Symbol cache for GOT lookup. When a symbol is found it is saved in a cache

for future lookups in the same GOT relocation table. Uses static buffer
for small symbol tables, mmap for larger ones. ok deraadt@

9 files changed, 123 insertions, 28 deletions

diff --git a/libexec/ld.so/alpha/rtld_machine.c b/libexec/ld.so/alpha/rtld_machine.c
index 8a2c61b9230..5dfd9864f13 100644
--- a/libexec/ld.so/alpha/rtld_machine.c
+++ b/libexec/ld.so/alpha/rtld_machine.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rtld_machine.c,v 1.26 2003/09/02 15:17:51 drahn Exp $ */
+/*	$OpenBSD: rtld_machine.c,v 1.27 2003/09/04 19:33:49 drahn Exp $ */
 
 /*
  * Copyright (c) 1999 Dale Rahn
@@ -107,9 +107,10 @@ _dl_md_reloc(elf_object_t *object, int rel, int relasz)
 		this = NULL;
 		switch (ELF64_R_TYPE(relas->r_info)) {
 		case R_TYPE(REFQUAD):
-			ooff = _dl_find_symbol(symn, _dl_objects, &this,
+			ooff =  _dl_find_symbol_bysym(object,
+			    ELF64_R_SYM(relas->r_info), _dl_objects, &this,
 			    SYM_SEARCH_ALL|SYM_WARNNOTFOUND|SYM_NOTPLT,
-			    sym->st_size, object);
+			    sym->st_size);
 			if (this == NULL)
 				goto resolve_failed;
 			*r_addr += ooff + this->st_value + relas->r_addend;
@@ -140,9 +141,10 @@ _dl_printf("unaligned RELATIVE: %p type: %d %s 0x%lx -> 0x%lx\n", r_addr,
 			*r_addr = ooff + this->st_value + relas->r_addend;
 			break;
 		case R_TYPE(GLOB_DAT):
-			ooff = _dl_find_symbol(symn, _dl_objects, &this,
+			ooff =  _dl_find_symbol_bysym(object,
+			    ELF64_R_SYM(relas->r_info), _dl_objects, &this,
 			    SYM_SEARCH_ALL|SYM_WARNNOTFOUND|SYM_NOTPLT,
-			    sym->st_size, object);
+			    sym->st_size);
 			if (this == NULL)
 				goto resolve_failed;
 			*r_addr = ooff + this->st_value + relas->r_addend;
diff --git a/libexec/ld.so/dlfcn.c b/libexec/ld.so/dlfcn.c
index b1e03fcca79..752c70a2085 100644
--- a/libexec/ld.so/dlfcn.c
+++ b/libexec/ld.so/dlfcn.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dlfcn.c,v 1.30 2003/09/02 15:17:51 drahn Exp $ */
+/*	$OpenBSD: dlfcn.c,v 1.31 2003/09/04 19:33:48 drahn Exp $ */
 
 /*
  * Copyright (c) 1998 Per Fogelstrom, Opsycon AB
@@ -304,6 +304,13 @@ _dl_show_objects(void)
 		    objtypename, object->refcount, object->load_name);
 		object = object->next;
 	}
+	{
+		extern int _dl_symcachestat_hits;
+		extern int _dl_symcachestat_lookups;
+	DL_DEB(("symcache lookups %d hits %d ratio %d% hits\n",
+	    _dl_symcachestat_lookups, _dl_symcachestat_hits,
+	    (_dl_symcachestat_hits * 100) / _dl_symcachestat_lookups));
+	}
 }
 
 static void
diff --git a/libexec/ld.so/i386/rtld_machine.c b/libexec/ld.so/i386/rtld_machine.c
index 971c1a9ea3e..326321ef763 100644
--- a/libexec/ld.so/i386/rtld_machine.c
+++ b/libexec/ld.so/i386/rtld_machine.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rtld_machine.c,v 1.11 2003/09/02 15:17:51 drahn Exp $ */
+/*	$OpenBSD: rtld_machine.c,v 1.12 2003/09/04 19:33:49 drahn Exp $ */
 
