Hi Dave,
> - Introduced support for xendumps of para-virtualized ia64 kernels.
> It should be noted that currently the ia64 Xen kernel does not
> lay down a switch_stack for the panic task, so only raw "bt -t"
> backtraces can be done on the panic task. (anderson@xxxxxxxxxx)
page_index may contain INVALID_MFN (0xffffffffffffffffUL).
I think it is better to check it.
Here is a patch for this.
---
--- crash-4.0-3.15-org/xendump.h 2006-12-21 09:57:29.000000000 +0900
+++ crash-4.0-3.15/xendump.h 2006-12-21 14:37:35.000000000 +0900
@@ -113,3 +113,8 @@
uint32_t hypercall_imm; /* Break imm for Xen hypercalls. */
/* #endif */
} xen_domctl_arch_setup_t;
+
+#ifdef IA64
+#define INVALID_MFN (0xffffffffffffffffUL)
+#endif
+
--- crash-4.0-3.15-org/xendump.c 2006-12-21 09:57:29.000000000 +0900
+++ crash-4.0-3.15/xendump.c 2006-12-21 14:42:48.000000000 +0900
@@ -31,6 +31,7 @@
static void xc_core_p2m_create(void);
static ulong xc_core_pfn_to_page_index(ulong);
+static int check_mfn_is_valid(ulong);
/*
* Determine whether a file is a xendump creation, and if TRUE,
@@ -1362,7 +1363,7 @@
off_t offset;
if (xd->flags & XC_CORE_NO_P2MM)
- return pfn;
+ return check_mfn_is_valid(pfn) ? pfn : PFN_NOT_FOUND;
idx = pfn/PFNS_PER_PAGE;
@@ -1405,6 +1406,34 @@
return mfn_idx;
}
+static int
+check_mfn_is_valid(ulong idx)
+{
+ ulong mfn;
+
+ if (idx >= xd->xc_core.header.xch_nr_pages)
+ return FALSE;
+
+ if (lseek(xd->xfd,
+ (off_t)xd->xc_core.header.xch_index_offset + idx * sizeof(ulong),
+ SEEK_SET) == -1) {
+ error(INFO, "cannot lseek to page index\n");
+ return FALSE;
+ }
+
+ if (read(xd->xfd, &mfn, sizeof(ulong)) != sizeof(ulong)) {
+ error(INFO, "cannot read index page %d\n", idx);
+ return FALSE;
+ }
+
+ if (mfn == INVALID_MFN) {
+ error(INFO, "idx: %lx indicates INVALID_MFN\n", idx);
+ return FALSE;
+ } else {
+ return TRUE;
+ }
+}
+
/*
* Store the panic task's stack hooks from where it was found
* in get_active_set_panic_task().
---
Thanks.
--
Itsuro ODA <oda@xxxxxxxxxxxxx>
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