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GNU C Library master sources branch master updated. glibc-2.27.9000-572-gfaaee1f

From: hjl at sourceware dot org
To: glibc-cvs at sourceware dot org
Date: 14 Jul 2018 13:46:52 -0000
Subject: GNU C Library master sources branch master updated. glibc-2.27.9000-572-gfaaee1f
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The branch, master has been updated
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- Log -----------------------------------------------------------------
http://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commitdiff;h=faaee1f07ed25b2779bfd935ffb29f431b80d6d3

commit faaee1f07ed25b2779bfd935ffb29f431b80d6d3
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Sat Jul 14 05:59:29 2018 -0700

    x86: Support shadow stack pointer in setjmp/longjmp
    
    Save and restore shadow stack pointer in setjmp and longjmp to support
    shadow stack in Intel CET.  Use feature_1 in tcbhead_t to check if
    shadow stack is enabled before saving and restoring shadow stack pointer.
    
    Reviewed-by: Carlos O'Donell <carlos@redhat.com>
    
    	* sysdeps/i386/__longjmp.S: Include <jmp_buf-ssp.h>.
    	(__longjmp): Restore shadow stack pointer if shadow stack is
    	enabled, SHADOW_STACK_POINTER_OFFSET is defined and __longjmp
    	isn't defined for __longjmp_cancel.
    	* sysdeps/i386/bsd-_setjmp.S: Include <jmp_buf-ssp.h>.
    	(_setjmp): Save shadow stack pointer if shadow stack is enabled
    	and SHADOW_STACK_POINTER_OFFSET is defined.
    	* sysdeps/i386/bsd-setjmp.S: Include <jmp_buf-ssp.h>.
    	(setjmp): Save shadow stack pointer if shadow stack is enabled
    	and SHADOW_STACK_POINTER_OFFSET is defined.
    	* sysdeps/i386/setjmp.S: Include <jmp_buf-ssp.h>.
    	(__sigsetjmp): Save shadow stack pointer if shadow stack is
    	enabled and SHADOW_STACK_POINTER_OFFSET is defined.
    	* sysdeps/unix/sysv/linux/i386/____longjmp_chk.S: Include
    	<jmp_buf-ssp.h>.
    	(____longjmp_chk): Restore shadow stack pointer if shadow stack
    	is enabled and SHADOW_STACK_POINTER_OFFSET is defined.
    	* sysdeps/unix/sysv/linux/x86/Makefile (gen-as-const-headers):
    	Remove jmp_buf-ssp.sym.
    	* sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S: Include
    	<jmp_buf-ssp.h>.
    	(____longjmp_chk): Restore shadow stack pointer if shadow stack
    	is enabled and SHADOW_STACK_POINTER_OFFSET is defined.
    	* sysdeps/x86/Makefile (gen-as-const-headers): Add
    	jmp_buf-ssp.sym.
    	* sysdeps/x86/jmp_buf-ssp.sym: New dummy file.
    	* sysdeps/x86_64/__longjmp.S: Include <jmp_buf-ssp.h>.
    	(__longjmp): Restore shadow stack pointer if shadow stack is
    	enabled, SHADOW_STACK_POINTER_OFFSET is defined and __longjmp
    	isn't defined for __longjmp_cancel.
    	* sysdeps/x86_64/setjmp.S: Include <jmp_buf-ssp.h>.
    	(__sigsetjmp): Save shadow stack pointer if shadow stack is
    	enabled and SHADOW_STACK_POINTER_OFFSET is defined.

