[PATCH v3 9/9] Do not fail for symbols removed in Xen4.

Xen-4.0+ removes some of the symbols that were necessary to process dump
files on Xen-3, and makedumpfile fails if they are not found.

Since most of these symbols are not needed for Xen4, we can simply remove
the checks. The only exception is "frame_table". This used to be a global
variable holding the address of the array of struct page_info. In Xen-4.0
the array is always located at a fixed address in virtual address space.
Xen adds a compatibility symbol for VMCOREINFO, but a "frame_table" symbol
does not exist as such, so we must use the fixed address instead.

Signed-off-by: Norbert Trapp <norbert.trapp@ts.fujitsu.com>
Signed-off-by: Petr Tesarik <ptesarik@suse.cz>

4 files changed, 94 insertions, 82 deletions

diff --git a/arch/ia64.c b/arch/ia64.c
index 3dbad6a..e629f94 100644
--- a/arch/ia64.c
+++ b/arch/ia64.c
@@ -335,26 +335,29 @@ get_xen_basic_info_ia64(void)
 
 	info->frame_table_vaddr = VIRT_FRAME_TABLE_ADDR; /* "frame_table" is same value */
 
-	if (SYMBOL(xenheap_phys_end) == NOT_FOUND_SYMBOL) {
-		ERRMSG("Can't get the symbol of xenheap_phys_end.\n");
-		return FALSE;
-	}
-	if (!readmem(VADDR_XEN, SYMBOL(xenheap_phys_end), &xen_end,
-	      sizeof(xen_end))) {
-		ERRMSG("Can't get the value of xenheap_phys_end.\n");
-		return FALSE;
-	}
-	if (SYMBOL(xen_pstart) == NOT_FOUND_SYMBOL) {
-		ERRMSG("Can't get the symbol of xen_pstart.\n");
-		return FALSE;
-	}
-	if (!readmem(VADDR_XEN, SYMBOL(xen_pstart), &xen_start,
-	    sizeof(xen_start))) {
-		ERRMSG("Can't get the value of xen_pstart.\n");
-		return FALSE;
+	if (!info->xen_crash_info.com ||
+	    info->xen_crash_info.com->xen_major_version < 4) {
+		if (SYMBOL(xenheap_phys_end) == NOT_FOUND_SYMBOL) {
+			ERRMSG("Can't get the symbol of xenheap_phys_end.\n");
+			return FALSE;
+		}
+		if (!readmem(VADDR_XEN, SYMBOL(xenheap_phys_end), &xen_end,
+			     sizeof(xen_end))) {
+			ERRMSG("Can't get the value of xenheap_phys_end.\n");
+			return FALSE;
+		}
+		if (SYMBOL(xen_pstart) == NOT_FOUND_SYMBOL) {
+			ERRMSG("Can't get the symbol of xen_pstart.\n");
+			return FALSE;
+		}
+		if (!readmem(VADDR_XEN, SYMBOL(xen_pstart), &xen_start,
+			     sizeof(xen_start))) {
+			ERRMSG("Can't get the value of xen_pstart.\n");
+			return FALSE;
+		}
+		info->xen_heap_start = paddr_to_pfn(xen_start);
+		info->xen_heap_end   = paddr_to_pfn(xen_end);
 	}
-	info->xen_heap_start = paddr_to_pfn(xen_start);
-	info->xen_heap_end   = paddr_to_pfn(xen_end);
 
 	return TRUE;
 }
diff --git a/arch/x86.c b/arch/x86.c
index cd2ca4d..7de0495 100644
--- a/arch/x86.c
+++ b/arch/x86.c
@@ -294,9 +294,6 @@ kvtop_xen_x86(unsigned long kvaddr)
 
 int get_xen_basic_info_x86(void)
 {
-	unsigned long frame_table_vaddr;
-	unsigned long xen_end;
-
 	if (!info->xen_phys_start) {
 		if (info->xen_crash_info_v < 2) {
 			ERRMSG("Can't get Xen physical start address.\n"
@@ -317,28 +314,34 @@ int get_xen_basic_info_x86(void)
 		return FALSE;
 	}
 
