GNU C Library master sources branch hjl/cet/setjmp created. glibc-2.26.9000-760-gf516888

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commit f5168887870e1046017e534b7b0eb8c52133d941
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Sat Jun 10 17:23:06 2017 -0700

    jmpbuf: Add paddings for architecture specific usage
    
    To support Shadow Stack (SHSTK) in Intel Control-flow Enforcement
    Technology (CET) in setjmp/longjmp, we need to save shadow stack
    pointer in jmp_buf.  The __saved_mask field in jmp_buf has type
    of __sigset_t.  On Linux, __sigset_t is defined as
    
     #define _SIGSET_NWORDS (1024 / (8 * sizeof (unsigned long int)))
    typedef struct
    {
      unsigned long int __val[_SIGSET_NWORDS];
    } __sigset_t;
    
    which is much bigger than expected by the __sigprocmask system call,
    which has
    
    typedef struct {
            unsigned long sig[_NSIG_WORDS];
    } sigset_t;
    
    We can shrink __sigset_t used by __saved_mask in jmp_buf to add paddings
    for architecture specific usage.  As long as the new __sigset_t is not
    smaller than sigset_t expected by the __sigprocmask system call, it should
    work correctly.  This patch adds an internal header file, <setjmpP.h>,
    to define __jmp_buf_sigset_t for __saved_mask in jmp_buf on Linux and
    verifies __jmp_buf_sigset_t has the suitable size for the __sigprocmask
    system call.   A run-time test, tst-sigsetjmp2.c, is added to verify that
    size of __jmp_buf_sigset_t is sufficient.  If size is too small, the test
    fails with
    
    rt_sigprocmask(SIG_SETMASK, strace: umoven: short read (4 < 8) @0x7fa8aa28effc
    0x7fa8aa28effc, NULL, 8) = -1 EFAULT (Bad address)
    rt_sigprocmask(SIG_SETMASK, strace: umoven: short read (4 < 8) @0x7fa8aa28effc
    0x7fa8aa28effc, NULL, 8) = -1 EFAULT (Bad address)
    rt_sigprocmask(SIG_SETMASK, NULL, 0x7fa8aa28effc, 8) = -1 EFAULT (Bad address)
    exit_group(1)                           = ?
    
    Tested with build-many-glibcs.py.
    
    	* debug/longjmp_chk.c: Include <setjmpP.h> instead of
    	<setjmp.h>.
    	* sysdeps/unix/sysv/linux/s390/longjmp_chk.c: Likewise.
    	* include/setjmpP.h: New file.
    	* setjmp/setjmpP.h: Likewise.
    	* sysdeps/generic/__jmpbuf_arch_t.h: Likewise.
    	* sysdeps/generic/__saved_mask.h: Likewise.
    	* sysdeps/unix/sysv/linux/__jmpbuf_arch_t.h: Likewise.
    	* sysdeps/unix/sysv/linux/__saved_mask.h: Likewise.
    	* setjmp/tst-sigsetjmp2.c: Likewise.
    	* setjmp/Makefile (tests): Add tst-sigsetjmp2.
    	* setjmp/longjmp.c: Include <setjmpP.h> instead of <setjmp.h>.
    	(__libc_siglongjmp): Cast &env[0].__saved_mask to "sigset_t *".
    	* setjmp/sigjmp.c: Include <setjmpP.h> instead of <setjmp.h>.
    	(__sigjmp_save): Cast &env[0].__saved_mask to "sigset_t *".

diff --git a/debug/longjmp_chk.c b/debug/longjmp_chk.c
index 1cea6c0..61be0da 100644
--- a/debug/longjmp_chk.c
+++ b/debug/longjmp_chk.c
@@ -15,7 +15,7 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <setjmp.h>
+#include <setjmpP.h>
 
