diff options
Diffstat (limited to 'src/VBox/ExtPacks/VBoxDTrace/onnv/lib/libdtrace/common/dt_link.c')
| -rw-r--r-- | src/VBox/ExtPacks/VBoxDTrace/onnv/lib/libdtrace/common/dt_link.c | 1634 |
1 files changed, 1634 insertions, 0 deletions
diff --git a/src/VBox/ExtPacks/VBoxDTrace/onnv/lib/libdtrace/common/dt_link.c b/src/VBox/ExtPacks/VBoxDTrace/onnv/lib/libdtrace/common/dt_link.c new file mode 100644 index 00000000..e910ac3f --- /dev/null +++ b/src/VBox/ExtPacks/VBoxDTrace/onnv/lib/libdtrace/common/dt_link.c @@ -0,0 +1,1634 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ + +/* + * Copyright 2008 Sun Microsystems, Inc. All rights reserved. + * Use is subject to license terms. + */ + +#pragma ident "%Z%%M% %I% %E% SMI" + +#define ELF_TARGET_ALL +#include <elf.h> + +#include <sys/types.h> +#include <sys/sysmacros.h> + +#include <unistd.h> +#include <strings.h> +#include <alloca.h> +#include <limits.h> +#include <stddef.h> +#include <stdlib.h> +#include <stdio.h> +#include <fcntl.h> +#include <errno.h> +#include <wait.h> +#include <assert.h> +#include <sys/ipc.h> + +#include <dt_impl.h> +#include <dt_provider.h> +#include <dt_program.h> +#include <dt_string.h> + +#define ESHDR_NULL 0 +#define ESHDR_SHSTRTAB 1 +#define ESHDR_DOF 2 +#define ESHDR_STRTAB 3 +#define ESHDR_SYMTAB 4 +#define ESHDR_REL 5 +#define ESHDR_NUM 6 + +#define PWRITE_SCN(index, data) \ + (lseek64(fd, (off64_t)elf_file.shdr[(index)].sh_offset, SEEK_SET) != \ + (off64_t)elf_file.shdr[(index)].sh_offset || \ + dt_write(dtp, fd, (data), elf_file.shdr[(index)].sh_size) != \ + elf_file.shdr[(index)].sh_size) + +static const char DTRACE_SHSTRTAB32[] = "\0" +".shstrtab\0" /* 1 */ +".SUNW_dof\0" /* 11 */ +".strtab\0" /* 21 */ +".symtab\0" /* 29 */ +#ifdef __sparc +".rela.SUNW_dof"; /* 37 */ +#else +".rel.SUNW_dof"; /* 37 */ +#endif + +static const char DTRACE_SHSTRTAB64[] = "\0" +".shstrtab\0" /* 1 */ +".SUNW_dof\0" /* 11 */ +".strtab\0" /* 21 */ +".symtab\0" /* 29 */ +".rela.SUNW_dof"; /* 37 */ + +static const char DOFSTR[] = "__SUNW_dof"; +static const char DOFLAZYSTR[] = "___SUNW_dof"; + +typedef struct dt_link_pair { + struct dt_link_pair *dlp_next; /* next pair in linked list */ + void *dlp_str; /* buffer for string table */ + void *dlp_sym; /* buffer for symbol table */ +} dt_link_pair_t; + +typedef struct dof_elf32 { + uint32_t de_nrel; /* relocation count */ +#ifdef __sparc + Elf32_Rela *de_rel; /* array of relocations for sparc */ +#else + Elf32_Rel *de_rel; /* array of relocations for x86 */ +#endif + uint32_t de_nsym; /* symbol count */ + Elf32_Sym *de_sym; /* array of symbols */ + uint32_t de_strlen; /* size of of string table */ + char *de_strtab; /* string table */ + uint32_t de_global; /* index of the first global symbol */ +} dof_elf32_t; + +static int +prepare_elf32(dtrace_hdl_t *dtp, const dof_hdr_t *dof, dof_elf32_t *dep) +{ + dof_sec_t *dofs, *s; + dof_relohdr_t *dofrh; + dof_relodesc_t *dofr; + char *strtab; + int i, j, nrel; + size_t strtabsz = 1; + uint32_t count = 0; + size_t base; + Elf32_Sym *sym; +#ifdef __sparc + Elf32_Rela *rel; +#else + Elf32_Rel *rel; +#endif + + /*LINTED*/ + dofs = (dof_sec_t *)((char *)dof + dof->dofh_secoff); + + /* + * First compute the size of the string table and the number of + * relocations present in the DOF. + */ + for (i = 0; i < dof->dofh_secnum; i++) { + if (dofs[i].dofs_type != DOF_SECT_URELHDR) + continue; + + /*LINTED*/ + dofrh = (dof_relohdr_t *)((char *)dof + dofs[i].dofs_offset); + + s = &dofs[dofrh->dofr_strtab]; + strtab = (char *)dof + s->dofs_offset; + assert(strtab[0] == '\0'); + strtabsz += s->dofs_size - 1; + + s = &dofs[dofrh->dofr_relsec]; + /*LINTED*/ + dofr = (dof_relodesc_t *)((char *)dof + s->dofs_offset); + count += s->dofs_size / s->dofs_entsize; + } + + dep->de_strlen = strtabsz; + dep->de_nrel = count; + dep->de_nsym = count + 1; /* the first symbol is always null */ + + if (dtp->dt_lazyload) { + dep->de_strlen += sizeof (DOFLAZYSTR); + dep->de_nsym++; + } else { + dep->de_strlen += sizeof (DOFSTR); + dep->de_nsym++; + } + + if ((dep->de_rel = calloc(dep->de_nrel, + sizeof (dep->de_rel[0]))) == NULL) { + return (dt_set_errno(dtp, EDT_NOMEM)); + } + + if ((dep->de_sym = calloc(dep->de_nsym, sizeof (Elf32_Sym))) == NULL) { + free(dep->de_rel); + return (dt_set_errno(dtp, EDT_NOMEM)); + } + + if ((dep->de_strtab = calloc(dep->de_strlen, 1)) == NULL) { + free(dep->de_rel); + free(dep->de_sym); + return (dt_set_errno(dtp, EDT_NOMEM)); + } + + count = 0; + strtabsz = 1; + dep->de_strtab[0] = '\0'; + rel = dep->de_rel; + sym = dep->de_sym; + dep->de_global = 1; + + /* + * The first symbol table entry must be zeroed and is always ignored. + */ + bzero(sym, sizeof (Elf32_Sym)); + sym++; + + /* + * Take a second pass through the DOF sections filling in the + * memory we allocated. + */ + for (i = 0; i < dof->dofh_secnum; i++) { + if (dofs[i].dofs_type != DOF_SECT_URELHDR) + continue; + + /*LINTED*/ + dofrh = (dof_relohdr_t *)((char *)dof + dofs[i].dofs_offset); + + s = &dofs[dofrh->dofr_strtab]; + strtab = (char *)dof + s->dofs_offset; + bcopy(strtab + 1, dep->de_strtab + strtabsz, s->dofs_size); + base = strtabsz; + strtabsz += s->dofs_size - 1; + + s = &dofs[dofrh->dofr_relsec]; + /*LINTED*/ + dofr = (dof_relodesc_t *)((char *)dof + s->dofs_offset); + nrel = s->dofs_size / s->dofs_entsize; + + s = &dofs[dofrh->dofr_tgtsec]; + + for (j = 0; j < nrel; j++) { +#if defined(__i386) || defined(__amd64) + rel->r_offset = s->dofs_offset + + dofr[j].dofr_offset; + rel->r_info = ELF32_R_INFO(count + dep->de_global, + R_386_32); +#elif defined(__sparc) + /* + * Add 4 bytes to hit the low half of this 64-bit + * big-endian address. + */ + rel->r_offset = s->dofs_offset + + dofr[j].dofr_offset + 4; + rel->r_info = ELF32_R_INFO(count + dep->de_global, + R_SPARC_32); +#else +#error unknown ISA +#endif + + sym->st_name = base + dofr[j].dofr_name - 1; + sym->st_value = 0; + sym->st_size = 0; + sym->st_info = ELF32_ST_INFO(STB_GLOBAL, STT_FUNC); + sym->st_other = 0; + sym->st_shndx = SHN_UNDEF; + + rel++; + sym++; + count++; + } + } + + /* + * Add a symbol for the DOF itself. We use a different symbol for + * lazily and actively loaded DOF to make them easy to distinguish. + */ + sym->st_name = strtabsz; + sym->st_value = 0; + sym->st_size = dof->dofh_filesz; + sym->st_info = ELF32_ST_INFO(STB_GLOBAL, STT_OBJECT); + sym->st_other = 0; + sym->st_shndx = ESHDR_DOF; + sym++; + + if (dtp->dt_lazyload) { + bcopy(DOFLAZYSTR, dep->de_strtab + strtabsz, + sizeof (DOFLAZYSTR)); + strtabsz += sizeof (DOFLAZYSTR); + } else { + bcopy(DOFSTR, dep->de_strtab + strtabsz, sizeof (DOFSTR)); + strtabsz += sizeof (DOFSTR); + } + + assert(count == dep->de_nrel); + assert(strtabsz == dep->de_strlen); + + return (0); +} + + +typedef struct dof_elf64 { + uint32_t de_nrel; + Elf64_Rela *de_rel; + uint32_t de_nsym; + Elf64_Sym *de_sym; + + uint32_t de_strlen; + char *de_strtab; + + uint32_t de_global; +} dof_elf64_t; + +static int +prepare_elf64(dtrace_hdl_t *dtp, const dof_hdr_t *dof, dof_elf64_t *dep) +{ + dof_sec_t *dofs, *s; + dof_relohdr_t *dofrh; + dof_relodesc_t *dofr; + char *strtab; + int i, j, nrel; + size_t strtabsz = 1; + uint32_t count = 0; + size_t base; + Elf64_Sym *sym; + Elf64_Rela *rel; + + /*LINTED*/ + dofs = (dof_sec_t *)((char *)dof + dof->dofh_secoff); + + /* + * First compute the size of the string table and the number of + * relocations present in the DOF. + */ + for (i = 0; i < dof->dofh_secnum; i++) { + if (dofs[i].dofs_type != DOF_SECT_URELHDR) + continue; + + /*LINTED*/ + dofrh = (dof_relohdr_t *)((char *)dof + dofs[i].dofs_offset); + + s = &dofs[dofrh->dofr_strtab]; + strtab = (char *)dof + s->dofs_offset; + assert(strtab[0] == '\0'); + strtabsz += s->dofs_size - 1; + + s = &dofs[dofrh->dofr_relsec]; + /*LINTED*/ + dofr = (dof_relodesc_t *)((char *)dof + s->dofs_offset); + count += s->dofs_size / s->dofs_entsize; + } + + dep->de_strlen = strtabsz; + dep->de_nrel = count; + dep->de_nsym = count + 1; /* the first symbol is always null */ + + if (dtp->dt_lazyload) { + dep->de_strlen += sizeof (DOFLAZYSTR); + dep->de_nsym++; + } else { + dep->de_strlen += sizeof (DOFSTR); + dep->de_nsym++; + } + + if ((dep->de_rel = calloc(dep->de_nrel, + sizeof (dep->de_rel[0]))) == NULL) { + return (dt_set_errno(dtp, EDT_NOMEM)); + } + + if ((dep->de_sym = calloc(dep->de_nsym, sizeof (Elf64_Sym))) == NULL) { + free(dep->de_rel); + return (dt_set_errno(dtp, EDT_NOMEM)); + } + + if ((dep->de_strtab = calloc(dep->de_strlen, 1)) == NULL) { + free(dep->de_rel); + free(dep->de_sym); + return (dt_set_errno(dtp, EDT_NOMEM)); + } + + count = 0; + strtabsz = 1; + dep->de_strtab[0] = '\0'; + rel = dep->de_rel; + sym = dep->de_sym; + dep->de_global = 1; + + /* + * The first symbol table entry must be zeroed and is always ignored. + */ + bzero(sym, sizeof (Elf64_Sym)); + sym++; + + /* + * Take a second pass through the DOF sections filling in the + * memory we allocated. + */ + for (i = 0; i < dof->dofh_secnum; i++) { + if (dofs[i].dofs_type != DOF_SECT_URELHDR) + continue; + + /*LINTED*/ + dofrh = (dof_relohdr_t *)((char *)dof + dofs[i].dofs_offset); + + s = &dofs[dofrh->dofr_strtab]; + strtab = (char *)dof + s->dofs_offset; + bcopy(strtab + 1, dep->de_strtab + strtabsz, s->dofs_size); + base = strtabsz; + strtabsz += s->dofs_size - 1; + + s = &dofs[dofrh->dofr_relsec]; + /*LINTED*/ + dofr = (dof_relodesc_t *)((char *)dof + s->dofs_offset); + nrel = s->dofs_size / s->dofs_entsize; + + s = &dofs[dofrh->dofr_tgtsec]; + + for (j = 0; j < nrel; j++) { +#if defined(__i386) || defined(__amd64) + rel->r_offset = s->dofs_offset + + dofr[j].dofr_offset; + rel->r_info = ELF64_R_INFO(count + dep->de_global, + R_AMD64_64); +#elif defined(__sparc) + rel->r_offset = s->dofs_offset + + dofr[j].dofr_offset; + rel->r_info = ELF64_R_INFO(count + dep->de_global, + R_SPARC_64); +#else +#error unknown ISA +#endif + + sym->st_name = base + dofr[j].dofr_name - 1; + sym->st_value = 0; + sym->st_size = 0; + sym->st_info = GELF_ST_INFO(STB_GLOBAL, STT_FUNC); + sym->st_other = 0; + sym->st_shndx = SHN_UNDEF; + + rel++; + sym++; + count++; + } + } + + /* + * Add a symbol for the DOF itself. We use a different symbol for + * lazily and actively loaded DOF to make them easy to distinguish. + */ + sym->st_name = strtabsz; + sym->st_value = 0; + sym->st_size = dof->dofh_filesz; + sym->st_info = GELF_ST_INFO(STB_GLOBAL, STT_OBJECT); + sym->st_other = 0; + sym->st_shndx = ESHDR_DOF; + sym++; + + if (dtp->dt_lazyload) { + bcopy(DOFLAZYSTR, dep->de_strtab + strtabsz, + sizeof (DOFLAZYSTR)); + strtabsz += sizeof (DOFLAZYSTR); + } else { + bcopy(DOFSTR, dep->de_strtab + strtabsz, sizeof (DOFSTR)); + strtabsz += sizeof (DOFSTR); + } + + assert(count == dep->de_nrel); + assert(strtabsz == dep->de_strlen); + + return (0); +} + +/* + * Write out an ELF32 file prologue consisting of a header, section headers, + * and a section header string table. The DOF data will follow this prologue + * and complete the contents of the given ELF file. + */ +static int +dump_elf32(dtrace_hdl_t *dtp, const dof_hdr_t *dof, int fd) +{ + struct { + Elf32_Ehdr ehdr; + Elf32_Shdr shdr[ESHDR_NUM]; + } elf_file; + + Elf32_Shdr *shp; + Elf32_Off off; + dof_elf32_t de; + int ret = 0; + uint_t nshdr; + + if (prepare_elf32(dtp, dof, &de) != 0) + return (-1); /* errno is set for us */ + + /* + * If there are no relocations, we only need enough sections for + * the shstrtab and the DOF. + */ + nshdr = de.de_nrel == 0 ? ESHDR_SYMTAB + 1 : ESHDR_NUM; + + bzero(&elf_file, sizeof (elf_file)); + + elf_file.ehdr.e_ident[EI_MAG0] = ELFMAG0; + elf_file.ehdr.e_ident[EI_MAG1] = ELFMAG1; + elf_file.ehdr.e_ident[EI_MAG2] = ELFMAG2; + elf_file.ehdr.e_ident[EI_MAG3] = ELFMAG3; + elf_file.ehdr.e_ident[EI_VERSION] = EV_CURRENT; + elf_file.ehdr.e_ident[EI_CLASS] = ELFCLASS32; +#if defined(_BIG_ENDIAN) + elf_file.ehdr.e_ident[EI_DATA] = ELFDATA2MSB; +#elif defined(_LITTLE_ENDIAN) + elf_file.ehdr.e_ident[EI_DATA] = ELFDATA2LSB; +#endif + elf_file.ehdr.e_type = ET_REL; +#if defined(__sparc) + elf_file.ehdr.e_machine = EM_SPARC; +#elif defined(__i386) || defined(__amd64) + elf_file.ehdr.e_machine = EM_386; +#endif + elf_file.ehdr.e_version = EV_CURRENT; + elf_file.ehdr.e_shoff = sizeof (Elf32_Ehdr); + elf_file.ehdr.e_ehsize = sizeof (Elf32_Ehdr); + elf_file.ehdr.e_phentsize = sizeof (Elf32_Phdr); + elf_file.ehdr.e_shentsize = sizeof (Elf32_Shdr); + elf_file.ehdr.e_shnum = nshdr; + elf_file.ehdr.e_shstrndx = ESHDR_SHSTRTAB; + off = sizeof (elf_file) + nshdr * sizeof (Elf32_Shdr); + + shp = &elf_file.shdr[ESHDR_SHSTRTAB]; + shp->sh_name = 1; /* DTRACE_SHSTRTAB32[1] = ".shstrtab" */ + shp->sh_type = SHT_STRTAB; + shp->sh_offset = off; + shp->sh_size = sizeof (DTRACE_SHSTRTAB32); + shp->sh_addralign = sizeof (char); + off = P2ROUNDUP(shp->sh_offset + shp->sh_size, 8); + + shp = &elf_file.shdr[ESHDR_DOF]; + shp->sh_name = 11; /* DTRACE_SHSTRTAB32[11] = ".SUNW_dof" */ + shp->sh_flags = SHF_ALLOC; + shp->sh_type = SHT_SUNW_dof; + shp->sh_offset = off; + shp->sh_size = dof->dofh_filesz; + shp->sh_addralign = 8; + off = shp->sh_offset + shp->sh_size; + + shp = &elf_file.shdr[ESHDR_STRTAB]; + shp->sh_name = 21; /* DTRACE_SHSTRTAB32[21] = ".strtab" */ + shp->sh_flags = SHF_ALLOC; + shp->sh_type = SHT_STRTAB; + shp->sh_offset = off; + shp->sh_size = de.de_strlen; + shp->sh_addralign = sizeof (char); + off = P2ROUNDUP(shp->sh_offset + shp->sh_size, 4); + + shp = &elf_file.shdr[ESHDR_SYMTAB]; + shp->sh_name = 29; /* DTRACE_SHSTRTAB32[29] = ".symtab" */ + shp->sh_flags = SHF_ALLOC; + shp->sh_type = SHT_SYMTAB; + shp->sh_entsize = sizeof (Elf32_Sym); + shp->sh_link = ESHDR_STRTAB; + shp->sh_offset = off; + shp->sh_info = de.de_global; + shp->sh_size = de.de_nsym * sizeof (Elf32_Sym); + shp->sh_addralign = 4; + off = P2ROUNDUP(shp->sh_offset + shp->sh_size, 4); + + if (de.de_nrel == 0) { + if (dt_write(dtp, fd, &elf_file, + sizeof (elf_file)) != sizeof (elf_file) || + PWRITE_SCN(ESHDR_SHSTRTAB, DTRACE_SHSTRTAB32) || + PWRITE_SCN(ESHDR_STRTAB, de.de_strtab) || + PWRITE_SCN(ESHDR_SYMTAB, de.de_sym) || + PWRITE_SCN(ESHDR_DOF, dof)) { + ret = dt_set_errno(dtp, errno); + } + } else { + shp = &elf_file.shdr[ESHDR_REL]; + shp->sh_name = 37; /* DTRACE_SHSTRTAB32[37] = ".rel.SUNW_dof" */ + shp->sh_flags = SHF_ALLOC; +#ifdef __sparc + shp->sh_type = SHT_RELA; +#else + shp->sh_type = SHT_REL; +#endif + shp->sh_entsize = sizeof (de.de_rel[0]); + shp->sh_link = ESHDR_SYMTAB; + shp->sh_info = ESHDR_DOF; + shp->sh_offset = off; + shp->sh_size = de.de_nrel * sizeof (de.de_rel[0]); + shp->sh_addralign = 4; + + if (dt_write(dtp, fd, &elf_file, + sizeof (elf_file)) != sizeof (elf_file) || + PWRITE_SCN(ESHDR_SHSTRTAB, DTRACE_SHSTRTAB32) || + PWRITE_SCN(ESHDR_STRTAB, de.de_strtab) || + PWRITE_SCN(ESHDR_SYMTAB, de.de_sym) || + PWRITE_SCN(ESHDR_REL, de.de_rel) || + PWRITE_SCN(ESHDR_DOF, dof)) { + ret = dt_set_errno(dtp, errno); + } + } + + free(de.de_strtab); + free(de.de_sym); + free(de.de_rel); + + return (ret); +} + +/* + * Write out an ELF64 file prologue consisting of a header, section headers, + * and a section header string table. The DOF data will follow this prologue + * and complete the contents of the given ELF file. + */ +static int +dump_elf64(dtrace_hdl_t *dtp, const dof_hdr_t *dof, int fd) +{ + struct { + Elf64_Ehdr ehdr; + Elf64_Shdr shdr[ESHDR_NUM]; + } elf_file; + + Elf64_Shdr *shp; + Elf64_Off off; + dof_elf64_t de; + int ret = 0; + uint_t nshdr; + + if (prepare_elf64(dtp, dof, &de) != 0) + return (-1); /* errno is set for us */ + + /* + * If there are no relocations, we only need enough sections for + * the shstrtab and the DOF. + */ + nshdr = de.de_nrel == 0 ? ESHDR_SYMTAB + 1 : ESHDR_NUM; + + bzero(&elf_file, sizeof (elf_file)); + + elf_file.ehdr.e_ident[EI_MAG0] = ELFMAG0; + elf_file.ehdr.e_ident[EI_MAG1] = ELFMAG1; + elf_file.ehdr.e_ident[EI_MAG2] = ELFMAG2; + elf_file.ehdr.e_ident[EI_MAG3] = ELFMAG3; + elf_file.ehdr.e_ident[EI_VERSION] = EV_CURRENT; + elf_file.ehdr.e_ident[EI_CLASS] = ELFCLASS64; +#if defined(_BIG_ENDIAN) + elf_file.ehdr.e_ident[EI_DATA] = ELFDATA2MSB; +#elif defined(_LITTLE_ENDIAN) + elf_file.ehdr.e_ident[EI_DATA] = ELFDATA2LSB; +#endif + elf_file.ehdr.e_type = ET_REL; +#if defined(__sparc) + elf_file.ehdr.e_machine = EM_SPARCV9; +#elif defined(__i386) || defined(__amd64) + elf_file.ehdr.e_machine = EM_AMD64; +#endif + elf_file.ehdr.e_version = EV_CURRENT; + elf_file.ehdr.e_shoff = sizeof (Elf64_Ehdr); + elf_file.ehdr.e_ehsize = sizeof (Elf64_Ehdr); + elf_file.ehdr.e_phentsize = sizeof (Elf64_Phdr); + elf_file.ehdr.e_shentsize = sizeof (Elf64_Shdr); + elf_file.ehdr.e_shnum = nshdr; + elf_file.ehdr.e_shstrndx = ESHDR_SHSTRTAB; + off = sizeof (elf_file) + nshdr * sizeof (Elf64_Shdr); + + shp = &elf_file.shdr[ESHDR_SHSTRTAB]; + shp->sh_name = 1; /* DTRACE_SHSTRTAB64[1] = ".shstrtab" */ + shp->sh_type = SHT_STRTAB; + shp->sh_offset = off; + shp->sh_size = sizeof (DTRACE_SHSTRTAB64); + shp->sh_addralign = sizeof (char); + off = P2ROUNDUP(shp->sh_offset + shp->sh_size, 8); + + shp = &elf_file.shdr[ESHDR_DOF]; + shp->sh_name = 11; /* DTRACE_SHSTRTAB64[11] = ".SUNW_dof" */ + shp->sh_flags = SHF_ALLOC; + shp->sh_type = SHT_SUNW_dof; + shp->sh_offset = off; + shp->sh_size = dof->dofh_filesz; + shp->sh_addralign = 8; + off = shp->sh_offset + shp->sh_size; + + shp = &elf_file.shdr[ESHDR_STRTAB]; + shp->sh_name = 21; /* DTRACE_SHSTRTAB64[21] = ".strtab" */ + shp->sh_flags = SHF_ALLOC; + shp->sh_type = SHT_STRTAB; + shp->sh_offset = off; + shp->sh_size = de.de_strlen; + shp->sh_addralign = sizeof (char); + off = P2ROUNDUP(shp->sh_offset + shp->sh_size, 8); + + shp = &elf_file.shdr[ESHDR_SYMTAB]; + shp->sh_name = 29; /* DTRACE_SHSTRTAB64[29] = ".symtab" */ + shp->sh_flags = SHF_ALLOC; + shp->sh_type = SHT_SYMTAB; + shp->sh_entsize = sizeof (Elf64_Sym); + shp->sh_link = ESHDR_STRTAB; + shp->sh_offset = off; + shp->sh_info = de.de_global; + shp->sh_size = de.de_nsym * sizeof (Elf64_Sym); + shp->sh_addralign = 8; + off = P2ROUNDUP(shp->sh_offset + shp->sh_size, 8); + + if (de.de_nrel == 0) { + if (dt_write(dtp, fd, &elf_file, + sizeof (elf_file)) != sizeof (elf_file) || + PWRITE_SCN(ESHDR_SHSTRTAB, DTRACE_SHSTRTAB64) || + PWRITE_SCN(ESHDR_STRTAB, de.de_strtab) || + PWRITE_SCN(ESHDR_SYMTAB, de.de_sym) || + PWRITE_SCN(ESHDR_DOF, dof)) { + ret = dt_set_errno(dtp, errno); + } + } else { + shp = &elf_file.shdr[ESHDR_REL]; + shp->sh_name = 37; /* DTRACE_SHSTRTAB64[37] = ".rel.SUNW_dof" */ + shp->sh_flags = SHF_ALLOC; + shp->sh_type = SHT_RELA; + shp->sh_entsize = sizeof (de.de_rel[0]); + shp->sh_link = ESHDR_SYMTAB; + shp->sh_info = ESHDR_DOF; + shp->sh_offset = off; + shp->sh_size = de.de_nrel * sizeof (de.de_rel[0]); + shp->sh_addralign = 8; + + if (dt_write(dtp, fd, &elf_file, + sizeof (elf_file)) != sizeof (elf_file) || + PWRITE_SCN(ESHDR_SHSTRTAB, DTRACE_SHSTRTAB64) || + PWRITE_SCN(ESHDR_STRTAB, de.de_strtab) || + PWRITE_SCN(ESHDR_SYMTAB, de.de_sym) || + PWRITE_SCN(ESHDR_REL, de.de_rel) || + PWRITE_SCN(ESHDR_DOF, dof)) { + ret = dt_set_errno(dtp, errno); + } + } + + free(de.de_strtab); + free(de.de_sym); + free(de.de_rel); + + return (ret); +} + +static int +dt_symtab_lookup(Elf_Data *data_sym, int nsym, uintptr_t addr, uint_t shn, + GElf_Sym *sym) +{ + int i, ret = -1; + GElf_Sym s; + + for (i = 0; i < nsym && gelf_getsym(data_sym, i, sym) != NULL; i++) { + if (GELF_ST_TYPE(sym->st_info) == STT_FUNC && + shn == sym->st_shndx && + sym->st_value <= addr && + addr < sym->st_value + sym->st_size) { + if (GELF_ST_BIND(sym->st_info) == STB_GLOBAL) + return (0); + + ret = 0; + s = *sym; + } + } + + if (ret == 0) + *sym = s; + return (ret); +} + +#if defined(__sparc) + +#define DT_OP_RET 0x81c7e008 +#define DT_OP_NOP 0x01000000 +#define DT_OP_CALL 0x40000000 +#define DT_OP_CLR_O0 0x90102000 + +#define DT_IS_MOV_O7(inst) (((inst) & 0xffffe000) == 0x9e100000) +#define DT_IS_RESTORE(inst) (((inst) & 0xc1f80000) == 0x81e80000) +#define DT_IS_RETL(inst) (((inst) & 0xfff83fff) == 0x81c02008) + +#define DT_RS2(inst) ((inst) & 0x1f) +#define DT_MAKE_RETL(reg) (0x81c02008 | ((reg) << 14)) + +/*ARGSUSED*/ +static int +dt_modtext(dtrace_hdl_t *dtp, char *p, int isenabled, GElf_Rela *rela, + uint32_t *off) +{ + uint32_t *ip; + + if ((rela->r_offset & (sizeof (uint32_t) - 1)) != 0) + return (-1); + + /*LINTED*/ + ip = (uint32_t *)(p + rela->r_offset); + + /* + * We only know about some specific relocation types. + */ + if (GELF_R_TYPE(rela->r_info) != R_SPARC_WDISP30 && + GELF_R_TYPE(rela->r_info) != R_SPARC_WPLT30) + return (-1); + + /* + * We may have already processed this object file in an earlier linker + * invocation. Check to see if the present instruction sequence matches + * the one we would install below. + */ + if (isenabled) { + if (ip[0] == DT_OP_NOP) { + (*off) += sizeof (ip[0]); + return (0); + } + } else { + if (DT_IS_RESTORE(ip[1])) { + if (ip[0] == DT_OP_RET) { + (*off) += sizeof (ip[0]); + return (0); + } + } else if (DT_IS_MOV_O7(ip[1])) { + if (DT_IS_RETL(ip[0])) + return (0); + } else { + if (ip[0] == DT_OP_NOP) { + (*off) += sizeof (ip[0]); + return (0); + } + } + } + + /* + * We only expect call instructions with a displacement of 0. + */ + if (ip[0] != DT_OP_CALL) { + dt_dprintf("found %x instead of a call instruction at %llx\n", + ip[0], (u_longlong_t)rela->r_offset); + return (-1); + } + + if (isenabled) { + /* + * It would necessarily indicate incorrect usage if an is- + * enabled probe were tail-called so flag that as an error. + * It's also potentially (very) tricky to handle gracefully, + * but could be done if this were a desired use scenario. + */ + if (DT_IS_RESTORE(ip[1]) || DT_IS_MOV_O7(ip[1])) { + dt_dprintf("tail call to is-enabled probe at %llx\n", + (u_longlong_t)rela->r_offset); + return (-1); + } + + + /* + * On SPARC, we take advantage of the fact that the first + * argument shares the same register as for the return value. + * The macro handles the work of zeroing that register so we + * don't need to do anything special here. We instrument the + * instruction in the delay slot as we'll need to modify the + * return register after that instruction has been emulated. + */ + ip[0] = DT_OP_NOP; + (*off) += sizeof (ip[0]); + } else { + /* + * If the call is followed by a restore, it's a tail call so + * change the call to a ret. If the call if followed by a mov + * of a register into %o7, it's a tail call in leaf context + * so change the call to a retl-like instruction that returns + * to that register value + 8 (rather than the typical %o7 + + * 8); the delay slot instruction is left, but should have no + * effect. Otherwise we change the call to be a nop. We + * identify the subsequent instruction as the probe point in + * all but the leaf tail-call case to ensure that arguments to + * the probe are complete and consistent. An astute, though + * largely hypothetical, observer would note that there is the + * possibility of a false-positive probe firing if the function + * contained a branch to the instruction in the delay slot of + * the call. Fixing this would require significant in-kernel + * modifications, and isn't worth doing until we see it in the + * wild. + */ + if (DT_IS_RESTORE(ip[1])) { + ip[0] = DT_OP_RET; + (*off) += sizeof (ip[0]); + } else if (DT_IS_MOV_O7(ip[1])) { + ip[0] = DT_MAKE_RETL(DT_RS2(ip[1])); + } else { + ip[0] = DT_OP_NOP; + (*off) += sizeof (ip[0]); + } + } + + return (0); +} + +#elif defined(__i386) || defined(__amd64) + +#define DT_OP_NOP 0x90 +#define DT_OP_RET 0xc3 +#define DT_OP_CALL 0xe8 +#define DT_OP_JMP32 0xe9 +#define DT_OP_REX_RAX 0x48 +#define DT_OP_XOR_EAX_0 0x33 +#define DT_OP_XOR_EAX_1 0xc0 + +static int +dt_modtext(dtrace_hdl_t *dtp, char *p, int isenabled, GElf_Rela *rela, + uint32_t *off) +{ + uint8_t *ip = (uint8_t *)(p + rela->r_offset - 1); + uint8_t ret; + + /* + * On x86, the first byte of the instruction is the call opcode and + * the next four bytes are the 32-bit address; the relocation is for + * the address operand. We back up the offset to the first byte of + * the instruction. For is-enabled probes, we later advance the offset + * so that it hits the first nop in the instruction sequence. + */ + (*off) -= 1; + + /* + * We only know about some specific relocation types. Luckily + * these types have the same values on both 32-bit and 64-bit + * x86 architectures. + */ + if (GELF_R_TYPE(rela->r_info) != R_386_PC32 && + GELF_R_TYPE(rela->r_info) != R_386_PLT32) + return (-1); + + /* + * We may have already processed this object file in an earlier linker + * invocation. Check to see if the present instruction sequence matches + * the one we would install. For is-enabled probes, we advance the + * offset to the first nop instruction in the sequence to match the + * text modification code below. + */ + if (!isenabled) { + if ((ip[0] == DT_OP_NOP || ip[0] == DT_OP_RET) && + ip[1] == DT_OP_NOP && ip[2] == DT_OP_NOP && + ip[3] == DT_OP_NOP && ip[4] == DT_OP_NOP) + return (0); + } else if (dtp->dt_oflags & DTRACE_O_LP64) { + if (ip[0] == DT_OP_REX_RAX && + ip[1] == DT_OP_XOR_EAX_0 && ip[2] == DT_OP_XOR_EAX_1 && + (ip[3] == DT_OP_NOP || ip[3] == DT_OP_RET) && + ip[4] == DT_OP_NOP) { + (*off) += 3; + return (0); + } + } else { + if (ip[0] == DT_OP_XOR_EAX_0 && ip[1] == DT_OP_XOR_EAX_1 && + (ip[2] == DT_OP_NOP || ip[2] == DT_OP_RET) && + ip[3] == DT_OP_NOP && ip[4] == DT_OP_NOP) { + (*off) += 2; + return (0); + } + } + + /* + * We expect either a call instrution with a 32-bit displacement or a + * jmp instruction with a 32-bit displacement acting as a tail-call. + */ + if (ip[0] != DT_OP_CALL && ip[0] != DT_OP_JMP32) { + dt_dprintf("found %x instead of a call or jmp instruction at " + "%llx\n", ip[0], (u_longlong_t)rela->r_offset); + return (-1); + } + + ret = (ip[0] == DT_OP_JMP32) ? DT_OP_RET : DT_OP_NOP; + + /* + * Establish the instruction sequence -- all nops for probes, and an + * instruction to clear the return value register (%eax/%rax) followed + * by nops for is-enabled probes. For is-enabled probes, we advance + * the offset to the first nop. This isn't stricly necessary but makes + * for more readable disassembly when the probe is enabled. + */ + if (!isenabled) { + ip[0] = ret; + ip[1] = DT_OP_NOP; + ip[2] = DT_OP_NOP; + ip[3] = DT_OP_NOP; + ip[4] = DT_OP_NOP; + } else if (dtp->dt_oflags & DTRACE_O_LP64) { + ip[0] = DT_OP_REX_RAX; + ip[1] = DT_OP_XOR_EAX_0; + ip[2] = DT_OP_XOR_EAX_1; + ip[3] = ret; + ip[4] = DT_OP_NOP; + (*off) += 3; + } else { + ip[0] = DT_OP_XOR_EAX_0; + ip[1] = DT_OP_XOR_EAX_1; + ip[2] = ret; + ip[3] = DT_OP_NOP; + ip[4] = DT_OP_NOP; + (*off) += 2; + } + + return (0); +} + +#else +#error unknown ISA +#endif + +/*PRINTFLIKE5*/ +static int +dt_link_error(dtrace_hdl_t *dtp, Elf *elf, int fd, dt_link_pair_t *bufs, + const char *format, ...) +{ + va_list ap; + dt_link_pair_t *pair; + + va_start(ap, format); + dt_set_errmsg(dtp, NULL, NULL, NULL, 0, format, ap); + va_end(ap); + + if (elf != NULL) + (void) elf_end(elf); + + if (fd >= 0) + (void) close(fd); + + while ((pair = bufs) != NULL) { + bufs = pair->dlp_next; + dt_free(dtp, pair->dlp_str); + dt_free(dtp, pair->dlp_sym); + dt_free(dtp, pair); + } + + return (dt_set_errno(dtp, EDT_COMPILER)); +} + +static int +process_obj(dtrace_hdl_t *dtp, const char *obj, int *eprobesp) +{ + static const char dt_prefix[] = "__dtrace"; + static const char dt_enabled[] = "enabled"; + static const char dt_symprefix[] = "$dtrace"; + static const char dt_symfmt[] = "%s%d.%s"; + int fd, i, ndx, eprobe, mod = 0; + Elf *elf = NULL; + GElf_Ehdr ehdr; + Elf_Scn *scn_rel, *scn_sym, *scn_str, *scn_tgt; + Elf_Data *data_rel, *data_sym, *data_str, *data_tgt; + GElf_Shdr shdr_rel, shdr_sym, shdr_str, shdr_tgt; + GElf_Sym rsym, fsym, dsym; + GElf_Rela rela; + char *s, *p, *r; + char pname[DTRACE_PROVNAMELEN]; + dt_provider_t *pvp; + dt_probe_t *prp; + uint32_t off, eclass, emachine1, emachine2; + size_t symsize, nsym, isym, istr, len; + key_t objkey; + dt_link_pair_t *pair, *bufs = NULL; + dt_strtab_t *strtab; + + if ((fd = open64(obj, O_RDWR)) == -1) { + return (dt_link_error(dtp, elf, fd, bufs, + "failed to open %s: %s", obj, strerror(errno))); + } + + if ((elf = elf_begin(fd, ELF_C_RDWR, NULL)) == NULL) { + return (dt_link_error(dtp, elf, fd, bufs, + "failed to process %s: %s", obj, elf_errmsg(elf_errno()))); + } + + switch (elf_kind(elf)) { + case ELF_K_ELF: + break; + case ELF_K_AR: + return (dt_link_error(dtp, elf, fd, bufs, "archives are not " + "permitted; use the contents of the archive instead: %s", + obj)); + default: + return (dt_link_error(dtp, elf, fd, bufs, + "invalid file type: %s", obj)); + } + + if (gelf_getehdr(elf, &ehdr) == NULL) { + return (dt_link_error(dtp, elf, fd, bufs, "corrupt file: %s", + obj)); + } + + if (dtp->dt_oflags & DTRACE_O_LP64) { + eclass = ELFCLASS64; +#if defined(__sparc) + emachine1 = emachine2 = EM_SPARCV9; +#elif defined(__i386) || defined(__amd64) + emachine1 = emachine2 = EM_AMD64; +#endif + symsize = sizeof (Elf64_Sym); + } else { + eclass = ELFCLASS32; +#if defined(__sparc) + emachine1 = EM_SPARC; + emachine2 = EM_SPARC32PLUS; +#elif defined(__i386) || defined(__amd64) + emachine1 = emachine2 = EM_386; +#endif + symsize = sizeof (Elf32_Sym); + } + + if (ehdr.e_ident[EI_CLASS] != eclass) { + return (dt_link_error(dtp, elf, fd, bufs, + "incorrect ELF class for object file: %s", obj)); + } + + if (ehdr.e_machine != emachine1 && ehdr.e_machine != emachine2) { + return (dt_link_error(dtp, elf, fd, bufs, + "incorrect ELF machine type for object file: %s", obj)); + } + + /* + * We use this token as a relatively unique handle for this file on the + * system in order to disambiguate potential conflicts between files of + * the same name which contain identially named local symbols. + */ + if ((objkey = ftok(obj, 0)) == (key_t)-1) { + return (dt_link_error(dtp, elf, fd, bufs, + "failed to generate unique key for object file: %s", obj)); + } + + scn_rel = NULL; + while ((scn_rel = elf_nextscn(elf, scn_rel)) != NULL) { + if (gelf_getshdr(scn_rel, &shdr_rel) == NULL) + goto err; + + /* + * Skip any non-relocation sections. + */ + if (shdr_rel.sh_type != SHT_RELA && shdr_rel.sh_type != SHT_REL) + continue; + + if ((data_rel = elf_getdata(scn_rel, NULL)) == NULL) + goto err; + + /* + * Grab the section, section header and section data for the + * symbol table that this relocation section references. + */ + if ((scn_sym = elf_getscn(elf, shdr_rel.sh_link)) == NULL || + gelf_getshdr(scn_sym, &shdr_sym) == NULL || + (data_sym = elf_getdata(scn_sym, NULL)) == NULL) + goto err; + + /* + * Ditto for that symbol table's string table. + */ + if ((scn_str = elf_getscn(elf, shdr_sym.sh_link)) == NULL || + gelf_getshdr(scn_str, &shdr_str) == NULL || + (data_str = elf_getdata(scn_str, NULL)) == NULL) + goto err; + + /* + * Grab the section, section header and section data for the + * target section for the relocations. For the relocations + * we're looking for -- this will typically be the text of the + * object file. + */ + if ((scn_tgt = elf_getscn(elf, shdr_rel.sh_info)) == NULL || + gelf_getshdr(scn_tgt, &shdr_tgt) == NULL || + (data_tgt = elf_getdata(scn_tgt, NULL)) == NULL) + goto err; + + /* + * We're looking for relocations to symbols matching this form: + * + * __dtrace[enabled]_<prov>___<probe> + * + * For the generated object, we need to record the location + * identified by the relocation, and create a new relocation + * in the generated object that will be resolved at link time + * to the location of the function in which the probe is + * embedded. In the target object, we change the matched symbol + * so that it will be ignored at link time, and we modify the + * target (text) section to replace the call instruction with + * one or more nops. + * + * If the function containing the probe is locally scoped + * (static), we create an alias used by the relocation in the + * generated object. The alias, a new symbol, will be global + * (so that the relocation from the generated object can be + * resolved), and hidden (so that it is converted to a local + * symbol at link time). Such aliases have this form: + * + * $dtrace<key>.<function> + * + * We take a first pass through all the relocations to + * populate our string table and count the number of extra + * symbols we'll require. + */ + strtab = dt_strtab_create(1); + nsym = 0; + isym = data_sym->d_size / symsize; + istr = data_str->d_size; + + for (i = 0; i < shdr_rel.sh_size / shdr_rel.sh_entsize; i++) { + + if (shdr_rel.sh_type == SHT_RELA) { + if (gelf_getrela(data_rel, i, &rela) == NULL) + continue; + } else { + GElf_Rel rel; + if (gelf_getrel(data_rel, i, &rel) == NULL) + continue; + rela.r_offset = rel.r_offset; + rela.r_info = rel.r_info; + rela.r_addend = 0; + } + + if (gelf_getsym(data_sym, GELF_R_SYM(rela.r_info), + &rsym) == NULL) { + dt_strtab_destroy(strtab); + goto err; + } + + s = (char *)data_str->d_buf + rsym.st_name; + + if (strncmp(s, dt_prefix, sizeof (dt_prefix) - 1) != 0) + continue; + + if (dt_symtab_lookup(data_sym, isym, rela.r_offset, + shdr_rel.sh_info, &fsym) != 0) { + dt_strtab_destroy(strtab); + goto err; + } + + if (GELF_ST_BIND(fsym.st_info) != STB_LOCAL) + continue; + + if (fsym.st_name > data_str->d_size) { + dt_strtab_destroy(strtab); + goto err; + } + + s = (char *)data_str->d_buf + fsym.st_name; + + /* + * If this symbol isn't of type function, we've really + * driven off the rails or the object file is corrupt. + */ + if (GELF_ST_TYPE(fsym.st_info) != STT_FUNC) { + dt_strtab_destroy(strtab); + return (dt_link_error(dtp, elf, fd, bufs, + "expected %s to be of type function", s)); + } + + len = snprintf(NULL, 0, dt_symfmt, dt_symprefix, + objkey, s) + 1; + if ((p = dt_alloc(dtp, len)) == NULL) { + dt_strtab_destroy(strtab); + goto err; + } + (void) snprintf(p, len, dt_symfmt, dt_symprefix, + objkey, s); + + if (dt_strtab_index(strtab, p) == -1) { + nsym++; + (void) dt_strtab_insert(strtab, p); + } + + dt_free(dtp, p); + } + + /* + * If needed, allocate the additional space for the symbol + * table and string table copying the old data into the new + * buffers, and marking the buffers as dirty. We inject those + * newly allocated buffers into the libelf data structures, but + * are still responsible for freeing them once we're done with + * the elf handle. + */ + if (nsym > 0) { + /* + * The first byte of the string table is reserved for + * the \0 entry. + */ + len = dt_strtab_size(strtab) - 1; + + assert(len > 0); + assert(dt_strtab_index(strtab, "") == 0); + + dt_strtab_destroy(strtab); + + if ((pair = dt_alloc(dtp, sizeof (*pair))) == NULL) + goto err; + + if ((pair->dlp_str = dt_alloc(dtp, data_str->d_size + + len)) == NULL) { + dt_free(dtp, pair); + goto err; + } + + if ((pair->dlp_sym = dt_alloc(dtp, data_sym->d_size + + nsym * symsize)) == NULL) { + dt_free(dtp, pair->dlp_str); + dt_free(dtp, pair); + goto err; + } + + pair->dlp_next = bufs; + bufs = pair; + + bcopy(data_str->d_buf, pair->dlp_str, data_str->d_size); + data_str->d_buf = pair->dlp_str; + data_str->d_size += len; + (void) elf_flagdata(data_str, ELF_C_SET, ELF_F_DIRTY); + + shdr_str.sh_size += len; + (void) gelf_update_shdr(scn_str, &shdr_str); + + bcopy(data_sym->d_buf, pair->dlp_sym, data_sym->d_size); + data_sym->d_buf = pair->dlp_sym; + data_sym->d_size += nsym * symsize; + (void) elf_flagdata(data_sym, ELF_C_SET, ELF_F_DIRTY); + + shdr_sym.sh_size += nsym * symsize; + (void) gelf_update_shdr(scn_sym, &shdr_sym); + + nsym += isym; + } else { + dt_strtab_destroy(strtab); + } + + /* + * Now that the tables have been allocated, perform the + * modifications described above. + */ + for (i = 0; i < shdr_rel.sh_size / shdr_rel.sh_entsize; i++) { + + if (shdr_rel.sh_type == SHT_RELA) { + if (gelf_getrela(data_rel, i, &rela) == NULL) + continue; + } else { + GElf_Rel rel; + if (gelf_getrel(data_rel, i, &rel) == NULL) + continue; + rela.r_offset = rel.r_offset; + rela.r_info = rel.r_info; + rela.r_addend = 0; + } + + ndx = GELF_R_SYM(rela.r_info); + + if (gelf_getsym(data_sym, ndx, &rsym) == NULL || + rsym.st_name > data_str->d_size) + goto err; + + s = (char *)data_str->d_buf + rsym.st_name; + + if (strncmp(s, dt_prefix, sizeof (dt_prefix) - 1) != 0) + continue; + + s += sizeof (dt_prefix) - 1; + + /* + * Check to see if this is an 'is-enabled' check as + * opposed to a normal probe. + */ + if (strncmp(s, dt_enabled, + sizeof (dt_enabled) - 1) == 0) { + s += sizeof (dt_enabled) - 1; + eprobe = 1; + *eprobesp = 1; + dt_dprintf("is-enabled probe\n"); + } else { + eprobe = 0; + dt_dprintf("normal probe\n"); + } + + if (*s++ != '_') + goto err; + + if ((p = strstr(s, "___")) == NULL || + p - s >= sizeof (pname)) + goto err; + + bcopy(s, pname, p - s); + pname[p - s] = '\0'; + + p = strhyphenate(p + 3); /* strlen("___") */ + + if (dt_symtab_lookup(data_sym, isym, rela.r_offset, + shdr_rel.sh_info, &fsym) != 0) + goto err; + + if (fsym.st_name > data_str->d_size) + goto err; + + assert(GELF_ST_TYPE(fsym.st_info) == STT_FUNC); + + /* + * If a NULL relocation name is passed to + * dt_probe_define(), the function name is used for the + * relocation. The relocation needs to use a mangled + * name if the symbol is locally scoped; the function + * name may need to change if we've found the global + * alias for the locally scoped symbol (we prefer + * global symbols to locals in dt_symtab_lookup()). + */ + s = (char *)data_str->d_buf + fsym.st_name; + r = NULL; + + if (GELF_ST_BIND(fsym.st_info) == STB_LOCAL) { + dsym = fsym; + dsym.st_name = istr; + dsym.st_info = GELF_ST_INFO(STB_GLOBAL, + STT_FUNC); + dsym.st_other = + ELF64_ST_VISIBILITY(STV_ELIMINATE); + (void) gelf_update_sym(data_sym, isym, &dsym); + + r = (char *)data_str->d_buf + istr; + istr += 1 + sprintf(r, dt_symfmt, + dt_symprefix, objkey, s); + isym++; + assert(isym <= nsym); + + } else if (strncmp(s, dt_symprefix, + strlen(dt_symprefix)) == 0) { + r = s; + if ((s = strchr(s, '.')) == NULL) + goto err; + s++; + } + + if ((pvp = dt_provider_lookup(dtp, pname)) == NULL) { + return (dt_link_error(dtp, elf, fd, bufs, + "no such provider %s", pname)); + } + + if ((prp = dt_probe_lookup(pvp, p)) == NULL) { + return (dt_link_error(dtp, elf, fd, bufs, + "no such probe %s", p)); + } + + assert(fsym.st_value <= rela.r_offset); + + off = rela.r_offset - fsym.st_value; + if (dt_modtext(dtp, data_tgt->d_buf, eprobe, + &rela, &off) != 0) { + goto err; + } + + if (dt_probe_define(pvp, prp, s, r, off, eprobe) != 0) { + return (dt_link_error(dtp, elf, fd, bufs, + "failed to allocate space for probe")); + } + + mod = 1; + (void) elf_flagdata(data_tgt, ELF_C_SET, ELF_F_DIRTY); + + /* + * This symbol may already have been marked to + * be ignored by another relocation referencing + * the same symbol or if this object file has + * already been processed by an earlier link + * invocation. + */ + if (rsym.st_shndx != SHN_SUNW_IGNORE) { + rsym.st_shndx = SHN_SUNW_IGNORE; + (void) gelf_update_sym(data_sym, ndx, &rsym); + } + } + } + + if (mod && elf_update(elf, ELF_C_WRITE) == -1) + goto err; + + (void) elf_end(elf); + (void) close(fd); + + while ((pair = bufs) != NULL) { + bufs = pair->dlp_next; + dt_free(dtp, pair->dlp_str); + dt_free(dtp, pair->dlp_sym); + dt_free(dtp, pair); + } + + return (0); + +err: + return (dt_link_error(dtp, elf, fd, bufs, + "an error was encountered while processing %s", obj)); +} + +int +dtrace_program_link(dtrace_hdl_t *dtp, dtrace_prog_t *pgp, uint_t dflags, + const char *file, int objc, char *const objv[]) +{ + char drti[PATH_MAX]; + dof_hdr_t *dof; + int fd, status, i, cur; + char *cmd, tmp; + size_t len; + int eprobes = 0, ret = 0; + + /* + * A NULL program indicates a special use in which we just link + * together a bunch of object files specified in objv and then + * unlink(2) those object files. + */ + if (pgp == NULL) { + const char *fmt = "%s -o %s -r"; + + len = snprintf(&tmp, 1, fmt, dtp->dt_ld_path, file) + 1; + + for (i = 0; i < objc; i++) + len += strlen(objv[i]) + 1; + + cmd = alloca(len); + + cur = snprintf(cmd, len, fmt, dtp->dt_ld_path, file); + + for (i = 0; i < objc; i++) + cur += snprintf(cmd + cur, len - cur, " %s", objv[i]); + + if ((status = system(cmd)) == -1) { + return (dt_link_error(dtp, NULL, -1, NULL, + "failed to run %s: %s", dtp->dt_ld_path, + strerror(errno))); + } + + if (WIFSIGNALED(status)) { + return (dt_link_error(dtp, NULL, -1, NULL, + "failed to link %s: %s failed due to signal %d", + file, dtp->dt_ld_path, WTERMSIG(status))); + } + + if (WEXITSTATUS(status) != 0) { + return (dt_link_error(dtp, NULL, -1, NULL, + "failed to link %s: %s exited with status %d\n", + file, dtp->dt_ld_path, WEXITSTATUS(status))); + } + + for (i = 0; i < objc; i++) { + if (strcmp(objv[i], file) != 0) + (void) unlink(objv[i]); + } + + return (0); + } + + for (i = 0; i < objc; i++) { + if (process_obj(dtp, objv[i], &eprobes) != 0) + return (-1); /* errno is set for us */ + } + + /* + * If there are is-enabled probes then we need to force use of DOF + * version 2. + */ + if (eprobes && pgp->dp_dofversion < DOF_VERSION_2) + pgp->dp_dofversion = DOF_VERSION_2; + + if ((dof = dtrace_dof_create(dtp, pgp, dflags)) == NULL) + return (-1); /* errno is set for us */ + + /* + * Create a temporary file and then unlink it if we're going to + * combine it with drti.o later. We can still refer to it in child + * processes as /dev/fd/<fd>. + */ + if ((fd = open64(file, O_RDWR | O_CREAT | O_TRUNC, 0666)) == -1) { + return (dt_link_error(dtp, NULL, -1, NULL, + "failed to open %s: %s", file, strerror(errno))); + } + + /* + * If -xlinktype=DOF has been selected, just write out the DOF. + * Otherwise proceed to the default of generating and linking ELF. + */ + switch (dtp->dt_linktype) { + case DT_LTYP_DOF: + if (dt_write(dtp, fd, dof, dof->dofh_filesz) < dof->dofh_filesz) + ret = errno; + + if (close(fd) != 0 && ret == 0) + ret = errno; + + if (ret != 0) { + return (dt_link_error(dtp, NULL, -1, NULL, + "failed to write %s: %s", file, strerror(ret))); + } + + return (0); + + case DT_LTYP_ELF: + break; /* fall through to the rest of dtrace_program_link() */ + + default: + return (dt_link_error(dtp, NULL, -1, NULL, + "invalid link type %u\n", dtp->dt_linktype)); + } + + + if (!dtp->dt_lazyload) + (void) unlink(file); + + if (dtp->dt_oflags & DTRACE_O_LP64) + status = dump_elf64(dtp, dof, fd); + else + status = dump_elf32(dtp, dof, fd); + + if (status != 0 || lseek(fd, 0, SEEK_SET) != 0) { + return (dt_link_error(dtp, NULL, -1, NULL, + "failed to write %s: %s", file, strerror(errno))); + } + + if (!dtp->dt_lazyload) { + const char *fmt = "%s -o %s -r -Blocal -Breduce /dev/fd/%d %s"; + + if (dtp->dt_oflags & DTRACE_O_LP64) { + (void) snprintf(drti, sizeof (drti), + "%s/64/drti.o", _dtrace_libdir); + } else { + (void) snprintf(drti, sizeof (drti), + "%s/drti.o", _dtrace_libdir); + } + + len = snprintf(&tmp, 1, fmt, dtp->dt_ld_path, file, fd, + drti) + 1; + + cmd = alloca(len); + + (void) snprintf(cmd, len, fmt, dtp->dt_ld_path, file, fd, drti); + + if ((status = system(cmd)) == -1) { + ret = dt_link_error(dtp, NULL, -1, NULL, + "failed to run %s: %s", dtp->dt_ld_path, + strerror(errno)); + goto done; + } + + (void) close(fd); /* release temporary file */ + + if (WIFSIGNALED(status)) { + ret = dt_link_error(dtp, NULL, -1, NULL, + "failed to link %s: %s failed due to signal %d", + file, dtp->dt_ld_path, WTERMSIG(status)); + goto done; + } + + if (WEXITSTATUS(status) != 0) { + ret = dt_link_error(dtp, NULL, -1, NULL, + "failed to link %s: %s exited with status %d\n", + file, dtp->dt_ld_path, WEXITSTATUS(status)); + goto done; + } + } else { + (void) close(fd); + } + +done: + dtrace_dof_destroy(dtp, dof); + return (ret); +} |