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authorAndroid (Google) Code Review <android-gerrit@google.com>2009-06-25 15:15:14 -0700
committerAndroid (Google) Code Review <android-gerrit@google.com>2009-06-25 15:15:14 -0700
commit6ee8f1b0444c0db94931d2cd64427ded8fba38b0 (patch)
tree127fc944b35e74cda8fa69ebe16b0632c3bfe7f6
parent380f24983e8e33d0b189dda198ec64c1766a359d (diff)
parentbc3a5c26f1b9cf29da6abfc3e197258ef4c03362 (diff)
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Merge change 2990 into donut
* changes: Add LD_LIBRARY_PATH support to bionic's linker
-rw-r--r--linker/linker.c56
1 files changed, 52 insertions, 4 deletions
diff --git a/linker/linker.c b/linker/linker.c
index e398f82..77f995e 100644
--- a/linker/linker.c
+++ b/linker/linker.c
@@ -53,6 +53,10 @@
#define SO_MAX 96
+/* Assume average path length of 64 and max 8 paths */
+#define LDPATH_BUFSIZE 512
+#define LDPATH_MAX 8
+
/* >>> IMPORTANT NOTE - READ ME BEFORE MODIFYING <<<
*
* Do NOT use malloc() and friends or pthread_*() code here.
@@ -66,7 +70,6 @@
* - should we do anything special for STB_WEAK symbols?
* - are we doing everything we should for ARM_COPY relocations?
* - cleaner error reporting
- * - configuration for paths (LD_LIBRARY_PATH?)
* - after linking, set as much stuff as possible to READONLY
* and NOEXEC
* - linker hardcodes PAGE_SIZE and PAGE_MASK because the kernel
@@ -89,6 +92,9 @@ static soinfo *freelist = NULL;
static soinfo *solist = &libdl_info;
static soinfo *sonext = &libdl_info;
+static char ldpaths_buf[LDPATH_BUFSIZE];
+static const char *ldpaths[LDPATH_MAX + 1];
+
int debug_verbosity;
static int pid;
@@ -503,13 +509,12 @@ static int _open_lib(const char *name)
return -1;
}
-/* TODO: Need to add support for initializing the so search path with
- * LD_LIBRARY_PATH env variable for non-setuid programs. */
static int open_library(const char *name)
{
int fd;
char buf[512];
const char **path;
+ int n;
TRACE("[ %5d opening %s ]\n", pid, name);
@@ -519,8 +524,21 @@ static int open_library(const char *name)
if ((name[0] == '/') && ((fd = _open_lib(name)) >= 0))
return fd;
+ for (path = ldpaths; *path; path++) {
+ n = snprintf(buf, sizeof(buf), "%s/%s", *path, name);
+ if (n < 0 || n >= (int)sizeof(buf)) {
+ WARN("Ignoring very long library path: %s/%s\n", *path, name);
+ continue;
+ }
+ if ((fd = _open_lib(buf)) >= 0)
+ return fd;
+ }
for (path = sopaths; *path; path++) {
- snprintf(buf, sizeof(buf), "%s/%s", *path, name);
+ n = snprintf(buf, sizeof(buf), "%s/%s", *path, name);
+ if (n < 0 || n >= (int)sizeof(buf)) {
+ WARN("Ignoring very long library path: %s/%s\n", *path, name);
+ continue;
+ }
if ((fd = _open_lib(buf)) >= 0)
return fd;
}
@@ -1683,6 +1701,29 @@ fail:
return -1;
}
+static void parse_library_path(char *path, char *delim)
+{
+ size_t len;
+ char *ldpaths_bufp = ldpaths_buf;
+ int i = 0;
+
+ len = strlcpy(ldpaths_buf, path, sizeof(ldpaths_buf));
+
+ while (i < LDPATH_MAX && (ldpaths[i] = strsep(&ldpaths_bufp, delim))) {
+ if (*ldpaths[i] != '\0')
+ ++i;
+ }
+
+ /* Forget the last path if we had to truncate; this occurs if the 2nd to
+ * last char isn't '\0' (i.e. not originally a delim). */
+ if (i > 0 && len >= sizeof(ldpaths_buf) &&
+ ldpaths_buf[sizeof(ldpaths_buf) - 2] != '\0') {
+ ldpaths[i - 1] = NULL;
+ } else {
+ ldpaths[i] = NULL;
+ }
+}
+
int main(int argc, char **argv)
{
return 0;
@@ -1701,6 +1742,7 @@ unsigned __linker_init(unsigned **elfdata)
unsigned *vecs = (unsigned*) (argv + argc + 1);
soinfo *si;
struct link_map * map;
+ char *ldpath_env = NULL;
pid = getpid();
@@ -1718,6 +1760,8 @@ unsigned __linker_init(unsigned **elfdata)
while(vecs[0] != 0) {
if(!strncmp((char*) vecs[0], "DEBUG=", 6)) {
debug_verbosity = atoi(((char*) vecs[0]) + 6);
+ } else if(!strncmp((char*) vecs[0], "LD_LIBRARY_PATH=", 16)) {
+ ldpath_env = (char*) vecs[0] + 16;
}
vecs++;
}
@@ -1777,6 +1821,10 @@ unsigned __linker_init(unsigned **elfdata)
si->wrprotect_start = 0xffffffff;
si->wrprotect_end = 0;
+ /* Use LD_LIBRARY_PATH if we aren't setuid/setgid */
+ if (ldpath_env && getuid() == geteuid() && getgid() == getegid())
+ parse_library_path(ldpath_env, ":");
+
if(link_image(si, 0)) {
char errmsg[] = "CANNOT LINK EXECUTABLE\n";
write(2, __linker_dl_err_buf, strlen(__linker_dl_err_buf));