Message ID | 20200313132509.GA745249@gmail.com |
---|---|
State | New |
Headers | show |
Series | PING: V3 [PATCH] x86: Remove ARCH_CET_LEGACY_BITMAP [BZ #25397] | expand |
On Fri, Mar 13, 2020 at 6:25 AM H.J. Lu <hjl.tools@gmail.com> wrote: > > On Tue, Mar 10, 2020 at 06:36:54AM -0700, H.J. Lu wrote: > > On Tue, Mar 10, 2020 at 02:13:37PM +0100, Florian Weimer wrote: > > > * H. J. Lu: > > > > > > >> I think the error message should say *where* indirect branch tracking > > > >> is not enabled. I assume this is a property of the loaded object. > > > > > > > > Fixed. Now I got > > > > > > > > .... libvirtd[1048]: internal error: Failed to load module > > > > '/usr/lib64/libvirt/storage-backend/libvirt_storage_backend_rbd.so': > > > > /usr/lib64/ceph/libceph-common.so.0: indirect branch tracking isn't > > > > enabled: Invalid argument > > > > > > What I meant is that the error message should say that the object > > > needs to be rebuilt with IBT/SHSTK support. In the above, it's > > > unclear whether the process or the object has to enable IBT. > > > > > > (The Invalid Argument part should also be suppressed.) > > > > Like this? The diff against V2 patch is: > > > > diff --git a/sysdeps/x86/dl-cet.c b/sysdeps/x86/dl-cet.c > > index f527a1414c..b2843488be 100644 > > --- a/sysdeps/x86/dl-cet.c > > +++ b/sysdeps/x86/dl-cet.c > > @@ -142,10 +142,10 @@ dl_cet_check (struct link_map *m, const char *program) > > /* When IBT is enabled, we cannot dlopen a shared > > object without IBT. */ > > if (found_ibt_legacy) > > - _dl_signal_error (EINVAL, > > + _dl_signal_error (0, > > m->l_initfini[ibt_legacy]->l_name, > > "dlopen", > > - N_("indirect branch tracking isn't enabled")); > > + N_("rebuilt with IBT support needed")); > > } > > > > if (enable_shstk_type != CET_PERMISSIVE) > > @@ -153,10 +153,10 @@ dl_cet_check (struct link_map *m, const char *program) > > /* When SHSTK is enabled, we cannot dlopen a shared > > object without SHSTK. */ > > if (found_shstk_legacy) > > - _dl_signal_error (EINVAL, > > + _dl_signal_error (0, > > m->l_initfini[shstk_legacy]->l_name, > > "dlopen", > > - N_("shadow stack isn't enabled")); > > + N_("rebuilt with SHSTK support needed")); > > } > > > > if (enable_ibt_type != CET_PERMISSIVE > > > > PING. > PING: https://sourceware.org/pipermail/libc-alpha/2020-March/111873.html
On 3/13/20 9:25 AM, H.J. Lu via Libc-alpha wrote: > On Tue, Mar 10, 2020 at 06:36:54AM -0700, H.J. Lu wrote: >> On Tue, Mar 10, 2020 at 02:13:37PM +0100, Florian Weimer wrote: >>> * H. J. Lu: >>> >>>>> I think the error message should say *where* indirect branch tracking >>>>> is not enabled. I assume this is a property of the loaded object. >>>> Fixed. Now I got >>>> >>>> .... libvirtd[1048]: internal error: Failed to load module >>>> '/usr/lib64/libvirt/storage-backend/libvirt_storage_backend_rbd.so': >>>> /usr/lib64/ceph/libceph-common.so.0: indirect branch tracking isn't >>>> enabled: Invalid argument >>> What I meant is that the error message should say that the object >>> needs to be rebuilt with IBT/SHSTK support. In the above, it's >>> unclear whether the process or the object has to enable IBT. >>> >>> (The Invalid Argument part should also be suppressed.) >> Like this? The diff against V2 patch is: >> >> diff --git a/sysdeps/x86/dl-cet.c b/sysdeps/x86/dl-cet.c >> index f527a1414c..b2843488be 100644 >> --- a/sysdeps/x86/dl-cet.c >> +++ b/sysdeps/x86/dl-cet.c >> @@ -142,10 +142,10 @@ dl_cet_check (struct link_map *m, const char *program) >> /* When IBT is enabled, we cannot dlopen a shared >> object without IBT. */ >> if (found_ibt_legacy) >> - _dl_signal_error (EINVAL, >> + _dl_signal_error (0, >> m->l_initfini[ibt_legacy]->l_name, >> "dlopen", >> - N_("indirect branch tracking isn't enabled")); >> + N_("rebuilt with IBT support needed")); >> } >> >> if (enable_shstk_type != CET_PERMISSIVE) >> @@ -153,10 +153,10 @@ dl_cet_check (struct link_map *m, const char *program) >> /* When SHSTK is enabled, we cannot dlopen a shared >> object without SHSTK. */ >> if (found_shstk_legacy) >> - _dl_signal_error (EINVAL, >> + _dl_signal_error (0, >> m->l_initfini[shstk_legacy]->l_name, >> "dlopen", >> - N_("shadow stack isn't enabled")); >> + N_("rebuilt with SHSTK support needed")); >> } >> >> if (enable_ibt_type != CET_PERMISSIVE >> > PING. Please post v4 with adjusted error message, and expanded comment in new test, and I'll review that quickly. > H.J. > --- > Since legacy bitmap doesn't cover jitted code generated by legacy JIT > engine, it isn't very useful. This patch removes ARCH_CET_LEGACY_BITMAP > and treats indirect branch tracking similar to shadow stack by removing > legacy bitmap support. OK. > > * sysdeps/unix/sysv/linux/x86/dl-cet.h > (dl_cet_allocate_legacy_bitmap): Removed. > * sysdeps/unix/sysv/linux/x86/include/asm/prctl.h > (ARCH_CET_LEGACY_BITMAP): Removed. > * sysdeps/x86/Makefile (tests): Add tst-cet-legacy-7. > (CFLAGS-tst-cet-legacy-mod-5a.c): Changed to > -fcf-protection=branch. > (CFLAGS-tst-cet-legacy-mod-6a.c): Likewise. > (CFLAGS-tst-cet-legacy-7.c): New. > * sysdeps/x86/dl-cet.c (dl_cet_mark_legacy_region): Removed. > (dl_cet_check): Remove legacy bitmap support. Don't allow > dlopening legacy shared library when IBT is enabled. Set > feature_1 if IBT or SHSTK is enabled in executable. > * sysdeps/x86/dl-procruntime.c (_dl_x86_legacy_bitmap): Removed. > * sysdeps/x86/tst-cet-legacy-4.c: Include <string.h> and > <support/check.h>. > (do_test): Check indirect branch tracking