From 5dbab7b3f4d3a8298aeb8ecde1cfbc4b16913d28 Mon Sep 17 00:00:00 2001 From: Iain Buclaw Date: Fri, 27 Nov 2020 13:15:44 +0100 Subject: [PATCH] libphobos: Fix segfault at run-time when using custom Fibers (PR 98025) When libphobos is configured with --enable-cet, this adds extra fields to the Fiber class to support the ucontext_t fallback implementation. These fields get omitted when compiling user code unless they also used `-fversion=CET' to build their project, which resulted in data being overwritten from within swapcontext(). On reviewing the ucontext_t definitions, it was found that the shadow stack fields were missing, and the struct size didn't match up on X32. This has been fixed in upstream druntime and merged down here. Reviewed-on: https://github.com/dlang/druntime/pull/3293 libphobos/ChangeLog: PR d/98025 * Makefile.in: Regenerate. * configure: Regenerate. * configure.ac (DCFG_ENABLE_CET): Substitute. * libdruntime/MERGE: Merge upstream druntime 0fe7974c. * libdruntime/Makefile.in: Regenerate. * libdruntime/core/thread.d: Import gcc.config. (class Fiber): Add ucontext_t fields when GNU_Enable_CET is true. * libdruntime/gcc/config.d.in (GNU_Enable_CET): Define. * src/Makefile.in: Regenerate. * testsuite/Makefile.in: Regenerate. --- libphobos/Makefile.in | 1 + libphobos/configure | 16 +++++++++++++--- libphobos/configure.ac | 11 ++++++++--- libphobos/libdruntime/MERGE | 2 +- libphobos/libdruntime/Makefile.in | 1 + libphobos/libdruntime/core/sys/posix/ucontext.d | 6 ++++-- libphobos/libdruntime/core/thread.d | 10 ++++++++++ libphobos/libdruntime/gcc/config.d.in | 3 +++ libphobos/src/Makefile.in | 1 + libphobos/testsuite/Makefile.in | 1 + 10 files changed, 43 insertions(+), 9 deletions(-) diff --git a/libphobos/Makefile.in b/libphobos/Makefile.in index f692b2f719e..a1395929819 100644 --- a/libphobos/Makefile.in +++ b/libphobos/Makefile.in @@ -217,6 +217,7 @@ CPPFLAGS = @CPPFLAGS@ CYGPATH_W = @CYGPATH_W@ DCFG_ARM_EABI_UNWINDER = @DCFG_ARM_EABI_UNWINDER@ DCFG_DLPI_TLS_MODID = @DCFG_DLPI_TLS_MODID@ +DCFG_ENABLE_CET = @DCFG_ENABLE_CET@ DCFG_HAVE_64BIT_ATOMICS = @DCFG_HAVE_64BIT_ATOMICS@ DCFG_HAVE_ATOMIC_BUILTINS = @DCFG_HAVE_ATOMIC_BUILTINS@ DCFG_HAVE_LIBATOMIC = @DCFG_HAVE_LIBATOMIC@ diff --git a/libphobos/configure b/libphobos/configure index 6d8461febf9..77a3125cbd6 100755 --- a/libphobos/configure +++ b/libphobos/configure @@ -722,6 +722,7 @@ LIBTOOL CFLAGS_FOR_BUILD CC_FOR_BUILD AR +DCFG_ENABLE_CET CET_DFLAGS CET_FLAGS RANLIB @@ -5652,11 +5653,20 @@ fi # To ensure that runtime code for CET is compiled in, add in D version flags. -if test "$enable_cet" = yes; then +if test x$enable_cet = xyes; then : + CET_DFLAGS="$CET_FLAGS -fversion=CET" + DCFG_ENABLE_CET=true + +else + + CET_DFLAGS= + DCFG_ENABLE_CET=false fi + + # This should be inherited in the recursive make, but ensure it is defined. test "$AR" || AR=ar @@ -11744,7 +11754,7 @@ else lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2 lt_status=$lt_dlunknown cat > conftest.