From: Florian Weimer <fweimer@redhat.com>
To: libc-alpha@sourceware.org
Subject: [PATCH 3/4] elf: Generalize name-based DSO recognition in ldconfig
Date: Thu, 10 Jun 2021 10:23:11 +0200 [thread overview]
Message-ID: <f1b7632ac80967bc23998c05f5a7c4d76c6e779c.1623312996.git.fweimer@redhat.com> (raw)
In-Reply-To: <cover.1623312996.git.fweimer@redhat.com>
This introduces <dl-is_dso.h> and the _dl_is_dso function. A
test ensures that the official names of libc.so, ld.so, and their
versioned names are recognized.
---
elf/Makefile | 2 +-
elf/dl-is_dso.h | 33 +++++++++++++++++++++++++++++++++
elf/ldconfig.c | 5 ++---
elf/tst-dl-is_dso.c | 35 +++++++++++++++++++++++++++++++++++
4 files changed, 71 insertions(+), 4 deletions(-)
create mode 100644 elf/dl-is_dso.h
create mode 100644 elf/tst-dl-is_dso.c
diff --git a/elf/Makefile b/elf/Makefile
index 5c47daee12..1751f5ec67 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -223,7 +223,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \
tst-single_threaded tst-single_threaded-pthread \
tst-tls-ie tst-tls-ie-dlmopen argv0test \
tst-glibc-hwcaps tst-glibc-hwcaps-prepend tst-glibc-hwcaps-mask \
- tst-tls20 tst-tls21 tst-dlmopen-dlerror
+ tst-tls20 tst-tls21 tst-dlmopen-dlerror tst-dl-is_dso
# reldep9
tests-internal += loadtest unload unload2 circleload1 \
neededtest neededtest2 neededtest3 neededtest4 \
diff --git a/elf/dl-is_dso.h b/elf/dl-is_dso.h
new file mode 100644
index 0000000000..94e00966a1
--- /dev/null
+++ b/elf/dl-is_dso.h
@@ -0,0 +1,33 @@
+/* Heuristic for recognizing DSO file names.
+ Copyright (C) 2021 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <stdbool.h>
+#include <string.h>
+
+/* Returns true if the file name looks like a DSO name. */
+static bool
+_dl_is_dso (const char *name)
+{
+ /* Recognize lib*.so*, ld-*.so*, ld.so.*, ld64.so.*. ld-*.so*
+ matches both platform dynamic linker names like ld-linux.so.2,
+ and versioned dynamic loader names like ld-2.12.so. */
+ return (((strncmp (name, "lib", 3) == 0 || strncmp (name, "ld-", 3) == 0)
+ && strstr (name, ".so") != NULL)
+ || strncmp (name, "ld.so.", 6) == 0
+ || strncmp (name, "ld64.so.", 8) == 0);
+}
diff --git a/elf/ldconfig.c b/elf/ldconfig.c
index 96bf7700b2..1037e8d0cf 100644
--- a/elf/ldconfig.c
+++ b/elf/ldconfig.c
@@ -43,6 +43,7 @@
#include <ldconfig.h>
#include <dl-cache.h>
#include <dl-hwcaps.h>
+#include <dl-is_dso.h>
#include <dl-procinfo.h>
@@ -842,9 +843,7 @@ search_dir (const struct dir_entry *entry)
subdirectory (if not already processing a glibc-hwcaps
subdirectory)? The dynamic linker is also considered as
shared library. */
- if (((strncmp (direntry->d_name, "lib", 3) != 0
- && strncmp (direntry->d_name, "ld-", 3) != 0)
- || strstr (direntry->d_name, ".so") == NULL)
+ if (!_dl_is_dso (direntry->d_name)
&& (direntry->d_type == DT_REG
|| (entry->hwcaps == NULL
&& !is_hwcap_platform (direntry->d_name))))
diff --git a/elf/tst-dl-is_dso.c b/elf/tst-dl-is_dso.c
new file mode 100644
index 0000000000..48d2cc9fbe
--- /dev/null
+++ b/elf/tst-dl-is_dso.c
@@ -0,0 +1,35 @@
+/* Test heuristic for recognizing DSO file names.
+ Copyright (C) 2021 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <dl-is_dso.h>
+#include <gnu/lib-names.h>
+#include <support/check.h>
+
+static int
+do_test (void)
+{
+ /* Official ABI names. */
+ TEST_VERIFY (_dl_is_dso (LIBC_SO));
+ TEST_VERIFY (_dl_is_dso (LD_SO));
+ /* Version-based names. The version number does not matter. */
+ TEST_VERIFY (_dl_is_dso ("libc-2.12.so"));
+ TEST_VERIFY (_dl_is_dso ("ld-2.12.so"));
+ return 0;
+}
+
+#include <support/test-driver.c>
--
2.31.1
next prev parent reply other threads:[~2021-06-10 8:23 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-10 8:22 [PATCH 0/4] Do not install shared objects under versioned names Florian Weimer
2021-06-10 8:23 ` [PATCH 1/4] nptl_db: Install libthread_db under a regular implementation name Florian Weimer
2021-06-27 21:32 ` Carlos O'Donell
2021-06-10 8:23 ` [PATCH 2/4] Makerules: Remove lib-version, $(subdir-version) Florian Weimer
2021-06-27 21:32 ` Carlos O'Donell
2021-06-10 8:23 ` Florian Weimer [this message]
2021-06-27 21:32 ` [PATCH 3/4] elf: Generalize name-based DSO recognition in ldconfig Carlos O'Donell
2021-06-10 8:23 ` [PATCH 4/4] Install shared objects under their ABI names Florian Weimer
2021-06-27 21:32 ` Carlos O'Donell
2021-06-14 11:04 ` [PATCH 0/4] Do not install shared objects under versioned names Florian Weimer
2021-06-14 14:49 ` Siddhesh Poyarekar
2021-06-27 20:43 ` Carlos O'Donell
2021-06-28 3:42 ` Siddhesh Poyarekar
2021-06-27 21:31 ` Carlos O'Donell
-- strict thread matches above, loose matches on Subject: below --
2021-06-09 11:15 [PATCH 0/4] Add --disable-major-minor-libraries configure option Florian Weimer
2021-06-09 11:16 ` [PATCH 3/4] elf: Generalize name-based DSO recognition in ldconfig Florian Weimer
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