Sanitize the type of struct user.u_ar0

struct user.u_ar0 is defined to contain a pointer offset on all
architectures in which it is defined (all architectures which define an
a.out format except SPARC.) However, it has a pointer type in the headers,
which is pointless -- <asm/user.h> is not exported to userspace, and it
just makes the code messy.

Redefine the field as "unsigned long" (which is the same size as a pointer
on all Linux architectures) and change the setting code to user offsetof()
instead of hand-coded arithmetic.

Cc: Linux Arch Mailing List <linux-arch@vger.kernel.org>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Håvard Skinnemoen <hskinnemoen@atmel.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/ia32/ia32_aout.c

@@ -172,8 +172,7 @@ static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file,
 	has_dumped = 1;
 	current->flags |= PF_DUMPCORE;
 	strncpy(dump.u_comm, current->comm, sizeof(current->comm));
-	dump.u_ar0 = (u32)(((unsigned long)(&dump.regs)) -
-			   ((unsigned long)(&dump)));
+	dump.u_ar0 = offsetof(struct user32, regs);
 	dump.signal = signr;
 	dump_thread32(regs, &dump);
 

fs/binfmt_aout.c

@@ -115,7 +115,7 @@ static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file, u
 	current->flags |= PF_DUMPCORE;
        	strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
 #ifndef __sparc__
-	dump.u_ar0 = (void *)(((unsigned long)(&dump.regs)) - ((unsigned long)(&dump)));
+	dump.u_ar0 = offsetof(struct user, regs);
 #endif
 	dump.signal = signr;
 	dump_thread(regs, &dump);

include/asm-alpha/user.h

@@ -39,7 +39,7 @@ struct user {
 	unsigned long	start_data;		/* data starting address */
 	unsigned long	start_stack;		/* stack starting address */
 	long int	signal;			/* signal causing core dump */
-	struct regs *	u_ar0;			/* help gdb find registers */
+	unsigned long	u_ar0;			/* help gdb find registers */
 	unsigned long	magic;			/* identifies a core file */
 	char		u_comm[32];		/* user command name */
 };

include/asm-arm/user.h

@@ -67,7 +67,7 @@ struct user{
 				   esp register.  */
   long int signal;     		/* Signal that caused the core dump. */
   int reserved;			/* No longer used */
-  struct pt_regs * u_ar0;	/* Used by gdb to help find the values for */
+  unsigned long u_ar0;		/* Used by gdb to help find the values for */
 				/* the registers. */
   unsigned long magic;		/* To uniquely identify a core file */
   char u_comm[32];		/* User command that was responsible */

include/asm-avr32/user.h

@@ -51,7 +51,7 @@ struct user {
 	unsigned long	start_data;		/* data starting address */
 	unsigned long	start_stack;		/* stack starting address */
 	long int	signal;			/* signal causing core dump */
-	struct regs *	u_ar0;			/* help gdb find registers */
+	unsigned long	u_ar0;			/* help gdb find registers */
 	unsigned long	magic;			/* identifies a core file */
 	char		u_comm[32];		/* user command name */
 };

include/asm-blackfin/user.h

@@ -75,7 +75,7 @@ struct user {
 					   esp register.  */
 	long int signal;	/* Signal that caused the core dump. */
 	int reserved;		/* No longer used */
-	struct user_regs_struct *u_ar0;
+	unsigned long u_ar0;
 	/* Used by gdb to help find the values for */
 	/* the registers. */
 	unsigned long magic;	/* To uniquely identify a core file */

include/asm-cris/user.h

@@ -38,7 +38,7 @@ struct user {
 	unsigned long	start_data;		/* data starting address */
 	unsigned long	start_stack;		/* stack starting address */
 	long int	signal;			/* signal causing core dump */
-	struct regs *	u_ar0;			/* help gdb find registers */
+	unsigned long	u_ar0;			/* help gdb find registers */
 	unsigned long	magic;			/* identifies a core file */
 	char		u_comm[32];		/* user command name */
 };

include/asm-h8300/user.h

@@ -62,8 +62,7 @@ struct user{
 				   esp register.  */
   long int signal;     		/* Signal that caused the core dump. */
   int reserved;			/* No longer used */
-  struct user_regs_struct *u_ar0;
-				/* Used by gdb to help find the values for */
+  unsigned long u_ar0;		/* Used by gdb to help find the values for */
 				/* the registers. */
   unsigned long magic;		/* To uniquely identify a core file */
   char u_comm[32];		/* User command that was responsible */

include/asm-ia64/user.h

@@ -44,7 +44,7 @@ struct user {
 	unsigned long	start_data;		/* data starting address */
 	unsigned long	start_stack;		/* stack starting address */
 	long int	signal;			/* signal causing core dump */
-	struct regs *	u_ar0;			/* help gdb find registers */
+	unsigned long	u_ar0;			/* help gdb find registers */
 	unsigned long	magic;			/* identifies a core file */
 	char		u_comm[32];		/* user command name */
 };

