diff options
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86/dl-cet.h | 20 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86/include/asm/prctl.h | 5 | ||||
| -rw-r--r-- | sysdeps/x86/Makefile | 9 | ||||
| -rw-r--r-- | sysdeps/x86/dl-cet.c | 217 | ||||
| -rw-r--r-- | sysdeps/x86/dl-procruntime.c | 11 | ||||
| -rw-r--r-- | sysdeps/x86/tst-cet-legacy-4.c | 19 | ||||
| -rw-r--r-- | sysdeps/x86/tst-cet-legacy-5.c | 3 | ||||
| -rw-r--r-- | sysdeps/x86/tst-cet-legacy-6.c | 3 | ||||
| -rw-r--r-- | sysdeps/x86/tst-cet-legacy-7.c | 38 | ||||
| -rw-r--r-- | sysdeps/x86/tst-cet-legacy-8.c | 48 |
10 files changed, 165 insertions, 208 deletions
diff --git a/sysdeps/unix/sysv/linux/x86/dl-cet.h b/sysdeps/unix/sysv/linux/x86/dl-cet.h index 9b2aaa238c..ae97a433a2 100644 --- a/sysdeps/unix/sysv/linux/x86/dl-cet.h +++ b/sysdeps/unix/sysv/linux/x86/dl-cet.h @@ -19,26 +19,6 @@ #include <asm/prctl.h> static inline int __attribute__ ((always_inline)) -dl_cet_allocate_legacy_bitmap (unsigned long *legacy_bitmap) -{ - /* Allocate legacy bitmap. */ -#ifdef __LP64__ - return (int) INTERNAL_SYSCALL_CALL (arch_prctl, - ARCH_CET_LEGACY_BITMAP, legacy_bitmap); -#else - unsigned long long legacy_bitmap_u64[2]; - int res = INTERNAL_SYSCALL_CALL (arch_prctl, - ARCH_CET_LEGACY_BITMAP, legacy_bitmap_u64); - if (res == 0) - { - legacy_bitmap[0] = legacy_bitmap_u64[0]; - legacy_bitmap[1] = legacy_bitmap_u64[1]; - } - return res; -#endif -} - -static inline int __attribute__ ((always_inline)) dl_cet_disable_cet (unsigned int cet_feature) { return (int) INTERNAL_SYSCALL_CALL (arch_prctl, ARCH_CET_DISABLE, diff --git a/sysdeps/unix/sysv/linux/x86/include/asm/prctl.h b/sysdeps/unix/sysv/linux/x86/include/asm/prctl.h index f67f3299b9..45ad0b052f 100644 --- a/sysdeps/unix/sysv/linux/x86/include/asm/prctl.h +++ b/sysdeps/unix/sysv/linux/x86/include/asm/prctl.h @@ -24,9 +24,4 @@ OUT: allocated shadow stack address: *addr. */ # define ARCH_CET_ALLOC_SHSTK 0x3004 -/* Return legacy region bitmap info in unsigned long long *addr: - address: addr[0]. - size: addr[1]. - */ -# define ARCH_CET_LEGACY_BITMAP 0x3005 #endif /* ARCH_CET_STATUS */ diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile index 95182a508c..4ffa699e5f 100644 --- a/sysdeps/x86/Makefile +++ b/sysdeps/x86/Makefile @@ -20,7 +20,8 @@ sysdep-dl-routines += dl-cet tests += tst-cet-legacy-1 tst-cet-legacy-1a tst-cet-legacy-2 \ tst-cet-legacy-2a tst-cet-legacy-3 tst-cet-legacy-4 \ - tst-cet-legacy-5a tst-cet-legacy-6a + tst-cet-legacy-5a tst-cet-legacy-6a tst-cet-legacy-7 \ + tst-cet-legacy-8 tst-cet-legacy-1a-ARGS = -- $(host-test-program-cmd) ifneq (no,$(have-tunables)) tests += tst-cet-legacy-4a tst-cet-legacy-4b tst-cet-legacy-4c \ @@ -43,14 +44,16 @@ CFLAGS-tst-cet-legacy-4b.c += -fcf-protection CFLAGS-tst-cet-legacy-mod-4.c += -fcf-protection=none CFLAGS-tst-cet-legacy-5a.c += -fcf-protection CFLAGS-tst-cet-legacy-5b.c += -fcf-protection -CFLAGS-tst-cet-legacy-mod-5a.c += -fcf-protection=none +CFLAGS-tst-cet-legacy-mod-5a.c += -fcf-protection=branch CFLAGS-tst-cet-legacy-mod-5b.c += -fcf-protection CFLAGS-tst-cet-legacy-mod-5c.c += -fcf-protection