X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=blobdiff_plain;f=src%2Fldso%2Fdynlink.c;h=57a5ba46044264374b77889108e14e7dd9a163bf;hp=d8f641aec344f259e3f3a69dab13617b3bd5b630;hb=cf8506ad94caa91fc1cd44b9134494dd6ecd6caf;hpb=6ab444d97a00fd8d04264cefef0291d3c7b5b701

diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index d8f641ae..57a5ba46 100644
--- a/src/ldso/dynlink.c
+++ b/src/ldso/dynlink.c
@@ -14,6 +14,7 @@
 #include <elf.h>
 #include <setjmp.h>
 #include <pthread.h>
+#include <ctype.h>
 #include <dlfcn.h>
 
 #include "reloc.h"
@@ -59,7 +60,7 @@ static int runtime;
 static jmp_buf rtld_fail;
 static pthread_rwlock_t lock;
 
-#define AUX_CNT 15
+#define AUX_CNT 24
 #define DYN_CNT 34
 
 static void decode_vec(size_t *v, size_t *a, size_t cnt)
@@ -92,10 +93,12 @@ static Sym *lookup(const char *s, uint32_t h, Sym *syms, uint32_t *hashtab, char
 }
 
 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON)
+#define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK)
 
 static void *find_sym(struct dso *dso, const char *s, int need_def)
 {
 	uint32_t h = hash(s);
+	void *def = 0;
 	if (h==0x6b366be && !strcmp(s, "dlopen")) rtld_used = 1;
 	if (h==0x6b3afd && !strcmp(s, "dlsym")) rtld_used = 1;
 	for (; dso; dso=dso->next) {
@@ -103,10 +106,14 @@ static void *find_sym(struct dso *dso, const char *s, int need_def)
 		if (!dso->global) continue;
 		sym = lookup(s, h, dso->syms, dso->hashtab, dso->strings);
 		if (sym && (!need_def || sym->st_shndx) && sym->st_value
-		 && (1<<(sym->st_info&0xf) & OK_TYPES))
-			return dso->base + sym->st_value;
+		 && (1<<(sym->st_info&0xf) & OK_TYPES)
+		 && (1<<(sym->st_info>>4) & OK_BINDS)) {
+			if (def && sym->st_info>>4 == STB_WEAK) continue;
+			def = dso->base + sym->st_value;
+			if (sym->st_info>>4 == STB_GLOBAL) break;
+		}
 	}
-	return 0;
+	return def;
 }
 
 static void do_relocs(unsigned char *base, size_t *rel, size_t rel_size, size_t stride, Sym *syms, char *strings, struct dso *dso)
@@ -404,6 +411,20 @@ static void load_deps(struct dso *p)
 	}
 }
 
+static void load_preload(char *s)
+{
+	int tmp;
+	char *z;
+	for (z=s; *z; s=z) {
+		for (   ; *s && isspace(*s); s++);
+		for (z=s; *z && !isspace(*z); z++);
+		tmp = *z;
+		*z = 0;
+		load_library(s);
+		*z = tmp;
+	}
+}
+
 static void make_global(struct dso *p)
 {
 	for (; p; p=p->next) p->global = 1;
@@ -449,15 +470,25 @@ void *__dynlink(int argc, char **argv, size_t *got)
 	struct dso *const lib = builtin_dsos+1;
 	struct dso *const vdso = builtin_dsos+2;
 	size_t vdso_base=0;
+	char *env_preload=0;
 
 	/* Find aux vector just past environ[] */
 	for (i=argc+1; argv[i]; i++)
 		if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16))
 			env_path = argv[i]+16;
+		else if (!memcmp(argv[i], "LD_PRELOAD=", 11))
+			env_preload = argv[i]+11;
 	auxv = (void *)(argv+i+1);
 
 	decode_vec(auxv, aux, AUX_CNT);
 
+	/* Only trust user/env if kernel says we're not suid/sgid */
+	if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
+	  || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) {
+		env_path = 0;
+		env_preload = 0;
+	}
+
 	for (i=0; auxv[i]; i+=2) {
 		if (auxv[i]==AT_SYSINFO_EHDR) {
 			vdso_base = auxv[i+1];
@@ -465,12 +496,6 @@ void *__dynlink(int argc, char **argv, size_t *got)
 		}
 	}
 
-	/* Only trust user/env if kernel says we're not suid/sgid */
-	if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
-	  || aux[AT_GID]!=aux[AT_EGID]) {
-		env_path = 0;
-	}
-
 	/* Relocate ldso's DYNAMIC pointer and load vector */
 	decode_vec((void *)(got[0] += aux[AT_BASE]), lib_dyn, DYN_CNT);
 
@@ -519,6 +544,7 @@ void *__dynlink(int argc, char **argv, size_t *got)
 		vdso->hashtab = (void *)(vdso->base + vdso_dyn[DT_HASH]);
 		vdso->strings = (void *)(vdso->base + vdso_dyn[DT_STRTAB]);
 		vdso->name = "linux-gate.so.1";
+		vdso->global = 1;
 
 		vdso->prev = lib;
 		lib->next = vdso;
@@ -540,6 +566,7 @@ void *__dynlink(int argc, char **argv, size_t *got)
 	head = tail = app;
 	libc = lib;
 	app->next = 0;
+	if (env_preload) load_preload(env_preload);
 	load_deps(head);
 
 	make_global(head);
@@ -611,11 +638,16 @@ end:
 	return p;
 }
 
-static void *do_dlsym(struct dso *p, const char *s)
+static void *do_dlsym(struct dso *p, const char *s, void *ra)
 {
 	size_t i;
 	uint32_t h;
 	Sym *sym;
+	if (p == RTLD_NEXT) {
+		for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
+		if (!p) p=head;
+		p=p->next;
+	}
 	if (p == head || p == RTLD_DEFAULT)
 		return find_sym(head, s, 0);
 	h = hash(s);
@@ -631,11 +663,11 @@ static void *do_dlsym(struct dso *p, const char *s)
 	return 0;
 }
 
-void *dlsym(void *p, const char *s)
+void *__dlsym(void *p, const char *s, void *ra)
 {
 	void *res;
 	pthread_rwlock_rdlock(&lock);
-	res = do_dlsym(p, s);
+	res = do_dlsym(p, s, ra);
 	pthread_rwlock_unlock(&lock);
 	return res;
 }