@@ -6076,6 +6076,43 @@ $as_echo "$libc_linker_feature" >&6; }
config_vars="$config_vars
have-depaudit = $libc_cv_depaudit"
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for linker that supports -z pack-relative-relocs" >&5
+$as_echo_n "checking for linker that supports -z pack-relative-relocs... " >&6; }
+libc_linker_feature=no
+if test x"$gnu_ld" = x"yes"; then
+ cat > conftest.c <<EOF
+int _start (void) { return 42; }
+EOF
+ if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS $no_ssp
+ -Wl,-z,pack-relative-relocs -nostdlib -nostartfiles
+ -fPIC -shared -o conftest.so conftest.c
+ 1>&5'
+ { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+ test $ac_status = 0; }; }
+ then
+ if ${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS $no_ssp -Wl,-z,pack-relative-relocs -nostdlib \
+ -nostartfiles -fPIC -shared -o conftest.so conftest.c 2>&1 \
+ | grep "warning: -z pack-relative-relocs ignored" > /dev/null 2>&1; then
+ true
+ else
+ libc_linker_feature=yes
+ fi
+ fi
+ rm -f conftest*
+fi
+if test $libc_linker_feature = yes; then
+ libc_cv_dt_relr=yes
+else
+ libc_cv_dt_relr=no
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_linker_feature" >&5
+$as_echo "$libc_linker_feature" >&6; }
+config_vars="$config_vars
+have-dt-relr = $libc_cv_dt_relr"
+
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for linker that supports --no-dynamic-linker" >&5
$as_echo_n "checking for linker that supports --no-dynamic-linker... " >&6; }
libc_linker_feature=no
@@ -1336,6 +1336,11 @@ LIBC_LINKER_FEATURE([--depaudit], [-Wl,--depaudit,x],
[libc_cv_depaudit=yes], [libc_cv_depaudit=no])
LIBC_CONFIG_VAR([have-depaudit], [$libc_cv_depaudit])
+LIBC_LINKER_FEATURE([-z pack-relative-relocs],
+ [-Wl,-z,pack-relative-relocs],
+ [libc_cv_dt_relr=yes], [libc_cv_dt_relr=no])
+LIBC_CONFIG_VAR([have-dt-relr], [$libc_cv_dt_relr])
+
LIBC_LINKER_FEATURE([--no-dynamic-linker],
[-Wl,--no-dynamic-linker],
[libc_cv_no_dynamic_linker=yes],
@@ -541,6 +541,25 @@ tests-special += \
# tests-special
endif
endif
+ifeq ($(have-dt-relr),yes)
+tests += \
+ tst-relr \
+# tests
+ifeq ($(have-fpie),yes)
+tests += \
+ tst-relr-pie \
+# tests
+tests-pie += \
+ tst-relr-pie \
+# tests-pie
+tests-special += \
+ $(objpfx)check-tst-relr-pie.out \
+# tests-special
+endif
+CFLAGS-tst-relr-pie.c += $(pie-ccflag)
+LDFLAGS-tst-relr += -Wl,-z,pack-relative-relocs
+LDFLAGS-tst-relr-pie += -Wl,-z,pack-relative-relocs
+endif
endif
tests-special += $(objpfx)tst-relro-ldso.out $(objpfx)tst-relro-libc.out
@@ -2783,3 +2802,9 @@ $(objpfx)check-abi-version-libc.out: $(common-objpfx)libc.so
| sed -ne '/.gnu.version_d/, /.gnu.version_r/ p' \
| grep GLIBC_ABI_DT_RELR > $@; \
$(evaluate-test)
+
+$(objpfx)check-tst-relr-pie.out: $(objpfx)tst-relr-pie
+ LC_ALL=C $(OBJDUMP) -p $< \
+ | sed -ne '/required from libc.so/,$$ p' \
+ | grep GLIBC_ABI_DT_RELR > $@; \
+ $(evaluate-test)
@@ -146,12 +146,46 @@ elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
# define ELF_DYNAMIC_DO_RELA(map, scope, lazy, skip_ifunc) /* Nothing to do. */
# endif
+# define ELF_DYNAMIC_DO_RELR(map) \