diff --git a/ChangeLog b/ChangeLog
index e5eead0..c984482 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,40 @@
+2018-07-14  Igor Tsimbalist  <igor.v.tsimbalist@intel.com>
+	    H.J. Lu  <hongjiu.lu@intel.com>
+
+	* sysdeps/i386/__longjmp.S: Include <jmp_buf-ssp.h>.
+	(__longjmp): Restore shadow stack pointer if shadow stack is
+	enabled, SHADOW_STACK_POINTER_OFFSET is defined and __longjmp
+	isn't defined for __longjmp_cancel.
+	* sysdeps/i386/bsd-_setjmp.S: Include <jmp_buf-ssp.h>.
+	(_setjmp): Save shadow stack pointer if shadow stack is enabled
+	and SHADOW_STACK_POINTER_OFFSET is defined.
+	* sysdeps/i386/bsd-setjmp.S: Include <jmp_buf-ssp.h>.
+	(setjmp): Save shadow stack pointer if shadow stack is enabled
+	and SHADOW_STACK_POINTER_OFFSET is defined.
+	* sysdeps/i386/setjmp.S: Include <jmp_buf-ssp.h>.
+	(__sigsetjmp): Save shadow stack pointer if shadow stack is
+	enabled and SHADOW_STACK_POINTER_OFFSET is defined.
+	* sysdeps/unix/sysv/linux/i386/____longjmp_chk.S: Include
+	<jmp_buf-ssp.h>.
+	(____longjmp_chk): Restore shadow stack pointer if shadow stack
+	is enabled and SHADOW_STACK_POINTER_OFFSET is defined.
+	* sysdeps/unix/sysv/linux/x86/Makefile (gen-as-const-headers):
+	Remove jmp_buf-ssp.sym.
+	* sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S: Include
+	<jmp_buf-ssp.h>.
+	(____longjmp_chk): Restore shadow stack pointer if shadow stack
+	is enabled and SHADOW_STACK_POINTER_OFFSET is defined.
+	* sysdeps/x86/Makefile (gen-as-const-headers): Add
+	jmp_buf-ssp.sym.
+	* sysdeps/x86/jmp_buf-ssp.sym: New dummy file.
+	* sysdeps/x86_64/__longjmp.S: Include <jmp_buf-ssp.h>.
+	(__longjmp): Restore shadow stack pointer if shadow stack is
+	enabled, SHADOW_STACK_POINTER_OFFSET is defined and __longjmp
+	isn't defined for __longjmp_cancel.
+	* sysdeps/x86_64/setjmp.S: Include <jmp_buf-ssp.h>.
+	(__sigsetjmp): Save shadow stack pointer if shadow stack is
+	enabled and SHADOW_STACK_POINTER_OFFSET is defined.
+
 2018-07-14  H.J. Lu  <hongjiu.lu@intel.com>
 
 	[BZ #22563]
diff --git a/sysdeps/i386/__longjmp.S b/sysdeps/i386/__longjmp.S
index b38333b..6e98ed5 100644
--- a/sysdeps/i386/__longjmp.S
+++ b/sysdeps/i386/__longjmp.S
@@ -18,14 +18,55 @@
 
 #include <sysdep.h>
 #include <jmpbuf-offsets.h>
+#include <jmp_buf-ssp.h>
 #include <asm-syntax.h>
 #include <stap-probe.h>
 
+/* Don't restore shadow stack register if
+   1. Shadow stack isn't enabled.  Or
+   2. __longjmp is defined for __longjmp_cancel.
+ */
+#if !SHSTK_ENABLED || defined __longjmp
+# undef SHADOW_STACK_POINTER_OFFSET
+#endif
+
 	.text
 ENTRY (__longjmp)
 #ifdef PTR_DEMANGLE
 	movl 4(%esp), %eax	/* User's jmp_buf in %eax.  */
 
+# ifdef SHADOW_STACK_POINTER_OFFSET
+#  if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
+	/* Check if Shadow Stack is enabled.  */
+	testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
+	jz L(skip_ssp)
+#  else
+	xorl %edx, %edx
+#  endif
+	/* Check and adjust the Shadow-Stack-Pointer.  */
+	rdsspd %edx
+	/* And compare it with the saved ssp value.  */
+	subl SHADOW_STACK_POINTER_OFFSET(%eax), %edx
+	je L(skip_ssp)
+	/* Count the number of frames to adjust and adjust it
+	   with incssp instruction.  The instruction can adjust
+	   the ssp by [0..255] value only thus use a loop if
+	   the number of frames is bigger than 255.  */
+	negl %edx
+	shrl $2, %edx
+	/* NB: We saved Shadow-Stack-Pointer of setjmp.  Since we are
+	       restoring Shadow-Stack-Pointer of setjmp's caller, we
+	       need to unwind shadow stack by one more frame.  */
+	addl $1, %edx
+	movl	$255, %ebx
+L(loop):
+	cmpl	%ebx, %edx
+	cmovb	%edx, %ebx
+	incsspd	%ebx
+	subl	%ebx, %edx
+	ja	L(loop)
+L(skip_ssp):
+# endif
 	/* Save the return address now.  */
 	movl (JB_PC*4)(%eax), %edx
 	/* Get the stack pointer.  */
@@ -56,6 +97,38 @@ ENTRY (__longjmp)
 #else
 	movl 4(%esp), %ecx	/* User's jmp_buf in %ecx.  */
 	movl 8(%esp), %eax	/* Second argument is return value.  */
+# ifdef SHADOW_STACK_POINTER_OFFSET
+#  if IS_IN (libc) && defined SHARED
+	/* Check if Shadow Stack is enabled.  */
+	testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
+	jz L(skip_ssp)
+#  endif
+	/* Check and adjust the Shadow-Stack-Pointer.  */
+	xorl %edx, %edx
+	/* Get the current ssp.  */
+	rdsspd	%edx
+	/* And compare it with the saved ssp value.  */
+	subl SHADOW_STACK_POINTER_OFFSET(%ecx), %edx
+	je L(skip_ssp)
+	/* Count the number of frames to adjust and adjust it
+	   with incssp instruction.  The instruction can adjust
+	   the ssp by [0..255] value only thus use a loop if
+	   the number of frames is bigger than 255.  */
+	negl %edx
+	shrl $2, %edx
+	/* NB: We saved Shadow-Stack-Pointer of setjmp.  Since we are
+	       restoring Shadow-Stack-Pointer of setjmp's caller, we
+	       need to unwind shadow stack by one more frame.  */
+	addl $1, %edx
+	movl	$255, %ebx
+L(loop):
+	cmpl	%ebx, %edx
+	cmovb	%edx, %ebx
+	incsspd	%ebx
+	subl	%ebx, %edx
+	ja	L(loop)
+L(skip_ssp):
+# endif
 	/* Save the return address now.  */
 	movl (JB_PC*4)(%ecx), %edx
 	LIBC_PROBE (longjmp, 3, 4@%ecx, -4@%eax, 4@%edx)
diff --git a/sysdeps/i386/bsd-_setjmp.S b/sysdeps/i386/bsd-_setjmp.S
index a626cc6..db47df0 100644
--- a/sysdeps/i386/bsd-_setjmp.S
+++ b/sysdeps/i386/bsd-_setjmp.S
@@ -22,12 +22,18 @@
 
