Author: kib
Date: Mon Apr 30 13:29:21 2012
New Revision: 234840
URL: http://svn.freebsd.org/changeset/base/234840
Log:
Split the symlook_obj1 into a loop iterating over the ELF object symbol
hash elements, and a helper matched_symbol() which match the given hash
entry and request, performing needed type and version checks.
Based on dragonflybsd support for GNU hash by John Marino <draco marino st>
Reviewed by: kan
Tested by: bapt
MFC after: 2 weeks
Modified:
head/libexec/rtld-elf/rtld.c
head/libexec/rtld-elf/rtld.h
Modified: head/libexec/rtld-elf/rtld.c
==============================================================================
--- head/libexec/rtld-elf/rtld.c Mon Apr 30 13:07:21 2012
(r234839)
+++ head/libexec/rtld-elf/rtld.c Mon Apr 30 13:29:21 2012
(r234840)
@@ -1,7 +1,8 @@
/*-
* Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra.
* Copyright 2003 Alexander Kabaev <k...@freebsd.org>.
- * Copyright 2009, 2010, 2011 Konstantin Belousov <k...@freebsd.org>.
+ * Copyright 2009-2012 Konstantin Belousov <k...@freebsd.org>.
+ * Copyright 2012 John Marino <dr...@marino.st>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -149,6 +150,8 @@ static int object_match_name(const Obj_
static void ld_utrace_log(int, void *, void *, size_t, int, const char *);
static void rtld_fill_dl_phdr_info(const Obj_Entry *obj,
struct dl_phdr_info *phdr_info);
+static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *,
+ const unsigned long);
void r_debug_state(struct r_debug *, struct link_map *) __noinline;
@@ -3439,28 +3442,15 @@ symlook_obj(SymLook *req, const Obj_Entr
return (mres);
}
-static int
-symlook_obj1(SymLook *req, const Obj_Entry *obj)
+/* Symbol match routine common to both hash functions */
+static bool
+matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result,
+ const unsigned long symnum)
{
- unsigned long symnum;
- const Elf_Sym *vsymp;
- Elf_Versym verndx;
- int vcount;
-
- if (obj->buckets == NULL)
- return (ESRCH);
-
- vsymp = NULL;
- vcount = 0;
- symnum = obj->buckets[req->hash % obj->nbuckets];
-
- for (; symnum != STN_UNDEF; symnum = obj->chains[symnum]) {
+ Elf_Versym verndx;
const Elf_Sym *symp;
const char *strp;
- if (symnum >= obj->nchains)
- return (ESRCH); /* Bad object */
-
symp = obj->symtab + symnum;
strp = obj->strtab + symp->st_name;
@@ -3468,103 +3458,128 @@ symlook_obj1(SymLook *req, const Obj_Ent
case STT_FUNC:
case STT_NOTYPE:
case STT_OBJECT:
+ case STT_COMMON:
case STT_GNU_IFUNC:
- if (symp->st_value == 0)
- continue;
+ if (symp->st_value == 0)
+ return (false);
/* fallthrough */
case STT_TLS:
- if (symp->st_shndx != SHN_UNDEF)
- break;
+ if (symp->st_shndx != SHN_UNDEF)
+ break;
#ifndef __mips__
- else if (((req->flags & SYMLOOK_IN_PLT) == 0) &&
- (ELF_ST_TYPE(symp->st_info) == STT_FUNC))
- break;
+ else if (((req->flags & SYMLOOK_IN_PLT) == 0) &&
+ (ELF_ST_TYPE(symp->st_info) == STT_FUNC))
+ break;
/* fallthrough */
#endif
default:
- continue;
+ return (false);
}
if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0)
- continue;
+ return (false);
if (req->ventry == NULL) {
- if (obj->versyms != NULL) {
- verndx = VER_NDX(obj->versyms[symnum]);
- if (verndx > obj->vernum) {
- _rtld_error("%s: symbol %s references wrong version %d",
- obj->path, obj->strtab + symnum, verndx);
- continue;
- }
- /*
- * If we are not called from dlsym (i.e. this is a normal
- * relocation from unversioned binary), accept the symbol
- * immediately if it happens to have first version after
- * this shared object became versioned. Otherwise, if
- * symbol is versioned and not hidden, remember it. If it
- * is the only symbol with this name exported by the
- * shared object, it will be returned as a match at the
- * end of the function. If symbol is global (verndx < 2)
- * accept it unconditionally.
- */
- if ((req->flags & SYMLOOK_DLSYM) == 0 &&
- verndx == VER_NDX_GIVEN) {
- req->sym_out = symp;
- req->defobj_out = obj;
- return (0);
- }
- else if (verndx >= VER_NDX_GIVEN) {
- if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 0) {
- if (vsymp == NULL)
- vsymp = symp;
- vcount ++;
- }
- continue;
+ if (obj->versyms != NULL) {
+ verndx = VER_NDX(obj->versyms[symnum]);
+ if (verndx > obj->vernum) {
+ _rtld_error(
+ "%s: symbol %s references wrong version %d",
+ obj->path, obj->strtab + symnum, verndx);
+ return (false);
+ }
+ /*
+ * If we are not called from dlsym (i.e. this
+ * is a normal relocation from unversioned
+ * binary), accept the symbol immediately if
+ * it happens to have first version after this
+ * shared object became versioned. Otherwise,
+ * if symbol is versioned and not hidden,
+ * remember it. If it is the only symbol with
+ * this name exported by the shared object, it
+ * will be returned as a match by the calling
+ * function. If symbol is global (verndx < 2)
+ * accept it unconditionally.
