binfmt_flat: replace flat_argvp_envp_on_stack with a Kconfig variable

This will eventually allow us to kill the need for an <asm/flat.h> for
many cases.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

arch/arm/Kconfig

@@ -30,6 +30,7 @@ config ARM
 	select ARCH_USE_BUILTIN_BSWAP
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select ARCH_WANT_IPC_PARSE_VERSION
+	select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
 	select BUILDTIME_EXTABLE_SORT if MMU
 	select CLONE_BACKWARDS
 	select CPU_PM if SUSPEND || CPU_IDLE

arch/arm/include/asm/flat.h

@@ -8,8 +8,6 @@
 
 #include <linux/uaccess.h>
 
-#define	flat_argvp_envp_on_stack()		1
-
 static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
 					u32 *addr, u32 *persistent)
 {

arch/c6x/include/asm/flat.h

@@ -4,7 +4,6 @@
 
 #include <asm/unaligned.h>
 
-#define flat_argvp_envp_on_stack()			0
 static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
 					u32 *addr, u32 *persistent)
 {

arch/h8300/Kconfig

@@ -2,6 +2,7 @@
 config H8300
         def_bool y
 	select ARCH_32BIT_OFF_T
+	select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
 	select BINFMT_FLAT_OLD_ALWAYS_RAM
 	select GENERIC_ATOMIC64
 	select HAVE_UID16

arch/h8300/include/asm/flat.h

@@ -8,8 +8,6 @@
 
 #include <asm/unaligned.h>
 
-#define	flat_argvp_envp_on_stack()		1
-
 /*
  * on the H8 a couple of the relocations have an instruction in the
  * top byte.  As there can only be 24bits of address space,  we just

arch/m68k/Kconfig

@@ -7,6 +7,7 @@ config M68K
 	select ARCH_MIGHT_HAVE_PC_PARPORT if ISA
 	select ARCH_NO_COHERENT_DMA_MMAP if !MMU
 	select ARCH_NO_PREEMPT if !COLDFIRE
+	select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
 	select HAVE_IDE
 	select HAVE_AOUT if MMU
 	select HAVE_DEBUG_BUGVERBOSE

arch/m68k/include/asm/flat.h

@@ -8,7 +8,6 @@
 
 #include <linux/uaccess.h>
 
-#define	flat_argvp_envp_on_stack()		1
 static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
 					u32 *addr, u32 *persistent)
 {

arch/microblaze/include/asm/flat.h

@@ -13,8 +13,6 @@
 
 #include <asm/unaligned.h>
 
-#define	flat_argvp_envp_on_stack()	0
-
 /*
  * Microblaze works a little differently from other arches, because
  * of the MICROBLAZE_64 reloc type. Here, a 32 bit address is split

arch/sh/include/asm/flat.h

@@ -11,7 +11,6 @@
 
 #include <asm/unaligned.h>
 
-#define	flat_argvp_envp_on_stack()		0
 static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
 					u32 *addr, u32 *persistent)
 {

arch/xtensa/include/asm/flat.h

@@ -4,7 +4,6 @@
 
 #include <asm/unaligned.h>
 
-#define flat_argvp_envp_on_stack()			0
 static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
 					u32 *addr, u32 *persistent)
 {

fs/Kconfig.binfmt

@@ -97,6 +97,9 @@ config BINFMT_FLAT
 	help
 	  Support uClinux FLAT format binaries.
 
+config BINFMT_FLAT_ARGVP_ENVP_ON_STACK
+	bool
+
 config BINFMT_FLAT_OLD_ALWAYS_RAM
 	bool
 

fs/binfmt_flat.c

@@ -124,14 +124,15 @@ static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start
 
 	sp -= bprm->envc + 1;
 	sp -= bprm->argc + 1;
-	sp -= flat_argvp_envp_on_stack() ? 2 : 0;
+	if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK))
+		sp -= 2; /* argvp + envp */
 	sp -= 1;  /* &argc */
 
 	current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
 	sp = (unsigned long __user *)current->mm->start_stack;
 
 	__put_user(bprm->argc, sp++);
-	if (flat_argvp_envp_on_stack()) {
+	if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) {
 		unsigned long argv, envp;
 		argv = (unsigned long)(sp + 2);
 		envp = (unsigned long)(sp + 2 + bprm->argc + 1);