From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ed1-x532.google.com ([2a00:1450:4864:20::532]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1msPxi-008smf-RJ for kexec@lists.infradead.org; Wed, 01 Dec 2021 13:47:57 +0000 Received: by mail-ed1-x532.google.com with SMTP id r11so102119477edd.9 for ; Wed, 01 Dec 2021 05:47:54 -0800 (PST) From: Ivan Khoronzhuk Subject: [RFC makedumpfile: add userinfo elf section 2/4] elf: add new "userinfo" ELF section to traverse debug information Date: Wed, 1 Dec 2021 15:47:28 +0200 Message-Id: <20211201134730.15943-3-ikhoronz@cisco.com> In-Reply-To: <20211201134730.15943-1-ikhoronz@cisco.com> References: <20211201134730.15943-1-ikhoronz@cisco.com> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: k-hagio-ab@nec.com, kexec@lists.infradead.org Cc: Ivan Khoronzhuk It's only for elf dumpfile, for compressed version should be added in separate file. It adds new note section to the NOTE segment. Signed-off-by: Ivan Khoronzhuk --- elf_info.h | 3 + makedumpfile.c | 155 ++++++++++++++++++++++++++++++++++++++++++++++++- makedumpfile.h | 10 ++++ 3 files changed, 167 insertions(+), 1 deletion(-) diff --git a/elf_info.h b/elf_info.h index d5416b3..ca96935 100644 --- a/elf_info.h +++ b/elf_info.h @@ -25,6 +25,9 @@ #define ERASEINFO_NOTE_NAME "ERASEINFO" #define ERASEINFO_NOTE_NAME_BYTES (sizeof(ERASEINFO_NOTE_NAME)) +#define USERINFO_NOTE_NAME "USERINFO" +#define USERINFO_NOTE_NAME_BYTES (sizeof(USERINFO_NOTE_NAME)) + #define MAX_SIZE_NHDR MAX(sizeof(Elf64_Nhdr), sizeof(Elf32_Nhdr)) int get_elf64_phdr(int fd, char *filename, int index, Elf64_Phdr *phdr); diff --git a/makedumpfile.c b/makedumpfile.c index 6b62b92..6b6b4d2 100644 --- a/makedumpfile.c +++ b/makedumpfile.c @@ -1396,6 +1396,23 @@ open_dump_file(void) return TRUE; } +int +open_userinfo_file(void) +{ + FILE *file_userinfo; + + if (info->flag_flatten || info->flag_dry_run || + !info->flag_insert_userinfo) { + file_userinfo = NULL; + } else if ((file_userinfo = fopen(info->name_userinfo, "r")) < 0) { + ERRMSG("Can't open the userinfo file(%s). %s\n", + info->name_userinfo, strerror(errno)); + return FALSE; + } + info->file_userinfo = file_userinfo; + return TRUE; +} + int check_file_is_writable(const char *path) { @@ -7080,12 +7097,26 @@ write_elf_phdr(struct cache_data *cd_hdr, Elf64_Phdr *load) return TRUE; } +unsigned long +get_size_userinfo(void) +{ + unsigned long size_userinfo = 0; + + if (info->file_userinfo) { + fseek(info->file_userinfo, 0, SEEK_END); + size_userinfo = ftell(info->file_userinfo); + fseek(info->file_userinfo, 0, SEEK_SET); + } + + return size_userinfo; +} + int write_elf_header(struct cache_data *cd_header) { int i, num_loads_dumpfile, phnum; off_t offset_note_memory, offset_note_dumpfile; - size_t size_note, size_eraseinfo = 0; + size_t size_note, size_eraseinfo = 0, size_userinfo; Elf64_Ehdr ehdr64; Elf32_Ehdr ehdr32; Elf64_Phdr note; @@ -7148,6 +7179,13 @@ write_elf_header(struct cache_data *cd_header) */ info->size_elf_eraseinfo = size_eraseinfo; + size_userinfo = get_size_userinfo(); + /* + * Store the size_userinfo for later use in write_elf_userinfo() + * function. + */ + info->size_elf_userinfo = size_userinfo; + /* * Write a PT_NOTE header. */ @@ -7224,6 +7262,19 @@ write_elf_header(struct cache_data *cd_header) roundup(size_eraseinfo, 4); } + /* + * Modify the note size in PT_NOTE header to accomodate userinfo data. + * Userinfo will be written later. + */ + if (info->size_elf_userinfo) { + if (is_elf64_memory()) + note.p_filesz += sizeof(Elf64_Nhdr); + else + note.p_filesz += sizeof(Elf32_Nhdr); + note.p_filesz += roundup(USERINFO_NOTE_NAME_BYTES, 4) + + roundup(size_userinfo, 4); + } + if (!write_elf_phdr(cd_header, ¬e)) goto out; @@ -8892,6 +8943,27 @@ out: return ret; } +/* + * Traverse through userinfo nodes and write it to the o/p dumpfile. + */ +int +write_userinfo(struct cache_data *cd_page) +{ + char buf[BUFSIZE_FGETS]; + int len; + + while (fgets(buf, BUFSIZE_FGETS, info->file_userinfo)) { + len = strlen(buf); + if (!len) + break; + + if (!write_cache(cd_page, buf, len)) + return FALSE; + } + + return TRUE; +} + int write_elf_eraseinfo(struct cache_data *cd_header) { @@ -8957,6 +9029,64 @@ write_elf_eraseinfo(struct cache_data *cd_header) return TRUE; } +static int +write_elf_userinfo(struct cache_data *cd_header) +{ + char note[MAX_SIZE_NHDR]; + char buf[USERINFO_NOTE_NAME_BYTES + 4]; + off_t offset_userinfo; + unsigned long note_header_size, size_note; + + DEBUG_MSG("user info size: %lu\n", info->size_elf_userinfo); + + if (!info->size_elf_userinfo) + return TRUE; + + DEBUG_MSG("Writing user info...