+ */
+ if ((req->flags & SYMLOOK_DLSYM) == 0 &&
+ verndx == VER_NDX_GIVEN) {
+ result->sym_out = symp;
+ return (true);
+ }
+ else if (verndx >= VER_NDX_GIVEN) {
+ if ((obj->versyms[symnum] & VER_NDX_HIDDEN)
+ == 0) {
+ if (result->vsymp == NULL)
+ result->vsymp = symp;
+ result->vcount++;
+ }
+ return (false);
+ }
}
- }
- req->sym_out = symp;
- req->defobj_out = obj;
- return (0);
- } else {
- if (obj->versyms == NULL) {
+ result->sym_out = symp;
+ return (true);
+ }
+ if (obj->versyms == NULL) {
if (object_match_name(obj, req->ventry->name)) {
- _rtld_error("%s: object %s should provide version %s for "
- "symbol %s", obj_rtld.path, obj->path,
- req->ventry->name, obj->strtab + symnum);
- continue;
+ _rtld_error("%s: object %s should provide version %s "
+ "for symbol %s", obj_rtld.path, obj->path,
+ req->ventry->name, obj->strtab + symnum);
+ return (false);
}
- } else {
+ } else {
verndx = VER_NDX(obj->versyms[symnum]);
if (verndx > obj->vernum) {
- _rtld_error("%s: symbol %s references wrong version %d",
- obj->path, obj->strtab + symnum, verndx);
- continue;
+ _rtld_error("%s: symbol %s references wrong version %d",
+ obj->path, obj->strtab + symnum, verndx);
+ return (false);
}
if (obj->vertab[verndx].hash != req->ventry->hash ||
strcmp(obj->vertab[verndx].name, req->ventry->name)) {
- /*
- * Version does not match. Look if this is a global symbol
- * and if it is not hidden. If global symbol (verndx < 2)
- * is available, use it. Do not return symbol if we are
- * called by dlvsym, because dlvsym looks for a specific
- * version and default one is not what dlvsym wants.
- */
- if ((req->flags & SYMLOOK_DLSYM) ||
- (obj->versyms[symnum] & VER_NDX_HIDDEN) ||
- (verndx >= VER_NDX_GIVEN))
- continue;
+ /*
+ * Version does not match. Look if this is a
+ * global symbol and if it is not hidden. If
+ * global symbol (verndx < 2) is available,
+ * use it. Do not return symbol if we are
+ * called by dlvsym, because dlvsym looks for
+ * a specific version and default one is not
+ * what dlvsym wants.
+ */
+ if ((req->flags & SYMLOOK_DLSYM) ||
+ (verndx >= VER_NDX_GIVEN) ||
+ (obj->versyms[symnum] & VER_NDX_HIDDEN))
+ return (false);
}
- }
- req->sym_out = symp;
- req->defobj_out = obj;
- return (0);
}
- }
- if (vcount == 1) {
- req->sym_out = vsymp;
- req->defobj_out = obj;
- return (0);
- }
- return (ESRCH);
+ result->sym_out = symp;
+ return (true);
+}
+
+static int
+symlook_obj1(SymLook *req, const Obj_Entry *obj)
+{
+ unsigned long symnum;
+ Sym_Match_Result matchres;
+
+ matchres.sym_out = NULL;
+ matchres.vsymp = NULL;
+ matchres.vcount = 0;
+
+ for (symnum = obj->buckets[req->hash % obj->nbuckets];
+ symnum != STN_UNDEF; symnum = obj->chains[symnum]) {
+ if (symnum >= obj->nchains)
+ return (ESRCH); /* Bad object */
+
+ if (matched_symbol(req, obj, &matchres, symnum)) {
+ req->sym_out = matchres.sym_out;
+ req->defobj_out = obj;
+ return (0);
+ }
+ }
+ if (matchres.vcount == 1) {
+ req->sym_out = matchres.vsymp;
+ req->defobj_out = obj;
+ return (0);
+ }
+ return (ESRCH);
}
static void
Modified: head/libexec/rtld-elf/rtld.h
==============================================================================
--- head/libexec/rtld-elf/rtld.h Mon Apr 30 13:07:21 2012
(r234839)
+++ head/libexec/rtld-elf/rtld.h Mon Apr 30 13:29:21 2012
(r234840)
@@ -126,6 +126,12 @@ typedef struct Struct_Ver_Entry {
const char *file;
} Ver_Entry;
+typedef struct Struct_Sym_Match_Result {
+ const Elf_Sym *sym_out;
+ const Elf_Sym *vsymp;
+ int vcount;
+} Sym_Match_Result;
+
#define VER_INFO_HIDDEN 0x01
/*
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