-	if (SYMBOL(frame_table) == NOT_FOUND_SYMBOL) {
-		ERRMSG("Can't get the symbol of frame_table.\n");
-		return FALSE;
-	}
-	if (!readmem(VADDR_XEN, SYMBOL(frame_table), &frame_table_vaddr,
-	    sizeof(frame_table_vaddr))) {
-		ERRMSG("Can't get the value of frame_table.\n");
-		return FALSE;
-	}
-	info->frame_table_vaddr = frame_table_vaddr;
+	if (SYMBOL(frame_table) != NOT_FOUND_SYMBOL) {
+		unsigned long frame_table_vaddr;
 
-	if (SYMBOL(xenheap_phys_end) == NOT_FOUND_SYMBOL) {
-		ERRMSG("Can't get the symbol of xenheap_phys_end.\n");
-		return FALSE;
-	}
-	if (!readmem(VADDR_XEN, SYMBOL(xenheap_phys_end), &xen_end,
-	    sizeof(xen_end))) {
-		ERRMSG("Can't get the value of xenheap_phys_end.\n");
-		return FALSE;
+		if (!readmem(VADDR_XEN, SYMBOL(frame_table),
+		    &frame_table_vaddr, sizeof(frame_table_vaddr))) {
+			ERRMSG("Can't get the value of frame_table.\n");
+			return FALSE;
+		}
+		info->frame_table_vaddr = frame_table_vaddr;
+	} else
+		info->frame_table_vaddr = FRAMETABLE_VIRT_START;
+
+	if (!info->xen_crash_info.com ||
+	    info->xen_crash_info.com->xen_major_version < 4) {
+		unsigned long xen_end;
+
+		if (SYMBOL(xenheap_phys_end) == NOT_FOUND_SYMBOL) {
+			ERRMSG("Can't get the symbol of xenheap_phys_end.\n");
+			return FALSE;
+		}
+		if (!readmem(VADDR_XEN, SYMBOL(xenheap_phys_end), &xen_end,
+		    sizeof(xen_end))) {
+			ERRMSG("Can't get the value of xenheap_phys_end.\n");
+			return FALSE;
+		}
+		info->xen_heap_start = 0;
+		info->xen_heap_end   = paddr_to_pfn(xen_end);
 	}
-	info->xen_heap_start = 0;
-	info->xen_heap_end   = paddr_to_pfn(xen_end);
 
 	return TRUE;
 }
diff --git a/arch/x86_64.c b/arch/x86_64.c
index 0ce9674..8e61b20 100644
--- a/arch/x86_64.c
+++ b/arch/x86_64.c
@@ -363,9 +363,6 @@ kvtop_xen_x86_64(unsigned long kvaddr)
 
 int get_xen_basic_info_x86_64(void)
 {
-	unsigned long frame_table_vaddr;
-	unsigned long xen_end;
-
  	if (!info->xen_phys_start) {
 		if (info->xen_crash_info_v < 2) {
 			ERRMSG("Can't get Xen physical start address.\n"
@@ -389,28 +386,34 @@ int get_xen_basic_info_x86_64(void)
 		return FALSE;
 	}
 
-	if (SYMBOL(frame_table) == NOT_FOUND_SYMBOL) {
-		ERRMSG("Can't get the symbol of frame_table.\n");
-		return FALSE;
-	}
-	if (!readmem(VADDR_XEN, SYMBOL(frame_table), &frame_table_vaddr,
-	    sizeof(frame_table_vaddr))) {
-		ERRMSG("Can't get the value of frame_table.\n");
-		return FALSE;
-	}
-	info->frame_table_vaddr = frame_table_vaddr;
+	if (SYMBOL(frame_table) != NOT_FOUND_SYMBOL) {
+		unsigned long frame_table_vaddr;
 
