diff options
Diffstat (limited to 'configure.in')
| -rw-r--r-- | configure.in | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/configure.in b/configure.in index 0916e9ec5c..a9ee7334d6 100644 --- a/configure.in +++ b/configure.in @@ -927,6 +927,7 @@ AC_CHECK_PROG_VER(SED, sed, --version, SED=: aux_missing="$aux_missing sed") AC_CHECK_TOOL(READELF, readelf, false) +AC_CHECK_TOOL(NM, nm, false) AC_CHECK_PROGS(AUTOCONF, autoconf, no) case "x$AUTOCONF" in @@ -2052,6 +2053,39 @@ if test $libc_cv_predef_fortify_source = yes; then fi AC_SUBST(CPPUNDEFS) +dnl Check for silly hacked compilers inserting -fstack-protector. +dnl This breaks badly for the early startup code we compile, since +dnl the compiled code can refer to a magic machine-dependent location +dnl for the canary value before we have sufficient setup for that to +dnl work. It's also questionable to build all of libc with this flag +dnl even when you're doing that for most applications you build, since +dnl libc's code is so heavily-used and performance-sensitive. If we +dnl ever really want to make that work, it should be enabled explicitly +dnl in the libc build, not inherited from implicit compiler settings. +AC_CACHE_CHECK([whether $CC implicitly enables -fstack-protector], + libc_cv_predef_stack_protector, [ +AC_TRY_COMPILE([extern void foobar (char *);], + [char large_array[2048]; foobar (large_array);], [ +libc_undefs=`$NM -u conftest.o | + LC_ALL=C $AWK '$1 == "U" { print $2 | "sort -u"; next } { exit(1) }' \ + 2>&AS_MESSAGE_LOG_FD` || { + AC_MSG_ERROR([confusing output from $NM -u]) +} +echo >&AS_MESSAGE_LOG_FD "libc_undefs='$libc_undefs'" +case "$libc_undefs" in +foobar) libc_cv_predef_stack_protector=no ;; +'__stack_chk_fail +foobar') libc_cv_predef_stack_protector=yes ;; +*) AC_MSG_ERROR([unexpected symbols in test: $libc_undefs]) ;; +esac], + [AC_MSG_ERROR([test compilation failed])]) +]) +libc_extra_cflags= +if test $libc_cv_predef_stack_protector = yes; then + libc_extra_cflags=-fno-stack-protector +fi +AC_SUBST(libc_extra_cflags) + ### End of automated tests. ### Now run sysdeps configure fragments. |