error. Use > FAIL_EXIT1. > * sysdeps/x86/tst-cet-legacy-7.c: New file. Hopefully you don't plan to include this in the commit log :-) > --- > sysdeps/unix/sysv/linux/x86/dl-cet.h | 20 -- > .../unix/sysv/linux/x86/include/asm/prctl.h | 5 - > sysdeps/x86/Makefile | 7 +- > sysdeps/x86/dl-cet.c | 217 +++++------------- > sysdeps/x86/dl-procruntime.c | 11 - > sysdeps/x86/tst-cet-legacy-4.c | 19 +- > sysdeps/x86/tst-cet-legacy-5.c | 2 +- > sysdeps/x86/tst-cet-legacy-6.c | 2 +- > sysdeps/x86/tst-cet-legacy-7.c | 36 +++ > 9 files changed, 111 insertions(+), 208 deletions(-) > create mode 100644 sysdeps/x86/tst-cet-legacy-7.c > > 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 > @@ -18,26 +18,6 @@ > #include <sys/prctl.h> > #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 > -} > - OK. > static inline int __attribute__ ((always_inline)) > dl_cet_disable_cet (unsigned int cet_feature) > { > 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 OK. > #endif /* ARCH_CET_STATUS */ > diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile > index 95182a508c..ec96b59a78 100644 > --- a/sysdeps/x86/Makefile > +++ b/sysdeps/x86/Makefile > @@ -20,7 +20,7 @@ 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 OK. > 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 +43,15 @@ 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 OK. > > $(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..b2843488be 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; > -} > - OK. > /* 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; OK. > > /* 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; OK. > > 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; OK. > } > > /* 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) OK. > { > - /* 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; OK. > } > - > - /* 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; OK. > } > } > > @@ -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_("rebuilt with IBT support needed")); > + } Suggest: "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_("rebuilt with SHSTK support needed")); > + } Suggest: "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) OK. > 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")); OK. > + } > } > > /* 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); OK. > + } > > + /* 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 OK. > #endif > diff --git a/sysdeps/x86/tst-cet-legacy-4.c b/sysdeps/x86/tst-cet-legacy-4.c > index a77078afc9..a922339333 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, "rebuilt with IBT support needed")) OK (needs adjustment if string is changed). > + 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..350c7e41df 100644 > --- a/sysdeps/x86/tst-cet-legacy-5.c > +++ b/sysdeps/x86/tst-cet-legacy-5.c > @@ -35,7 +35,7 @@ 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, "rebuilt with SHSTK support needed") == NULL) OK (also needs adjustment) > { > 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..9f2748fcb6 100644 > --- a/sysdeps/x86/tst-cet-legacy-6.c > +++ b/sysdeps/x86/tst-cet-legacy-6.c > @@ -35,7 +35,7 @@ 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, "rebuilt with SHSTK support needed") == NULL) OK. (also needs adjustment) > { > 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..cf4c2779ce > --- /dev/null > +++ b/sysdeps/x86/tst-cet-legacy-7.c > @@ -0,0 +1,36 @@ > +/* 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> > + Needs a pargraph explaining what this test is supposed to do. I expect this test is supposed to just pass and not fail because it's run with -fcf-protection=none. What about the equivalent test to test for failure? > +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; OK. > +} > + > +#include <support/test-driver.c> > -- 2.24.1
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 @@ -18,26 +18,6 @@ #include <sys/prctl.h> #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) { 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..ec96b59a78 100644 --- a/sysdeps/x86/Makefile +++ b/sysdeps/x86/Makefile @@ -20,7 +20,7 @@ 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-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 +43,15 @@ 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 $(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..b2843488be 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_("rebuilt with IBT support needed")); + } + + 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_("rebuilt with SHSTK support needed")); + } + + 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..a922339333 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, "rebuilt with IBT support needed")) + 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..350c7e41df 100644 --- a/sysdeps/x86/tst-cet-legacy-5.c +++ b/sysdeps/x86/tst-cet-legacy-5.c @@ -35,7 +35,7 @@ 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, "rebuilt with SHSTK support needed") == 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..9f2748fcb6 100644 --- a/sysdeps/x86/tst-cet-legacy-6.c +++ b/sysdeps/x86/tst-cet-legacy-6.c @@ -35,7 +35,7 @@ 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, "rebuilt with SHSTK support needed") == 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..cf4c2779ce --- /dev/null +++ b/sysdeps/x86/tst-cet-legacy-7.c @@ -0,0 +1,36 @@ +/* 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> + +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>