fix 338160: Implement QGetTlsAddr query so that GDB+V gdbsrv can print __thread variables.
To implement QGetTlsAddr, gdbsrv has to know how to get the glibc dtv
address and the module id from the link_map.
These 2 things are dependent on the internals of glibc.
The dependency is mostly isolated in a few lines of arch dependent
code or in an external utility that used a hack + -ldl lib to find
the offset of the modid in the link_map structure.
Tested on x86/amd64/ppc64/s390x. Somewhat tested on ppc32 and arm64.
Untested/a few #ifdef-ed lines not compiled on arm/mips32/mips64
and darwin.
For more background info about thread local storage handling, see
'ELF Handling For Thread-Local Storage' http://www.akkadia.org/drepper/tls.pdf
Changes:
* auxprogs/getoff.c new auxilliary program to get platform specific offsets
(currently only the offset for the module id in struct link_map).
* configure.ac : check for dlinfo(RTLD_DI_TLS_MODID) needed for getoff.c
* new gdbserver_tests/hgtls, testing various types of __thread variables
* various m_gdbserver files:
- implement decoding of the QGetTlsAddr query
- for each platform: platform specific code to get the dtv
- call to external program getoff-<platform> the first time an
__thread variable is printed.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14283 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/configure.ac b/configure.ac
index 949a989..21b7782 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1449,6 +1449,37 @@
test x$ac_have_pthread_create_glibc_2_0 = xyes)
+# Check for dlinfo RTLD_DI_TLS_MODID
+AC_MSG_CHECKING([for dlinfo RTLD_DI_TLS_MODID])
+
+safe_LIBS="$LIBS"
+LIBS="-ldl"
+AC_LINK_IFELSE([AC_LANG_PROGRAM([[
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#include <link.h>
+#include <dlfcn.h>
+]], [[
+ size_t sizes[10000];
+ size_t modid_offset;
+ (void) dlinfo ((void*)sizes, RTLD_DI_TLS_MODID, &modid_offset);
+ return 0;
+]])], [
+ac_have_dlinfo_rtld_di_tls_modid=yes
+AC_MSG_RESULT([yes])
+AC_DEFINE([HAVE_DLINFO_RTLD_DI_TLS_MODID], 1,
+ [Define to 1 if you have a dlinfo that can do RTLD_DI_TLS_MODID.])
+], [
+ac_have_dlinfo_rtld_di_tls_modid=no
+AC_MSG_RESULT([no])
+])
+LIBS=$safe_LIBS
+
+AM_CONDITIONAL(HAVE_DLINFO_RTLD_DI_TLS_MODID,
+ test x$ac_have_dlinfo_rtld_di_tls_modid = xyes)
+
+
# Check for eventfd_t, eventfd() and eventfd_read()
AC_MSG_CHECKING([for eventfd()])