From 7f07872b8aea16611890865700fbfefd586bc1fb Mon Sep 17 00:00:00 2001 From: Christophe Lyon Date: Wed, 4 Jul 2018 17:55:34 +0200 Subject: nptl: Use linker-defined symbol to find start of .tdata section. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit phdr->p_vaddr of TLS segment is not a valid value for FDPIC so we can either translate phdr->p_vaddr using loadmap (not easy here) or use a new linker script defined symbol, whih this patch does. * libpthread/nptl/sysdeps/generic/libc-tls.c (__tdata_start): Declare. (__libc_setup_tls): Support __FDPIC__. Signed-off-by: Mickaël Guêné Signed-off-by: Christophe Lyon --- libpthread/nptl/sysdeps/generic/libc-tls.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/libpthread/nptl/sysdeps/generic/libc-tls.c b/libpthread/nptl/sysdeps/generic/libc-tls.c index 58e77ff10..725f3dfc7 100644 --- a/libpthread/nptl/sysdeps/generic/libc-tls.c +++ b/libpthread/nptl/sysdeps/generic/libc-tls.c @@ -36,6 +36,11 @@ extern ElfW(Phdr) *_dl_phdr; extern size_t _dl_phnum; +#ifdef __FDPIC__ +/* phdr->p_vaddr is not valid in FDPIC mode. To find tdata start we + use the linker script defined symbol __tdata_start. */ +extern int __tdata_start; +#endif static dtv_t static_dtv[2 + TLS_SLOTINFO_SURPLUS]; @@ -130,7 +135,11 @@ __libc_setup_tls (size_t tcbsize, size_t tcbalign) /* Remember the values we need. */ memsz = phdr->p_memsz; filesz = phdr->p_filesz; +#ifdef __FDPIC__ + initimage = (void *) &__tdata_start; +#else initimage = (void *) phdr->p_vaddr; +#endif align = phdr->p_align; if (phdr->p_align > max_align) max_align = phdr->p_align; -- cgit v1.2.3