[Crash-utility] Re: PATCH] support vmcores with 64k page size on 4k page size kernels

Hi Dave Recently there were changes made to kexec tools to support 64K page size. With those changes vmcore file obtained from a kernel which supports 64K page size cannot be analyzed using crash on a machine running with kernel supporting 4K page size. The following changes in crash tool resolves the problem. Look if the symbol __hash_page_64k exists. This symbol is defined only for kernels with 64K PAGE SIZE support. If yes then the dump was taken with a kernel supporting 64k page size. So use the vmcore page size[64K] instead of getpagesize(). Thanks -Sachin ------------------------------------------------------------------------------------------------------------------------ * Recently there were changes made to kexec tools to support 64K page size. With those changes vmcore file obtained from a kernel which supports 64K page size cannot be analyzed using crash on a machine running with kernel supporting 4K page size. The following change were made in crash tool to solve the problem. Look if the symbol __hash_page_64k exists. If yes then the dump was taken with a kernel supporting 64k page size. So change the page size accordingly. Signed-Off-By: Sachin Sant <sachinp(a)in.ibm.com&gt; -- diff -Naurp crash-4.0/defs.h crash-4.0-new/defs.h --- crash-4.0/defs.h 2006-09-14 21:41:50.000000000 -0400 +++ crash-4.0-new/defs.h 2006-09-14 21:48:37.000000000 -0400 @@ -2297,6 +2297,7 @@ struct efi_memory_desc_t { #define _64BIT_ #define MACHINE_TYPE "PPC64" +#define PPC64_64K_PAGE_SIZE 65536 #define PAGEBASE(X) (((ulong)(X)) & (ulong)machdep->pagemask) #define PTOV(X) ((unsigned long)(X)+(machdep->kvbase)) diff -Naurp crash-4.0/ppc64.c crash-4.0-new/ppc64.c --- crash-4.0/ppc64.c 2006-09-14 21:41:50.000000000 -0400 +++ crash-4.0-new/ppc64.c 2006-09-14 21:50:26.000000000 -0400 @@ -67,19 +67,6 @@ ppc64_init(int when) machdep->verify_symbol = ppc64_verify_symbol; if (pc->flags & KERNEL_DEBUG_QUERY) return; - machdep->pagesize = memory_page_size(); - machdep->pageshift = ffs(machdep->pagesize) - 1; - machdep->pageoffset = machdep->pagesize - 1; - machdep->pagemask = ~((ulonglong)machdep->pageoffset); - machdep->stacksize = 4 * machdep->pagesize; - if ((machdep->pgd = (char *)malloc(PAGESIZE())) == NULL) - error(FATAL, "cannot malloc pgd space."); - if ((machdep->pmd = (char *)malloc(PAGESIZE())) == NULL) - error(FATAL, "cannot malloc pmd space."); - if ((machdep->ptbl = (char *)malloc(PAGESIZE())) == NULL) - error(FATAL, "cannot malloc ptbl space."); - if ((machdep->machspec->level4 = (char *)malloc(PAGESIZE())) == NULL) - error(FATAL, "cannot malloc level4 space."); machdep->last_pgd_read = 0; machdep->last_pmd_read = 0; machdep->last_ptbl_read = 0; @@ -93,6 +80,40 @@ ppc64_init(int when) break; case PRE_GDB: + /* + * Recently there were changes made to kexec tools + * to support 64K page size. With those changes + * vmcore file obtained from a kernel which supports + * 64K page size cannot be analyzed using crash on a + * machine running with kernel supporting 4K page size + * + * The following modifications are required in crash + * tool to be in sync with kexec tools. + * + * Look if the following symbol exists. If yes then + * the dump was taken with a kernel supporting 64k + * page size. So change the page size accordingly. + * + * Also moved the following code block from + * PRE_SYMTAB case here. + */ + if (symbol_exists("__hash_page_64K")) + machdep->pagesize = PPC64_64K_PAGE_SIZE; + else + machdep->pagesize = memory_page_size(); + machdep->pageshift = ffs(machdep->pagesize) - 1; + machdep->pageoffset = machdep->pagesize - 1; + machdep->pagemask = ~((ulonglong)machdep->pageoffset); + machdep->stacksize = 4 * machdep->pagesize; + if ((machdep->pgd = (char *)malloc(PAGESIZE())) == NULL) + error(FATAL, "cannot malloc pgd space."); + if ((machdep->pmd = (char *)malloc(PAGESIZE())) == NULL) + error(FATAL, "cannot malloc pmd space."); + if ((machdep->ptbl = (char *)malloc(PAGESIZE())) == NULL) + error(FATAL, "cannot malloc ptbl space."); + if ((machdep->machspec->level4 = (char *)malloc(PAGESIZE())) == NULL) + error(FATAL, "cannot malloc level4 space."); + machdep->kvbase = symbol_value("_stext"); machdep->identity_map_base = machdep->kvbase; machdep->is_kvaddr = generic_is_kvaddr;