binfmt_flat: replace flat_argvp_envp_on_stack with a Kconfig variable

Christoph Hellwig · Greg Ungerer · commit bdd15a288492 · 2019-06-24T09:16:46.000+10:00
This will eventually allow us to kill the need for an &lt;asm/flat.h&gt; for
many cases.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Tested-by: Vladimir Murzin &lt;vladimir.murzin@arm.com&gt;
Reviewed-by: Vladimir Murzin &lt;vladimir.murzin@arm.com&gt;
Signed-off-by: Greg Ungerer &lt;gerg@linux-m68k.org&gt;
diff --git a/arch/arm/Kconfig b/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
diff --git a/arch/arm/include/asm/flat.h b/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)
 {
diff --git a/arch/c6x/include/asm/flat.h b/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)
 {
diff --git a/arch/h8300/Kconfig b/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
diff --git a/arch/h8300/include/asm/flat.h b/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
diff --git a/arch/m68k/Kconfig b/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
diff --git a/arch/m68k/include/asm/flat.h b/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)
 {
diff --git a/arch/microblaze/include/asm/flat.h b/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
diff --git a/arch/sh/include/asm/flat.h b/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)
 {
diff --git a/arch/xtensa/include/asm/flat.h b/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)
 {
diff --git a/fs/Kconfig.binfmt b/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
 
diff --git a/fs/binfmt_flat.c b/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);

Original file line number	Diff line number	Diff line change
`@@ -8,8 +8,6 @@`
`8`	`8`
`9`	`9`	`#include <linux/uaccess.h>`
`10`	`10`
`11`		`-#define flat_argvp_envp_on_stack() 1`
`12`		`-`
`13`	`11`	`static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,`
`14`	`12`	`u32 addr, u32 persistent)`
`15`	`13`	`{`
Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,6 @@`
`4`	`4`
`5`	`5`	`#include <asm/unaligned.h>`
`6`	`6`
`7`		`-#define flat_argvp_envp_on_stack() 0`
`8`	`7`	`static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,`
`9`	`8`	`u32 addr, u32 persistent)`
`10`	`9`	`{`
Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,6 @@`
`8`	`8`
`9`	`9`	`#include <linux/uaccess.h>`
`10`	`10`
`11`		`-#define flat_argvp_envp_on_stack() 1`
`12`	`11`	`static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,`
`13`	`12`	`u32 addr, u32 persistent)`
`14`	`13`	`{`
Original file line number	Diff line number	Diff line change
`@@ -11,7 +11,6 @@`
`11`	`11`
`12`	`12`	`#include <asm/unaligned.h>`
`13`	`13`
`14`		`-#define flat_argvp_envp_on_stack() 0`
`15`	`14`	`static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,`
`16`	`15`	`u32 addr, u32 persistent)`
`17`	`16`	`{`