[Crash-utility] [Patch 2/4][kexec-tools] Recognise NT_NOCOREDUMP elf-note type

The kernel vmcore may contain a new elf-note of type NT_NOCOREDUMP. Include this new note, whose address and length are made available at /sys/kernel/nt_nocoredump, while loading elf-headers. Signed-off-by: K.Prasad <prasad(a)linux.vnet.ibm.com&gt; --- diff --git a/kexec/crashdump-elf.c b/kexec/crashdump-elf.c index 8d82db9..b009227 100644 --- a/kexec/crashdump-elf.c +++ b/kexec/crashdump-elf.c @@ -39,7 +39,9 @@ int FUNC(struct kexec_info *info, long int nr_cpus = 0; uint64_t notes_addr, notes_len; uint64_t vmcoreinfo_addr, vmcoreinfo_len; + uint64_t nt_nocoredump_addr, nt_nocoredump_len; int has_vmcoreinfo = 0; + int has_nt_nocoredump = 0; uint64_t vmcoreinfo_addr_xen, vmcoreinfo_len_xen; int has_vmcoreinfo_xen = 0; int (*get_note_info)(int cpu, uint64_t *addr, uint64_t *len); @@ -57,6 +59,9 @@ int FUNC(struct kexec_info *info, has_vmcoreinfo = 1; } + if (get_kernel_nt_nocoredump(&nt_nocoredump_addr, &nt_nocoredump_len) == 0) + has_nt_nocoredump = 1; + if (xen_present() && get_xen_vmcoreinfo(&vmcoreinfo_addr_xen, &vmcoreinfo_len_xen) == 0) { has_vmcoreinfo_xen = 1; @@ -179,6 +184,21 @@ int FUNC(struct kexec_info *info, dbgprintf_phdr("vmcoreinfo header", phdr); } + if (has_nt_nocoredump && !(info->kexec_flags & KEXEC_PRESERVE_CONTEXT)) { + phdr = (PHDR *) bufp; + bufp += sizeof(PHDR); + phdr->p_type = PT_NOTE; + phdr->p_flags = 0; + phdr->p_offset = phdr->p_paddr = nt_nocoredump_addr; + phdr->p_vaddr = 0; + phdr->p_filesz = phdr->p_memsz = nt_nocoredump_len; + /* Do we need any alignment of segments? */ + phdr->p_align = 0; + + (elf->e_phnum)++; + dbgprintf_phdr("nocoredump note present", phdr); + } + if (has_vmcoreinfo_xen) { phdr = (PHDR *) bufp; bufp += sizeof(PHDR); diff --git a/kexec/crashdump.c b/kexec/crashdump.c index 945b052..0ee05f0 100644 --- a/kexec/crashdump.c +++ b/kexec/crashdump.c @@ -136,12 +136,43 @@ static int get_vmcoreinfo(const char *kdump_info, uint64_t *addr, uint64_t *len) return 0; } +static int get_nt_nocoredump(const char *kdump_info, uint64_t *addr, uint64_t *len) +{ + char line[MAX_LINE]; + int count; + FILE *fp; + unsigned int temp2; + unsigned long long temp; + + *addr = 0; + *len = 0; + + if (!(fp = fopen(kdump_info, "r"))) + return -1; + if (!fgets(line, sizeof(line), fp)) + die("Cannot parse %s: %s\n", kdump_info, strerror(errno)); + count = sscanf(line, "%Lx %x", &temp, &temp2); + if (count != 2) + die("Cannot parse %s: %s\n", kdump_info, strerror(errno)); + + *addr = (uint64_t) temp; + *len = (uint64_t) temp2; + + fclose(fp); + return 0; +} /* Returns the physical address of start of crash notes buffer for a kernel. */ int get_kernel_vmcoreinfo(uint64_t *addr, uint64_t *len) { return get_vmcoreinfo("/sys/kernel/vmcoreinfo", addr, len); } +/* Returns the physical address of start of nocoredump buffer for a kernel. */ +int get_kernel_nt_nocoredump(uint64_t *addr, uint64_t *len) +{ + return get_nt_nocoredump("/sys/kernel/nt_nocoredump", addr, len); +} + int get_xen_vmcoreinfo(uint64_t *addr, uint64_t *len) { return get_vmcoreinfo("/sys/hypervisor/vmcoreinfo", addr, len); -- 1.7.4.1