From: "Vivek Das Mohapatra" <vivek@collabora.com>
To: libc-alpha <libc-alpha@sourceware.org>
Subject: [RFC][PATCH v7 10/20] Abstract the loaded-DSO search code into a private helper function
Date: Wed, 16 Dec 2020 13:26:40 +0000 [thread overview]
Message-ID: <20201216132650.22949-11-vivek@collabora.com> (raw)
In-Reply-To: <20201216132650.22949-1-vivek@collabora.com>
---
elf/dl-load.c | 38 ++++++++++++++++++++++++++++++++++++++
sysdeps/generic/ldsodefs.h | 4 ++++
2 files changed, 42 insertions(+)
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 0c8cb763c1..3fda5de71b 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -2038,6 +2038,44 @@ _dl_find_proxy (Lmid_t nsid, const char *name)
return NULL;
}
+/* search for a shared object in a given namespace. */
+struct link_map *
+_dl_find_dso (const char *name, Lmid_t nsid)
+{
+ struct link_map *l;
+
+ for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next)
+ {
+ /* If the requested name matches the soname of a loaded object,
+ use that object. Elide this check for names that have not
+ yet been opened. */
+ if (__glibc_unlikely ((l->l_faked | l->l_removed) != 0))
+ continue;
+ if (!_dl_name_match_p (name, l))
+ {
+ const char *soname;
+
+ if (__glibc_likely (l->l_soname_added)
+ || l->l_info[DT_SONAME] == NULL)
+ continue;
+
+ soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
+ + l->l_info[DT_SONAME]->d_un.d_val);
+ if (strcmp (name, soname) != 0)
+ continue;
+
+ /* We have a match on a new name -- cache it. */
+ add_name_to_object (l, soname);
+ l->l_soname_added = 1;
+ }
+
+ /* We have a match. */
+ return l;
+ }
+
+ return NULL;
+}
+
/* Map in the shared object file NAME. */
struct link_map *
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index 5411263cc0..13cbe30482 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -1239,6 +1239,10 @@ extern void _dl_show_scope (struct link_map *new, int from)
extern struct link_map *_dl_find_dso_for_object (const ElfW(Addr) addr);
rtld_hidden_proto (_dl_find_dso_for_object)
+extern struct link_map *_dl_find_dso (const char *name, Lmid_t nsid);
+rtld_hidden_proto (_dl_find_dso)
+
+
/* Initialization which is normally done by the dynamic linker. */
extern void _dl_non_dynamic_init (void)
attribute_hidden;
--
2.20.1
next prev parent reply other threads:[~2020-12-16 13:27 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-16 13:26 [RFC][PATCH v7 00/20] Implementation of RTLD_SHARED for dlmopen Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 01/20] Declare and describe the dlmopen RTLD_SHARED flag Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 02/20] include/link.h: Update the link_map struct to allow proxies Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 03/20] elf/dl-object.c: Implement a helper function to proxy link_map entries Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 04/20] elf/dl-load.c, elf-dl-open.c: Implement RTLD_SHARED dlmopen proxying Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 05/20] elf/dl-fini.c: Handle proxy link_map entries in the shutdown path Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 06/20] elf/dl-init.c: Skip proxied link map entries in the dl init path Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 07/20] elf/dl-open.c: Don't try libc linit in namespaces with no libc mapping Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 08/20] elf/dl-open.c: when creating a proxy check the libc_map in NS 0 Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 09/20] Define a new dynamic section tag - DT_GNU_FLAGS_1 Vivek Das Mohapatra
2020-12-16 13:26 ` Vivek Das Mohapatra [this message]
2020-12-16 13:26 ` [RFC][PATCH v7 11/20] Compare loaded DSOs by file ID and check for DF_GNU_1_UNIQUE Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 12/20] Use the new DSO finder helper function since we have it Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 13/20] Use the DSO search helper to check for preloaded DT_GNU_UNIQUE DSOs Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 14/20] When loading DSOs into alternate namespaces check for DT_GNU_UNIQUE Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 15/20] Suppress audit calls when a (new) namespace is empty Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 16/20] Suppress inter-namespace DSO sharing for audit libraries Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 17/20] dlsym, dlvsym should be able to look up symbols via DSO proxies Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 18/20] Add DT_GNU_FLAGS_1/DF_GNU_1_UNIQUE dynamic section+flag to glibc DSOs Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 19/20] Add dlmopen / RTLD_SHARED tests Vivek Das Mohapatra
2020-12-16 13:26 ` [RFC][PATCH v7 20/20] Restore separate libc loading for the TLS/namespace storage test Vivek Das Mohapatra
2021-01-07 17:00 ` Ping " Vivek Das Mohapatra
2021-01-07 19:55 ` Adhemerval Zanella
2021-01-08 0:33 ` Vivek Das Mohapatra
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