diff --git a/dump/dump.c b/dump/dump.c index 236559b03a..e7a3b54ebe 100644 --- a/dump/dump.c +++ b/dump/dump.c @@ -380,31 +380,60 @@ static void write_elf_phdr_note(DumpState *s, Error **errp) } } -static void write_elf_section(DumpState *s, int type, Error **errp) +static void prepare_elf_section_hdr_zero(DumpState *s) { - Elf32_Shdr shdr32; - Elf64_Shdr shdr64; - int shdr_size; - void *shdr; + if (dump_is_64bit(s)) { + Elf64_Shdr *shdr64 = s->elf_section_hdrs; + + shdr64->sh_info = cpu_to_dump32(s, s->phdr_num); + } else { + Elf32_Shdr *shdr32 = s->elf_section_hdrs; + + shdr32->sh_info = cpu_to_dump32(s, s->phdr_num); + } +} + +static void prepare_elf_section_hdrs(DumpState *s) +{ + size_t len, sizeof_shdr; + + /* + * Section ordering: + * - HDR zero + */ + sizeof_shdr = dump_is_64bit(s) ? sizeof(Elf64_Shdr) : sizeof(Elf32_Shdr); + len = sizeof_shdr * s->shdr_num; + s->elf_section_hdrs = g_malloc0(len); + + /* + * The first section header is ALWAYS a special initial section + * header. + * + * The header should be 0 with one exception being that if + * phdr_num is PN_XNUM then the sh_info field contains the real + * number of segment entries. + * + * As we zero allocate the buffer we will only need to modify + * sh_info for the PN_XNUM case. + */ + if (s->phdr_num >= PN_XNUM) { + prepare_elf_section_hdr_zero(s); + } +} + +static void write_elf_section_headers(DumpState *s, Error **errp) +{ + size_t sizeof_shdr = dump_is_64bit(s) ? sizeof(Elf64_Shdr) : sizeof(Elf32_Shdr); int ret; - if (type == 0) { - shdr_size = sizeof(Elf32_Shdr); - memset(&shdr32, 0, shdr_size); - shdr32.sh_info = cpu_to_dump32(s, s->phdr_num); - shdr = &shdr32; - } else { - shdr_size = sizeof(Elf64_Shdr); - memset(&shdr64, 0, shdr_size); - shdr64.sh_info = cpu_to_dump32(s, s->phdr_num); - shdr = &shdr64; + prepare_elf_section_hdrs(s); + + ret = fd_write_vmcore(s->elf_section_hdrs, s->shdr_num * sizeof_shdr, s); + if (ret < 0) { + error_setg_errno(errp, -ret, "dump: failed to write section headers"); } - ret = fd_write_vmcore(shdr, shdr_size, s); - if (ret < 0) { - error_setg_errno(errp, -ret, - "dump: failed to write section header table"); - } + g_free(s->elf_section_hdrs); } static void write_data(DumpState *s, void *buf, int length, Error **errp) @@ -591,12 +620,10 @@ static void dump_begin(DumpState *s, Error **errp) return; } - /* write section to vmcore */ - if (s->shdr_num) { - write_elf_section(s, 1, errp); - if (*errp) { - return; - } + /* write section headers to vmcore */ + write_elf_section_headers(s, errp); + if (*errp) { + return; } /* write notes to vmcore */ diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h index b62513d87d..9995f65dc8 100644 --- a/include/sysemu/dump.h +++ b/include/sysemu/dump.h @@ -177,6 +177,8 @@ typedef struct DumpState { int64_t filter_area_begin; /* Start address of partial guest memory area */ int64_t filter_area_length; /* Length of partial guest memory area */ + void *elf_section_hdrs; /* Pointer to section header buffer */ + uint8_t *note_buf; /* buffer for notes */ size_t note_buf_offset; /* the writing place in note_buf */ uint32_t nr_cpus; /* number of guest's cpu */