 /*
  * Copyright (c) 2002 Dale Rahn
@@ -237,11 +237,12 @@ _dl_md_reloc(elf_object_t *object, int rel, int relsz)
 				value += loff;
 			} else {
 				this = NULL;
-				ooff = _dl_find_symbol(symn, _dl_objects,
+				ooff = _dl_find_symbol_bysym(object,
+				    ELF_R_SYM(rels->r_info), _dl_objects,
 				    &this, SYM_SEARCH_ALL|SYM_WARNNOTFOUND|
 				    ((type == R_TYPE(JUMP_SLOT))?
 					SYM_PLT:SYM_NOTPLT),
-				    sym->st_size, object);
+				    sym->st_size);
 				if (this == NULL) {
 resolve_failed:
 					_dl_printf("%s: %s: can't resolve "
diff --git a/libexec/ld.so/loader.c b/libexec/ld.so/loader.c
index a6d77780a1f..dac1f42f17b 100644
--- a/libexec/ld.so/loader.c
+++ b/libexec/ld.so/loader.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: loader.c,v 1.67 2003/09/02 15:17:51 drahn Exp $ */
+/*	$OpenBSD: loader.c,v 1.68 2003/09/04 19:33:48 drahn Exp $ */
 
 /*
  * Copyright (c) 1998 Per Fogelstrom, Opsycon AB
@@ -42,6 +42,7 @@
 #include "archdep.h"
 #include "resolve.h"
 #include "sod.h"
+#include "stdlib.h"
 
 /*
  * Local decls.
@@ -599,21 +600,50 @@ _dl_boot_bind(const long sp, long *dl_data, Elf_Dyn *dynamicp)
 	 */
 }
 
+#define DL_SM_SYMBUF_CNT 512
+sym_cache _dl_sm_symcache_buffer[DL_SM_SYMBUF_CNT];
+
 void
 _dl_rtld(elf_object_t *object)
 {
+	size_t sz;
 	if (object->next)
 		_dl_rtld(object->next);
 
 	if (object->status & STAT_RELOC_DONE)
 		return;
 
+	sz = 0;
+	if (object->nchains < DL_SM_SYMBUF_CNT) {
+		_dl_symcache = _dl_sm_symcache_buffer;
+		DL_DEB(("using static buffer for %d entries\n",
+		    object->nchains));
+		_dl_memset(_dl_symcache, 0,
+		    sizeof (sym_cache) * object->nchains);
+	} else {
+		sz = ELF_ROUND(sizeof (sym_cache) * object->nchains,
+		    _dl_pagesz);
+		DL_DEB(("allocating symcache sz %x with mmap\n", sz));
+
+		_dl_symcache = (void *)_dl_mmap(0, sz, PROT_READ|PROT_WRITE,
+		    MAP_PRIVATE|MAP_ANON, -1, 0);
+		if (_dl_symcache == (void *)MAP_FAILED) {
+			sz = 0;
+			_dl_symcache = NULL;
+		}
+	}
 	/*
 	 * Do relocation information first, then GOT.
 	 */
 	_dl_md_reloc(object, DT_REL, DT_RELSZ);
 	_dl_md_reloc(object, DT_RELA, DT_RELASZ);
 	_dl_md_reloc_got(object, !(_dl_bindnow || object->dyn.bind_now));
+
+	if (_dl_symcache != NULL) {
+		if (sz != 0) 
+			_dl_munmap( _dl_symcache, sz);
+		_dl_symcache = NULL;
+	}
 	object->status |= STAT_RELOC_DONE;
 }
 
diff --git a/libexec/ld.so/powerpc/rtld_machine.c b/libexec/ld.so/powerpc/rtld_machine.c
index bd4f2040e94..3500e888f53 100644
--- a/libexec/ld.so/powerpc/rtld_machine.c
+++ b/libexec/ld.so/powerpc/rtld_machine.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rtld_machine.c,v 1.30 2003/09/02 15:17:52 drahn Exp $ */
+/*	$OpenBSD: rtld_machine.c,v 1.31 2003/09/04 19:33:49 drahn Exp $ */
 
