diff mbox series

[v2,1/2] package/lvm2: Fix runtime crash when using uclibc

Message ID 20180726131023.28695-1-m.niestroj@grinn-global.com
State Superseded
Headers show
Series [v2,1/2] package/lvm2: Fix runtime crash when using uclibc | expand

Commit Message

Marcin Niestroj July 26, 2018, 1:10 p.m. UTC 
When using uclibc libdevmapper.so was calling dm_task_get_info_base()
function recursively, leading to segmentation fault. This was
happening because uclibc linker loader just takes first existing
'dm_task_get_info' (which is 'dm_task_get_info_base') symbol in elf
binary, instead of default version.

Add upstreamable lvm2 patch [1], which introduces
--enable-symvers[=STYLE] switch. Use that switch to disable symbol
versions, as we do not plan to support binaries compiled against
old libdevmapper library.

[1] https://www.redhat.com/archives/dm-devel/2018-July/msg00187.html

Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
---
Changes v1 -> v2:
 * Add SoB in patch itself (suggested by Thomas)
 * Make this patch first in series, so it can be applied for LTS
   branches (sugested by Thomas)
 * Rebase patch on current lvm2 Buildroot master version (2.02.173),
   so it can apply cleanly

 ...gure-Introduce-enable-symvers-option.patch | 277 ++++++++++++++++++
 package/lvm2/lvm2.mk                          |   3 +-
 2 files changed, 279 insertions(+), 1 deletion(-)
 create mode 100644 package/lvm2/0001-configure-Introduce-enable-symvers-option.patch

Comments

Thomas Petazzoni July 26, 2018, 1:42 p.m. UTC | #1 
Hello,

Thanks for this new iteration.

On Thu, 26 Jul 2018 15:10:22 +0200, Marcin Niestroj wrote:

> + configure                 | 32 ++++++++++++++++++++++++++++++--

I missed that in the review of the previous version. Is there a reason
to patch the configure script itself? In Buildroot, our general rule is
to not patch configure, but instead patch configure.ac and use
<pkg>_AUTORECONF = YES to regenerate the configure script.

Is there a reason to not follow this rule in this specific situation ?

Thanks!

Thomas
Marcin Niestroj July 26, 2018, 1:54 p.m. UTC | #2 
Hi,

On 26.07.2018 15:42, Thomas Petazzoni wrote:
> Hello,
> 
> Thanks for this new iteration.
> 
> On Thu, 26 Jul 2018 15:10:22 +0200, Marcin Niestroj wrote:
> 
>> + configure                 | 32 ++++++++++++++++++++++++++++++--
> 
> I missed that in the review of the previous version. Is there a reason
> to patch the configure script itself? In Buildroot, our general rule is
> to not patch configure, but instead patch configure.ac and use
> <pkg>_AUTORECONF = YES to regenerate the configure script.
> 
> Is there a reason to not follow this rule in this specific situation ?

I've prepared this patch to go to lvm2 upstream. I looked at other
commits, they also included changes in 'configure' script.

I agree, that this is not necessary with Buildroot. But we have to
choose between:
1) keep 'configure' changes in Buildroot lvm2 patch, so we have
    nearly the same patch as posted upstream
2) remove 'configure' changes, so we make the lvm2 patch smaller
    and cleaner.

Choice is up to you :)

Regards,
Marcin

> 
> Thanks!
> 
> Thomas
>
Thomas Petazzoni July 26, 2018, 2:12 p.m. UTC | #3 
Hello,

On Thu, 26 Jul 2018 15:54:01 +0200, Marcin Niestroj wrote:

> I've prepared this patch to go to lvm2 upstream. I looked at other
> commits, they also included changes in 'configure' script.
> 
> I agree, that this is not necessary with Buildroot. But we have to
> choose between:
> 1) keep 'configure' changes in Buildroot lvm2 patch, so we have
>     nearly the same patch as posted upstream
> 2) remove 'configure' changes, so we make the lvm2 patch smaller
>     and cleaner.
> 
> Choice is up to you :)

Meh, why is upstream keeping the configure script under version
control ?

Anyway OK, let's use the patch that hopefully will make its way
upstream.