include/asm-m32r/user.h

@@ -38,7 +38,7 @@ struct user {
 	unsigned long	start_data;		/* data starting address */
 	unsigned long	start_stack;		/* stack starting address */
 	long int	signal;			/* signal causing core dump */
-	struct regs *	u_ar0;			/* help gdb find registers */
+	unsigned long	u_ar0;			/* help gdb find registers */
 	unsigned long	magic;			/* identifies a core file */
 	char		u_comm[32];		/* user command name */
 };

include/asm-m68k/user.h

@@ -72,8 +72,7 @@ struct user{
 				   esp register.  */
   long int signal;		/* Signal that caused the core dump. */
   int reserved;			/* No longer used */
-  struct user_regs_struct *u_ar0;
-				/* Used by gdb to help find the values for */
+  unsigned long u_ar0;		/* Used by gdb to help find the values for */
 				/* the registers. */
   struct user_m68kfp_struct* u_fpstate;	/* Math Co-processor pointer. */
   unsigned long magic;		/* To uniquely identify a core file */

include/asm-mips/user.h

@@ -44,7 +44,7 @@ struct user {
 	unsigned long	start_data;		/* data starting address */
 	unsigned long	start_stack;		/* stack starting address */
 	long int	signal;			/* signal causing core dump */
-	struct regs *	u_ar0;			/* help gdb find registers */
+	unsigned long	u_ar0;			/* help gdb find registers */
 	unsigned long	magic;			/* identifies a core file */
 	char		u_comm[32];		/* user command name */
 };

include/asm-powerpc/user.h

@@ -38,7 +38,7 @@ struct user {
 	unsigned long	start_data;		/* data starting address */
 	unsigned long	start_stack;		/* stack starting address */
 	long int	signal;			/* signal causing core dump */
-	struct regs *	u_ar0;			/* help gdb find registers */
+	unsigned long	u_ar0;			/* help gdb find registers */
 	unsigned long	magic;			/* identifies a core file */
 	char		u_comm[32];		/* user command name */
 };

include/asm-s390/user.h

@@ -63,8 +63,7 @@ struct user {
 				   the top of the stack is always found in the
 				   esp register.  */
   long int signal;     		/* Signal that caused the core dump. */
-  struct user_regs_struct *u_ar0;
-				/* Used by gdb to help find the values for */
+  unsigned long u_ar0;		/* Used by gdb to help find the values for */
 				/* the registers. */
   unsigned long magic;		/* To uniquely identify a core file */
   char u_comm[32];		/* User command that was responsible */

include/asm-sh/user.h

@@ -52,7 +52,7 @@ struct user {
 	unsigned long	start_data;		/* data starting address */
 	unsigned long	start_stack;		/* stack starting address */
 	long int	signal;			/* signal causing core dump */
-	struct regs *	u_ar0;			/* help gdb find registers */
+	unsigned long	u_ar0;			/* help gdb find registers */
 	struct user_fpu_struct* u_fpstate;	/* Math Co-processor pointer */
 	unsigned long	magic;			/* identifies a core file */
 	char		u_comm[32];		/* user command name */

include/asm-v850/user.h

@@ -38,7 +38,7 @@ struct user {
 	unsigned long	start_data;		/* data starting address */
 	unsigned long	start_stack;		/* stack starting address */
 	long int	signal;			/* signal causing core dump */
-	struct regs *	u_ar0;			/* help gdb find registers */
+	unsigned long	u_ar0;			/* help gdb find registers */
 	unsigned long	magic;			/* identifies a core file */
 	char		u_comm[32];		/* user command name */
 };

include/asm-x86/user_32.h

@@ -116,7 +116,7 @@ struct user{
 				   esp register.  */
   long int signal;     		/* Signal that caused the core dump. */
   int reserved;			/* No longer used */
-  struct user_pt_regs * u_ar0;	/* Used by gdb to help find the values for */
+  unsigned long u_ar0;		/* Used by gdb to help find the values for */
 				/* the registers. */
   struct user_i387_struct* u_fpstate;	/* Math Co-processor pointer. */
   unsigned long magic;		/* To uniquely identify a core file */

include/asm-x86/user_64.h

@@ -118,7 +118,7 @@ struct user{
   long int signal;		/* Signal that caused the core dump. */
   int reserved;			/* No longer used */
   int pad1;
-  struct user_pt_regs * u_ar0;	/* Used by gdb to help find the values for */
+  unsigned long u_ar0;		/* Used by gdb to help find the values for */
 				/* the registers. */
   struct user_i387_struct* u_fpstate;	/* Math Co-processor pointer. */
   unsigned long magic;		/* To uniquely identify a core file */