+ do { \
+ ElfW(Addr) l_addr = (map)->l_addr, *where = 0; \
+ const ElfW(Relr) *r, *end; \
+ if ((map)->l_info[DT_RELR] == NULL) \
+ break; \
+ r = (const ElfW(Relr) *)D_PTR((map), l_info[DT_RELR]); \
+ end = (const ElfW(Relr) *)((const char *)r + \
+ (map)->l_info[DT_RELRSZ]->d_un.d_val); \
+ for (; r < end; r++) \
+ { \
+ ElfW(Relr) entry = *r; \
+ if ((entry & 1) == 0) \
+ { \
+ where = (ElfW(Addr) *)(l_addr + entry); \
+ *where++ += l_addr; \
+ } \
+ else \
+ { \
+ for (long int i = 0; (entry >>= 1) != 0; i++) \
+ if ((entry & 1) != 0) \
+ where[i] += l_addr; \
+ where += CHAR_BIT * sizeof(ElfW(Relr)) - 1; \
+ } \
+ } \
+ } while (0);
+
/* This can't just be an inline function because GCC is too dumb
to inline functions containing inlines themselves. */
+# ifdef RTLD_BOOTSTRAP
+# define DO_RTLD_BOOTSTRAP 1
+# else
+# define DO_RTLD_BOOTSTRAP 0
+# endif
# define ELF_DYNAMIC_RELOCATE(map, scope, lazy, consider_profile, skip_ifunc) \
do { \
int edr_lazy = elf_machine_runtime_setup ((map), (scope), (lazy), \
(consider_profile)); \
+ if (((map) != &GL(dl_rtld_map) || DO_RTLD_BOOTSTRAP)) \
+ ELF_DYNAMIC_DO_RELR (map); \
ELF_DYNAMIC_DO_REL ((map), (scope), edr_lazy, skip_ifunc); \
ELF_DYNAMIC_DO_RELA ((map), (scope), edr_lazy, skip_ifunc); \
} while (0)
@@ -89,6 +89,7 @@ elf_get_dynamic_info (struct link_map *l, bool bootstrap,
# if ! ELF_MACHINE_NO_REL
ADJUST_DYN_INFO (DT_REL);
# endif
+ ADJUST_DYN_INFO (DT_RELR);
ADJUST_DYN_INFO (DT_JMPREL);
ADJUST_DYN_INFO (VERSYMIDX (DT_VERSYM));
ADJUST_DYN_INFO (ADDRIDX (DT_GNU_HASH));
@@ -113,6 +114,8 @@ elf_get_dynamic_info (struct link_map *l, bool bootstrap,
if (info[DT_REL] != NULL)
assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel)));
#endif
+ if (info[DT_RELR] != NULL)
+ assert (info[DT_RELRENT]->d_un.d_val == sizeof (ElfW(Relr)));
if (bootstrap || static_pie_bootstrap)
{
assert (info[DT_RUNPATH] == NULL);
new file mode 100644
@@ -0,0 +1 @@
+#include "tst-relr.c"
new file mode 100644
@@ -0,0 +1,65 @@
+/* Basic tests for DT_RELR.
+ Copyright (C) 2022 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <link.h>
+#include <stdbool.h>
+#include <array_length.h>
+#include <support/check.h>
+
+static int o, x;
+
+#define ELEMS O O O O O O O O X X X X X X X O O X O O X X X E X E E O X O E
+#define E 0,
+
+#define O &o,
+#define X &x,
+void *arr[] = { ELEMS };
+#undef O
+#undef X
+
+#define O 1,
+#define X 2,
+static char val[] = { ELEMS };
+
+static int
+do_test (void)
+{
+ ElfW(Dyn) *d = _DYNAMIC;
+ if (d)
+ {
+ bool has_relr = false;
+ for (; d->d_tag != DT_NULL; d++)
+ if (d->d_tag == DT_RELR)
+ has_relr = true;
+
+#if defined __PIE__ || defined __pie__ || defined PIE || defined pie
+ TEST_VERIFY (has_relr);
+#else
+ TEST_VERIFY (!has_relr);
+#endif
+ }
+
+ for (int i = 0; i < array_length (arr); i++)
+ TEST_VERIFY ((arr[i] == 0 && val[i] == 0)
+ || (arr[i] == &o && val[i] == 1)
+ || (arr[i] == &x && val[i] == 2));
+
+ return 0;
+}
+
+#include <support/test-driver.c>