Thomas
diff mbox series

Patch

diff --git a/package/lvm2/0001-configure-Introduce-enable-symvers-option.patch b/package/lvm2/0001-configure-Introduce-enable-symvers-option.patch
new file mode 100644
index 0000000000..8ca39c2cab
--- /dev/null
+++ b/package/lvm2/0001-configure-Introduce-enable-symvers-option.patch
@@ -0,0 +1,277 @@ 
+From f563334a76e31442f7b8693d2d350e6981c51c46 Mon Sep 17 00:00:00 2001
+From: Marcin Niestroj <m.niestroj@grinn-global.com>
+Date: Fri, 20 Jul 2018 14:26:44 +0200
+Subject: [PATCH] configure: Introduce --enable-symvers option
+
+Only few libc (e.g. glibc) libraries support full symbol version
+resolution in runtime. There are lot of standard libraries that do not
+support that, such as dietlibc, musl and uclibc. Hence there is no
+reason to generate symbol versions when compiling against them.
+
+Additionally libdevmapper.so was broken when compiled against
+uclibc. Runtime linker loader caused calling dm_task_get_info_base()
+function recursively, leading to segmentation fault.
+
+Introduce --enable-symvers[=STYLE] option, which allows to choose
+between gnu and disabled symbol versioning. By default gnu symbol
+versioning is used to provide backward compatibility.
+__GNUC__ check is replaced now with GNU_SYMVER, which is generated by
+configure script. Additionally ld version script is included only in
+case of gnu option, which slightly reduces output size.
+
+Providing --disable-symvers to configure script when building against
+uclibc library fixes segmentation fault error described above, due to
+lack of several versions of the same symbol in libdevmapper.so
+library.
+
+Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
+---
+ configure                 | 32 ++++++++++++++++++++++++++++++--
+ configure.in              | 28 +++++++++++++++++++++++++---
+ include/configure.h.in    |  3 +++
+ lib/misc/lib.h            | 10 +++++-----
+ libdm/datastruct/bitset.c |  5 +----
+ libdm/ioctl/libdm-iface.c |  2 +-
+ libdm/libdm-deptree.c     |  2 +-
+ libdm/libdm-stats.c       |  2 +-
+ 8 files changed, 67 insertions(+), 17 deletions(-)
+
+diff --git a/configure b/configure
+index e1ae0e884..c5d11c1b6 100755
+--- a/configure
++++ b/configure
+@@ -985,6 +985,7 @@ enable_fsadm
+ enable_blkdeactivate
+ enable_dmeventd
+ enable_selinux
++enable_symvers
+ enable_nls
+ with_localedir
+ with_confdir
+@@ -1729,6 +1730,9 @@ Optional Features:
+   --disable-blkdeactivate disable blkdeactivate
+   --enable-dmeventd       enable the device-mapper event daemon
+   --disable-selinux       disable selinux support
++  --enable-symvers[=STYLE]
++                          enables symbol versioning of the shared library
++                          [default=gnu]
+   --enable-nls            enable Native Language Support
+ 
+ Optional Packages:
+@@ -3169,7 +3173,6 @@ if test -z "$CFLAGS"; then :
+ fi
+ case "$host_os" in
+ 	linux*)
+-		CLDFLAGS="$CLDFLAGS -Wl,--version-script,.export.sym"
+ 		ELDFLAGS="-Wl,--export-dynamic"
+ 		# FIXME Generate list and use --dynamic-list=.dlopen.sym
+ 		CLDWHOLEARCHIVE="-Wl,-whole-archive"
+@@ -3190,7 +3193,6 @@ case "$host_os" in
+ 		;;
+ 	darwin*)
+ 		CFLAGS="$CFLAGS -no-cpp-precomp -fno-common"
+-		CLDFLAGS="$CLDFLAGS"
+ 		ELDFLAGS=
+ 		CLDWHOLEARCHIVE="-all_load"
+ 		CLDNOWHOLEARCHIVE=
+@@ -14609,6 +14611,32 @@ done
+ 	LIBS=$lvm_saved_libs
+ fi
+ 
++################################################################################
