From 1bdda52fe92fd01b424cd6fbb63e3df96a95015c Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Fri, 29 Nov 2019 10:44:59 -0300 Subject: elf: Move vDSO setup to rtld (BZ#24967) This patch moves the vDSO setup from libc to loader code, just after the vDSO link_map setup. For static case the initialization is moved to _dl_non_dynamic_init instead. Instead of using the mangled pointer, the vDSO data is set as attribute_relro (on _rtld_global_ro for shared or _dl_vdso_* for static). It is read-only even with partial relro. It fixes BZ#24967 now that the vDSO pointer is setup earlier than malloc interposition is called. Also, vDSO calls should not be a problem for static dlopen as indicated by BZ#20802. The vDSO pointer would be zero-initialized and the syscall will be issued instead. Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu, arm-linux-gnueabihf, powerpc64le-linux-gnu, powerpc64-linux-gnu, powerpc-linux-gnu, s390x-linux-gnu, sparc64-linux-gnu, and sparcv9-linux-gnu. I also run some tests on mips. Reviewed-by: Siddhesh Poyarekar --- sysdeps/unix/sysv/linux/powerpc/Makefile | 1 - .../unix/sysv/linux/powerpc/get_timebase_freq.c | 5 +-- sysdeps/unix/sysv/linux/powerpc/init-first.c | 50 ---------------------- sysdeps/unix/sysv/linux/powerpc/libc-vdso.h | 10 ----- 4 files changed, 2 insertions(+), 64 deletions(-) delete mode 100644 sysdeps/unix/sysv/linux/powerpc/init-first.c (limited to 'sysdeps/unix/sysv/linux/powerpc') diff --git a/sysdeps/unix/sysv/linux/powerpc/Makefile b/sysdeps/unix/sysv/linux/powerpc/Makefile index 1596238afa..cc2f804d86 100644 --- a/sysdeps/unix/sysv/linux/powerpc/Makefile +++ b/sysdeps/unix/sysv/linux/powerpc/Makefile @@ -13,7 +13,6 @@ gen-as-const-headers += ucontext_i.sym endif ifeq ($(subdir),elf) -sysdep_routines += dl-vdso ifeq ($(build-shared),yes) # This is needed for DSO loading from static binaries. sysdep-dl-routines += dl-static diff --git a/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c b/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c index ebd0d2f880..81f7c73f38 100644 --- a/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c +++ b/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c @@ -21,7 +21,7 @@ #include #include -#include +#include static uint64_t get_timebase_freq_fallback (void) @@ -101,8 +101,7 @@ uint64_t __get_timebase_freq (void) { /* The vDSO does not have a fallback mechanism (such calling a syscall). */ - __typeof (VDSO_SYMBOL (get_tbfreq)) vdsop = VDSO_SYMBOL (get_tbfreq); - PTR_DEMANGLE (vdsop); + uint64_t (*vdsop)(void) = GLRO(dl_vdso_get_tbfreq); if (vdsop == NULL) return get_timebase_freq_fallback (); diff --git a/sysdeps/unix/sysv/linux/powerpc/init-first.c b/sysdeps/unix/sysv/linux/powerpc/init-first.c deleted file mode 100644 index d20938c1da..0000000000 --- a/sysdeps/unix/sysv/linux/powerpc/init-first.c +++ /dev/null @@ -1,50 +0,0 @@ -/* Initialization code run first thing by the ELF startup code. Linux/PowerPC. - Copyright (C) 2007-2020 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 - . */ - -#include -#include - -unsigned long long (*VDSO_SYMBOL(get_tbfreq)) (void) attribute_hidden; -#if defined(__PPC64__) || defined(__powerpc64__) -void *VDSO_SYMBOL(sigtramp_rt64) attribute_hidden; -#else -void *VDSO_SYMBOL(sigtramp32) attribute_hidden; -void *VDSO_SYMBOL(sigtramp_rt32) attribute_hidden; -#endif - -static inline void -__libc_vdso_platform_setup_arch (void) -{ - VDSO_SYMBOL (get_tbfreq) = get_vdso_mangle_symbol (HAVE_GET_TBFREQ); - - /* PPC64 uses only one signal trampoline symbol, while PPC32 will use - two depending if SA_SIGINFO is used (__kernel_sigtramp_rt32) or not - (__kernel_sigtramp32). - There is no need to pointer mangle these symbol because they will - used only for pointer comparison. */ -#if defined(__PPC64__) || defined(__powerpc64__) - VDSO_SYMBOL(sigtramp_rt64) = get_vdso_symbol (HAVE_SIGTRAMP_RT64); -#else - VDSO_SYMBOL(sigtramp32) = get_vdso_symbol (HAVE_SIGTRAMP_32); - VDSO_SYMBOL(sigtramp_rt32) = get_vdso_symbol (HAVE_SIGTRAMP_RT32); -#endif -} - -#define VDSO_SETUP_ARCH __libc_vdso_platform_setup_arch - -#include diff --git a/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h b/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h index 2f18a762d8..8dae14057c 100644 --- a/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h +++ b/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h @@ -54,14 +54,4 @@ # define VDSO_IFUNC_RET(value) ((void *) (value)) #endif -#include_next - -extern unsigned long long (*VDSO_SYMBOL(get_tbfreq)) (void); -#if defined(__PPC64__) || defined(__powerpc64__) -extern void *VDSO_SYMBOL(sigtramp_rt64); -#else -extern void *VDSO_SYMBOL(sigtramp32); -extern void *VDSO_SYMBOL(sigtramp_rt32); -#endif - #endif /* _LIBC_VDSO_H */ -- cgit v1.2.3-70-g09d2