[PATCH 3/5] xen: Use per_cpu__crash_notes or crash_notes array

[Daniel Kiper]

Newer Xen versions (at least 4.2) use crash_notes array
instead of per_cpu__crash_notes. Take into account that.

Signed-off-by: Daniel Kiper <daniel.kiper at oracle.com>

diff -Npru crash-6.1.0.orig/xen_hyper.c crash-6.1.0/xen_hyper.c
--- crash-6.1.0.orig/xen_hyper.c	2012-09-27 21:19:15.000000000 +0200
+++ crash-6.1.0/xen_hyper.c	2012-11-12 15:56:17.000000000 +0100
@@ -645,15 +645,22 @@ xen_hyper_dumpinfo_init(void)
 		error(FATAL, "cannot malloc dumpinfo table context_xen_core_array space.\n");
 	}
 	BZERO(xhdit->context_xen_core_array, size);
-	addr = symbol_value("per_cpu__crash_notes");
+	if (symbol_exists("per_cpu__crash_notes"))
+		addr = symbol_value("per_cpu__crash_notes");
+	else
+		get_symbol_data("crash_notes", sizeof(ulong), &addr);
 	for (i = 0; i < machdep->get_smp_cpus(); i++) {
 		ulong addr_notes;
 
-		addr_notes = xen_hyper_per_cpu(addr, i);
+		if (symbol_exists("per_cpu__crash_notes"))
+			addr_notes = xen_hyper_per_cpu(addr, i);
+		else
+			addr_notes = addr + i * STRUCT_SIZE("crash_note_range_t") +
+					MEMBER_OFFSET("crash_note_range_t", "start");
 		if (xhdit->note_ver == XEN_HYPER_ELF_NOTE_V4) {
 			if (!readmem(addr_notes, KVADDR, &(xhdit->context_array[i].note),
-			sizeof(ulong), "per_cpu__crash_notes", RETURN_ON_ERROR)) {
-				error(WARNING, "cannot read per_cpu__crash_notes.\n");
+			sizeof(ulong), "crash_notes", RETURN_ON_ERROR)) {
+				error(WARNING, "cannot read crash_notes.\n");
 				return;
 			}
 		} else {
@@ -678,7 +685,7 @@ xen_hyper_dumpinfo_init(void)
 	xhdit->xen_info_cpu = samp_cpuid;
 	if (!xen_hyper_fill_elf_notes(xhdit->context_array[samp_cpuid].note,
 	buf, XEN_HYPER_ELF_NOTE_FILL_T_NOTE)) {
-		error(FATAL, "cannot read per_cpu__crash_notes.\n");
+		error(FATAL, "cannot read crash_notes.\n");
 	}
 	bp = buf;