diff options
Diffstat (limited to 'meta/recipes-core/glibc/glibc/0035-x86_64-Avoid-lazy-relocation-of-tlsdesc-BZ-27137.patch')
| -rw-r--r-- | meta/recipes-core/glibc/glibc/0035-x86_64-Avoid-lazy-relocation-of-tlsdesc-BZ-27137.patch | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/meta/recipes-core/glibc/glibc/0035-x86_64-Avoid-lazy-relocation-of-tlsdesc-BZ-27137.patch b/meta/recipes-core/glibc/glibc/0035-x86_64-Avoid-lazy-relocation-of-tlsdesc-BZ-27137.patch new file mode 100644 index 0000000000..899111b118 --- /dev/null +++ b/meta/recipes-core/glibc/glibc/0035-x86_64-Avoid-lazy-relocation-of-tlsdesc-BZ-27137.patch @@ -0,0 +1,56 @@ +From 8f7e09f4dbdb5c815a18b8285fbc5d5d7bc17d86 Mon Sep 17 00:00:00 2001 +From: Szabolcs Nagy <szabolcs.nagy@arm.com> +Date: Thu, 11 Feb 2021 11:29:23 +0000 +Subject: [PATCH] x86_64: Avoid lazy relocation of tlsdesc [BZ #27137] + +Lazy tlsdesc relocation is racy because the static tls optimization and +tlsdesc management operations are done without holding the dlopen lock. + +This similar to the commit b7cf203b5c17dd6d9878537d41e0c7cc3d270a67 +for aarch64, but it fixes a different race: bug 27137. + +Another issue is that ld auditing ignores DT_BIND_NOW and thus tries to +relocate tlsdesc lazily, but that does not work in a BIND_NOW module +due to missing DT_TLSDESC_PLT. Unconditionally relocating tlsdesc at +load time fixes this bug 27721 too. +--- + sysdeps/x86_64/dl-machine.h | 19 ++++++++++++++----- + 1 file changed, 14 insertions(+), 5 deletions(-) +--- +Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=patch;h=8f7e09f4dbdb5c815a18b8285fbc5d5d7bc17d86] +Signed-off-by: Akash Hadke <akash.hadke@kpit.com> +Signed-off-by: Akash Hadke <hadkeakash4@gmail.com> +--- +diff --git a/sysdeps/x86_64/dl-machine.h b/sysdeps/x86_64/dl-machine.h +index 103eee6c3f..9a876a371e 100644 +--- a/sysdeps/x86_64/dl-machine.h ++++ b/sysdeps/x86_64/dl-machine.h +@@ -570,12 +570,21 @@ elf_machine_lazy_rel (struct link_map *map, + } + else if (__glibc_likely (r_type == R_X86_64_TLSDESC)) + { +- struct tlsdesc volatile * __attribute__((__unused__)) td = +- (struct tlsdesc volatile *)reloc_addr; ++ const Elf_Symndx symndx = ELFW (R_SYM) (reloc->r_info); ++ const ElfW (Sym) *symtab = (const void *)D_PTR (map, l_info[DT_SYMTAB]); ++ const ElfW (Sym) *sym = &symtab[symndx]; ++ const struct r_found_version *version = NULL; + +- td->arg = (void*)reloc; +- td->entry = (void*)(D_PTR (map, l_info[ADDRIDX (DT_TLSDESC_PLT)]) +- + map->l_addr); ++ if (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL) ++ { ++ const ElfW (Half) *vernum = ++ (const void *)D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]); ++ version = &map->l_versions[vernum[symndx] & 0x7fff]; ++ } ++ ++ /* Always initialize TLS descriptors completely at load time, in ++ case static TLS is allocated for it that requires locking. */ ++ elf_machine_rela (map, reloc, sym, version, reloc_addr, skip_ifunc); + } + else if (__glibc_unlikely (r_type == R_X86_64_IRELATIVE)) + { +-- +2.27.0 |