 #define __longjmp ____longjmp_chk
 #define __libc_siglongjmp __longjmp_chk
diff --git a/include/setjmpP.h b/include/setjmpP.h
new file mode 100644
index 0000000..8aa6a25
--- /dev/null
+++ b/include/setjmpP.h
@@ -0,0 +1 @@
+#include <setjmp/setjmpP.h>
diff --git a/setjmp/Makefile b/setjmp/Makefile
index ca80b8e..e0a1f4a 100644
--- a/setjmp/Makefile
+++ b/setjmp/Makefile
@@ -28,7 +28,7 @@ routines	:= setjmp sigjmp bsd-setjmp bsd-_setjmp \
 		   longjmp __longjmp jmp-unwind
 
 tests		:= tst-setjmp jmpbug bug269-setjmp tst-setjmp-fp \
-		   tst-sigsetjmp tst-setjmp-static
+		   tst-sigsetjmp tst-setjmp-static tst-sigsetjmp2
 tests-static	:= tst-setjmp-static
 
 
diff --git a/setjmp/longjmp.c b/setjmp/longjmp.c
index 2453c2c..e144a87 100644
--- a/setjmp/longjmp.c
+++ b/setjmp/longjmp.c
@@ -16,7 +16,7 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stddef.h>
-#include <setjmp.h>
+#include <setjmpP.h>
 #include <signal.h>
 
 
@@ -31,7 +31,8 @@ __libc_siglongjmp (sigjmp_buf env, int val)
 
   if (env[0].__mask_was_saved)
     /* Restore the saved signal mask.  */
-    (void) __sigprocmask (SIG_SETMASK, &env[0].__saved_mask,
+    (void) __sigprocmask (SIG_SETMASK,
+			  (sigset_t *) &env[0].__saved_mask,
 			  (sigset_t *) NULL);
 
   /* Call the machine-dependent function to restore machine state.  */
diff --git a/debug/longjmp_chk.c b/setjmp/setjmpP.h
similarity index 68%
copy from debug/longjmp_chk.c
copy to setjmp/setjmpP.h
index 1cea6c0..e65d72b 100644
--- a/debug/longjmp_chk.c
+++ b/setjmp/setjmpP.h
@@ -1,4 +1,5 @@
-/* Copyright (C) 2009-2017 Free Software Foundation, Inc.
+/* Internal __sigset_t type used in struct __jmp_buf_tag.
+   Copyright (C) 2017 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
@@ -15,9 +16,17 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <setjmp.h>
+/*
+ *	ISO C99 Standard: 7.13 Nonlocal jumps	<setjmp.h>
+ */
+
+#ifndef	_SETJMPP_H
+#define	_SETJMPP_H	1
 
-#define __longjmp ____longjmp_chk
-#define __libc_siglongjmp __longjmp_chk
+#include <__jmpbuf_arch_t.h>
+#undef __sigset_t
+#define __sigset_t __jmpbuf_arch_t
+#include <setjmp.h>
+#include <__saved_mask.h>
 
-#include <setjmp/longjmp.c>
+#endif /* setjmpP.h  */
diff --git a/setjmp/sigjmp.c b/setjmp/sigjmp.c
index 30839ae..32b727f 100644
--- a/setjmp/sigjmp.c
+++ b/setjmp/sigjmp.c
@@ -16,7 +16,7 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stddef.h>
-#include <setjmp.h>
+#include <setjmpP.h>
 #include <signal.h>
 
