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detect broken linker handling of __ehdr_start

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Older versions of ld on ia64 support __ehdr_start, but generate relocs
when they shouldn't.  This causes the ld.so to not run because it tries
to resolve the __ehdr_start symbol (but it's not exported).
This commit is contained in:
Mike Frysinger
2014-08-06 23:44:29 -04:00
parent 898c62f488
commit 61b1ef6e7c
3 changed files with 44 additions and 11 deletions
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6
ChangeLog
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@ -1,3 +1,9 @@
2014-08-12 Mike Frysinger <vapier@gentoo.org>
* configure.ac: Change __ehdr_start code to dereference the struct.
Run readelf on the output to look for relocations.
* configure: Regenerated.
2014-08-12 Joseph Myers <joseph@codesourcery.com> 2014-08-12 Joseph Myers <joseph@codesourcery.com>
[BZ #17261] [BZ #17261]

26
configure vendored
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@ -6965,8 +6965,11 @@ if test $libc_cv_predef_stack_protector = yes; then
fi fi
libc_extra_cppflags= libc_extra_cppflags=
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the linker provides __ehdr_start" >&5 # Some linkers on some architectures support __ehdr_start but with
$as_echo_n "checking whether the linker provides __ehdr_start... " >&6; } # bugs. Make sure usage of it does not create relocations in the
# output (as the linker should resolve them all for us).
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the linker provides working __ehdr_start" >&5
$as_echo_n "checking whether the linker provides working __ehdr_start... " >&6; }
if ${libc_cv_ehdr_start+:} false; then : if ${libc_cv_ehdr_start+:} false; then :
$as_echo_n "(cached) " >&6 $as_echo_n "(cached) " >&6
else else
@ -6980,12 +6983,20 @@ LIBS=
cat confdefs.h - <<_ACEOF >conftest.$ac_ext cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */ /* end confdefs.h. */
extern const char __ehdr_start __attribute__ ((visibility ("hidden"))); typedef struct {
const char *ehdr (void) { return &__ehdr_start; } char foo;
long val;
} Ehdr;
extern const Ehdr __ehdr_start __attribute__ ((visibility ("hidden")));
long ehdr (void) { return __ehdr_start.val; }
_ACEOF _ACEOF
if ac_fn_c_try_link "$LINENO"; then : if ac_fn_c_try_link "$LINENO"; then :
libc_cv_ehdr_start=yes if $READELF -r conftest | fgrep __ehdr_start >/dev/null; then
libc_cv_ehdr_start=broken
else
libc_cv_ehdr_start=yes
fi
else else
libc_cv_ehdr_start=no libc_cv_ehdr_start=no
fi fi
@ -6998,9 +7009,12 @@ LIBS="$old_LIBS"
fi fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_ehdr_start" >&5 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_ehdr_start" >&5
$as_echo "$libc_cv_ehdr_start" >&6; } $as_echo "$libc_cv_ehdr_start" >&6; }
if test $libc_cv_ehdr_start = yes; then if test "$libc_cv_ehdr_start" = yes; then
$as_echo "#define HAVE_EHDR_START 1" >>confdefs.h $as_echo "#define HAVE_EHDR_START 1" >>confdefs.h
elif test "$libc_cv_ehdr_start" = broken; then
{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: linker is broken -- you should upgrade" >&5
$as_echo "$as_me: WARNING: linker is broken -- you should upgrade" >&2;}
fi fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for __builtin_trap with no external dependencies" >&5 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for __builtin_trap with no external dependencies" >&5

23
configure.ac
View File

@ -1880,7 +1880,10 @@ if test $libc_cv_predef_stack_protector = yes; then
fi fi
libc_extra_cppflags= libc_extra_cppflags=
AC_CACHE_CHECK([whether the linker provides __ehdr_start], # Some linkers on some architectures support __ehdr_start but with
# bugs. Make sure usage of it does not create relocations in the
# output (as the linker should resolve them all for us).
AC_CACHE_CHECK([whether the linker provides working __ehdr_start],
libc_cv_ehdr_start, [ libc_cv_ehdr_start, [
old_CFLAGS="$CFLAGS" old_CFLAGS="$CFLAGS"
old_LDFLAGS="$LDFLAGS" old_LDFLAGS="$LDFLAGS"
@ -1889,16 +1892,26 @@ CFLAGS="$CFLAGS -fPIC"
LDFLAGS="$LDFLAGS -nostdlib -nostartfiles -shared" LDFLAGS="$LDFLAGS -nostdlib -nostartfiles -shared"
LIBS= LIBS=
AC_LINK_IFELSE([AC_LANG_SOURCE([ AC_LINK_IFELSE([AC_LANG_SOURCE([
extern const char __ehdr_start __attribute__ ((visibility ("hidden"))); typedef struct {
const char *ehdr (void) { return &__ehdr_start; } char foo;
long val;
} Ehdr;
extern const Ehdr __ehdr_start __attribute__ ((visibility ("hidden")));
long ehdr (void) { return __ehdr_start.val; }
])], ])],
[libc_cv_ehdr_start=yes], [libc_cv_ehdr_start=no]) [if $READELF -r conftest | fgrep __ehdr_start >/dev/null; then
libc_cv_ehdr_start=broken
else
libc_cv_ehdr_start=yes
fi], [libc_cv_ehdr_start=no])
CFLAGS="$old_CFLAGS" CFLAGS="$old_CFLAGS"
LDFLAGS="$old_LDFLAGS" LDFLAGS="$old_LDFLAGS"
LIBS="$old_LIBS" LIBS="$old_LIBS"
]) ])
if test $libc_cv_ehdr_start = yes; then if test "$libc_cv_ehdr_start" = yes; then
AC_DEFINE([HAVE_EHDR_START]) AC_DEFINE([HAVE_EHDR_START])
elif test "$libc_cv_ehdr_start" = broken; then
AC_MSG_WARN([linker is broken -- you should upgrade])
fi fi
AC_CACHE_CHECK(for __builtin_trap with no external dependencies, AC_CACHE_CHECK(for __builtin_trap with no external dependencies,