diff options
authorChristophe Lyon <>2018-07-04 15:55:34 (GMT)
committerWaldemar Brodkorb <>2018-08-10 14:02:45 (GMT)
commit7f07872b8aea16611890865700fbfefd586bc1fb (patch)
parent4d6b4178c8e49dd6d3067a399e2a49d5379b7750 (diff)
nptl: Use linker-defined symbol to find start of .tdata section.
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 <>
1 files changed, 9 insertions, 0 deletions
diff --git a/libpthread/nptl/sysdeps/generic/libc-tls.c b/libpthread/nptl/sysdeps/generic/libc-tls.c
index 58e77ff..725f3df 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;
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;
initimage = (void *) phdr->p_vaddr;
align = phdr->p_align;
if (phdr->p_align > max_align)
max_align = phdr->p_align;