Re: [Crash-utility] crash version 4.0-3.15 is available

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(a)redhat.com) 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(a)valinux.co.jp&gt;