diff options
Diffstat (limited to 'meta/recipes-core/glibc/glibc/0012-Quote-from-bug-1443-which-explains-what-the-patch-do.patch')
| -rw-r--r-- | meta/recipes-core/glibc/glibc/0012-Quote-from-bug-1443-which-explains-what-the-patch-do.patch | 58 |
1 files changed, 0 insertions, 58 deletions
diff --git a/meta/recipes-core/glibc/glibc/0012-Quote-from-bug-1443-which-explains-what-the-patch-do.patch b/meta/recipes-core/glibc/glibc/0012-Quote-from-bug-1443-which-explains-what-the-patch-do.patch deleted file mode 100644 index a0b46c0479..0000000000 --- a/meta/recipes-core/glibc/glibc/0012-Quote-from-bug-1443-which-explains-what-the-patch-do.patch +++ /dev/null @@ -1,58 +0,0 @@ -From 8ca8e5cd78cbd37a713e1181f8f6641b57352aa8 Mon Sep 17 00:00:00 2001 -From: Khem Raj <raj.khem@gmail.com> -Date: Wed, 18 Mar 2015 00:20:09 +0000 -Subject: [PATCH] Quote from bug 1443 which explains what the patch does : - - We build some random program and link it with -lust. When we run it, - it dies with a SIGSEGV before reaching main(). - - Libust.so depends on liburcu-bp.so from the usermode-rcu package. - Although libust.so is not prelinked, liburcu-bp.so IS prelinked; this - is critical. - - Libust.so uses a TLS / __thread variable that is defined in liburcu- - bp.so. There are special ARM-specific relocation types that allow two - shared libraries to share thread-specific data. This is critical too. - - One more critical issue: although liburcu-bp.so is prelinked, we can't - load it at its prelinked address, because we also link against - librt.so, and librt.so uses that address. - - The dynamic linker is forced to relink liburcu-bp.so at a different - address. In the course of relinking, it processes the special ARM - relocation record mentioned above. The prelinker has already filled - in the information, which is a short offset into a table of thread- - specific data that is allocated per-thread for each library that uses - TLS. Because the normal behavior of a relocation is to add the symbol - value to an addend stored at the address being relocated, we end up - adding the short offset to itself, doubling it. - - Now we have an awkward situation. The libust.so library doesn't know - about the addend, so its TLS data for this element is correct. The - liburcu-bp.so library has a different offset for the element. When we - go to initialize the element for the first time in liburcu-bp.so, we - write the address of the result at the doubled (broken) offset. - Later, when we refer to the address from libust.so, we check the value - at the correct offset, but it's NULL, so we eat hot SIGSEGV. - -Upstream-Status: Pending - -Signed-off-by: Andrei Dinu <andrei.adrianx.dinu@intel.com> -Signed-off-by: Khem Raj <raj.khem@gmail.com> ---- - sysdeps/arm/dl-machine.h | 2 +- - 1 file changed, 1 insertion(+), 1 deletion(-) - -diff --git a/sysdeps/arm/dl-machine.h b/sysdeps/arm/dl-machine.h -index 90856779b1..a29bb86c56 100644 ---- a/sysdeps/arm/dl-machine.h -+++ b/sysdeps/arm/dl-machine.h -@@ -510,7 +510,7 @@ elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc, - - case R_ARM_TLS_DTPOFF32: - if (sym != NULL) -- *reloc_addr += sym->st_value; -+ *reloc_addr = sym->st_value; - break; - - case R_ARM_TLS_TPOFF32: |