 /* This function is called by the `sigsetjmp' macro
@@ -28,7 +28,7 @@ __sigjmp_save (sigjmp_buf env, int savemask)
 {
   env[0].__mask_was_saved = (savemask &&
 			     __sigprocmask (SIG_BLOCK, (sigset_t *) NULL,
-					    &env[0].__saved_mask) == 0);
+					    (sigset_t *) &env[0].__saved_mask) == 0);
 
   return 0;
 }
diff --git a/setjmp/tst-sigsetjmp2.c b/setjmp/tst-sigsetjmp2.c
new file mode 100644
index 0000000..1c5adeb
--- /dev/null
+++ b/setjmp/tst-sigsetjmp2.c
@@ -0,0 +1,56 @@
+/* Test that sigprocmask does not read from the unused part of jmpbuf.
+   Copyright (C) 2017 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdlib.h>
+#include <signal.h>
+#include <setjmp.h>
+#include <string.h>
+#include <errno.h>
+#include <__jmpbuf_arch_t.h>
+#include <support/next_to_fault.h>
+
+#define SIZEOF_SIGSET_T sizeof (__jmp_buf_sigset_t)
+
+static int
+do_test (void)
+{
+  sigjmp_buf sj;
+  struct support_next_to_fault sigset_t_buf
+    = support_next_to_fault_allocate (SIZEOF_SIGSET_T);
+  sigset_t *m_p = (sigset_t *) sigset_t_buf.buffer;
+  sigset_t m;
+
+  sigemptyset (&m);
+  memcpy (m_p, &m, SIZEOF_SIGSET_T);
+  sigprocmask (SIG_SETMASK, m_p, NULL);
+  memcpy (&m, m_p, SIZEOF_SIGSET_T);
+  if (sigsetjmp (sj, 0) == 0)
+    {
+      sigaddset (&m, SIGUSR1);
+      memcpy (m_p, &m, SIZEOF_SIGSET_T);
+      sigprocmask (SIG_SETMASK, m_p, NULL);
+      memcpy (&m, m_p, SIZEOF_SIGSET_T);
+      siglongjmp (sj, 1);
+      return EXIT_FAILURE;
+    }
+  sigprocmask (SIG_SETMASK, NULL, m_p);
+  memcpy (&m, m_p, SIZEOF_SIGSET_T);
+  return sigismember (&m, SIGUSR1) ? EXIT_SUCCESS : EXIT_FAILURE;
+}
+
+#include <support/test-driver.c>
diff --git a/debug/longjmp_chk.c b/sysdeps/generic/__jmpbuf_arch_t.h
similarity index 79%
copy from debug/longjmp_chk.c
copy to sysdeps/generic/__jmpbuf_arch_t.h
index 1cea6c0..b663202 100644
--- a/debug/longjmp_chk.c
+++ b/sysdeps/generic/__jmpbuf_arch_t.h
@@ -1,4 +1,5 @@
-/* Copyright (C) 2009-2017 Free Software Foundation, Inc.
+/* Generic __jmpbuf_arch_t defition.
+   Copyright (C) 2017 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
@@ -15,9 +16,9 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <setjmp.h>
+#include <bits/types/__sigset_t.h>
 
