4.4.30-stable review

@@ -44,22 +44,19 @@
 
 /* Exception table entry */
 #ifdef __ASSEMBLY__
-# define _ASM_EXTABLE_HANDLE(from, to, handler)			\
+# define _ASM_EXTABLE(from,to)					\
 	.pushsection "__ex_table","a" ;				\
-	.balign 4 ;						\
+	.balign 8 ;						\
 	.long (from) - . ;					\
 	.long (to) - . ;					\
-	.long (handler) - . ;					\
 	.popsection
 
-# define _ASM_EXTABLE(from, to)					\
-	_ASM_EXTABLE_HANDLE(from, to, ex_handler_default)
-
-# define _ASM_EXTABLE_FAULT(from, to)				\
-	_ASM_EXTABLE_HANDLE(from, to, ex_handler_fault)
-
-# define _ASM_EXTABLE_EX(from, to)				\
-	_ASM_EXTABLE_HANDLE(from, to, ex_handler_ext)
+# define _ASM_EXTABLE_EX(from,to)				\
+	.pushsection "__ex_table","a" ;				\
+	.balign 8 ;						\
+	.long (from) - . ;					\
+	.long (to) - . + 0x7ffffff0 ;				\
+	.popsection
 
 # define _ASM_NOKPROBE(entry)					\
 	.pushsection "_kprobe_blacklist","aw" ;			\

@@ -92,24 +89,19 @@
 	.endm
 
 #else
-# define _EXPAND_EXTABLE_HANDLE(x) #x
-# define _ASM_EXTABLE_HANDLE(from, to, handler)			\
+# define _ASM_EXTABLE(from,to)					\
 	" .pushsection \"__ex_table\",\"a\"\n"			\
-	" .balign 4\n"						\
+	" .balign 8\n"						\
 	" .long (" #from ") - .\n"				\
 	" .long (" #to ") - .\n"				\
-	" .long (" _EXPAND_EXTABLE_HANDLE(handler) ") - .\n"	\
 	" .popsection\n"
 
-# define _ASM_EXTABLE(from, to)					\
-	_ASM_EXTABLE_HANDLE(from, to, ex_handler_default)
-
-# define _ASM_EXTABLE_FAULT(from, to)				\
-	_ASM_EXTABLE_HANDLE(from, to, ex_handler_fault)
-
-# define _ASM_EXTABLE_EX(from, to)				\
-	_ASM_EXTABLE_HANDLE(from, to, ex_handler_ext)
-
+# define _ASM_EXTABLE_EX(from,to)				\
+	" .pushsection \"__ex_table\",\"a\"\n"			\
+	" .balign 8\n"						\
+	" .long (" #from ") - .\n"				\
+	" .long (" #to ") - . + 0x7ffffff0\n"			\
+	" .popsection\n"
 /* For C file, we already have NOKPROBE_SYMBOL macro */
 #endif
 

@@ -90,11 +90,12 @@ static inline bool __chk_range_not_ok(un
 	likely(!__range_not_ok(addr, size, user_addr_max()))
 
 /*
- * The exception table consists of triples of addresses relative to the
- * exception table entry itself. The first address is of an instruction
- * that is allowed to fault, the second is the target at which the program
- * should continue. The third is a handler function to deal with the fault
- * caused by the instruction in the first field.
+ * The exception table consists of pairs of addresses relative to the
+ * exception table enty itself: the first is the address of an
+ * instruction that is allowed to fault, and the second is the address
+ * at which the program should continue.  No registers are modified,
+ * so it is entirely up to the continuation code to figure out what to
+ * do.
  *
  * All the routines below use bits of fixup code that are out of line
  * with the main instruction path.  This means when everything is well,

@@ -103,14 +104,13 @@ static inline bool __chk_range_not_ok(un
  */
 
 struct exception_table_entry {
-	int insn, fixup, handler;
+	int insn, fixup;
 };
 /* This is not the generic standard exception_table_entry format */
 #define ARCH_HAS_SORT_EXTABLE
 #define ARCH_HAS_SEARCH_EXTABLE
 
