cross-arch: don't corrupt personality flags upon exec()

Historically, the top three bytes of personality have been used for
things such as ADDR_NO_RANDOMIZE, which made sense only for specific
architectures.

We now however have a flag there that is general no matter the
architecture (UNAME26); generally we have to be careful to preserve the
personality flags across exec().

This patch tries to fix all architectures that forcefully overwrite
personality flags during exec() (ppc32 and s390 have been fixed recently
by commits f9783ec8 ("[S390] Do not clobber personality flags on
exec") and 59e4c3a2 ("powerpc/32: Don't clobber personality flags on
exec") in a similar way already).
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/avr32/include/asm/elf.h

@@ -102,6 +102,7 @@ typedef struct user_fpu_struct elf_fpregset_t;
 
 #define ELF_PLATFORM  (NULL)
 
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX_32BIT)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX_32BIT | (current->personality & (~PER_MASK)))
 
 #endif /* __ASM_AVR32_ELF_H */

arch/blackfin/include/asm/elf.h

@@ -132,6 +132,7 @@ do {											\
 
 #define ELF_PLATFORM  (NULL)
 
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX | (current->personality & (~PER_MASK)))
 
 #endif

arch/c6x/include/asm/elf.h

@@ -77,7 +77,8 @@ do {								\
 
 #define ELF_PLATFORM  (NULL)
 
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX | (current->personality & (~PER_MASK)))
 
 /* C6X specific section types */
 #define SHT_C6000_UNWIND	0x70000001

arch/cris/include/asm/elf.h

@@ -86,6 +86,7 @@ typedef unsigned long elf_fpregset_t;
 
 #define ELF_PLATFORM  (NULL)
 
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX | (current->personality & (~PER_MASK)))
 
 #endif

arch/frv/include/asm/elf.h

@@ -137,6 +137,7 @@ do {											\
 
 #define ELF_PLATFORM  (NULL)
 
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX | (current->personality & (~PER_MASK)))
 
 #endif

arch/h8300/include/asm/elf.h

@@ -54,7 +54,8 @@ typedef unsigned long elf_fpregset_t;
 
 #define ELF_PLATFORM  (NULL)
 
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX | (current->personality & (~PER_MASK)))
 
 #define R_H8_NONE       0
 #define R_H8_DIR32      1

arch/hexagon/include/asm/elf.h

@@ -217,7 +217,8 @@ do {					\
 #define ELF_PLATFORM  (NULL)
 
 #ifdef __KERNEL__
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX | (current->personality & (~PER_MASK)))
 #endif
 
 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1

arch/m32r/include/asm/elf.h

@@ -128,6 +128,7 @@ typedef elf_fpreg_t elf_fpregset_t;
    intent than poking at uname or /proc/cpuinfo.  */
 #define ELF_PLATFORM	(NULL)
 
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX | (current->personality & (~PER_MASK)))
 
 #endif  /* _ASM_M32R__ELF_H */

arch/m68k/include/asm/elf.h

@@ -113,6 +113,7 @@ typedef struct user_m68kfp_struct elf_fpregset_t;
 
 #define ELF_PLATFORM  (NULL)
 
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX | (current->personality & (~PER_MASK)))
 
 #endif

arch/microblaze/include/asm/elf.h

@@ -116,7 +116,8 @@ do {							\
 } while (0)
 
 #ifdef __KERNEL__
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX_32BIT)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX_32BIT | (current->personality & (~PER_MASK)))
 #endif
 
 #endif /* __uClinux__ */

arch/mn10300/include/asm/elf.h

@@ -151,7 +151,8 @@ do {						\
 #define ELF_PLATFORM  (NULL)
 
 #ifdef __KERNEL__
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX | (current->personality & (~PER_MASK)))
 #endif
 
 #endif /* _ASM_ELF_H */

arch/openrisc/include/asm/elf.h

@@ -110,7 +110,8 @@ extern void dump_elf_thread(elf_greg_t *dest, struct pt_regs *pt);
 
 #define ELF_PLATFORM	(NULL)
 
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX | (current->personality & (~PER_MASK)))
 
 #endif /* __KERNEL__ */
 #endif

arch/score/include/asm/elf.h

@@ -54,7 +54,7 @@ typedef elf_fpreg_t	elf_fpregset_t;
 
 #define SET_PERSONALITY(ex)					\
 do {								\
-	set_personality(PER_LINUX);				\
+	set_personality(PER_LINUX | (current->personality & (~PER_MASK))); \
 } while (0)
 
 struct task_struct;

arch/sh/include/asm/elf.h

@@ -183,7 +183,8 @@ do {									\
 } while (0)
 #endif
 
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX_32BIT)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX_32BIT | (current->personality & (~PER_MASK)))
 
 #ifdef CONFIG_VSYSCALL
 /* vDSO has arch_setup_additional_pages */

arch/sparc/include/asm/elf_32.h

@@ -128,6 +128,7 @@ typedef struct {
 
 #define ELF_PLATFORM	(NULL)
 
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX | (current->personality & (~PER_MASK)))
 
 #endif /* !(__ASMSPARC_ELF_H) */

arch/xtensa/include/asm/elf.h

@@ -189,7 +189,8 @@ typedef struct {
 #endif
 } elf_xtregs_t;
 
-#define SET_PERSONALITY(ex) set_personality(PER_LINUX_32BIT)
+#define SET_PERSONALITY(ex) \
+	set_personality(PER_LINUX_32BIT | (current->personality & (~PER_MASK)))
 
 struct task_struct;