Partial revert of 3d8b2ec42 to add back DSO_pathbyaddr

Commit 3d8b2ec42 removed various unused functions. However now we need to
use one of them! This commit resurrects DSO_pathbyaddr(). We're not going to
resurrect the Windows version though because what we need to achieve can be
done a different way on Windows.

Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit cb6ea61c161e88aa0268c77f308469a67b2ec063)

1 files changed, 34 insertions, 0 deletions

diff --git a/crypto/dso/dso_dl.c b/crypto/dso/dso_dl.c
index bc29fb23e0..d80bf562c7 100644
--- a/crypto/dso/dso_dl.c
+++ b/crypto/dso/dso_dl.c
@@ -22,6 +22,7 @@ static DSO_FUNC_TYPE dl_bind_func(DSO *dso, const char *symname);
 static char *dl_name_converter(DSO *dso, const char *filename);
 static char *dl_merger(DSO *dso, const char *filespec1,
                        const char *filespec2);
+static int dl_pathbyaddr(void *addr, char *path, int sz);
 static void *dl_globallookup(const char *name);
 
 static DSO_METHOD dso_meth_dl = {
@@ -34,6 +35,7 @@ static DSO_METHOD dso_meth_dl = {
     dl_merger,
     NULL,                       /* init */
     NULL,                       /* finish */
+    dl_pathbyaddr,
     dl_globallookup
 };
 
@@ -235,6 +237,38 @@ static char *dl_name_converter(DSO *dso, const char *filename)
     return (translated);
 }
 
+static int dl_pathbyaddr(void *addr, char *path, int sz)
+{
+    struct shl_descriptor inf;
+    int i, len;
+
+    if (addr == NULL) {
+        union {
+            int (*f) (void *, char *, int);
+            void *p;
+        } t = {
+            dl_pathbyaddr
+        };
+        addr = t.p;
+    }
+
+    for (i = -1; shl_get_r(i, &inf) == 0; i++) {
+        if (((size_t)addr >= inf.tstart && (size_t)addr < inf.tend) ||
+            ((size_t)addr >= inf.dstart && (size_t)addr < inf.dend)) {
+            len = (int)strlen(inf.filename);
+            if (sz <= 0)
+                return len + 1;
+            if (len >= sz)
+                len = sz - 1;
+            memcpy(path, inf.filename, len);
+            path[len++] = 0;
+            return len;
+        }
+    }
+
+    return -1;
+}
+
 static void *dl_globallookup(const char *name)
 {
     void *ret;