-extern int fixup_exception(struct pt_regs *regs, int trapnr);
-extern bool ex_has_fault_handler(unsigned long ip);
+extern int fixup_exception(struct pt_regs *regs);
 extern int early_fixup_exception(unsigned long *ip);
 
 /*

@@ -1000,7 +1000,7 @@ int kprobe_fault_handler(struct pt_regs
 		 * In case the user-specified fault handler returned
 		 * zero, try to fix up.
 		 */
-		if (fixup_exception(regs, trapnr))
+		if (fixup_exception(regs))
 			return 1;
 
 		/*

@@ -199,7 +199,7 @@ do_trap_no_signal(struct task_struct *ts
 	}
 
 	if (!user_mode(regs)) {
-		if (!fixup_exception(regs, trapnr)) {
+		if (!fixup_exception(regs)) {
 			tsk->thread.error_code = error_code;
 			tsk->thread.trap_nr = trapnr;
 			die(str, regs, error_code);

@@ -453,7 +453,7 @@ do_general_protection(struct pt_regs *re
 
 	tsk = current;
 	if (!user_mode(regs)) {
-		if (fixup_exception(regs, X86_TRAP_GP))
+		if (fixup_exception(regs))
 			return;
 
 		tsk->thread.error_code = error_code;

@@ -699,7 +699,7 @@ static void math_error(struct pt_regs *r
 	conditional_sti(regs);
 
 	if (!user_mode(regs)) {
-		if (!fixup_exception(regs, trapnr)) {
+		if (!fixup_exception(regs)) {
 			task->thread.error_code = error_code;
 			task->thread.trap_nr = trapnr;
 			die(str, regs, error_code);

144 lines not on this page · raw message

@@ -663,7 +663,7 @@ no_context(struct pt_regs *regs, unsigne
 	int sig;
 
 	/* Are we prepared to handle this kernel fault? */
-	if (fixup_exception(regs, X86_TRAP_PF)) {
+	if (fixup_exception(regs)) {
 		/*
 		 * Any interrupt that takes a fault gets the fixup. This makes
 		 * the below recursive fault logic only apply to a faults from

@@ -209,35 +209,6 @@ static int compare_relative_table(const
 	return 0;
 }
 
-static void x86_sort_relative_table(char *extab_image, int image_size)
-{
-	int i;
-
-	i = 0;
-	while (i < image_size) {
-		uint32_t *loc = (uint32_t *)(extab_image + i);
-
-		w(r(loc) + i, loc);
-		w(r(loc + 1) + i + 4, loc + 1);
-		w(r(loc + 2) + i + 8, loc + 2);
-
-		i += sizeof(uint32_t) * 3;
-	}
-
-	qsort(extab_image, image_size / 12, 12, compare_relative_table);
-
-	i = 0;
-	while (i < image_size) {
-		uint32_t *loc = (uint32_t *)(extab_image + i);
-
-		w(r(loc) - i, loc);
-		w(r(loc + 1) - (i + 4), loc + 1);
-		w(r(loc + 2) - (i + 8), loc + 2);
-
-		i += sizeof(uint32_t) * 3;
-	}
-}
-
 static void sort_relative_table(char *extab_image, int image_size)
 {
 	int i;

@@ -310,9 +281,6 @@ do_file(char const *const fname)
 		break;
 	case EM_386:
 	case EM_X86_64:
-		custom_sort = x86_sort_relative_table;
-		break;
-
 	case EM_S390:
 		custom_sort = sort_relative_table;
 		break;

@@ -394,11 +394,7 @@ do {									\
 #define __get_user_asm_ex(x, addr, itype, rtype, ltype)			\
 	asm volatile("1:	mov"itype" %1,%"rtype"0\n"		\
 		     "2:\n"						\
-		     ".section .fixup,\"ax\"\n"				\
-                     "3:xor"itype" %"rtype"0,%"rtype"0\n"		\
-		     "  jmp 2b\n"					\
-		     ".previous\n"					\
-		     _ASM_EXTABLE_EX(1b, 3b)				\
+		     _ASM_EXTABLE_EX(1b, 2b)				\
 		     : ltype(x) : "m" (__m(addr)))
 
 #define __put_user_nocheck(x, ptr, size)			\