From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48817) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e3ZW2-0002C2-C2 for qemu-devel@nongnu.org; Sat, 14 Oct 2017 23:23:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e3ZVz-0006EZ-66 for qemu-devel@nongnu.org; Sat, 14 Oct 2017 23:23:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50036) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1e3ZVy-0006EK-Sm for qemu-devel@nongnu.org; Sat, 14 Oct 2017 23:22:59 -0400 Date: Sun, 15 Oct 2017 06:22:55 +0300 From: "Michael S. Tsirkin" Message-ID: <1508036858-13479-6-git-send-email-mst@redhat.com> References: <1508036858-13479-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1508036858-13479-1-git-send-email-mst@redhat.com> Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PULL 05/26] dump: add guest ELF note List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau From: Marc-Andr=C3=A9 Lureau Read the guest ELF PT_NOTE from guest memory when fw_cfg etc/vmcoreinfo entry provides the location, and write it as an additional note in the dump. Signed-off-by: Marc-Andr=C3=A9 Lureau Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- include/sysemu/dump.h | 2 + dump.c | 107 ++++++++++++++++++++++++++++++++++++++++++++= ++++++ 2 files changed, 109 insertions(+) diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h index 2672a15..df43bd0 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 *guest_note; /* ELF note content */ + size_t guest_note_size; } DumpState; =20 uint16_t cpu_to_dump16(DumpState *s, uint16_t val); diff --git a/dump.c b/dump.c index 7ebcf55..1479f1f 100644 --- a/dump.c +++ b/dump.c @@ -25,6 +25,8 @@ #include "qapi/qmp/qerror.h" #include "qmp-commands.h" #include "qapi-event.h" +#include "qemu/error-report.h" +#include "hw/misc/vmcoreinfo.h" =20 #include #ifdef CONFIG_LZO @@ -37,6 +39,13 @@ #define ELF_MACHINE_UNAME "Unknown" #endif =20 +#define MAX_GUEST_NOTE_SIZE (1 << 20) /* 1MB should be enough */ + +#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) { @@ -75,6 +84,8 @@ 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->guest_note); + s->guest_note =3D NULL; if (s->resume) { if (s->detached) { qemu_mutex_lock_iothread(); @@ -234,6 +245,19 @@ static inline int cpu_index(CPUState *cpu) return cpu->cpu_index + 1; } =20 +static void write_guest_note(WriteCoreDumpFunction f, DumpState *s, + Error **errp) +{ + int ret; + + if (s->guest_note) { + ret =3D f(s->guest_note, s->guest_note_size, s); + if (ret < 0) { + error_setg(errp, "dump: failed to write guest note"); + } + } +} + static void write_elf64_notes(WriteCoreDumpFunction f, DumpState *s, Error **errp) { @@ -257,6 +281,8 @@ static void write_elf64_notes(WriteCoreDumpFunction f= , DumpState *s, return; } } + + write_guest_note(f, s, errp); } =20 static void write_elf32_note(DumpState *s, Error **errp) @@ -302,6 +328,8 @@ static void write_elf32_notes(WriteCoreDumpFunction f= , DumpState *s, return; } } + + write_guest_note(f, s, errp); } =20 static void write_elf_section(DumpState *s, int type, Error **errp) @@ -713,6 +741,44 @@ static int buf_write_note(const void *buf, size_t si= ze, 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) { @@ -1491,6 +1557,7 @@ static void dump_init(DumpState *s, int fd, bool ha= s_format, DumpGuestMemoryFormat format, bool paging, bool ha= s_filter, int64_t begin, int64_t length, Error **errp) { + VMCoreInfoState *vmci =3D vmcoreinfo_find(); CPUState *cpu; int nr_cpus; Error *err =3D NULL; @@ -1568,6 +1635,46 @@ static void dump_init(DumpState *s, int fd, bool h= as_format, goto cleanup; } =20 + /* + * The goal of this block is to copy the guest note out of + * the guest. Failure to do so is not fatal for dumping. + */ + if (vmci) { + uint64_t addr, note_head_size, name_size, desc_size; + uint32_t size; + uint16_t format; + + note_head_size =3D s->dump_info.d_class =3D=3D ELFCLASS32 ? + sizeof(Elf32_Nhdr) : sizeof(Elf64_Nhdr); + + format =3D le16_to_cpu(vmci->vmcoreinfo.guest_format); + size =3D le32_to_cpu(vmci->vmcoreinfo.size); + addr =3D le64_to_cpu(vmci->vmcoreinfo.paddr); + if (!vmci->has_vmcoreinfo) { + warn_report("guest note is not present"); + } else if (size < note_head_size || size > MAX_GUEST_NOTE_SIZE) = { + warn_report("guest note size is invalid: %" PRIu32, size); + } else if (format !=3D VMCOREINFO_FORMAT_ELF) { + warn_report("guest note format is unsupported: %" PRIu16, fo= rmat); + } else { + s->guest_note =3D g_malloc(size + 1); /* +1 for adding \0 */ + cpu_physical_memory_read(addr, s->guest_note, size); + + get_note_sizes(s, s->guest_note, NULL, &name_size, &desc_siz= e); + s->guest_note_size =3D ELF_NOTE_SIZE(note_head_size, name_si= ze, + desc_size); + if (name_size > MAX_GUEST_NOTE_SIZE || + desc_size > MAX_GUEST_NOTE_SIZE || + s->guest_note_size > size) { + warn_report("Invalid guest note header"); + g_free(s->guest_note); + s->guest_note =3D NULL; + } else { + s->note_size +=3D s->guest_note_size; + } + } + } + /* get memory mapping */ if (paging) { qemu_get_guest_memory_mapping(&s->list, &s->guest_phys_blocks, &= err); --=20 MST