X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=blobdiff_plain;f=src%2Fldso%2Fdynlink.c;h=9e9415cae9a62e9b01571ffef83468c688c66084;hp=cb35759bad6de15296c09143aff8e0ef3f20a74f;hb=32de61e81a64c8bb2cd23e3476f00433692f8e59;hpb=368ba4a0a9aa5cc9a769872adbef6da433babf54

diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index cb35759b..9e9415ca 100644
--- a/src/ldso/dynlink.c
+++ b/src/ldso/dynlink.c
@@ -48,7 +48,7 @@ struct dso
 };
 
 static struct dso *head, *tail, *libc;
-static int trust_env;
+static char *env_path, *sys_path;
 
 #define AUX_CNT 15
 #define DYN_CNT 34
@@ -114,7 +114,7 @@ static void do_relocs(unsigned char *base, size_t *rel, size_t rel_size, size_t
 			sym = syms + sym_index;
 			name = strings + sym->st_name;
 			ctx = IS_COPY(type) ? dso->next : dso;
-			sym_val = (size_t)find_sym(ctx, name, 1);
+			sym_val = (size_t)find_sym(ctx, name, IS_PLT(type));
 			sym_size = sym->st_size;
 		}
 		do_single_reloc(reloc_addr, type, sym_val, sym_size, base, rel[2]);
@@ -123,7 +123,7 @@ static void do_relocs(unsigned char *base, size_t *rel, size_t rel_size, size_t
 
 static void *map_library(int fd, size_t *lenp, unsigned char **basep, size_t *dynp)
 {
-	size_t buf[896/sizeof(size_t)];
+	Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 	size_t phsize;
 	size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 	size_t this_min, this_max;
@@ -137,11 +137,11 @@ static void *map_library(int fd, size_t *lenp, unsigned char **basep, size_t *dy
 
 	ssize_t l = read(fd, buf, sizeof buf);
 	if (l<sizeof *eh) return 0;
-	eh = (void *)buf;
+	eh = buf;
 	phsize = eh->e_phentsize * eh->e_phnum;
 	if (phsize + sizeof *eh > l) return 0;
 	if (eh->e_phoff + phsize > l) {
-		l = pread(fd, buf+sizeof *eh, phsize, eh->e_phoff);
+		l = pread(fd, buf+1, phsize, eh->e_phoff);
 		if (l != phsize) return 0;
 		eh->e_phoff = sizeof *eh;
 	}
@@ -205,6 +205,22 @@ static void *map_library(int fd, size_t *lenp, unsigned char **basep, size_t *dy
 	return map;
 }
 
+static int path_open(const char *name, const char *search)
+{
+	char buf[2*NAME_MAX+2];
+	const char *s=search, *z;
+	int l, fd;
+	for (;;) {
+		while (*s==':') s++;
+		if (!*s) return -1;
+		z = strchr(s, ':');
+		l = z ? z-s : strlen(s);
+		snprintf(buf, sizeof buf, "%.*s/%s", l, s, name);
+		if ((fd = open(buf, O_RDONLY))>=0) return fd;
+		s += l;
+	}
+}
+
 static struct dso *load_library(const char *name)
 {
 	unsigned char *base, *map;
@@ -242,14 +258,20 @@ static struct dso *load_library(const char *name)
 	if (name[0] == '/') {
 		fd = open(name, O_RDONLY);
 	} else {
-		static const char path[] = "/lib/\0/usr/local/lib/\0/usr/lib/\0";
-		const char *s;
-		char buf[NAME_MAX+32];
 		if (strlen(name) > NAME_MAX || strchr(name, '/')) return 0;
-		for (s=path; *s; s+=strlen(s)+1) {
-			strcpy(buf, s);
-			strcat(buf, name);
-			if ((fd = open(buf, O_RDONLY))>=0) break;
+		fd = -1;
+		if (env_path) fd = path_open(name, env_path);
+		if (fd < 0) {
+			if (!sys_path) {
+				FILE *f = fopen(ETC_LDSO_PATH, "r");
+				if (f) {
+					if (getline(&sys_path, (size_t[1]){0}, f) > 0)
+						sys_path[strlen(sys_path)-1]=0;
+					fclose(f);
+				}
+			}
+			if (sys_path) fd = path_open(name, sys_path);
+			else fd = path_open(name, "/lib:/usr/local/lib:/usr/lib");
 		}
 	}
 	if (fd < 0) return 0;
@@ -313,15 +335,25 @@ static void reloc_all(struct dso *p)
 		if (p->relocated) continue;
 		decode_vec(p->dynv, dyn, DYN_CNT);
 		do_relocs(p->base, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
-			2+(dyn[DT_PLTREL]==DT_RELA), p->syms, p->strings, p);
+			2+(dyn[DT_PLTREL]==DT_RELA), p->syms, p->strings, head);
 		do_relocs(p->base, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ],
-			2, p->syms, p->strings, p);
+			2, p->syms, p->strings, head);
 		do_relocs(p->base, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ],
-			3, p->syms, p->strings, p);
+			3, p->syms, p->strings, head);
 		p->relocated = 1;
 	}
 }
 
+static void free_all(struct dso *p)
+{
+	struct dso *n;
+	while (p) {
+		n = p->next;
+		if (p->map) free(p);
+		p = n;
+	}
+}
+
 void *__dynlink(int argc, char **argv, size_t *got)
 {
 	size_t *auxv, aux[AUX_CNT] = {0};
@@ -332,11 +364,19 @@ void *__dynlink(int argc, char **argv, size_t *got)
 	struct dso lib, app;
 
 	/* Find aux vector just past environ[] */
-	for (i=argc+1; argv[i]; i++);
+	for (i=argc+1; argv[i]; i++)
+		if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16))
+			env_path = argv[i]+16;
 	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]) {
+		env_path = 0;
+	}
+
 	/* Relocate ldso's DYNAMIC pointer and load vector */
 	decode_vec((void *)(got[0] += aux[AT_BASE]), lib_dyn, DYN_CNT);
 
@@ -375,11 +415,6 @@ void *__dynlink(int argc, char **argv, size_t *got)
 
 	/* At this point the standard library is fully functional */
 
-	/* Only trust user/env if kernel says we're not suid/sgid */
-	trust_env = (aux[0]&0x7800)==0x7800
-		&& aux[AT_UID]==aux[AT_EUID]
-		&& aux[AT_GID]==aux[AT_EGID];
-
 	head = tail = &app;
 	libc = &lib;
 	app.next = 0;
@@ -387,6 +422,9 @@ void *__dynlink(int argc, char **argv, size_t *got)
 
 	reloc_all(head);
 
+	free_all(head);
+	free(sys_path);
+
 	errno = 0;
 	return (void *)aux[AT_ENTRY];
 }