From 263b0e480c9b0fda77a89f5d6375d8a39de5c166 Mon Sep 17 00:00:00 2001 From: Philipp Rudo Date: Mon, 6 Aug 2018 13:39:52 +0200 Subject: [PATCH] s390/kdump: Make elfcorehdr size calculation ABI compliant There are two ways to pass the vmcoreinfo to the crash kernel 1) via the os_info mechanism and 2) via the lowcore->vmcore_info field. In the Linux kernel only the second way is used. However, the first way is ABI for stand-alone kdump. So other OSes use it to pass additional debug info. Make the elfcorehdr size calculation aware of both possible ways. Fixes: 8cce437fbb5c ("s390/kdump: Fix elfcorehdr size calculation") Signed-off-by: Philipp Rudo Acked-by: Heiko Carstens Signed-off-by: Heiko Carstens --- arch/s390/kernel/crash_dump.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c index c3620bafc374..4b2773e1ddfe 100644 --- a/arch/s390/kernel/crash_dump.c +++ b/arch/s390/kernel/crash_dump.c @@ -478,26 +478,20 @@ static void *nt_vmcoreinfo(void *ptr) static size_t nt_vmcoreinfo_size(void) { - const char *name = "VMCOREINFO"; - char nt_name[11]; - Elf64_Nhdr note; - void *addr; - - if (copy_oldmem_kernel(&addr, &S390_lowcore.vmcore_info, sizeof(addr))) - return 0; - - if (copy_oldmem_kernel(¬e, addr, sizeof(note))) - return 0; + const char *name = VMCOREINFO_NOTE_NAME; + unsigned long size; + void *vmcoreinfo; - memset(nt_name, 0, sizeof(nt_name)); - if (copy_oldmem_kernel(nt_name, addr + sizeof(note), - sizeof(nt_name) - 1)) - return 0; + vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size); + if (vmcoreinfo) + return nt_size_name(size, name); - if (strcmp(nt_name, name) != 0) + vmcoreinfo = get_vmcoreinfo_old(&size); + if (!vmcoreinfo) return 0; - return nt_size_name(note.n_descsz, name); + kfree(vmcoreinfo); + return nt_size_name(size, name); } /* -- 2.45.2