\n"); + + /* calculate the userinfo ELF note offset */ + get_pt_note(NULL, &size_note); + cd_header->offset = info->offset_note_dumpfile + + roundup(size_note, 4) + + roundup(info->size_elf_eraseinfo, 4); + + /* Write userinfo ELF note header. */ + memset(note, 0, sizeof(note)); + if (is_elf64_memory()) { + Elf64_Nhdr *nh = (Elf64_Nhdr *)note; + + note_header_size = sizeof(Elf64_Nhdr); + nh->n_namesz = USERINFO_NOTE_NAME_BYTES; + nh->n_descsz = info->size_elf_userinfo; + nh->n_type = 0; + } else { + Elf32_Nhdr *nh = (Elf32_Nhdr *)note; + + note_header_size = sizeof(Elf32_Nhdr); + nh->n_namesz = USERINFO_NOTE_NAME_BYTES; + nh->n_descsz = info->size_elf_userinfo; + nh->n_type = 0; + } + if (!write_cache(cd_header, note, note_header_size)) + return FALSE; + + /* Write userinfo Note name */ + memset(buf, 0, sizeof(buf)); + memcpy(buf, USERINFO_NOTE_NAME, USERINFO_NOTE_NAME_BYTES); + if (!write_cache(cd_header, buf, + roundup(USERINFO_NOTE_NAME_BYTES, 4))) + return FALSE; + + offset_userinfo = cd_header->offset; + if (!write_userinfo(cd_header)) + return FALSE; + + DEBUG_MSG("offset_userinfo: %llx, size_userinfo: %ld\n", + (unsigned long long)offset_userinfo, info->size_elf_userinfo); + + return TRUE; +} + int write_kdump_eraseinfo(struct cache_data *cd_page) { @@ -9260,6 +9390,18 @@ close_dump_file(void) info->fd_dumpfile = -1; } +void +close_userinfo_file(void) +{ + if (info->flag_flatten || info->flag_dry_run) + return; + + if (fclose(info->file_userinfo) < 0) + ERRMSG("Can't close the userinfo file(%s). %s\n", + info->name_userinfo, strerror(errno)); + info->file_userinfo = NULL; +} + void close_dump_bitmap(void) { @@ -10193,6 +10335,9 @@ writeout_dumpfile(void) if (!open_dump_file()) return FALSE; + if (!open_userinfo_file()) + return FALSE; + if (info->flag_flatten) { if (!write_start_flat_header()) return FALSE; @@ -10211,6 +10356,8 @@ writeout_dumpfile(void) goto write_cache_enospc; if (!write_elf_eraseinfo(&cd_header)) goto out; + if (!write_elf_userinfo(&cd_header)) + goto out; } else { if (!write_kdump_header()) goto out; @@ -10235,6 +10382,7 @@ out: free_cache_data(&cd_page); close_dump_file(); + close_userinfo_file(); if ((ret == FALSE) && info->flag_nospace) return NOSPACE; @@ -11693,6 +11841,7 @@ static struct option longopts[] = { {"check-params", no_argument, NULL, OPT_CHECK_PARAMS}, {"dry-run", no_argument, NULL, OPT_DRY_RUN}, {"show-stats", no_argument, NULL, OPT_SHOW_STATS}, + {"userinfo", required_argument, NULL, OPT_USERINFO}, {0, 0, 0, 0} }; @@ -11821,6 +11970,10 @@ main(int argc, char *argv[]) case OPT_COMPRESS_ZSTD: info->flag_compress = DUMP_DH_COMPRESSED_ZSTD; break; + case OPT_USERINFO: + info->flag_insert_userinfo = 1; + info->name_userinfo = optarg; + break; case OPT_XEN_PHYS_START: info->xen_phys_start = strtoul(optarg, NULL, 0); break; diff --git a/makedumpfile.h b/makedumpfile.h index d583249..b28b0a5 100644 --- a/makedumpfile.h +++ b/makedumpfile.h @@ -1359,6 +1359,7 @@ struct DumpInfo { int flag_elf_dumpfile; /* flag of creating ELF dumpfile */ int flag_generate_vmcoreinfo;/* flag of generating vmcoreinfo file */ int flag_read_vmcoreinfo; /* flag of reading vmcoreinfo file */ + int flag_insert_userinfo; /* flag of inserting userinfo file into ELF note section */ int flag_show_usage; /* flag of showing usage */ int flag_show_version; /* flag of showing version */ int flag_check_params; /* only check parameters */ @@ -1469,6 +1470,9 @@ struct DumpInfo { int fd_xen_syms; char *name_xen_syms; + FILE *file_userinfo; + char *name_userinfo; + /* * Dump memory image info: */ @@ -1512,6 +1516,11 @@ struct DumpInfo { */ unsigned long size_elf_eraseinfo; + /* + * userinfo in dump memory image info: + */ + unsigned long size_elf_userinfo; + /* * for Xen extraction */ @@ -2481,6 +2490,7 @@ struct elf_prstatus { #define OPT_EXCLUDE_XEN_DOM 'X' #define OPT_VMLINUX 'x' #define OPT_COMPRESS_ZSTD 'z' +#define OPT_USERINFO 'u' #define OPT_START 256 #define OPT_SPLIT OPT_START+0 #define OPT_REASSEMBLE OPT_START+1 -- 2.20.1 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec