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path: root/cddl/contrib/opensolaris/lib/libdtrace/common/dt_link.c
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Diffstat (limited to 'cddl/contrib/opensolaris/lib/libdtrace/common/dt_link.c')
-rw-r--r--cddl/contrib/opensolaris/lib/libdtrace/common/dt_link.c148
1 files changed, 55 insertions, 93 deletions
diff --git a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_link.c b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_link.c
index f13e10769250..c52826c6b818 100644
--- a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_link.c
+++ b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_link.c
@@ -237,7 +237,7 @@ printf("%s:%s(%d): DOODAD\n",__FUNCTION__,__FILE__,__LINE__);
rel->r_offset = s->dofs_offset +
dofr[j].dofr_offset;
rel->r_info = ELF32_R_INFO(count + dep->de_global,
- R_386_32);
+ R_386_PC32);
#elif defined(__mips__)
/* XXX */
printf("%s:%s(%d): DOODAD\n",__FUNCTION__,__FILE__,__LINE__);
@@ -253,15 +253,6 @@ printf("%s:%s(%d): DOODAD\n",__FUNCTION__,__FILE__,__LINE__);
#elif defined(__riscv__)
/* XXX */
printf("%s:%s(%d): DOODAD\n",__FUNCTION__,__FILE__,__LINE__);
-#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
@@ -270,7 +261,7 @@ printf("%s:%s(%d): DOODAD\n",__FUNCTION__,__FILE__,__LINE__);
sym->st_value = 0;
sym->st_size = 0;
sym->st_info = ELF32_ST_INFO(STB_GLOBAL, STT_FUNC);
- sym->st_other = 0;
+ sym->st_other = ELF32_ST_VISIBILITY(STV_HIDDEN);
sym->st_shndx = SHN_UNDEF;
rel++;
@@ -287,11 +278,7 @@ printf("%s:%s(%d): DOODAD\n",__FUNCTION__,__FILE__,__LINE__);
sym->st_value = 0;
sym->st_size = dof->dofh_filesz;
sym->st_info = ELF32_ST_INFO(STB_GLOBAL, STT_OBJECT);
-#ifdef illumos
- sym->st_other = 0;
-#else
sym->st_other = ELF32_ST_VISIBILITY(STV_HIDDEN);
-#endif
sym->st_shndx = ESHDR_DOF;
sym++;
@@ -448,18 +435,8 @@ prepare_elf64(dtrace_hdl_t *dtp, const dof_hdr_t *dof, dof_elf64_t *dep)
#elif defined(__i386) || defined(__amd64)
rel->r_offset = s->dofs_offset +
dofr[j].dofr_offset;
-#ifdef illumos
rel->r_info = ELF64_R_INFO(count + dep->de_global,
- R_AMD64_64);
-#else
- rel->r_info = ELF64_R_INFO(count + dep->de_global,
- R_X86_64_RELATIVE);
-#endif
-#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);
+ R_X86_64_PC64);
#else
#error unknown ISA
#endif
@@ -468,7 +445,7 @@ prepare_elf64(dtrace_hdl_t *dtp, const dof_hdr_t *dof, dof_elf64_t *dep)
sym->st_value = 0;
sym->st_size = 0;
sym->st_info = GELF_ST_INFO(STB_GLOBAL, STT_FUNC);
- sym->st_other = 0;
+ sym->st_other = ELF64_ST_VISIBILITY(STV_HIDDEN);
sym->st_shndx = SHN_UNDEF;
rel++;
@@ -485,11 +462,7 @@ prepare_elf64(dtrace_hdl_t *dtp, const dof_hdr_t *dof, dof_elf64_t *dep)
sym->st_value = 0;
sym->st_size = dof->dofh_filesz;
sym->st_info = GELF_ST_INFO(STB_GLOBAL, STT_OBJECT);
-#ifdef illumos
- sym->st_other = 0;
-#else
sym->st_other = ELF64_ST_VISIBILITY(STV_HIDDEN);
-#endif
sym->st_shndx = ESHDR_DOF;
sym++;
@@ -797,16 +770,15 @@ dump_elf64(dtrace_hdl_t *dtp, const dof_hdr_t *dof, int fd)
}
static int
-dt_symtab_lookup(Elf_Data *data_sym, int nsym, uintptr_t addr, uint_t shn,
- GElf_Sym *sym, int uses_funcdesc, Elf *elf)
+dt_symtab_lookup(Elf_Data *data_sym, int start, int end, uintptr_t addr,
+ uint_t shn, GElf_Sym *sym, int uses_funcdesc, Elf *elf)
{
- int i, ret = -1;
Elf64_Addr symval;
Elf_Scn *opd_scn;
Elf_Data *opd_desc;
- GElf_Sym s;
+ int i;
- for (i = 0; i < nsym && gelf_getsym(data_sym, i, sym) != NULL; i++) {
+ for (i = start; i < end && gelf_getsym(data_sym, i, sym) != NULL; i++) {
if (GELF_ST_TYPE(sym->st_info) == STT_FUNC) {
symval = sym->st_value;
if (uses_funcdesc) {
@@ -816,20 +788,12 @@ dt_symtab_lookup(Elf_Data *data_sym, int nsym, uintptr_t addr, uint_t shn,
*(uint64_t*)((char *)opd_desc->d_buf + symval);
}
if ((uses_funcdesc || shn == sym->st_shndx) &&
- symval <= addr &&
- addr < symval + sym->st_size) {
- if (GELF_ST_BIND(sym->st_info) == STB_GLOBAL)
- return (0);
-
- ret = 0;
- s = *sym;
- }
+ symval <= addr && addr < symval + sym->st_size)
+ return (0);
}
}
- if (ret == 0)
- *sym = s;
- return (ret);
+ return (-1);
}
#if defined(__aarch64__)
@@ -1237,10 +1201,11 @@ process_obj(dtrace_hdl_t *dtp, const char *obj, int *eprobesp)
dt_provider_t *pvp;
dt_probe_t *prp;
uint32_t off, eclass, emachine1, emachine2;
- size_t symsize, nsym, isym, istr, len;
+ size_t symsize, osym, nsym, isym, istr, len;
key_t objkey;
dt_link_pair_t *pair, *bufs = NULL;
dt_strtab_t *strtab;
+ void *tmp;
if ((fd = open64(obj, O_RDWR)) == -1) {
return (dt_link_error(dtp, elf, fd, bufs,
@@ -1374,12 +1339,13 @@ process_obj(dtrace_hdl_t *dtp, const char *obj, int *eprobesp)
* 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:
+ * To avoid runtime overhead, the relocations added to the
+ * generated object should be resolved at static link time. We
+ * therefore create aliases for the functions that contain
+ * probes. An alias is global (so that the relocation from the
+ * generated object can be resolved), and hidden (so that its
+ * address is known at static link time). Such aliases have this
+ * form:
*
* $dtrace<key>.<function>
*
@@ -1417,16 +1383,13 @@ process_obj(dtrace_hdl_t *dtp, const char *obj, int *eprobesp)
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,
- (emachine1 == EM_PPC64), elf) != 0) {
+ if (dt_symtab_lookup(data_sym, 0, isym, rela.r_offset,
+ shdr_rel.sh_info, &fsym, (emachine1 == EM_PPC64),
+ elf) != 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;
@@ -1462,12 +1425,12 @@ process_obj(dtrace_hdl_t *dtp, const char *obj, int *eprobesp)
}
/*
- * 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 any probes were found, 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) {
/*
@@ -1501,7 +1464,9 @@ process_obj(dtrace_hdl_t *dtp, const char *obj, int *eprobesp)
bufs = pair;
bcopy(data_str->d_buf, pair->dlp_str, data_str->d_size);
+ tmp = data_str->d_buf;
data_str->d_buf = pair->dlp_str;
+ pair->dlp_str = tmp;
data_str->d_size += len;
(void) elf_flagdata(data_str, ELF_C_SET, ELF_F_DIRTY);
@@ -1509,16 +1474,20 @@ process_obj(dtrace_hdl_t *dtp, const char *obj, int *eprobesp)
(void) gelf_update_shdr(scn_str, &shdr_str);
bcopy(data_sym->d_buf, pair->dlp_sym, data_sym->d_size);
+ tmp = data_sym->d_buf;
data_sym->d_buf = pair->dlp_sym;
+ pair->dlp_sym = tmp;
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);
+ osym = isym;
nsym += isym;
} else {
dt_strtab_destroy(strtab);
+ continue;
}
/*
@@ -1577,8 +1546,11 @@ process_obj(dtrace_hdl_t *dtp, const char *obj, int *eprobesp)
bcopy(s, pname, p - s);
pname[p - s] = '\0';
- if (dt_symtab_lookup(data_sym, isym, rela.r_offset,
- shdr_rel.sh_info, &fsym,
+ if (dt_symtab_lookup(data_sym, osym, isym,
+ rela.r_offset, shdr_rel.sh_info, &fsym,
+ (emachine1 == EM_PPC64), elf) != 0 &&
+ dt_symtab_lookup(data_sym, 0, osym,
+ rela.r_offset, shdr_rel.sh_info, &fsym,
(emachine1 == EM_PPC64), elf) != 0)
goto err;
@@ -1588,37 +1560,30 @@ process_obj(dtrace_hdl_t *dtp, const char *obj, int *eprobesp)
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()).
+ * If this is our first time encountering this symbol,
+ * emit an alias.
*/
s = (char *)data_str->d_buf + fsym.st_name;
- r = NULL;
- if (GELF_ST_BIND(fsym.st_info) == STB_LOCAL) {
+ if (strncmp(s, dt_symprefix,
+ sizeof (dt_symprefix) - 1) != 0) {
+ u_int bind = GELF_ST_BIND(fsym.st_info);
+
dsym = fsym;
dsym.st_name = istr;
- dsym.st_info = GELF_ST_INFO(STB_GLOBAL,
- STT_FUNC);
- dsym.st_other =
- ELF64_ST_VISIBILITY(STV_ELIMINATE);
+ dsym.st_info = GELF_ST_INFO(bind == STB_LOCAL ?
+ STB_GLOBAL : bind, STT_FUNC);
+ dsym.st_other = GELF_ST_VISIBILITY(STV_HIDDEN);
(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);
+ 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) {
+ } else {
r = s;
- if ((s = strchr(s, '.')) == NULL)
- goto err;
+ s = strchr(s, '.');
+ assert(s != NULL);
s++;
}
@@ -1697,9 +1662,6 @@ process_obj(dtrace_hdl_t *dtp, const char *obj, int *eprobesp)
(void) elf_end(elf);
(void) close(fd);
-#ifndef illumos
- if (nsym > 0)
-#endif
while ((pair = bufs) != NULL) {
bufs = pair->dlp_next;
dt_free(dtp, pair->dlp_str);
generated by cgit v1.2.3 (git 2.25.1) at 2025-11-07 15:24:18 +0000