From nobody Wed Nov 5 10:07:48 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1499336397760116.72330468870734; Thu, 6 Jul 2017 03:19:57 -0700 (PDT) Received: from localhost ([::1]:50442 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dT3t5-00072G-Gj for importer@patchew.org; Thu, 06 Jul 2017 06:19:55 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35270) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dT3pr-0004Rt-TS for qemu-devel@nongnu.org; Thu, 06 Jul 2017 06:16:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dT3pq-0000Zx-Gz for qemu-devel@nongnu.org; Thu, 06 Jul 2017 06:16:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54050) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dT3pq-0000Ze-7J for qemu-devel@nongnu.org; Thu, 06 Jul 2017 06:16:34 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 40823C0587C0 for ; Thu, 6 Jul 2017 10:16:33 +0000 (UTC) Received: from localhost (ovpn-112-36.ams2.redhat.com [10.36.112.36]) by smtp.corp.redhat.com (Postfix) with ESMTP id AC21F60F88; Thu, 6 Jul 2017 10:16:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 40823C0587C0 Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=marcandre.lureau@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 40823C0587C0 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= To: qemu-devel@nongnu.org Date: Thu, 6 Jul 2017 12:16:08 +0200 Message-Id: <20170706101611.27031-5-marcandre.lureau@redhat.com> In-Reply-To: <20170706101611.27031-1-marcandre.lureau@redhat.com> References: <20170706101611.27031-1-marcandre.lureau@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Thu, 06 Jul 2017 10:16:33 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 4/7] dump: add vmcoreinfo ELF note X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ehabkost@redhat.com, anderson@redhat.com, =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , imammedo@redhat.com, lersek@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Type: text/plain; charset="utf-8" Read the vmcoreinfo ELF PT_NOTE from guest memory when vmcoreinfo device provides the location, and write it as an ELF note in the dump. There are now 2 possible sources of phys_base information. (1) arch guessed value from cpu_dump_info_get() (2) vmcoreinfo ELF note NUMBER(phys_base)=3D field NUMBER(phys_base) in vmcoreinfo has only been recently introduced in Linux 4.10 (401721ecd1dc "kexec: export the value of phys_base instead of symbol address"). Since (2) has better chances to be accurate, the guessed value is replaced by the value from the vmcoreinfo ELF note. The phys_base value is stored in the same dump field locations as before, and may duplicate the information available in the vmcoreinfo ELF PT_NOTE. Crash tools should be prepared to handle this case. Signed-off-by: Marc-Andr=C3=A9 Lureau --- include/sysemu/dump.h | 2 + dump.c | 125 ++++++++++++++++++++++++++++++++++++++++++++++= ++++ 2 files changed, 127 insertions(+) diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h index 2672a15f8b..111a7dcaa4 100644 --- a/include/sysemu/dump.h +++ b/include/sysemu/dump.h @@ -192,6 +192,8 @@ typedef struct DumpState { * this could be used to calculate * how much work we have * finished. */ + uint8_t *vmcoreinfo; /* ELF note content */ + size_t vmcoreinfo_size; } DumpState; =20 uint16_t cpu_to_dump16(DumpState *s, uint16_t val); diff --git a/dump.c b/dump.c index d9090a24cc..f699198204 100644 --- a/dump.c +++ b/dump.c @@ -26,6 +26,8 @@ #include "qapi/qmp/qerror.h" #include "qmp-commands.h" #include "qapi-event.h" +#include "qemu/error-report.h" +#include "hw/acpi/vmcoreinfo.h" =20 #include #ifdef CONFIG_LZO @@ -38,6 +40,11 @@ #define ELF_MACHINE_UNAME "Unknown" #endif =20 +#define ELF_NOTE_SIZE(hdr_size, name_size, desc_size) \ + ((DIV_ROUND_UP((hdr_size), 4) + \ + DIV_ROUND_UP((name_size), 4) + \ + DIV_ROUND_UP((desc_size), 4)) * 4) + uint16_t cpu_to_dump16(DumpState *s, uint16_t val) { if (s->dump_info.d_endian =3D=3D ELFDATA2LSB) { @@ -76,6 +83,8 @@ static int dump_cleanup(DumpState *s) guest_phys_blocks_free(&s->guest_phys_blocks); memory_mapping_list_free(&s->list); close(s->fd); + g_free(s->vmcoreinfo); + s->vmcoreinfo =3D NULL; if (s->resume) { if (s->detached) { qemu_mutex_lock_iothread(); @@ -235,6 +244,19 @@ static inline int cpu_index(CPUState *cpu) return cpu->cpu_index + 