 #include <sysdep.h>
 #include <jmpbuf-offsets.h>
+#include <jmp_buf-ssp.h>
 #include <stap-probe.h>
 
 #define PARMS	4		/* no space for saved regs */
 #define JMPBUF	PARMS
 #define SIGMSK	JMPBUF+4
 
+/* Don't save shadow stack register if shadow stack isn't enabled.  */
+#if !SHSTK_ENABLED
+# undef SHADOW_STACK_POINTER_OFFSET
+#endif
+
 ENTRY (_setjmp)
 
 	xorl %eax, %eax
@@ -51,6 +57,21 @@ ENTRY (_setjmp)
 	movl %ebp, (JB_BP*4)(%edx) /* Save caller's frame pointer.  */
 
 	movl %eax, JB_SIZE(%edx) /* No signal mask set.  */
+#ifdef SHADOW_STACK_POINTER_OFFSET
+# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
+	/* Check if Shadow Stack is enabled.  */
+	testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
+	jz L(skip_ssp)
+# else
+	xorl %ecx, %ecx
+# endif
+	/* Get the current Shadow-Stack-Pointer and save it.  */
+	rdsspd %ecx
+	movl %ecx, SHADOW_STACK_POINTER_OFFSET(%edx)
+# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
+L(skip_ssp):
+# endif
+#endif
 	ret
 END (_setjmp)
 libc_hidden_def (_setjmp)
diff --git a/sysdeps/i386/bsd-setjmp.S b/sysdeps/i386/bsd-setjmp.S
index 2da8b73..1290d0d 100644
--- a/sysdeps/i386/bsd-setjmp.S
+++ b/sysdeps/i386/bsd-setjmp.S
@@ -22,12 +22,18 @@
 
 #include <sysdep.h>
 #include <jmpbuf-offsets.h>
+#include <jmp_buf-ssp.h>
 #include <stap-probe.h>
 
 #define PARMS  4		/* no space for saved regs */
 #define JMPBUF PARMS
 #define SIGMSK JMPBUF+4
 
+/* Don't save shadow stack register if shadow stack isn't enabled.  */
+#if !SHSTK_ENABLED
+# undef SHADOW_STACK_POINTER_OFFSET
+#endif
+
 ENTRY (setjmp)
 	/* Note that we have to use a non-exported symbol in the next
 	   jump since otherwise gas will emit it as a jump through the
@@ -51,6 +57,21 @@ ENTRY (setjmp)
 #endif
 	movl %ecx, (JB_PC*4)(%eax)
 	movl %ebp, (JB_BP*4)(%eax) /* Save caller's frame pointer.  */
+#ifdef SHADOW_STACK_POINTER_OFFSET
+# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
+	/* Check if Shadow Stack is enabled.  */
+	testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
+	jz L(skip_ssp)
+# else
+	xorl %ecx, %ecx
+# endif
+	/* Get the current Shadow-Stack-Pointer and save it.  */
+	rdsspd %ecx
+	movl %ecx, SHADOW_STACK_POINTER_OFFSET(%eax)
+# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
+L(skip_ssp):
+# endif
+#endif
 
 	/* Call __sigjmp_save.  */
 	pushl $1
diff --git a/sysdeps/i386/setjmp.S b/sysdeps/i386/setjmp.S
index 6a08701..889337b 100644
--- a/sysdeps/i386/setjmp.S
+++ b/sysdeps/i386/setjmp.S
@@ -18,6 +18,7 @@
 