$ac_ext <<_LT_EOF -#line 11747 "configure" +#line 11757 "configure" #include "confdefs.h" #if HAVE_DLFCN_H @@ -11850,7 +11860,7 @@ else lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2 lt_status=$lt_dlunknown cat > conftest.$ac_ext <<_LT_EOF -#line 11853 "configure" +#line 11863 "configure" #include "confdefs.h" #if HAVE_DLFCN_H diff --git a/libphobos/configure.ac b/libphobos/configure.ac index 60aee3ffe8b..2d51e465a15 100644 --- a/libphobos/configure.ac +++ b/libphobos/configure.ac @@ -69,10 +69,15 @@ AC_PROG_MAKE_SET GCC_CET_FLAGS(CET_FLAGS) AC_SUBST(CET_FLAGS) # To ensure that runtime code for CET is compiled in, add in D version flags. -if test "$enable_cet" = yes; then +AS_IF([test x$enable_cet = xyes], [ CET_DFLAGS="$CET_FLAGS -fversion=CET" - AC_SUBST(CET_DFLAGS) -fi + DCFG_ENABLE_CET=true +], [ + CET_DFLAGS= + DCFG_ENABLE_CET=false +]) +AC_SUBST(CET_DFLAGS) +AC_SUBST(DCFG_ENABLE_CET) # This should be inherited in the recursive make, but ensure it is defined. test "$AR" || AR=ar diff --git a/libphobos/libdruntime/MERGE b/libphobos/libdruntime/MERGE index 6b65a44e6d2..7162844b9b6 100644 --- a/libphobos/libdruntime/MERGE +++ b/libphobos/libdruntime/MERGE @@ -1,4 +1,4 @@ -d37ef985a97eb446371ab4b2315a52b87233fbf3 +0fe7974cf53b75db59461de2a3d6e53ce933d297 The first line of this file holds the git revision number of the last merge done from the dlang/druntime repository. diff --git a/libphobos/libdruntime/Makefile.in b/libphobos/libdruntime/Makefile.in index 0b895142a13..99ee8b92afa 100644 --- a/libphobos/libdruntime/Makefile.in +++ b/libphobos/libdruntime/Makefile.in @@ -577,6 +577,7 @@ CPPFLAGS = @CPPFLAGS@ CYGPATH_W = @CYGPATH_W@ DCFG_ARM_EABI_UNWINDER = @DCFG_ARM_EABI_UNWINDER@ DCFG_DLPI_TLS_MODID = @DCFG_DLPI_TLS_MODID@ +DCFG_ENABLE_CET = @DCFG_ENABLE_CET@ DCFG_HAVE_64BIT_ATOMICS = @DCFG_HAVE_64BIT_ATOMICS@ DCFG_HAVE_ATOMIC_BUILTINS = @DCFG_HAVE_ATOMIC_BUILTINS@ DCFG_HAVE_LIBATOMIC = @DCFG_HAVE_LIBATOMIC@ diff --git a/libphobos/libdruntime/core/sys/posix/ucontext.d b/libphobos/libdruntime/core/sys/posix/ucontext.d index 49a7c3e389a..2e518aefa84 100644 --- a/libphobos/libdruntime/core/sys/posix/ucontext.d +++ b/libphobos/libdruntime/core/sys/posix/ucontext.d @@ -114,7 +114,7 @@ version (CRuntime_Glibc) enum NGREG = 23; - alias c_long greg_t; + alias long greg_t; alias greg_t[NGREG] gregset_t; alias _libc_fpstate* fpregset_t; } @@ -123,7 +123,7 @@ version (CRuntime_Glibc) { gregset_t gregs; fpregset_t fpregs; - c_ulong[8] __reserved1; + ulong[8] __reserved1; } struct ucontext_t @@ -134,6 +134,7 @@ version (CRuntime_Glibc) mcontext_t uc_mcontext; sigset_t uc_sigmask; _libc_fpstate __fpregs_mem; + ulong[4] __ssp; } } else version (X86) @@ -205,6 +206,7 @@ version (CRuntime_Glibc) mcontext_t uc_mcontext; sigset_t uc_sigmask; _libc_fpstate __fpregs_mem; + c_ulong[4] __ssp; } } else version (HPPA) diff --git a/libphobos/libdruntime/core/thread.d b/libphobos/libdruntime/core/thread.d index eaf088d53c1..7506a8b3ee3 100644 --- a/libphobos/libdruntime/core/thread.d +++ b/libphobos/libdruntime/core/thread.d @@ -52,6 +52,7 @@ version (Solaris) version (GNU) { import gcc.builtins; + import gcc.config; version (GNU_StackGrowsDown) version = StackGrowsDown; } @@ -5123,6 +5124,15 @@ private: ucontext_t m_utxt = void; ucontext_t* m_ucur = null; } + else static if (GNU_Enable_CET) + { + // When libphobos was built with --enable-cet, these fields need to + // always be present in the Fiber class layout. + import core.sys.posix.ucontext; + static ucontext_t sm_utxt = void; + ucontext_t m_utxt = void; + ucontext_t* m_ucur = null; + } private: diff --git a/libphobos/libdruntime/gcc/config.d.in b/libphobos/libdruntime/gcc/config.d.in index 6301aaff069..9ac7d055271 100644 --- a/libphobos/libdruntime/gcc/config.d.in +++ b/libphobos/libdruntime/gcc/config.d.in @@ -49,3 +49,6 @@ enum GNU_Have_LibAtomic = @DCFG_HAVE_LIBATOMIC@; // Do we have qsort_r function enum Have_Qsort_R = @DCFG_HAVE_QSORT_R@; + +// Whether libphobos been configured with --enable-cet. +enum GNU_Enable_CET = @DCFG_ENABLE_CET@; diff --git a/libphobos/src/Makefile.in b/libphobos/src/Makefile.in index 4a0612a613b..2e721783d06 100644 --- a/libphobos/src/Makefile.in +++ b/libphobos/src/Makefile.in @@ -333,6 +333,7 @@ CPPFLAGS = @CPPFLAGS@ CYGPATH_W = @CYGPATH_W@ DCFG_ARM_EABI_UNWINDER = @DCFG_ARM_EABI_UNWINDER@ DCFG_DLPI_TLS_MODID = @DCFG_DLPI_TLS_MODID@ +DCFG_ENABLE_CET = @DCFG_ENABLE_CET@ DCFG_HAVE_64BIT_ATOMICS = @DCFG_HAVE_64BIT_ATOMICS@ DCFG_HAVE_ATOMIC_BUILTINS = @DCFG_HAVE_ATOMIC_BUILTINS@ DCFG_HAVE_LIBATOMIC = @DCFG_HAVE_LIBATOMIC@ diff --git a/libphobos/testsuite/Makefile.in b/libphobos/testsuite/Makefile.in index 2f6911d4d47..c38a4688258 100644 --- a/libphobos/testsuite/Makefile.in +++ b/libphobos/testsuite/Makefile.in @@ -161,6 +161,7 @@ CPPFLAGS = @CPPFLAGS@ CYGPATH_W = @CYGPATH_W@ DCFG_ARM_EABI_UNWINDER = @DCFG_ARM_EABI_UNWINDER@ DCFG_DLPI_TLS_MODID = @DCFG_DLPI_TLS_MODID@ +DCFG_ENABLE_CET = @DCFG_ENABLE_CET@ DCFG_HAVE_64BIT_ATOMICS = @DCFG_HAVE_64BIT_ATOMICS@ DCFG_HAVE_ATOMIC_BUILTINS = @DCFG_HAVE_ATOMIC_BUILTINS@ DCFG_HAVE_LIBATOMIC = @DCFG_HAVE_LIBATOMIC@ -- 2.30.2