. (http://www.uwsg.iu.edu/hypermail/linux/kernel/0707.0/1806.html) Dan Aloni created the patch set for the above implementation. (http://www.uwsg.iu.edu/hypermail/linux/kernel/0707.1/1053.html) And I updated it for multi architectures and memory models. (http://lists.infradead.org/pipermail/kexec/2007-August/000479.html) Signed-off-by: Dan Aloni Signed-off-by: Ken'ichi Ohmichi Signed-off-by: Bernhard Walle Signed-off-by: Daisuke Nishimura Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kexec.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ kernel/ksysfs.c | 10 ++++++ 2 files changed, 120 insertions(+) (limited to 'kernel') diff --git a/kernel/kexec.c b/kernel/kexec.c index d8de12e943cf..67828befbfc3 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -21,16 +21,26 @@ #include #include #include +#include +#include +#include #include #include #include #include #include +#include /* Per cpu memory for storing cpu states in case of system crash. */ note_buf_t* crash_notes; +/* vmcoreinfo stuff */ +unsigned char vmcoreinfo_data[VMCOREINFO_BYTES]; +u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4]; +unsigned int vmcoreinfo_size = 0; +unsigned int vmcoreinfo_max_size = sizeof(vmcoreinfo_data); + /* Location of the reserved area for the crash kernel */ struct resource crashk_res = { .name = "Crash kernel", @@ -1060,6 +1070,7 @@ void crash_kexec(struct pt_regs *regs) if (kexec_crash_image) { struct pt_regs fixed_regs; crash_setup_regs(&fixed_regs, regs); + crash_save_vmcoreinfo(); machine_crash_shutdown(&fixed_regs); machine_kexec(kexec_crash_image); } @@ -1134,3 +1145,102 @@ static int __init crash_notes_memory_init(void) return 0; } module_init(crash_notes_memory_init) + +void crash_save_vmcoreinfo(void) +{ + u32 *buf; + + if (!vmcoreinfo_size) + return; + + vmcoreinfo_append_str("CRASHTIME=%d", xtime.tv_sec); + + buf = (u32 *)vmcoreinfo_note; + + buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data, + vmcoreinfo_size); + + final_note(buf); +} + +void vmcoreinfo_append_str(const char *fmt, ...) +{ + va_list args; + char buf[0x50]; + int r; + + va_start(args, fmt); + r = vsnprintf(buf, sizeof(buf), fmt, args); + va_end(args); + + if (r + vmcoreinfo_size > vmcoreinfo_max_size) + r = vmcoreinfo_max_size - vmcoreinfo_size; + + memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r); + + vmcoreinfo_size += r; +} + +/* + * provide an empty default implementation here -- architecture + * code may override this + */ +void __attribute__ ((weak)) arch_crash_save_vmcoreinfo(void) +{} + +unsigned long __attribute__ ((weak)) paddr_vmcoreinfo_note(void) +{ + return __pa((unsigned long)(char *)&vmcoreinfo_note); +} + +static int __init crash_save_vmcoreinfo_init(void) +{ + vmcoreinfo_append_str("OSRELEASE=%s\n", UTS_RELEASE); + vmcoreinfo_append_str("PAGESIZE=%d\n", PAGE_SIZE); + + SYMBOL(init_uts_ns); + SYMBOL(node_online_map); + SYMBOL(swapper_pg_dir); + SYMBOL(_stext); + +#ifndef CONFIG_NEED_MULTIPLE_NODES + SYMBOL(mem_map); + SYMBOL(contig_page_data); +#endif +#ifdef CONFIG_SPARSEMEM + SYMBOL(mem_section); + LENGTH(mem_section, NR_SECTION_ROOTS); + SIZE(mem_section); + OFFSET(mem_section, section_mem_map); +#endif + SIZE(page); + SIZE(pglist_data); + SIZE(zone); + SIZE(free_area); + SIZE(list_head); + OFFSET(page, flags); + OFFSET(page, _count); + OFFSET(page, mapping); + OFFSET(page, lru); + OFFSET(pglist_data, node_zones); + OFFSET(pglist_data, nr_zones); +#ifdef CONFIG_FLAT_NODE_MEM_MAP + OFFSET(pglist_data, node_mem_map); +#endif + OFFSET(pglist_data, node_start_pfn); + OFFSET(pglist_data, node_spanned_pages); + OFFSET(pglist_data, node_id); + OFFSET(zone, free_area); + OFFSET(zone, vm_stat); + OFFSET(zone, spanned_pages); + OFFSET(free_area, free_list); + OFFSET(list_head, next); + OFFSET(list_head, prev); + LENGTH(zone.free_area, MAX_ORDER); + + arch_crash_save_vmcoreinfo(); + + return 0; +} + +module_init(crash_save_vmcoreinfo_init) diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index 6046939d0804..38b38f957ef0 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -61,6 +61,15 @@ static ssize_t kexec_crash_loaded_show(struct kset *kset, char *page) return sprintf(page, "%d\n", !!kexec_crash_image); } KERNEL_ATTR_RO(kexec_crash_loaded); + +static ssize_t vmcoreinfo_show(struct kset *kset, char *page) +{ + return sprintf(page, "%lx %x\n", + paddr_vmcoreinfo_note(), + vmcoreinfo_max_size); +} +KERNEL_ATTR_RO(vmcoreinfo); + #endif /* CONFIG_KEXEC */ /* @@ -96,6 +105,7 @@ static struct attribute * kernel_attrs[] = { #ifdef CONFIG_KEXEC &kexec_loaded_attr.attr, &kexec_crash_loaded_attr.attr, + &vmcoreinfo_attr.attr, #endif NULL }; -- cgit v1.2.2