CFLAGS-tst-cet-legacy-6a.c += -fcf-protection CFLAGS-tst-cet-legacy-6b.c += -fcf-protection -CFLAGS-tst-cet-legacy-mod-6a.c += -fcf-protection=none +CFLAGS-tst-cet-legacy-mod-6a.c += -fcf-protection=branch CFLAGS-tst-cet-legacy-mod-6b.c += -fcf-protection CFLAGS-tst-cet-legacy-mod-6c.c += -fcf-protection +CFLAGS-tst-cet-legacy-7.c += -fcf-protection=none +CFLAGS-tst-cet-legacy-8.c += -mshstk $(objpfx)tst-cet-legacy-1: $(objpfx)tst-cet-legacy-mod-1.so \ $(objpfx)tst-cet-legacy-mod-2.so diff --git a/sysdeps/x86/dl-cet.c b/sysdeps/x86/dl-cet.c index ca3b5849bc..c7029f1b51 100644 --- a/sysdeps/x86/dl-cet.c +++ b/sysdeps/x86/dl-cet.c @@ -33,63 +33,6 @@ # error GNU_PROPERTY_X86_FEATURE_1_SHSTK != X86_FEATURE_1_SHSTK #endif -static int -dl_cet_mark_legacy_region (struct link_map *l) -{ - /* Mark PT_LOAD segments with PF_X in legacy code page bitmap. */ - size_t i, phnum = l->l_phnum; - const ElfW(Phdr) *phdr = l->l_phdr; -#ifdef __x86_64__ - typedef unsigned long long word_t; -#else - typedef unsigned long word_t; -#endif - unsigned int bits_to_set; - word_t mask_to_set; -#define BITS_PER_WORD (sizeof (word_t) * 8) -#define BITMAP_FIRST_WORD_MASK(start) \ - (~((word_t) 0) << ((start) & (BITS_PER_WORD - 1))) -#define BITMAP_LAST_WORD_MASK(nbits) \ - (~((word_t) 0) >> (-(nbits) & (BITS_PER_WORD - 1))) - - word_t *bitmap = (word_t *) GL(dl_x86_legacy_bitmap)[0]; - word_t bitmap_size = GL(dl_x86_legacy_bitmap)[1]; - word_t *p; - size_t page_size = GLRO(dl_pagesize); - - for (i = 0; i < phnum; i++) - if (phdr[i].p_type == PT_LOAD && (phdr[i].p_flags & PF_X)) - { - /* One bit in legacy bitmap represents a page. */ - ElfW(Addr) start = (phdr[i].p_vaddr + l->l_addr) / page_size; - ElfW(Addr) len = (phdr[i].p_memsz + page_size - 1) / page_size; - ElfW(Addr) end = start + len; - - if ((end / 8) > bitmap_size) - return -EINVAL; - - p = bitmap + (start / BITS_PER_WORD); - bits_to_set = BITS_PER_WORD - (start % BITS_PER_WORD); - mask_to_set = BITMAP_FIRST_WORD_MASK (start); - - while (len >= bits_to_set) - { - *p |= mask_to_set; - len -= bits_to_set; - bits_to_set = BITS_PER_WORD; - mask_to_set = ~((word_t) 0); - p++; - } - if (len) - { - mask_to_set &= BITMAP_LAST_WORD_MASK (end); - *p |= mask_to_set; - } - } - - return 0; -} - /* Check if object M is compatible with CET. */ static void @@ -117,6 +60,8 @@ dl_cet_check (struct link_map *m, const char *program) if (ibt_enabled || shstk_enabled) { struct link_map *l = NULL; + unsigned int ibt_legacy = 0, shstk_legacy = 0; + bool found_ibt_legacy = false, found_shstk_legacy = false; /* Check if IBT and SHSTK are enabled in object. */ bool enable_ibt = (ibt_enabled @@ -142,10 +87,7 @@ dl_cet_check (struct link_map *m, const char *program) support IBT nor SHSTK. */ if (enable_ibt || enable_shstk) { - int res; unsigned int i; - unsigned int first_legacy, last_legacy; - bool need_legacy_bitmap = false; i = m->l_searchlist.r_nlist; while (i-- > 0) @@ -167,91 +109,25 @@ dl_cet_check (struct link_map *m, const char *program) continue; #endif - if (enable_ibt - && enable_ibt_type != CET_ALWAYS_ON - && !