-#define __longjmp ____longjmp_chk
-#define __libc_siglongjmp __longjmp_chk
-
-#include <setjmp/longjmp.c>
+typedef struct
+  {
+    __sigset_t __saved_mask;
+  } __jmpbuf_arch_t;
diff --git a/debug/longjmp_chk.c b/sysdeps/generic/__saved_mask.h
similarity index 80%
copy from debug/longjmp_chk.c
copy to sysdeps/generic/__saved_mask.h
index 1cea6c0..5a59d5f 100644
--- a/debug/longjmp_chk.c
+++ b/sysdeps/generic/__saved_mask.h
@@ -1,4 +1,5 @@
-/* Copyright (C) 2009-2017 Free Software Foundation, Inc.
+/* Generic __saved_mask defition.
+   Copyright (C) 2017 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
@@ -15,9 +16,5 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <setjmp.h>
-
-#define __longjmp ____longjmp_chk
-#define __libc_siglongjmp __longjmp_chk
-
-#include <setjmp/longjmp.c>
+/* Saved signal mask.  */
+#define __saved_mask __saved_mask.__saved_mask
diff --git a/sysdeps/unix/sysv/linux/__jmpbuf_arch_t.h b/sysdeps/unix/sysv/linux/__jmpbuf_arch_t.h
new file mode 100644
index 0000000..e2372e8
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/__jmpbuf_arch_t.h
@@ -0,0 +1,43 @@
+/* __jmpbuf_arch_t defition for Linux.
+   Copyright (C) 2017 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <bits/types/__sigset_t.h>
+
+/* The biggest signal number + 1.  As of kernel 4.13, the maximum number
+   of signals is 128 on MIPS.  Define it to 257 to leave some rooms for
+   the future.  */
+#define _JUMP_BUF_SIGSET_NSIG	257
+/* Number of longs to hold all signals.  */
+#define _JUMP_BUF_SIGSET_NWORDS \
+  ((_JUMP_BUF_SIGSET_NSIG - 1 + 7) / (8 * sizeof (unsigned long int)))
+
+typedef struct
+  {
+    unsigned long int __val[_JUMP_BUF_SIGSET_NWORDS];
+  } __jmp_buf_sigset_t;
+
+typedef union
+  {
+    __sigset_t __saved_mask_compat;
+    struct
+      {
+	__jmp_buf_sigset_t __saved_mask;
+	/* Paddings for architecture specific usage.  */
+	unsigned long int __padding[12];
+      } __saved;
+  } __jmpbuf_arch_t;
diff --git a/setjmp/sigjmp.c b/sysdeps/unix/sysv/linux/__saved_mask.h
similarity index 57%
copy from setjmp/sigjmp.c
copy to sysdeps/unix/sysv/linux/__saved_mask.h
index 30839ae..aad8871 100644
--- a/setjmp/sigjmp.c
+++ b/sysdeps/unix/sysv/linux/__saved_mask.h
@@ -1,4 +1,5 @@
-/* Copyright (C) 1992-2017 Free Software Foundation, Inc.
+/* __saved_mask defition for Linux.
+   Copyright (C) 2017 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
@@ -15,20 +16,19 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <stddef.h>
-#include <setjmp.h>
+/* Saved signal mask.  */
+#define __saved_mask __saved_mask.__saved.__saved_mask
+
 #include <signal.h>
 
-/* This function is called by the `sigsetjmp' macro
-   before doing a `__setjmp' on ENV[0].__jmpbuf.
-   Always return zero.  */
+#define _SIGPROCMASK_NSIG_WORDS (_NSIG / (8 * sizeof (unsigned long int)))
 
-int
-__sigjmp_save (sigjmp_buf env, int savemask)
-{
-  env[0].__mask_was_saved = (savemask &&
-			     __sigprocmask (SIG_BLOCK, (sigset_t *) NULL,
-					    &env[0].__saved_mask) == 0);
+typedef struct
+  {
+    unsigned long int __val[_SIGPROCMASK_NSIG_WORDS];
+  } __sigprocmask_sigset_t;
 
-  return 0;
-}
+extern jmp_buf ___buf;
+extern  __typeof (___buf[0].__saved_mask) ___saved_mask;
+_Static_assert (sizeof (___saved_mask) >= sizeof (__sigprocmask_sigset_t),
+		"size of ___saved_mask < size of __sigprocmask_sigset_t");
diff --git a/sysdeps/unix/sysv/linux/s390/longjmp_chk.c b/sysdeps/unix/sysv/linux/s390/longjmp_chk.c
index 878cbd4..5e474bb 100644
--- a/sysdeps/unix/sysv/linux/s390/longjmp_chk.c
+++ b/sysdeps/unix/sysv/linux/s390/longjmp_chk.c
@@ -24,7 +24,7 @@
 /* this is a copy from debug/longjmp_chk.c because we need an unique name
    for __longjmp_chk, but it is already named via a define
    for __libc_siglongjmp in debug/longjmp_chk.c.  */
-# include <setjmp.h>
+# include <setjmpP.h>
 
 // XXX Should move to include/setjmp.h
 extern void ____longjmp_chk (__jmp_buf __env, int __val)

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