1; } =20 +static void write_vmcoreinfo_note(WriteCoreDumpFunction f, DumpState *s, + Error **errp) +{ + int ret; + + if (s->vmcoreinfo) { + ret =3D f(s->vmcoreinfo, s->vmcoreinfo_size, s); + if (ret < 0) { + error_setg(errp, "dump: failed to write vmcoreinfo"); + } + } +} + static void write_elf64_notes(WriteCoreDumpFunction f, DumpState *s, Error **errp) { @@ -258,6 +280,8 @@ static void write_elf64_notes(WriteCoreDumpFunction f, = DumpState *s, return; } } + + write_vmcoreinfo_note(f, s, errp); } =20 static void write_elf32_note(DumpState *s, Error **errp) @@ -303,6 +327,8 @@ static void write_elf32_notes(WriteCoreDumpFunction f, = DumpState *s, return; } } + + write_vmcoreinfo_note(f, s, errp); } =20 static void write_elf_section(DumpState *s, int type, Error **errp) @@ -714,6 +740,44 @@ static int buf_write_note(const void *buf, size_t size= , void *opaque) return 0; } =20 +/* + * This function retrieves various sizes from an elf header. + * + * @note has to be a valid ELF note. The return sizes are unmodified + * (not padded or rounded up to be multiple of 4). + */ +static void get_note_sizes(DumpState *s, const void *note, + uint64_t *note_head_size, + uint64_t *name_size, + uint64_t *desc_size) +{ + uint64_t note_head_sz; + uint64_t name_sz; + uint64_t desc_sz; + + if (s->dump_info.d_class =3D=3D ELFCLASS64) { + const Elf64_Nhdr *hdr =3D note; + note_head_sz =3D sizeof(Elf64_Nhdr); + name_sz =3D tswap64(hdr->n_namesz); + desc_sz =3D tswap64(hdr->n_descsz); + } else { + const Elf32_Nhdr *hdr =3D note; + note_head_sz =3D sizeof(Elf32_Nhdr); + name_sz =3D tswap32(hdr->n_namesz); + desc_sz =3D tswap32(hdr->n_descsz); + } + + if (note_head_size) { + *note_head_size =3D note_head_sz; + } + if (name_size) { + *name_size =3D name_sz; + } + if (desc_size) { + *desc_size =3D desc_sz; + } +} + /* write common header, sub header and elf note to vmcore */ static void create_header32(DumpState *s, Error **errp) { @@ -1488,10 +1552,40 @@ static int64_t dump_calculate_size(DumpState *s) return total; } =20 +static void vmcoreinfo_update_phys_base(DumpState *s) +{ + uint64_t size, note_head_size, name_size, phys_base; + char **lines; + uint8_t *vmci; + size_t i; + + get_note_sizes(s, s->vmcoreinfo, ¬e_head_size, &name_size, &size); + note_head_size =3D ROUND_UP(note_head_size, 4); + name_size =3D ROUND_UP(name_size, 4); + vmci =3D s->vmcoreinfo + note_head_size + name_size; + *(vmci + size) =3D '\0'; + + lines =3D g_strsplit((char *)vmci, "\n", -1); + for (i =3D 0; lines[i]; i++) { + if (g_str_has_prefix(lines[i], "NUMBER(phys_base)=3D")) { + if (qemu_strtou64(lines[i] + 18, NULL, 16, + &phys_base) < 0) { + error_report("Failed to read NUMBER(phys_base)=3D"); + } else { + s->dump_info.phys_base =3D phys_base; + } + break; + } + } + + g_strfreev(lines); +} + static void dump_init(DumpState *s, int fd, bool has_format, DumpGuestMemoryFormat format, bool paging, bool has_= filter, int64_t begin, int64_t length, Error **errp) { + Object *vmcoreinfo_dev =3D find_vmcoreinfo_dev(); CPUState *cpu; int nr_cpus; Error *err =3D NULL; @@ -1563,6 +1657,37 @@ static void dump_init(DumpState *s, int fd, bool has= _format, goto cleanup; } =20 +#define MAX_VMCOREINFO_SIZE (1 << 20) /* 1MB should be enough */ + if (vmcoreinfo_dev) { + uint64_t addr, note_head_size, name_size, desc_size; + uint32_t size; + + note_head_size =3D s->dump_info.d_class =3D=3D ELFCLASS32 ? + sizeof(Elf32_Nhdr) : sizeof(Elf64_Nhdr); + + if (!vmcoreinfo_get(VMCOREINFO(vmcoreinfo_dev), + &addr, &size, &err)) { + error_report_err(err); + } else if (size < note_head_size || size > MAX_VMCOREINFO_SIZE) { + error_report("vmcoreinfo size is invalid: %u", size); + } else { + s->vmcoreinfo =3D g_malloc(size + 1); /* +1 for adding \0 */ + cpu_physical_memory_read(addr, s->vmcoreinfo, size); + + get_note_sizes(s, s->vmcoreinfo, NULL, &name_size, &desc_size); + s->vmcoreinfo_size =3D ELF_NOTE_SIZE(note_head_size, name_size, + desc_size); + if (s->vmcoreinfo_size > size) { + error_report("Invalid vmcoreinfo header, size mismatch"); + g_free(s->vmcoreinfo); + s->vmcoreinfo =3D NULL; + } else { + vmcoreinfo_update_phys_base(s); + s->note_size +=3D s->vmcoreinfo_size; + } + } + } + /* get memory mapping */ if (paging) { qemu_get_guest_memory_mapping(&s->list, &s->guest_phys_blocks, &er= r); --=20 2.13.1.395.gf7b71de06