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 <da-x@monatomic.org>
Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/kexec.c b/kernel/kexec.c
index d8de12e..67828be 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -21,16 +21,26 @@
#include <linux/hardirq.h>
#include <linux/elf.h>
#include <linux/elfcore.h>
+#include <linux/utsrelease.h>
+#include <linux/utsname.h>
+#include <linux/numa.h>
#include <asm/page.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/semaphore.h>
+#include <asm/sections.h>
/* 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 @@
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 @@
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 6046939..38b38f9 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -61,6 +61,15 @@
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 @@
#ifdef CONFIG_KEXEC
&kexec_loaded_attr.attr,
&kexec_crash_loaded_attr.attr,
+ &vmcoreinfo_attr.attr,
#endif
NULL
};