(l->l_cet & lc_ibt)) + /* IBT is enabled only if it is enabled in executable as + well as all shared objects. */ + enable_ibt &= (enable_ibt_type == CET_ALWAYS_ON + || (l->l_cet & lc_ibt) != 0); + if (!found_ibt_legacy && enable_ibt != ibt_enabled) { - /* Remember the first and last legacy objects. */ - if (!need_legacy_bitmap) - last_legacy = i; - first_legacy = i; - need_legacy_bitmap = true; + found_ibt_legacy = true; + ibt_legacy = i; } /* SHSTK is enabled only if it is enabled in executable as well as all shared objects. */ enable_shstk &= (enable_shstk_type == CET_ALWAYS_ON || (l->l_cet & lc_shstk) != 0); - } - - if (need_legacy_bitmap) - { - if (GL(dl_x86_legacy_bitmap)[0]) - { - /* Change legacy bitmap to writable. */ - if (__mprotect ((void *) GL(dl_x86_legacy_bitmap)[0], - GL(dl_x86_legacy_bitmap)[1], - PROT_READ | PROT_WRITE) < 0) - { -mprotect_failure: - if (program) - _dl_fatal_printf ("%s: mprotect legacy bitmap failed\n", - l->l_name); - else - _dl_signal_error (EINVAL, l->l_name, "dlopen", - N_("mprotect legacy bitmap failed")); - } - } - else + if (enable_shstk != shstk_enabled) { - /* Allocate legacy bitmap. */ - int res = dl_cet_allocate_legacy_bitmap - (GL(dl_x86_legacy_bitmap)); - if (res != 0) - { - if (program) - _dl_fatal_printf ("%s: legacy bitmap isn't available\n", - l->l_name); - else - _dl_signal_error (EINVAL, l->l_name, "dlopen", - N_("legacy bitmap isn't available")); - } + found_shstk_legacy = true; + shstk_legacy = i; } - - /* Put legacy shared objects in legacy bitmap. */ - for (i = first_legacy; i <= last_legacy; i++) - { - l = m->l_initfini[i]; - - if (l->l_init_called || (l->l_cet & lc_ibt)) - continue; - -#ifdef SHARED - if (l == &GL(dl_rtld_map) - || l->l_real == &GL(dl_rtld_map) - || (program && l == m)) - continue; -#endif - - /* If IBT is enabled in executable and IBT isn't enabled - in this shard object, mark PT_LOAD segments with PF_X - in legacy code page bitmap. */ - res = dl_cet_mark_legacy_region (l); - if (res != 0) - { - if (program) - _dl_fatal_printf ("%s: failed to mark legacy code region\n", - l->l_name); - else - _dl_signal_error (-res, l->l_name, "dlopen", - N_("failed to mark legacy code region")); - } - } - - /* Change legacy bitmap to read-only. */ - if (__mprotect ((void *) GL(dl_x86_legacy_bitmap)[0], - GL(dl_x86_legacy_bitmap)[1], PROT_READ) < 0) - goto mprotect_failure; } } @@ -259,23 +135,40 @@ mprotect_failure: if (enable_ibt != ibt_enabled || enable_shstk != shstk_enabled) { - if (!program - && enable_shstk_type != CET_PERMISSIVE) + if (!program) { - /* When SHSTK is enabled, we can't dlopening a shared - object without SHSTK. */ - if (enable_shstk != shstk_enabled) - _dl_signal_error (EINVAL, l->l_name, "dlopen", - N_("shadow stack isn't enabled")); - return; + if (enable_ibt_type != CET_PERMISSIVE) + { + /* When IBT is enabled, we cannot dlopen a shared + object without IBT. */ + if (found_ibt_legacy) + _dl_signal_error (0, + m->l_initfini[ibt_legacy]->l_name, + "dlopen", + N_("rebuild shared object with IBT support enabled")); + } + + if (enable_shstk_type != CET_PERMISSIVE) + { + /* When SHSTK is enabled, we cannot dlopen a shared + object without SHSTK. */ + if (found_shstk_legacy) + _dl_signal_error (0, + m->l_initfini[shstk_legacy]->l_name, + "dlopen", + N_("rebuild shared object with SHSTK support enabled")); + } + + if (enable_ibt_type != CET_PERMISSIVE + && enable_shstk_type != CET_PERMISSIVE) + return; } /* Disable IBT and/or SHSTK if they are enabled by kernel, but disabled in executable or shared objects. */ unsigned int cet_feature = 0; - /* Disable IBT only during program startup. */ - if (program && !enable_ibt) + if (!enable_ibt) cet_feature |= GNU_PROPERTY_X86_FEATURE_1_IBT; if (!enable_shstk) cet_feature |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; @@ -286,8 +179,14 @@ mprotect_failure: if (program) _dl_fatal_printf ("%s: can't disable CET\n", program); else - _dl_signal_error (-res, l->l_name, "dlopen", - N_("can't disable CET")); + { + if (found_ibt_legacy) + l = m->l_initfini[ibt_legacy]; + else + l = m->l_initfini[shstk_legacy]; + _dl_signal_error (-res, l->l_name, "dlopen", + N_("can't disable CET")); + } } /* Clear the disabled bits in dl_x86_feature_1. */ @@ -297,17 +196,21 @@ mprotect_failure: } #ifdef SHARED - if (program - && (!shstk_enabled - || enable_shstk_type != CET_PERMISSIVE) - && (ibt_enabled || shstk_enabled)) + if (program && (ibt_enabled || shstk_enabled)) { - /* Lock CET if IBT or SHSTK is enabled in executable. Don't - lock CET if SHSTK is enabled permissively. */ - int res = dl_cet_lock_cet (); - if (res != 0) - _dl_fatal_printf ("%s: can't lock CET\n", program); + if ((!ibt_enabled + || enable_ibt_type != CET_PERMISSIVE) + && (!shstk_enabled + || enable_shstk_type != CET_PERMISSIVE)) + { + /* Lock CET if IBT or SHSTK is enabled in executable unless + IBT or SHSTK is enabled permissively. */ + int res = dl_cet_lock_cet (); + if (res != 0) + _dl_fatal_printf ("%s: can't lock CET\n", program); + } + /* Set feature_1 if IBT or SHSTK is enabled in executable. */ cet_feature_changed = true; } #endif diff --git a/sysdeps/x86/dl-procruntime.c b/sysdeps/x86/dl-procruntime.c index fb36801f3e..5e39a38133 100644 --- a/sysdeps/x86/dl-procruntime.c +++ b/sysdeps/x86/dl-procruntime.c @@ -54,15 +54,4 @@ PROCINFO_CLASS unsigned int _dl_x86_feature_1[2] # else , # endif - -# if !defined PROCINFO_DECL && defined SHARED - ._dl_x86_legacy_bitmap -# else -PROCINFO_CLASS unsigned long _dl_x86_legacy_bitmap[2] -# endif -# if !defined SHARED || defined PROCINFO_DECL -; -# else -, -# endif #endif diff --git a/sysdeps/x86/tst-cet-legacy-4.c b/sysdeps/x86/tst-cet-legacy-4.c index a77078afc9..ee54b878ed 100644 --- a/sysdeps/x86/tst-cet-legacy-4.c +++ b/sysdeps/x86/tst-cet-legacy-4.c @@ -20,6 +20,9 @@ #include <dlfcn.h> #include <stdio.h> #include <stdlib.h> +#include <string.h> + +#include <support/check.h> static int do_test (void) @@ -31,22 +34,18 @@ do_test (void) h = dlopen (modname, RTLD_LAZY); if (h == NULL) { - printf ("cannot open '%s': %s\n", modname, dlerror ()); - exit (1); + const char *err = dlerror (); + if (!strstr (err, "rebuild shared object with IBT support enabled")) + FAIL_EXIT1 ("incorrect dlopen '%s' error: %s\n", modname, err); + return 0; } fp = dlsym (h, "test"); if (fp == NULL) - { - printf ("cannot get symbol 'test': %s\n", dlerror ()); - exit (1); - } + FAIL_EXIT1 ("cannot get symbol 'test': %s\n", dlerror ()); if (fp () != 0) - { - puts ("test () != 0"); - exit (1); - } + FAIL_EXIT1 ("test () != 0"); dlclose (h); diff --git a/sysdeps/x86/tst-cet-legacy-5.c b/sysdeps/x86/tst-cet-legacy-5.c index 6c9bba06f5..e2e95b6749 100644 --- a/sysdeps/x86/tst-cet-legacy-5.c +++ b/sysdeps/x86/tst-cet-legacy-5.c @@ -35,7 +35,8 @@ do_test_1 (const char *modname, bool fail) if (fail) { const char *err = dlerror (); - if (strstr (err, "shadow stack isn't enabled") == NULL) + if (strstr (err, "rebuild shared object with SHSTK support enabled") + == NULL) { printf ("incorrect dlopen '%s' error: %s\n", modname, err); diff --git a/sysdeps/x86/tst-cet-legacy-6.c b/sysdeps/x86/tst-cet-legacy-6.c index 877e77747d..bdbbb9075f 100644 --- a/sysdeps/x86/tst-cet-legacy-6.c +++ b/sysdeps/x86/tst-cet-legacy-6.c @@ -35,7 +35,8 @@ do_test_1 (const char *modname, bool fail) if (fail) { const char *err = dlerror (); - if (strstr (err, "shadow stack isn't enabled") == NULL) + if (strstr (err, "rebuild shared object with SHSTK support enabled") + == NULL) { printf ("incorrect dlopen '%s' error: %s\n", modname, err); diff --git a/sysdeps/x86/tst-cet-legacy-7.c b/sysdeps/x86/tst-cet-legacy-7.c new file mode 100644 index 0000000000..58bcb29a5f --- /dev/null +++ b/sysdeps/x86/tst-cet-legacy-7.c @@ -0,0 +1,38 @@ +/* Check compatibility of legacy executable with a JIT engine. + Copyright (C) 2020 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 <stdio.h> +#include <sys/mman.h> +#include <support/xunistd.h> + +/* Check that mmapped legacy code works with -fcf-protection=none. */ + +static int +do_test (void) +{ + void (*funcp) (void); + funcp = xmmap (NULL, 0x1000, PROT_EXEC | PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, -1); + printf ("mmap = %p\n", funcp); + /* Write RET instruction. */ + *(char *) funcp = 0xc3; + funcp (); + return 0; +} + +#include <support/test-driver.c> diff --git a/sysdeps/x86/tst-cet-legacy-8.c b/sysdeps/x86/tst-cet-legacy-8.c new file mode 100644 index 0000000000..11e811588c --- /dev/null +++ b/sysdeps/x86/tst-cet-legacy-8.c @@ -0,0 +1,48 @@ +/* Check incompatibility with legacy JIT engine. + Copyright (C) 2020 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 <stdio.h> +#include <stdlib.h> +#include <x86intrin.h> +#include <sys/mman.h> +#include <support/test-driver.h> +#include <support/xsignal.h> +#include <support/xunistd.h> + +/* Check that mmapped legacy code trigges segfault with -fcf-protection. */ + +static int +do_test (void) +{ + /* NB: This test should trigger SIGSEGV on CET platforms. If SHSTK + is disabled, assuming IBT is also disabled. */ + if (_get_ssp () == 0) + return EXIT_UNSUPPORTED; + + void (*funcp) (void); + funcp = xmmap (NULL, 0x1000, PROT_EXEC | PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, -1); + printf ("mmap = %p\n", funcp); + /* Write RET instruction. */ + *(char *) funcp = 0xc3; + funcp (); + return EXIT_FAILURE; +} + +#define EXPECTED_SIGNAL (_get_ssp () == 0 ? 0 : SIGSEGV) +#include <support/test-driver.c> |