From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45007) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YUugS-0002Wc-U5 for qemu-devel@nongnu.org; Mon, 09 Mar 2015 06:13:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YUugI-00040C-0a for qemu-devel@nongnu.org; Mon, 09 Mar 2015 06:13:12 -0400 Received: from e06smtp13.uk.ibm.com ([195.75.94.109]:43374) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YUugH-0003zU-OC for qemu-devel@nongnu.org; Mon, 09 Mar 2015 06:13:01 -0400 Received: from /spool/local by e06smtp13.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 9 Mar 2015 10:12:59 -0000 Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id 64F571B0806E for ; Mon, 9 Mar 2015 10:13:16 +0000 (GMT) Received: from d06av08.portsmouth.uk.ibm.com (d06av08.portsmouth.uk.ibm.com [9.149.37.249]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t29ACuSl9240970 for ; Mon, 9 Mar 2015 10:12:56 GMT Received: from d06av08.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av08.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t29ACt7f032456 for ; Mon, 9 Mar 2015 04:12:56 -0600 From: Thomas Huth Date: Mon, 9 Mar 2015 11:12:52 +0100 Message-Id: <1425895973-15239-2-git-send-email-thuth@linux.vnet.ibm.com> In-Reply-To: <1425895973-15239-1-git-send-email-thuth@linux.vnet.ibm.com> References: <1425895973-15239-1-git-send-email-thuth@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH v2 1/2] elf-loader: Provide the possibility to relocate s390 ELF files List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: cornelia.huck@de.ibm.com, borntraeger@de.ibm.com, agraf@suse.de, Thomas Huth On s390, we would like to load our "BIOS" s390-ccw.img to the end of the RAM. Therefor we need the possibility to relocate the ELF file so that it can also run from different addresses. This patch adds the necessary code to the QEMU ELF loader function. Signed-off-by: Thomas Huth --- hw/core/loader.c | 2 + include/elf.h | 2 + include/hw/elf_ops.h | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 82 insertions(+), 0 deletions(-) diff --git a/hw/core/loader.c b/hw/core/loader.c index e45dc0b..76d8aca 100644 --- a/hw/core/loader.c +++ b/hw/core/loader.c @@ -297,6 +297,7 @@ static void *load_at(int fd, int offset, int size) #undef elf_phdr #undef elf_shdr #undef elf_sym +#undef elf_rela #undef elf_note #undef elf_word #undef elf_sword @@ -307,6 +308,7 @@ static void *load_at(int fd, int offset, int size) #define elf_note elf64_note #define elf_shdr elf64_shdr #define elf_sym elf64_sym +#define elf_rela elf64_rela #define elf_word uint64_t #define elf_sword int64_t #define bswapSZs bswap64s diff --git a/include/elf.h b/include/elf.h index a516584..3e75f05 100644 --- a/include/elf.h +++ b/include/elf.h @@ -1508,6 +1508,7 @@ struct elf32_fdpic_loadmap { #define elf_shdr elf32_shdr #define elf_sym elf32_sym #define elf_addr_t Elf32_Off +#define elf_rela elf32_rela #ifdef ELF_USES_RELOCA # define ELF_RELOC Elf32_Rela @@ -1523,6 +1524,7 @@ struct elf32_fdpic_loadmap { #define elf_shdr elf64_shdr #define elf_sym elf64_sym #define elf_addr_t Elf64_Off +#define elf_rela elf64_rela #ifdef ELF_USES_RELOCA # define ELF_RELOC Elf64_Rela diff --git a/include/hw/elf_ops.h b/include/hw/elf_ops.h index a517753..16a627b 100644 --- a/include/hw/elf_ops.h +++ b/include/hw/elf_ops.h @@ -49,6 +49,13 @@ static void glue(bswap_sym, SZ)(struct elf_sym *sym) bswap16s(&sym->st_shndx); } +static void glue(bswap_rela, SZ)(struct elf_rela *rela) +{ + bswapSZs(&rela->r_offset); + bswapSZs(&rela->r_info); + bswapSZs((elf_word *)&rela->r_addend); +} + static struct elf_shdr *glue(find_section, SZ)(struct elf_shdr *shdr_table, int n, int type) { @@ -182,6 +189,75 @@ static int glue(load_symbols, SZ)(struct elfhdr *ehdr, int fd, int must_swab, return -1; } +static int glue(elf_reloc, SZ)(struct elfhdr *ehdr, int fd, int must_swab, + uint64_t (*translate_fn)(void *, uint64_t), + void *translate_opaque, uint8_t *data, + struct elf_phdr *ph, int elf_machine) +{ + struct elf_shdr *reltab, *shdr_table = NULL; + struct elf_rela *rels = NULL; + int nrels, i, ret = -1; + elf_word wordval; + void *addr; + + shdr_table = load_at(fd, ehdr->e_shoff, + sizeof(struct elf_shdr) * ehdr->e_shnum); + if (!shdr_table) { + return -1; + } + if (must_swab) { + for (i = 0; i < ehdr->e_shnum; i++) { + glue(bswap_shdr, SZ)(&shdr_table[i]); + } + } + + reltab = glue(find_section, SZ)(shdr_table, ehdr->e_shnum, SHT_RELA); + if (!reltab) { + goto fail; + } + rels = load_at(fd, reltab->sh_offset, reltab->sh_size); + if (!rels) { + goto fail; + } + nrels = reltab->sh_size / sizeof(struct elf_rela); + + for (i = 0; i < nrels; i++) { + if (must_swab) { + glue(bswap_rela, SZ)(&rels[i]); + } + if (rels[i].r_offset < ph->p_vaddr || + rels[i].r_offset >= ph->p_vaddr + ph->p_filesz) { + continue; + } + addr = &data[rels[i].r_offset - ph->p_vaddr]; + switch (elf_machine) { + case EM_S390: + switch (rels[i].r_info) { + case R_390_RELATIVE: + wordval = *(elf_word *)addr; + if (must_swab) { + bswapSZs(&wordval); + } + wordval = translate_fn(translate_opaque, wordval); + if (must_swab) { + bswapSZs(&wordval); + } + *(elf_word *)addr = wordval; + break; + default: + fprintf(stderr, "Unsupported relocation type %i!\n", + (int)rels[i].r_info); + } + } + } + + ret = 0; +fail: + g_free(rels); + g_free(shdr_table); + return ret; +} + static int glue(load_elf, SZ)(const char *name, int fd, uint64_t (*translate_fn)(void *, uint64_t), void *translate_opaque, @@ -271,6 +347,8 @@ static int glue(load_elf, SZ)(const char *name, int fd, linked at the wrong physical address. */ if (translate_fn) { addr = translate_fn(translate_opaque, ph->p_paddr); + glue(elf_reloc, SZ)(&ehdr, fd, must_swab, translate_fn, + translate_opaque, data, ph, elf_machine); } else { addr = ph->p_paddr; } -- 1.7.1