++{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to enable symbol versioning" >&5
++$as_echo_n "checking whether to enable symbol versioning... " >&6; }
++# Check whether --enable-symvers was given.
++if test "${enable_symvers+set}" = set; then :
++  enableval=$enable_symvers;
++  case "$enableval" in
++    gnu|no) ;;
++    *) as_fn_error $? "Unknown argument to enable/disable symvers" "$LINENO" 5 ;;
++  esac
++else
++  enable_symvers=gnu
++fi
++
++{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $enable_symvers" >&5
++$as_echo "$enable_symvers" >&6; }
++
++if test x$GCC = xyes && test x$enable_symvers = xgnu ; then
++
++$as_echo "#define GNU_SYMVER 1" >>confdefs.h
++
++  case "$host_os" in
++    linux*) CLDFLAGS="$CLDFLAGS -Wl,--version-script,.export.sym" ;;
++  esac
++fi
++
+ ################################################################################
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to enable internationalisation" >&5
+ $as_echo_n "checking whether to enable internationalisation... " >&6; }
+diff --git a/configure.in b/configure.in
+index 2e5e015c8..09c390850 100644
+--- a/configure.in
++++ b/configure.in
+@@ -30,12 +30,10 @@ AC_CANONICAL_TARGET([])
+ AS_IF([test -z "$CFLAGS"], [COPTIMISE_FLAG="-O2"])
+ case "$host_os" in
+ 	linux*)
+-		CLDFLAGS="$CLDFLAGS -Wl,--version-script,.export.sym"
+ 		ELDFLAGS="-Wl,--export-dynamic"
+ 		# FIXME Generate list and use --dynamic-list=.dlopen.sym
+ 		CLDWHOLEARCHIVE="-Wl,-whole-archive"
+ 		CLDNOWHOLEARCHIVE="-Wl,-no-whole-archive"
+-		LDDEPS="$LDDEPS .export.sym"
+ 		LIB_SUFFIX=so
+ 		DEVMAPPER=yes
+ 		BUILD_LVMETAD=no
+@@ -51,7 +49,6 @@ case "$host_os" in
+ 		;;
+ 	darwin*)
+ 		CFLAGS="$CFLAGS -no-cpp-precomp -fno-common"
+-		CLDFLAGS="$CLDFLAGS"
+ 		ELDFLAGS=
+ 		CLDWHOLEARCHIVE="-all_load"
+ 		CLDNOWHOLEARCHIVE=
+@@ -1742,6 +1739,31 @@ package as well (which may be called readline-devel or something similar).])
+ 	LIBS=$lvm_saved_libs
+ fi
+ 
++################################################################################
++dnl -- Symbol versioning
++AC_MSG_CHECKING(whether to enable symbol versioning)
++AC_ARG_ENABLE(symvers,
++              AC_HELP_STRING([--enable-symvers[[[=STYLE]]]],
++                             [enables symbol versioning of the shared library [default=gnu]]),
++                             [
++  case "$enableval" in
++    gnu|no) ;;
++    *) AC_MSG_ERROR(Unknown argument to enable/disable symvers) ;;
++  esac],
++                             enable_symvers=gnu)
++AC_MSG_RESULT($enable_symvers)
++
++if test x$GCC = xyes && test x$enable_symvers = xgnu ; then
++  AC_DEFINE(GNU_SYMVER, 1,
++            [Define to use GNU versioning in the shared library.])
++  case "$host_os" in
++    linux*)
++      CLDFLAGS="$CLDFLAGS -Wl,--version-script,.export.sym"
++      LDDEPS="$LDDEPS .export.sym"
++      ;;
++  esac
++fi
++
+ ################################################################################
+ dnl -- Internationalisation stuff
+ AC_MSG_CHECKING(whether to enable internationalisation)
+diff --git a/include/configure.h.in b/include/configure.h.in
+index 51726506c..3fc181b1e 100644
+--- a/include/configure.h.in
++++ b/include/configure.h.in
+@@ -151,6 +151,9 @@
+ /* Path to fsadm binary. */
+ #undef FSADM_PATH
+ 
++/* Define to use GNU versioning in the shared library. */
++#undef GNU_SYMVER
++
+ /* Define to 1 if you have the `alarm' function. */
+ #undef HAVE_ALARM
+ 
+diff --git a/lib/misc/lib.h b/lib/misc/lib.h
+index 8ed06f81d..9b3ce8a03 100644
