Merge branch 'master' into devel/sphinx

6 files changed, 78 insertions, 13 deletions

diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog
index f756eb5..ea4997d 100644
--- a/libgcc/ChangeLog
+++ b/libgcc/ChangeLog
@@ -1,3 +1,24 @@
+2022-10-18  Jonathan Wakely  <jwakely@redhat.com>
+
+	* Makefile.in: Quote variable.
+
+2022-10-17  H.J. Lu  <hjl.tools@gmail.com>
+
+	* unwind-generic.h (_Unwind_Frames_Increment): Add the EXC
+	argument.
+	* unwind.inc (_Unwind_RaiseException_Phase2): Pass EXC to
+	_Unwind_Frames_Increment.
+	(_Unwind_ForcedUnwind_Phase2): Likewise.
+	* config/i386/shadow-stack-unwind.h (_Unwind_Frames_Increment):
+	Take the EXC argument.  Return _URC_FATAL_PHASE2_ERROR if the
+	return address on normal stack doesn't match the return address
+	on shadow stack.
+
+2022-10-17  Florian Weimer  <fweimer@redhat.com>
+
+	* unwind-dw2.h (struct frame_state_reg_info): Move cfa_how member
+	and reduce its size.
+
 2022-10-14  Jakub Jelinek  <jakub@redhat.com>
 
 	* config/i386/t-softfp (softfp_extensions): Add bfsf.
diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in
index 1fe708a..6e2a0470 100644
--- a/libgcc/Makefile.in
+++ b/libgcc/Makefile.in
@@ -310,7 +310,7 @@ CRTSTUFF_T_CFLAGS =
 MULTIDIR := $(shell $(CC) $(CFLAGS) -print-multi-directory)
 MULTIOSDIR := $(shell $(CC) $(CFLAGS) -print-multi-os-directory)
 
-MULTIOSSUBDIR := $(shell if test $(MULTIOSDIR) != .; then echo /$(MULTIOSDIR); fi)
+MULTIOSSUBDIR := $(shell if test "$(MULTIOSDIR)" != .; then echo /$(MULTIOSDIR); fi)
 inst_libdir = $(libsubdir)$(MULTISUBDIR)
 inst_slibdir = $(slibdir)$(MULTIOSSUBDIR)
 
diff --git a/libgcc/config/i386/shadow-stack-unwind.h b/libgcc/config/i386/shadow-stack-unwind.h
index 2b02682..89d4416 100644
--- a/libgcc/config/i386/shadow-stack-unwind.h
+++ b/libgcc/config/i386/shadow-stack-unwind.h
@@ -54,10 +54,39 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
    aligned.  If the original shadow stack is 8 byte aligned, we just
    need to pop 2 slots, one restore token, from shadow stack.  Otherwise,
    we need to pop 3 slots, one restore token + 4 byte padding, from
-   shadow stack.  */
-#ifndef __x86_64__
+   shadow stack.
+
+   When popping a stack frame, we compare the return address on normal
+   stack against the return address on shadow stack.  If they don't match,
+   return _URC_FATAL_PHASE2_ERROR for the corrupted return address on
+   normal stack.  Don't check the return address for
+   1. Non-catchable exception where exception_class == 0.  Process will
+      be terminated.
+   2. Zero return address which marks the outermost stack frame.
+   3. Signal stack frame since kernel puts a restore token on shadow
+      stack.
+ */
 #undef _Unwind_Frames_Increment
-#define _Unwind_Frames_Increment(context, frames)	\
+#ifdef __x86_64__
+#define _Unwind_Frames_Increment(exc, context, frames)	\
+    {							\
+      frames++;						\
+      if (exc->exception_class != 0			\
+	  && _Unwind_GetIP (context) != 0		\
+	  && !_Unwind_IsSignalFrame (context))		\
+	{						\
+	  _Unwind_Word ssp = _get_ssp ();		\
+	  if (ssp != 0)					\
+	    {						\
+	      ssp += 8 * frames;			\
+	      _Unwind_Word ra = *(_Unwind_Word *) ssp;	\
+	      if (ra != _Unwind_GetIP (context))	\
+		return _URC_FATAL_PHASE2_ERROR;		\
+	    }						\
+	}						\
+    }
+#else
+#define _Unwind_Frames_Increment(exc, context, frames)	\
   if (_Unwind_IsSignalFrame (context))			\
     do							\
       {							\
@@ -83,5 +112,19 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
       }							\
     while (0);						\
   else							\
-    frames++;
+    {							\
+      frames++;						\
+      if (exc->exception_class != 0			\
+	  && _Unwind_GetIP (context) != 0)		\
+	{						\
+	  _Unwind_Word ssp = _get_ssp ();		\
+	  if (ssp != 0)					\
+	    {						\
+	      ssp += 4 * frames;			\
+	      _Unwind_Word ra = *(_Unwind_Word *) ssp;	\
+	      if (ra != _Unwind_GetIP (context))	\
+		return _URC_FATAL_PHASE2_ERROR;		\
+	    }						\
+	}						\
+    }
 #endif
diff --git a/libgcc/unwind-dw2.h b/libgcc/unwind-dw2.h
index af34e00..a0834b1 100644
--- a/libgcc/unwind-dw2.h
+++ b/libgcc/unwind-dw2.h
@@ -50,6 +50,12 @@ typedef struct
     } reg[__LIBGCC_DWARF_FRAME_REGISTERS__+1];
     unsigned char how[__LIBGCC_DWARF_FRAME_REGISTERS__+1];
 