 #include <sysdep.h>
 #include <jmpbuf-offsets.h>
+#include <jmp_buf-ssp.h>
 #include <asm-syntax.h>
 #include <stap-probe.h>
 
@@ -25,6 +26,11 @@
 #define JMPBUF	PARMS
 #define SIGMSK	JMPBUF+4
 
+/* Don't save shadow stack register if shadow stack isn't enabled.  */
+#if !SHSTK_ENABLED
+# undef SHADOW_STACK_POINTER_OFFSET
+#endif
+
 ENTRY (__sigsetjmp)
 
 	movl JMPBUF(%esp), %eax
@@ -46,6 +52,21 @@ ENTRY (__sigsetjmp)
 	movl %ecx, (JB_PC*4)(%eax)
 	movl %ebp, (JB_BP*4)(%eax) /* Save caller's frame pointer.  */
 
+#ifdef SHADOW_STACK_POINTER_OFFSET
+# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
+	/* Check if Shadow Stack is enabled.  */
+	testl $X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
+	jz L(skip_ssp)
+# else
+	xorl %ecx, %ecx
+# endif
+	/* Get the current Shadow-Stack-Pointer and save it.  */
+	rdsspd %ecx
+	movl %ecx, SHADOW_STACK_POINTER_OFFSET(%eax)
+# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
+L(skip_ssp):
+# endif
+#endif
 #if IS_IN (rtld)
 	/* In ld.so we never save the signal mask.  */
 	xorl %eax, %eax
diff --git a/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S b/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S
index 3452433..a7640d9 100644
--- a/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S
+++ b/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S
@@ -17,9 +17,14 @@
 
 #include <sysdep.h>
 #include <jmpbuf-offsets.h>
+#include <jmp_buf-ssp.h>
 #include <asm-syntax.h>
 #include <stap-probe.h>
 
+/* Don't restore shadow stack register if shadow stack isn't enabled.  */
+#if !SHSTK_ENABLED
+# undef SHADOW_STACK_POINTER_OFFSET
+#endif
 
 	.section .rodata.str1.1,"aMS",@progbits,1
 	.type	longjmp_msg,@object
@@ -46,6 +51,38 @@ longjmp_msg:
 ENTRY (____longjmp_chk)
 	movl	4(%esp), %ecx	/* User's jmp_buf in %ecx.  */
 
+#ifdef SHADOW_STACK_POINTER_OFFSET
+# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
+	/* Check if Shadow Stack is enabled.  */
+	testl	$X86_FEATURE_1_SHSTK, %gs:FEATURE_1_OFFSET
+	jz	L(skip_ssp)
+# else
+	xorl	%edx, %edx
+# endif
+	/* Check and adjust the Shadow-Stack-Pointer.  */
+	rdsspd	%edx
+	/* And compare it with the saved ssp value.  */
+	subl	SHADOW_STACK_POINTER_OFFSET(%ecx), %edx
+	je	L(skip_ssp)
+	/* Count the number of frames to adjust and adjust it
+	   with incssp instruction.  The instruction can adjust
+	   the ssp by [0..255] value only thus use a loop if
+	   the number of frames is bigger than 255.  */
+	negl	%edx
+	shrl	$2, %edx
+	/* NB: We saved Shadow-Stack-Pointer of setjmp.  Since we are
+	       restoring Shadow-Stack-Pointer of setjmp's caller, we
+	       need to unwind shadow stack by one more frame.  */
+	addl	$1, %edx
+	movl	$255, %ebx
+L(loop):
+	cmpl	%ebx, %edx
+	cmovb	%edx, %ebx
+	incsspd	%ebx
+	subl	%ebx, %edx
+	ja	L(loop)
+L(skip_ssp):
+#endif
 	/* Save the return address now.  */
 	movl	(JB_PC*4)(%ecx), %edx
 	/* Get the stack pointer.  */
diff --git a/sysdeps/unix/sysv/linux/x86/Makefile b/sysdeps/unix/sysv/linux/x86/Makefile
index c55a43e..111ff9f 100644
--- a/sysdeps/unix/sysv/linux/x86/Makefile
+++ b/sysdeps/unix/sysv/linux/x86/Makefile
@@ -21,6 +21,5 @@ sysdep_routines += dl-vdso
 endif
 
 ifeq ($(subdir),setjmp)
-gen-as-const-headers += jmp_buf-ssp.sym
 tests += tst-saved_mask-1
 endif
diff --git a/sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S b/sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S
index 8a9f2e1..7eb26fa 100644
--- a/sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S
+++ b/sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S
@@ -20,7 +20,13 @@
 #include <asm-syntax.h>
 #include <stap-probe.h>
 