+--- a/lib/misc/lib.h
++++ b/lib/misc/lib.h
+@@ -42,16 +42,16 @@
+  * macro DM_EXPORT_SYMBOL to export the function and bind it to the
+  * specified version string.
+  *
+- * Since versioning is only available when compiling with GCC the entire
+- * compatibility version should be enclosed in '#if defined(__GNUC__)',
+- * for example:
++ * Since versioning is only available when compiling with GCC
++ * and GLIBC the entire compatibility version should be enclosed
++ * in '#if defined(GNU_SYMVER)', for example:
+  *
+  *   int dm_foo(int bar)
+  *   {
+  *     return bar;
+  *   }
+  *
+- *   #if defined(__GNUC__)
++ *   #if defined(GNU_SYMVER)
+  *   // Backward compatible dm_foo() version 1.02.104
+  *   int dm_foo_v1_02_104(void);
+  *   int dm_foo_v1_02_104(void)
+@@ -68,7 +68,7 @@
+  * versions of library symbols prior to the introduction of symbol
+  * versioning: it must never be used for new symbols.
+  */
+-#if defined(__GNUC__)
++#if defined(GNU_SYMVER)
+ #define DM_EXPORT_SYMBOL(func, ver) \
+ 	__asm__(".symver " #func "_v" #ver ", " #func "@DM_" #ver )
+ #define DM_EXPORT_SYMBOL_BASE(func) \
+diff --git a/libdm/datastruct/bitset.c b/libdm/datastruct/bitset.c
+index b0826e1eb..2ec3f8f84 100644
+--- a/libdm/datastruct/bitset.c
++++ b/libdm/datastruct/bitset.c
+@@ -242,7 +242,7 @@ bad:
+ 	return NULL;
+ }
+ 
+-#if defined(__GNUC__)
++#if defined(GNU_SYMVER)
+ /*
+  * Maintain backward compatibility with older versions that did not
+  * accept a 'min_num_bits' argument to dm_bitset_parse_list().
+@@ -253,7 +253,4 @@ dm_bitset_t dm_bitset_parse_list_v1_02_129(const char *str, struct dm_pool *mem)
+ 	return dm_bitset_parse_list(str, mem, 0);
+ }
+ DM_EXPORT_SYMBOL(dm_bitset_parse_list, 1_02_129);
+-
+-#else /* if defined(__GNUC__) */
+-
+ #endif
+diff --git a/libdm/ioctl/libdm-iface.c b/libdm/ioctl/libdm-iface.c
+index c47e08467..b98afb15d 100644
+--- a/libdm/ioctl/libdm-iface.c
++++ b/libdm/ioctl/libdm-iface.c
+@@ -2137,7 +2137,7 @@ void dm_lib_exit(void)
+ 	_version_checked = 0;
+ }
+ 
+-#if defined(__GNUC__)
++#if defined(GNU_SYMVER)
+ /*
+  * Maintain binary backward compatibility.
+  * Version script mechanism works with 'gcc' compatible compilers only.
+diff --git a/libdm/libdm-deptree.c b/libdm/libdm-deptree.c
+index cf4fd62e7..474871da5 100644
+--- a/libdm/libdm-deptree.c
++++ b/libdm/libdm-deptree.c
+@@ -4110,7 +4110,7 @@ void dm_tree_node_set_callback(struct dm_tree_node *dnode,
+ 	dnode->callback_data = data;
+ }
+ 
+-#if defined(__GNUC__)
++#if defined(GNU_SYMVER)
+ /*
+  * Backward compatible implementations.
+  *
+diff --git a/libdm/libdm-stats.c b/libdm/libdm-stats.c
+index bc498675f..d424928c7 100644
+--- a/libdm/libdm-stats.c
++++ b/libdm/libdm-stats.c
+@@ -5064,7 +5064,7 @@ int dm_stats_start_filemapd(int fd, uint64_t group_id, const char *path,
+  * current dm_stats_create_region() version.
+  */
+ 
+-#if defined(__GNUC__)
++#if defined(GNU_SYMVER)
+ int dm_stats_create_region_v1_02_106(struct dm_stats *dms, uint64_t *region_id,
+ 				     uint64_t start, uint64_t len, int64_t step,
+ 				     int precise, const char *program_id,
+-- 
+2.18.0
+
diff --git a/package/lvm2/lvm2.mk b/package/lvm2/lvm2.mk
index 20e0dd0d5c..ccdc2c38e6 100644
--- a/package/lvm2/lvm2.mk
+++ b/package/lvm2/lvm2.mk
@@ -19,7 +19,8 @@  LVM2_CONF_OPTS += \
 	--enable-pkgconfig \
 	--enable-cmdlib \
 	--enable-dmeventd \
-	--disable-nls
+	--disable-nls \
+	--disable-symvers
 
 LVM2_DEPENDENCIES += host-pkgconf