 /*
  * Copyright (c) 1999 Dale Rahn
@@ -204,10 +204,11 @@ _dl_printf("object relocation size %x, numrela %x\n",
 		if (ELF32_R_SYM(relas->r_info) &&
 		    !(ELF32_ST_BIND(sym->st_info) == STB_LOCAL &&
 		    ELF32_ST_TYPE (sym->st_info) == STT_NOTYPE)) {
-			ooff = _dl_find_symbol(symn, _dl_objects, &this,
-			    SYM_SEARCH_ALL|SYM_NOWARNNOTFOUND|
+			ooff = _dl_find_symbol_bysym(object,
+			    ELF32_R_SYM(relas->r_info), _dl_objects,
+			    &this, SYM_SEARCH_ALL|SYM_NOWARNNOTFOUND|
 			    ((type == RELOC_JMP_SLOT) ? SYM_PLT:SYM_NOTPLT),
-			    sym->st_size, object);
+			    sym->st_size);
 
 			if (!this && ELF32_ST_BIND(sym->st_info) == STB_GLOBAL) {
 				_dl_printf("%s: %s :can't resolve reference '%s'\n",
@@ -393,12 +394,13 @@ _dl_printf(" symn [%s] val 0x%x\n", symn, val);
 			    cobj = cobj->next) {
 				if (object != cobj) {
 					/* only look in this object */
-					src_loff = _dl_find_symbol(symn, cobj,
-					    &cpysrc,
+					src_loff = _dl_find_symbol_bysym(object,
+					    ELF32_R_SYM(relas->r_info),
+					    cobj, &cpysrc,
 					    SYM_SEARCH_SELF|SYM_NOWARNNOTFOUND|
 					    ((type == RELOC_JMP_SLOT) ?
 					        SYM_PLT : SYM_NOTPLT),
-					    sym->st_size, object);
+					    sym->st_size);
 				}
 			}
 			if (cpysrc == NULL) {
diff --git a/libexec/ld.so/resolve.c b/libexec/ld.so/resolve.c
index 07b464ff2cf..f08b07707c8 100644
--- a/libexec/ld.so/resolve.c
+++ b/libexec/ld.so/resolve.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: resolve.c,v 1.20 2003/09/02 15:17:51 drahn Exp $ */
+/*	$OpenBSD: resolve.c,v 1.21 2003/09/04 19:33:48 drahn Exp $ */
 
 /*
  * Copyright (c) 1998 Per Fogelstrom, Opsycon AB
@@ -188,6 +188,45 @@ int find_symbol_obj(elf_object_t *object, const char *name, unsigned long hash,
     int flags, const Elf_Sym **ref, const Elf_Sym **weak_sym,
     elf_object_t **weak_object);
 
+sym_cache *_dl_symcache;
+int _dl_symcachestat_hits;
+int _dl_symcachestat_lookups;
+
+Elf_Addr
+_dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx,
+    elf_object_t *startlook, const Elf_Sym **ref, int flags, int req_size)
+{
+	Elf_Addr ret;
+	const Elf_Sym *sym;
+	const char *symn;
+
+	_dl_symcachestat_lookups ++;
+	if ((_dl_symcache != NULL) &&
+	     (symidx < req_obj->nchains) &&
+	     (_dl_symcache[symidx].sym != NULL) &&
+	     (_dl_symcache[symidx].flags == flags)) {
+
+		_dl_symcachestat_hits++;
+		*ref = _dl_symcache[symidx].sym;
+		return _dl_symcache[symidx].offset;
+	}
+
+	sym = req_obj->dyn.symtab;
+	sym += symidx;
+	symn = req_obj->dyn.strtab + sym->st_name;
+
+	ret = _dl_find_symbol(symn, startlook, ref, flags, req_size, req_obj);
+
+	if ((_dl_symcache != NULL) &&
+	     (symidx < req_obj->nchains)) {
+		_dl_symcache[symidx].sym = *ref;
+		_dl_symcache[symidx].offset = ret;
+		_dl_symcache[symidx].flags = flags;
+	}
+
+	return ret;
+}
+
 Elf_Addr
 _dl_find_symbol(const char *name, elf_object_t *startlook,
     const Elf_Sym **ref, int flags, int req_size, elf_object_t *req_obj)
diff --git a/libexec/ld.so/resolve.h b/libexec/ld.so/resolve.h
index e5b31ae562b..49c0e6f6740 100644
--- a/libexec/ld.so/resolve.h
+++ b/libexec/ld.so/resolve.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: resolve.h,v 1.28 2003/09/02 15:17:51 drahn Exp $ */
+/*	$OpenBSD: resolve.h,v 1.29 2003/09/04 19:33:48 drahn Exp $ */
 