+/* Don't restore shadow stack register if shadow stack isn't enabled.  */
+#if !SHSTK_ENABLED
+# undef SHADOW_STACK_POINTER_OFFSET
+#endif
+
 #include <sigaltstack-offsets.h>
+#include <jmp_buf-ssp.h>
 
 	.section .rodata.str1.1,"aMS",@progbits,1
 	.type	longjmp_msg,@object
@@ -105,6 +111,38 @@ ENTRY(____longjmp_chk)
 	cfi_restore (%rsi)
 
 .Lok:
+#ifdef SHADOW_STACK_POINTER_OFFSET
+# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
+	/* Check if Shadow Stack is enabled.  */
+	testl	$X86_FEATURE_1_SHSTK, %fs:FEATURE_1_OFFSET
+	jz	L(skip_ssp)
+# else
+	xorl	%eax, %eax
+# endif
+	/* Check and adjust the Shadow-Stack-Pointer.  */
+	rdsspq	%rax
+	/* And compare it with the saved ssp value.  */
+	subq	SHADOW_STACK_POINTER_OFFSET(%rdi), %rax
+	je	L(skip_ssp)
+	/* Count the number of frames to adjust and adjust it
+	   with incssp instruction.  The instruction can adjust
+	   the ssp by [0..255] value only thus use a loop if
+	   the number of frames is bigger than 255.  */
+	negq	%rax
+	shrq	$3, %rax
+	/* NB: We saved Shadow-Stack-Pointer of setjmp.  Since we are
+	       restoring Shadow-Stack-Pointer of setjmp's caller, we
+	       need to unwind shadow stack by one more frame.  */
+	addq	$1, %rax
+	movl	$255, %ebx
+L(loop):
+	cmpq	%rbx, %rax
+	cmovb	%rax, %rbx
+	incsspq	%rbx
+	subq	%rbx, %rax
+	ja	L(loop)
+L(skip_ssp):
+#endif
 	LIBC_PROBE (longjmp, 3, LP_SIZE@%RDI_LP, -4@%esi, LP_SIZE@%RDX_LP)
 	/* We add unwind information for the target here.  */
 	cfi_def_cfa(%rdi, 0)
diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
index d25d6f0..65292f4 100644
--- a/sysdeps/x86/Makefile
+++ b/sysdeps/x86/Makefile
@@ -10,5 +10,6 @@ tests-static += tst-get-cpu-features-static
 endif
 
 ifeq ($(subdir),setjmp)
+gen-as-const-headers += jmp_buf-ssp.sym
 sysdep_routines += __longjmp_cancel
 endif
diff --git a/sysdeps/x86/jmp_buf-ssp.sym b/sysdeps/x86/jmp_buf-ssp.sym
new file mode 100644
index 0000000..1aaaedc
--- /dev/null
+++ b/sysdeps/x86/jmp_buf-ssp.sym
@@ -0,0 +1 @@
+-- FIXME: Define SHADOW_STACK_POINTER_OFFSET to support shadow stack.
diff --git a/sysdeps/x86_64/__longjmp.S b/sysdeps/x86_64/__longjmp.S
index a487e0e..d7d123e 100644
--- a/sysdeps/x86_64/__longjmp.S
+++ b/sysdeps/x86_64/__longjmp.S
@@ -17,9 +17,18 @@
 
 #include <sysdep.h>
 #include <jmpbuf-offsets.h>
+#include <jmp_buf-ssp.h>
 #include <asm-syntax.h>
 #include <stap-probe.h>
 
