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/get_timebase_freq.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c') 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 (); -- cgit 1.4.1