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authorMagnus Damm <magnus@valinux.co.jp>2006-12-06 20:40:41 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-07 08:39:46 -0800
commit85916f8166b59eeac63d2b4f7f1df8de849334b4 (patch)
tree176176a0a75cfe42043c463a4391dd9f7975a69c /kernel/kexec.c
parent6d4df677f8a60ea6bc0ef1a596c1a3a79b1d4882 (diff)
downloadlwn-85916f8166b59eeac63d2b4f7f1df8de849334b4.tar.gz
lwn-85916f8166b59eeac63d2b4f7f1df8de849334b4.zip
[PATCH] Kexec / Kdump: Unify elf note code
The elf note saving code is currently duplicated over several architectures. This cleanup patch simply adds code to a common file and then replaces the arch-specific code with calls to the newly added code. The only drawback with this approach is that s390 doesn't fully support kexec-on-panic which for that arch leads to introduction of unused code. Signed-off-by: Magnus Damm <magnus@valinux.co.jp> Cc: Vivek Goyal <vgoyal@in.ibm.com> Cc: Andi Kleen <ak@suse.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/kexec.c')
-rw-r--r--kernel/kexec.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/kernel/kexec.c b/kernel/kexec.c
index d43692cf2321..afbbbe981be2 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -20,6 +20,8 @@
#include <linux/syscalls.h>
#include <linux/ioport.h>
#include <linux/hardirq.h>
+#include <linux/elf.h>
+#include <linux/elfcore.h>
#include <asm/page.h>
#include <asm/uaccess.h>
@@ -1066,6 +1068,60 @@ void crash_kexec(struct pt_regs *regs)
}
}
+static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
+ size_t data_len)
+{
+ struct elf_note note;
+
+ note.n_namesz = strlen(name) + 1;
+ note.n_descsz = data_len;
+ note.n_type = type;
+ memcpy(buf, &note, sizeof(note));
+ buf += (sizeof(note) + 3)/4;
+ memcpy(buf, name, note.n_namesz);
+ buf += (note.n_namesz + 3)/4;
+ memcpy(buf, data, note.n_descsz);
+ buf += (note.n_descsz + 3)/4;
+
+ return buf;
+}
+
+static void final_note(u32 *buf)
+{
+ struct elf_note note;
+
+ note.n_namesz = 0;
+ note.n_descsz = 0;
+ note.n_type = 0;
+ memcpy(buf, &note, sizeof(note));
+}
+
+void crash_save_cpu(struct pt_regs *regs, int cpu)
+{
+ struct elf_prstatus prstatus;
+ u32 *buf;
+
+ if ((cpu < 0) || (cpu >= NR_CPUS))
+ return;
+
+ /* Using ELF notes here is opportunistic.
+ * I need a well defined structure format
+ * for the data I pass, and I need tags
+ * on the data to indicate what information I have
+ * squirrelled away. ELF notes happen to provide
+ * all of that, so there is no need to invent something new.
+ */
+ buf = (u32*)per_cpu_ptr(crash_notes, cpu);
+ if (!buf)
+ return;
+ memset(&prstatus, 0, sizeof(prstatus));
+ prstatus.pr_pid = current->pid;
+ elf_core_copy_regs(&prstatus.pr_reg, regs);
+ buf = append_elf_note(buf, "CORE", NT_PRSTATUS, &prstatus,
+ sizeof(prstatus));
+ final_note(buf);
+}
+
static int __init crash_notes_memory_init(void)
{
/* Allocate memory for saving cpu registers. */