+/* Don't restore shadow stack register if
+   1. Shadow stack isn't enabled.  Or
+   2. __longjmp is defined for __longjmp_cancel.
+ */
+#if !SHSTK_ENABLED || defined __longjmp
+# undef SHADOW_STACK_POINTER_OFFSET
+#endif
+
 /* Jump to the position specified by ENV, causing the
    setjmp call there to return VAL, or 1 if VAL is 0.
    void __longjmp (__jmp_buf env, int val).  */
@@ -42,6 +51,41 @@ ENTRY(__longjmp)
 	orq %rax, %r9
 # endif
 #endif
+#ifdef SHADOW_STACK_POINTER_OFFSET
+# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
+	/* Check if Shadow Stack is enabled.  */
+	testl $X86_FEATURE_1_SHSTK, %fs:FEATURE_1_OFFSET
+	jz L(skip_ssp)
+# else
+	xorl %eax, %eax
+# endif
+	/* Check and adjust the Shadow-Stack-Pointer.  */
+	/* Get the current ssp.  */
+	rdsspq %rax
+	/* And compare it with the saved ssp value.  */
+	subq SHADOW_STACK_POINTER_OFFSET(%rdi), %rax
+	je L(skip_ssp)
+	/* Count the number of frames to adjust and adjust it
+	   with incssp instruction.  The instruction can adjust
+	   the ssp by [0..255] value only thus use a loop if
+	   the number of frames is bigger than 255.  */
+	negq %rax
+	shrq $3, %rax
+	/* NB: We saved Shadow-Stack-Pointer of setjmp.  Since we are
+	       restoring Shadow-Stack-Pointer of setjmp's caller, we
+	       need to unwind shadow stack by one more frame.  */
+	addq $1, %rax
+
+	movl $255, %ebx
+L(loop):
+	cmpq %rbx, %rax
+	cmovb %rax, %rbx
+	incsspq %rbx
+	subq %rbx, %rax
+	ja L(loop)
+
+L(skip_ssp):
+#endif
 	LIBC_PROBE (longjmp, 3, LP_SIZE@%RDI_LP, -4@%esi, LP_SIZE@%RDX_LP)
 	/* We add unwind information for the target here.  */
 	cfi_def_cfa(%rdi, 0)
diff --git a/sysdeps/x86_64/setjmp.S b/sysdeps/x86_64/setjmp.S
index e0a648e..78a8bf4 100644
--- a/sysdeps/x86_64/setjmp.S
+++ b/sysdeps/x86_64/setjmp.S
@@ -18,9 +18,15 @@
 
 #include <sysdep.h>
 #include <jmpbuf-offsets.h>
+#include <jmp_buf-ssp.h>
 #include <asm-syntax.h>
 #include <stap-probe.h>
 
+/* Don't save shadow stack register if shadow stack isn't enabled.  */
+#if !SHSTK_ENABLED
+# undef SHADOW_STACK_POINTER_OFFSET
+#endif
+
 ENTRY (__sigsetjmp)
 	/* Save registers.  */
 	movq %rbx, (JB_RBX*8)(%rdi)
@@ -54,6 +60,21 @@ ENTRY (__sigsetjmp)
 #endif
 	movq %rax, (JB_PC*8)(%rdi)
 
+#ifdef SHADOW_STACK_POINTER_OFFSET
+# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
+	/* Check if Shadow Stack is enabled.  */
+	testl $X86_FEATURE_1_SHSTK, %fs:FEATURE_1_OFFSET
+	jz L(skip_ssp)
+# else
+	xorl %eax, %eax
+# endif
+	/* Get the current Shadow-Stack-Pointer and save it.  */
+	rdsspq %rax
+	movq %rax, SHADOW_STACK_POINTER_OFFSET(%rdi)
+# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
+L(skip_ssp):
+# endif
+#endif
 #if IS_IN (rtld)
 	/* In ld.so we never save the signal mask.  */
 	xorl %eax, %eax

http://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commitdiff;h=ebff9c5cfae62e84dbd0456d564bd882818dc15f

commit ebff9c5cfae62e84dbd0456d564bd882818dc15f
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Sat Jul 14 05:53:05 2018 -0700

    x86: Rename __glibc_reserved1 to feature_1 in tcbhead_t [BZ #22563]
    
    feature_1 has X86_FEATURE_1_IBT and X86_FEATURE_1_SHSTK bits for CET
    run-time control.
    
    CET_ENABLED, IBT_ENABLED and SHSTK_ENABLED are defined to 1 or 0 to
    indicate that if CET, IBT and SHSTK are enabled.
    
    <tls-setup.h> is added to set up thread-local data.
    
    Reviewed-by: Carlos O'Donell <carlos@redhat.com>
    
    	[BZ #22563]
    	* nptl/pthread_create.c: Include <tls-setup.h>.
    	(__pthread_create_2_1): Call tls_setup_tcbhead.
    	* sysdeps/generic/tls-setup.h: New file.
    	* sysdeps/x86/nptl/tls-setup.h: Likewise.
    	* sysdeps/i386/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New.
    	* sysdeps/x86_64/nptl/tcb-offsets.sym (FEATURE_1_OFFSET):
    	Likewise.
    	* sysdeps/i386/nptl/tls.h (tcbhead_t): Rename __glibc_reserved1
    	to feature_1.
    	* sysdeps/x86_64/nptl/tls.h (tcbhead_t): Likewise.
    	* sysdeps/x86/sysdep.h (X86_FEATURE_1_IBT): New.
    	(X86_FEATURE_1_SHSTK): Likewise.
    	(CET_ENABLED): Likewise.
    	(IBT_ENABLED): Likewise.
    	(SHSTK_ENABLED): Likewise.