+    enum {
+      CFA_UNSET,
+      CFA_REG_OFFSET,
+      CFA_EXP
+    } cfa_how : 8;
+
     /* Used to implement DW_CFA_remember_state.  */
     struct frame_state_reg_info *prev;
 
@@ -58,11 +64,6 @@ typedef struct
     _Unwind_Sword cfa_offset;
     _Unwind_Word cfa_reg;
     const unsigned char *cfa_exp;
-    enum {
-      CFA_UNSET,
-      CFA_REG_OFFSET,
-      CFA_EXP
-    } cfa_how;
   } regs;
 
   /* The PC described by the current frame state.  */
diff --git a/libgcc/unwind-generic.h b/libgcc/unwind-generic.h
index a87c9b3..bf72128 100644
--- a/libgcc/unwind-generic.h
+++ b/libgcc/unwind-generic.h
@@ -292,6 +292,6 @@ EXCEPTION_DISPOSITION _GCC_specific_handler (PEXCEPTION_RECORD, void *,
 #define _Unwind_Frames_Extra(frames)
 
 /* Increment frame count.  */
-#define _Unwind_Frames_Increment(context, frames) frames++
+#define _Unwind_Frames_Increment(exc, context, frames) frames++
 
 #endif /* unwind.h */
diff --git a/libgcc/unwind.inc b/libgcc/unwind.inc
index 5efd8af..a7111a7 100644
--- a/libgcc/unwind.inc
+++ b/libgcc/unwind.inc
@@ -73,7 +73,7 @@ _Unwind_RaiseException_Phase2(struct _Unwind_Exception *exc,
       gcc_assert (!match_handler);
 
       uw_update_context (context, &fs);
-      _Unwind_Frames_Increment (context, frames);
+      _Unwind_Frames_Increment (exc, context, frames);
     }
 
   *frames_p = frames;
@@ -191,7 +191,7 @@ _Unwind_ForcedUnwind_Phase2 (struct _Unwind_Exception *exc,
       /* Update cur_context to describe the same frame as fs, and discard
 	 the previous context if necessary.  */
       uw_advance_context (context, &fs);
-      _Unwind_Frames_Increment (context, frames);
+      _Unwind_Frames_Increment (exc, context, frames);
     }
 
   *frames_p = frames;