 /*
  * Copyright (c) 1998 Per Fogelstrom, Opsycon AB
@@ -145,6 +145,8 @@ extern void _dl_md_reloc_got(elf_object_t *object, int lazy);
 
 Elf_Addr _dl_find_symbol(const char *name, elf_object_t *startlook,
     const Elf_Sym **ref, int flags, int sym_size, elf_object_t *object);
+Elf_Addr _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx,
+    elf_object_t *startlook, const Elf_Sym **ref, int flags, int req_size);
 /*
  * defines for _dl_find_symbol() flag field, three bits of meaning
  * myself	- clear: search all objects,	set: search only this object
@@ -209,4 +211,13 @@ extern char *_dl_debug;
 #define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1))
 #define ELF_TRUNC(x,malign) ((x) & ~((malign)-1))
 
+/* symbol lookup cache */
+typedef struct sym_cache {
+	const Elf_Sym	*sym;
+	Elf_Addr	offset;
+	int flags;
+} sym_cache;
+
+extern sym_cache *_dl_symcache;
+
 #endif /* _RESOLVE_H_ */
diff --git a/libexec/ld.so/sparc/rtld_machine.c b/libexec/ld.so/sparc/rtld_machine.c
index c39b6886ed2..3ec0a6705df 100644
--- a/libexec/ld.so/sparc/rtld_machine.c
+++ b/libexec/ld.so/sparc/rtld_machine.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rtld_machine.c,v 1.18 2003/09/02 15:17:52 drahn Exp $ */
+/*	$OpenBSD: rtld_machine.c,v 1.19 2003/09/04 19:33:49 drahn Exp $ */
 
 /*
  * Copyright (c) 1999 Dale Rahn
@@ -251,12 +251,13 @@ _dl_md_reloc(elf_object_t *object, int rel, int relasz)
 				value += loff;
 			} else {
 				this = NULL;
-				ooff = _dl_find_symbol(symn,
+				ooff = _dl_find_symbol_bysym(object,
+				    ELF_R_SYM(relas->r_info),
 				    _dl_objects, &this,
 				    SYM_SEARCH_ALL|SYM_WARNNOTFOUND|
 				    ((type == R_TYPE(JMP_SLOT)) ?
 					SYM_PLT : SYM_NOTPLT),
-				    sym->st_size, object);
+				    sym->st_size);
 				if (this == NULL) {
 resolve_failed:
 					_dl_printf("%s: %s: can't resolve "
diff --git a/libexec/ld.so/sparc64/rtld_machine.c b/libexec/ld.so/sparc64/rtld_machine.c
index dbdf035323c..9e4fa21efed 100644
--- a/libexec/ld.so/sparc64/rtld_machine.c
+++ b/libexec/ld.so/sparc64/rtld_machine.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rtld_machine.c,v 1.29 2003/09/02 15:17:52 drahn Exp $ */
+/*	$OpenBSD: rtld_machine.c,v 1.30 2003/09/04 19:33:50 drahn Exp $ */
 
 /*
  * Copyright (c) 1999 Dale Rahn
@@ -272,11 +272,13 @@ _dl_md_reloc(elf_object_t *object, int rel, int relasz)
 				value += loff;
 			} else {
 				this = NULL;
-				ooff = _dl_find_symbol(symn, _dl_objects,
-				    &this, SYM_SEARCH_ALL|SYM_WARNNOTFOUND|
-				    ((type == R_TYPE(JMP_SLOT))?
-					SYM_PLT:SYM_NOTPLT),
-				    sym->st_size, object);
+				ooff = _dl_find_symbol_bysym(object,
+				    ELF_R_SYM(relas->r_info),
+				    _dl_objects, &this,
+				    SYM_SEARCH_ALL|SYM_WARNNOTFOUND|
+				    ((type == R_TYPE(JMP_SLOT)) ?
+					SYM_PLT : SYM_NOTPLT),
+				    sym->st_size);
 				if (this == NULL) {
 resolve_failed:
 					_dl_printf("%s: %s: can't resolve "