diff --git a/ChangeLog b/ChangeLog
index 981e65e..e5eead0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,22 @@
+2018-07-14  H.J. Lu  <hongjiu.lu@intel.com>
+
+	[BZ #22563]
+	* nptl/pthread_create.c: Include <tls-setup.h>.
+	(__pthread_create_2_1): Call tls_setup_tcbhead.
+	* sysdeps/generic/tls-setup.h: New file.
+	* sysdeps/x86/nptl/tls-setup.h: Likewise.
+	* sysdeps/i386/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New.
+	* sysdeps/x86_64/nptl/tcb-offsets.sym (FEATURE_1_OFFSET):
+	Likewise.
+	* sysdeps/i386/nptl/tls.h (tcbhead_t): Rename __glibc_reserved1
+	to feature_1.
+	* sysdeps/x86_64/nptl/tls.h (tcbhead_t): Likewise.
+	* sysdeps/x86/sysdep.h (X86_FEATURE_1_IBT): New.
+	(X86_FEATURE_1_SHSTK): Likewise.
+	(CET_ENABLED): Likewise.
+	(IBT_ENABLED): Likewise.
+	(SHSTK_ENABLED): Likewise.
+
 2018-07-13  Rafal Luzynski  <digitalfreak@lingonborough.com>
 
 	[BZ #23208]
diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index 92c945b..5f5a007 100644
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -32,6 +32,7 @@
 #include <exit-thread.h>
 #include <default-sched.h>
 #include <futex-internal.h>
+#include <tls-setup.h>
 #include "libioP.h"
 
 #include <shlib-compat.h>
@@ -712,6 +713,9 @@ __pthread_create_2_1 (pthread_t *newthread, const pthread_attr_t *attr,
   THREAD_COPY_POINTER_GUARD (pd);
 #endif
 
+  /* Setup tcbhead.  */
+  tls_setup_tcbhead (pd);
+
   /* Verify the sysinfo bits were copied in allocate_stack if needed.  */
 #ifdef NEED_DL_SYSINFO
   CHECK_THREAD_SYSINFO (pd);
diff --git a/sysdeps/generic/tls-setup.h b/sysdeps/generic/tls-setup.h
new file mode 100644
index 0000000..8d0c36d
--- /dev/null
+++ b/sysdeps/generic/tls-setup.h
@@ -0,0 +1,22 @@
+/* Definitions to set up thread-local data.  Generic version.
+   Copyright (C) 2018 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/>.  */
+
+static inline void __attribute__ ((always_inline))
+tls_setup_tcbhead (struct pthread *pd)
+{
+}
diff --git a/sysdeps/i386/nptl/tcb-offsets.sym b/sysdeps/i386/nptl/tcb-offsets.sym
index 7d7fe5e..fbac241 100644
--- a/sysdeps/i386/nptl/tcb-offsets.sym
+++ b/sysdeps/i386/nptl/tcb-offsets.sym
@@ -12,3 +12,4 @@ CLEANUP			offsetof (struct pthread, cleanup)
 CLEANUP_PREV		offsetof (struct _pthread_cleanup_buffer, __prev)
 MUTEX_FUTEX		offsetof (pthread_mutex_t, __data.__lock)
 POINTER_GUARD		offsetof (tcbhead_t, pointer_guard)
+FEATURE_1_OFFSET	offsetof (tcbhead_t, feature_1)
diff --git a/sysdeps/i386/nptl/tls.h b/sysdeps/i386/nptl/tls.h
index afb71ce..21e23cd 100644
--- a/sysdeps/i386/nptl/tls.h
+++ b/sysdeps/i386/nptl/tls.h
@@ -41,7 +41,10 @@ typedef struct
   uintptr_t stack_guard;
   uintptr_t pointer_guard;
   int gscope_flag;
-  int __glibc_reserved1;
+  /* Bit 0: X86_FEATURE_1_IBT.
+     Bit 1: X86_FEATURE_1_SHSTK.
+   */
+  unsigned int feature_1;
   /* Reservation of some values for the TM ABI.  */
   void *__private_tm[3];
   /* GCC split stack support.  */
diff --git a/sysdeps/x86/nptl/tls-setup.h b/sysdeps/x86/nptl/tls-setup.h
new file mode 100644
index 0000000..ef5a4df
--- /dev/null
+++ b/sysdeps/x86/nptl/tls-setup.h
@@ -0,0 +1,23 @@
+/* Definitions to set up thread-local data.  x86 version.
+   Copyright (C) 2018 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/>.  */
+
+static inline void __attribute__ ((always_inline))
+tls_setup_tcbhead (struct pthread *pd)
+{
+  pd->header.feature_1 = THREAD_GETMEM (THREAD_SELF, header.feature_1);
+}
diff --git a/sysdeps/x86/sysdep.h b/sysdeps/x86/sysdep.h
index afcb7cf..976566a 100644
--- a/sysdeps/x86/sysdep.h
+++ b/sysdeps/x86/sysdep.h
@@ -21,6 +21,33 @@
 