-	if (SYMBOL(xenheap_phys_end) == NOT_FOUND_SYMBOL) {
-		ERRMSG("Can't get the symbol of xenheap_phys_end.\n");
-		return FALSE;
-	}
-	if (!readmem(VADDR_XEN, SYMBOL(xenheap_phys_end), &xen_end,
-	    sizeof(xen_end))) {
-		ERRMSG("Can't get the value of xenheap_phys_end.\n");
-		return FALSE;
+		if (!readmem(VADDR_XEN, SYMBOL(frame_table),
+			     &frame_table_vaddr, sizeof(frame_table_vaddr))) {
+			ERRMSG("Can't get the value of frame_table.\n");
+			return FALSE;
+		}
+		info->frame_table_vaddr = frame_table_vaddr;
+	} else
+		info->frame_table_vaddr = FRAMETABLE_VIRT_START;
+
+	if (!info->xen_crash_info.com ||
+	    info->xen_crash_info.com->xen_major_version < 4) {
+		unsigned long xen_end;
+
+		if (SYMBOL(xenheap_phys_end) == NOT_FOUND_SYMBOL) {
+			ERRMSG("Can't get the symbol of xenheap_phys_end.\n");
+			return FALSE;
+		}
+		if (!readmem(VADDR_XEN, SYMBOL(xenheap_phys_end), &xen_end,
+			     sizeof(xen_end))) {
+			ERRMSG("Can't get the value of xenheap_phys_end.\n");
+			return FALSE;
+		}
+		info->xen_heap_start = 0;
+		info->xen_heap_end   = paddr_to_pfn(xen_end);
 	}
-	info->xen_heap_start = 0;
-	info->xen_heap_end   = paddr_to_pfn(xen_end);
 
 	return TRUE;
 }
diff --git a/makedumpfile.c b/makedumpfile.c
index 46c03a5..b2ea917 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -6252,23 +6252,26 @@ get_xen_info(void)
 	if (!get_xen_basic_info_arch())
 		return FALSE;
 
-	if (SYMBOL(alloc_bitmap) == NOT_FOUND_SYMBOL) {
-		ERRMSG("Can't get the symbol of alloc_bitmap.\n");
-		return FALSE;
-	}
-	if (!readmem(VADDR_XEN, SYMBOL(alloc_bitmap), &info->alloc_bitmap,
-	      sizeof(info->alloc_bitmap))) {
-		ERRMSG("Can't get the value of alloc_bitmap.\n");
-		return FALSE;
-	}
-	if (SYMBOL(max_page) == NOT_FOUND_SYMBOL) {
-		ERRMSG("Can't get the symbol of max_page.\n");
-		return FALSE;
-	}
-	if (!readmem(VADDR_XEN, SYMBOL(max_page), &info->max_page,
-	    sizeof(info->max_page))) {
-		ERRMSG("Can't get the value of max_page.\n");
-		return FALSE;
+	if (!info->xen_crash_info.com ||
+	    info->xen_crash_info.com->xen_major_version < 4) {
+		if (SYMBOL(alloc_bitmap) == NOT_FOUND_SYMBOL) {
+			ERRMSG("Can't get the symbol of alloc_bitmap.\n");
+			return FALSE;
+		}
+		if (!readmem(VADDR_XEN, SYMBOL(alloc_bitmap), &info->alloc_bitmap,
+		      sizeof(info->alloc_bitmap))) {
+			ERRMSG("Can't get the value of alloc_bitmap.\n");
+			return FALSE;
+		}
+		if (SYMBOL(max_page) == NOT_FOUND_SYMBOL) {
+			ERRMSG("Can't get the symbol of max_page.\n");
+			return FALSE;
+		}
+		if (!readmem(VADDR_XEN, SYMBOL(max_page), &info->max_page,
+		    sizeof(info->max_page))) {
+			ERRMSG("Can't get the value of max_page.\n");
+			return FALSE;
+		}
 	}
 
 	/*