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authorRich Felker <dalias@aerifal.cx>2011-08-16 00:24:36 -0400
committerRich Felker <dalias@aerifal.cx>2011-08-16 00:24:36 -0400
commit2719cc86285d85df42f13ba0ae5b07b262c39686 (patch)
tree6295a259551ca4841518210a7a9056c3058b8a1d /src/ldso
parentce7c6341d38ecd3af4d1e01032e9ea8b4078aa97 (diff)
downloadmusl-2719cc86285d85df42f13ba0ae5b07b262c39686.tar.gz
LD_PRELOAD support
Diffstat (limited to 'src/ldso')
-rw-r--r--src/ldso/dynlink.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index 7a26e9ed..ced1637c 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"
@@ -410,6 +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;
@@ -455,11 +470,14 @@ 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);
@@ -475,6 +493,7 @@ void *__dynlink(int argc, char **argv, size_t *got)
if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
|| aux[AT_GID]!=aux[AT_EGID]) {
env_path = 0;
+ env_preload = 0;
}
/* Relocate ldso's DYNAMIC pointer and load vector */
@@ -547,6 +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);