 #include <sysdeps/generic/sysdep.h>
 
+/* __CET__ is defined by GCC with Control-Flow Protection values:
+
+enum cf_protection_level
+{
+  CF_NONE = 0,
+  CF_BRANCH = 1 << 0,
+  CF_RETURN = 1 << 1,
+  CF_FULL = CF_BRANCH | CF_RETURN,
+  CF_SET = 1 << 2
+};
+*/
+
+/* Set if CF_BRANCH (IBT) is enabled.  */
+#define X86_FEATURE_1_IBT	(1U << 0)
+/* Set if CF_RETURN (SHSTK) is enabled.  */
+#define X86_FEATURE_1_SHSTK	(1U << 1)
+
+#ifdef __CET__
+# define CET_ENABLED	1
+# define IBT_ENABLED	(__CET__ & X86_FEATURE_1_IBT)
+# define SHSTK_ENABLED	(__CET__ & X86_FEATURE_1_SHSTK)
+#else
+# define CET_ENABLED	0
+# define IBT_ENABLED	0
+# define SHSTK_ENABLED	0
+#endif
+
 #ifdef	__ASSEMBLER__
 
 /* Syntactic details of assembler.  */
diff --git a/sysdeps/x86_64/nptl/tcb-offsets.sym b/sysdeps/x86_64/nptl/tcb-offsets.sym
index be63404..387621e 100644
--- a/sysdeps/x86_64/nptl/tcb-offsets.sym
+++ b/sysdeps/x86_64/nptl/tcb-offsets.sym
@@ -12,6 +12,7 @@ MUTEX_FUTEX		offsetof (pthread_mutex_t, __data.__lock)
 MULTIPLE_THREADS_OFFSET	offsetof (tcbhead_t, multiple_threads)
 POINTER_GUARD		offsetof (tcbhead_t, pointer_guard)
 VGETCPU_CACHE_OFFSET	offsetof (tcbhead_t, vgetcpu_cache)
+FEATURE_1_OFFSET	offsetof (tcbhead_t, feature_1)
 
 -- Not strictly offsets, but these values are also used in the TCB.
 TCB_CANCELSTATE_BITMASK	 CANCELSTATE_BITMASK
diff --git a/sysdeps/x86_64/nptl/tls.h b/sysdeps/x86_64/nptl/tls.h
index 65c0051..f042a02 100644
--- a/sysdeps/x86_64/nptl/tls.h
+++ b/sysdeps/x86_64/nptl/tls.h
@@ -51,7 +51,10 @@ typedef struct
   uintptr_t stack_guard;
   uintptr_t pointer_guard;
   unsigned long int vgetcpu_cache[2];
-  int __glibc_reserved1;
+  /* Bit 0: X86_FEATURE_1_IBT.
+     Bit 1: X86_FEATURE_1_SHSTK.
+   */
+  unsigned int feature_1;
   int __glibc_unused1;
   /* Reservation of some values for the TM ABI.  */
   void *__private_tm[4];

-----------------------------------------------------------------------

Summary of changes:
 ChangeLog                                        |   56 +++++++++++++++++
 nptl/pthread_create.c                            |    4 +
 sysdeps/generic/tls-setup.h                      |   22 +++++++
 sysdeps/i386/__longjmp.S                         |   73 ++++++++++++++++++++++
 sysdeps/i386/bsd-_setjmp.S                       |   21 ++++++
 sysdeps/i386/bsd-setjmp.S                        |   21 ++++++
 sysdeps/i386/nptl/tcb-offsets.sym                |    1 +
 sysdeps/i386/nptl/tls.h                          |    5 +-
 sysdeps/i386/setjmp.S                            |   21 ++++++
 sysdeps/unix/sysv/linux/i386/____longjmp_chk.S   |   37 +++++++++++
 sysdeps/unix/sysv/linux/x86/Makefile             |    1 -
 sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S |   38 +++++++++++
 sysdeps/x86/Makefile                             |    1 +
 sysdeps/x86/jmp_buf-ssp.sym                      |    1 +
 sysdeps/x86/nptl/tls-setup.h                     |   23 +++++++
 sysdeps/x86/sysdep.h                             |   27 ++++++++
 sysdeps/x86_64/__longjmp.S                       |   44 +++++++++++++
 sysdeps/x86_64/nptl/tcb-offsets.sym              |    1 +
 sysdeps/x86_64/nptl/tls.h                        |    5 +-
 sysdeps/x86_64/setjmp.S                          |   21 ++++++
 20 files changed, 420 insertions(+), 3 deletions(-)
 create mode 100644 sysdeps/generic/tls-setup.h
 create mode 100644 sysdeps/x86/jmp_buf-ssp.sym
 create mode 100644 sysdeps/x86/nptl/tls-setup.h


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