[OE-core] [PATCH 1/2] glibc: Fix scope resolution in glibc to be breadth first.
Mark Hatle
mark.hatle at windriver.com
Sat Aug 20 02:17:42 UTC 2016
On 8/19/16 8:44 PM, Mark Hatle wrote:
> The ELF specification indicates symbol resolution should be breadth first, not
> depth first.
>
> The dl-deps.c: dl_build_locale_scope function is processing in a depth first
> mode. This is causes certain symbols to be incorrectly reported when
> LD_TRACE_PRELINKING=1 is enabled.
>
> See glibc BZ #20488 for more information.
>
> Signed-off-by: Mark Hatle <mark.hatle at windriver.com>
> ---
> .../glibc/glibc/0026-build_local_scope.patch | 56 ++++++++++++++++++++++
> meta/recipes-core/glibc/glibc_2.24.bb | 1 +
> 2 files changed, 57 insertions(+)
> create mode 100644 meta/recipes-core/glibc/glibc/0026-build_local_scope.patch
>
> diff --git a/meta/recipes-core/glibc/glibc/0026-build_local_scope.patch b/meta/recipes-core/glibc/glibc/0026-build_local_scope.patch
> new file mode 100644
> index 0000000..435a8c8
> --- /dev/null
> +++ b/meta/recipes-core/glibc/glibc/0026-build_local_scope.patch
> @@ -0,0 +1,56 @@
> +From 6e4ec5a3c5fe63b6458036f18d43124de4a7e724 Mon Sep 17 00:00:00 2001
> +From: Mark Hatle <mark.hatle at windriver.com>
> +Date: Thu, 18 Aug 2016 14:07:58 -0500
> +Subject: [PATCH] elf/dl-deps.c: Make _dl_build_local_scope breadth first
> +
> +According to the ELF specification:
> +
> +When resolving symbolic references, the dynamic linker examines the symbol
> +tables with a breadth-first search.
> +
> +This function was using a depth first search. By doing so the conflict
> +resolution reported to the prelinker (when LD_TRACE_PRELINKING=1 is set)
> +was incorrect. This caused problems when their were various circular
> +dependencies between libraries. The problem usually manifested itself by
> +the wrong IFUNC being executed.
> +
> +[BZ# 20488]
> +
> +Upstream-Status: Pending
Above can be changes to:
Upstream-Status: Submitted [libc-alpha]
> +
> +Signed-off-by: Mark Hatle <mark.hatle at windriver.com>
> +---
> + elf/dl-deps.c | 14 ++++++++++----
> + 1 file changed, 10 insertions(+), 4 deletions(-)
> +
> +diff --git a/elf/dl-deps.c b/elf/dl-deps.c
> +index 6a82987..fc37c87 100644
> +--- a/elf/dl-deps.c
> ++++ b/elf/dl-deps.c
> +@@ -73,13 +73,19 @@ _dl_build_local_scope (struct link_map **list, struct link_map *map)
> + {
> + struct link_map **p = list;
> + struct link_map **q;
> ++ struct link_map **r;
> +
> + *p++ = map;
> + map->l_reserved = 1;
> +- if (map->l_initfini)
> +- for (q = map->l_initfini + 1; *q; ++q)
> +- if (! (*q)->l_reserved)
> +- p += _dl_build_local_scope (p, *q);
> ++
> ++ for (r = list; r < p; ++r)
> ++ if ((*r)->l_initfini)
> ++ for (q = (*r)->l_initfini + 1; *q; ++q)
> ++ if (! (*q)->l_reserved)
> ++ {
> ++ *p++ = *q;
> ++ (*q)->l_reserved = 1;
> ++ }
> + return p - list;
> + }
> +
> +--
> +2.5.5
> +
> diff --git a/meta/recipes-core/glibc/glibc_2.24.bb b/meta/recipes-core/glibc/glibc_2.24.bb
> index e446e7a..a3ac738 100644
> --- a/meta/recipes-core/glibc/glibc_2.24.bb
> +++ b/meta/recipes-core/glibc/glibc_2.24.bb
> @@ -36,6 +36,7 @@ SRC_URI = "${GLIBC_GIT_URI};branch=${SRCBRANCH};name=glibc \
> file://0023-eglibc-Install-PIC-archives.patch \
> file://0024-eglibc-Forward-port-cross-locale-generation-support.patch \
> file://0025-Define-DUMMY_LOCALE_T-if-not-defined.patch \
> + file://0026-build_local_scope.patch \
> "
>
> SRC_URI += "\
>
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