Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu

Pull m68nommu updates from Greg Ungerer:
 "A series of cleanups for the FLAT format binary loader, binfmt_flat,
  from Christoph.

  The end goal is to support no-MMU on RISC-V, and the last patch
  enables that"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
  riscv: add binfmt_flat support
  binfmt_flat: don't offset the data start
  binfmt_flat: move the MAX_SHARED_LIBS definition to binfmt_flat.c
  binfmt_flat: remove the persistent argument from flat_get_addr_from_rp
  binfmt_flat: provide an asm-generic/flat.h
  binfmt_flat: make support for old format binaries optional
  binfmt_flat: add a ARCH_HAS_BINFMT_FLAT option
  binfmt_flat: add endianess annotations
  binfmt_flat: use fixed size type for the on-disk format
  binfmt_flat: consolidate two version of flat_v2_reloc_t
  binfmt_flat: remove the unused OLD_FLAT_FLAG_RAM definition
  binfmt_flat: remove the uapi <linux/flat.h> header
  binfmt_flat: replace flat_argvp_envp_on_stack with a Kconfig variable
  binfmt_flat: remove flat_old_ram_flag
  binfmt_flat: provide a default version of flat_get_relocate_addr
  binfmt_flat: remove flat_set_persistent
  binfmt_flat: remove flat_reloc_valid

21 files changed, 145 insertions, 187 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ad00e17d6988..d850feb5cc0a 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -4,6 +4,7 @@ config ARM
 	default y
 	select ARCH_32BIT_OFF_T
 	select ARCH_CLOCKSOURCE_DATA
+	select ARCH_HAS_BINFMT_FLAT
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
@@ -30,6 +31,7 @@ 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/Kbuild b/arch/arm/include/asm/Kbuild
index a8f149ab45b8..6b2dc15b6dff 100644
--- a/arch/arm/include/asm/Kbuild
+++ b/arch/arm/include/asm/Kbuild
@@ -5,6 +5,7 @@ generic-y += early_ioremap.h
 generic-y += emergency-restart.h
 generic-y += exec.h
 generic-y += extable.h
+generic-y += flat.h
 generic-y += irq_regs.h
 generic-y += kdebug.h
 generic-y += local.h
diff --git a/arch/c6x/Kconfig b/arch/c6x/Kconfig
index c5e6b70e1510..b4fb61c83494 100644
--- a/arch/c6x/Kconfig
+++ b/arch/c6x/Kconfig
@@ -7,6 +7,7 @@
 config C6X
 	def_bool y
 	select ARCH_32BIT_OFF_T
+	select ARCH_HAS_BINFMT_FLAT
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select CLKDEV_LOOKUP
diff --git a/arch/c6x/include/asm/flat.h b/arch/c6x/include/asm/flat.h
index 76fd0bb962a3..9e6544b51386 100644
--- a/arch/c6x/include/asm/flat.h
+++ b/arch/c6x/include/asm/flat.h
@@ -4,11 +4,8 @@
 
 #include <asm/unaligned.h>
 
-#define flat_argvp_envp_on_stack()			0
-#define flat_old_ram_flag(flags)			(flags)
-#define flat_reloc_valid(reloc, size)			((reloc) <= (size))
 static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
-					u32 *addr, u32 *persistent)
+					u32 *addr)
 {
 	*addr = get_unaligned((__force u32 *)rp);
 	return 0;
@@ -18,7 +15,5 @@ static inline int flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 rel)
 	put_unaligned(addr, (__force u32 *)rp);
 	return 0;
 }
-#define flat_get_relocate_addr(rel)			(rel)
-#define flat_set_persistent(relval, p)			0
 
 #endif /* __ASM_C6X_FLAT_H */
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index ecfc4b4b6373..ec800e9d5aad 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -2,6 +2,9 @@
 config H8300
         def_bool y
 	select ARCH_32BIT_OFF_T
+	select ARCH_HAS_BINFMT_FLAT
+	select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
+	select BINFMT_FLAT_OLD_ALWAYS_RAM
 	select GENERIC_ATOMIC64
 	select HAVE_UID16
 	select VIRT_TO_BUS
diff --git a/arch/h8300/include/asm/flat.h b/arch/h8300/include/asm/flat.h
index f4cdfcbdd2ba..78070f924177 100644
--- a/arch/h8300/include/asm/flat.h
+++ b/arch/h8300/include/asm/flat.h
@@ -8,11 +8,6 @@
 
 #include <asm/unaligned.h>
 
-#define	flat_argvp_envp_on_stack()		1
-#define	flat_old_ram_flag(flags)		1
-#define	flat_reloc_valid(reloc, size)		((reloc) <= (size))
-#define	flat_set_persistent(relval, p)		0
-
 /*
  * 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
@@ -22,7 +17,7 @@
 
 #define	flat_get_relocate_addr(rel)		(rel & ~0x00000001)
 static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
-					u32 *addr, u32 *persistent)
+					u32 *addr)
 {
 	u32 val = get_unaligned((__force u32 *)rp);
 	if (!(flags & FLAT_FLAG_GOTPIC))
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 00f5c98a5e05..8f765cfefca6 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -3,12 +3,14 @@ config M68K
 	bool
 	default y
 	select ARCH_32BIT_OFF_T
+	select ARCH_HAS_BINFMT_FLAT
 	select ARCH_HAS_DMA_MMAP_PGPROT if MMU && !COLDFIRE
 	select ARCH_HAS_DMA_PREP_COHERENT
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE if HAS_DMA
 	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 DMA_DIRECT_REMAP if HAS_DMA && MMU && !COLDFIRE
 	select HAVE_IDE
 	select HAVE_AOUT if MMU
diff --git a/arch/m68k/include/asm/flat.h b/arch/m68k/include/asm/flat.h
index 4f1d1e373420..46379e08cdd6 100644
--- a/arch/m68k/include/asm/flat.h
+++ b/arch/m68k/include/asm/flat.h
@@ -6,35 +6,7 @@
 #ifndef __M68KNOMMU_FLAT_H__
 #define __M68KNOMMU_FLAT_H__
 
-#include <linux/uaccess.h>
-
-#define	flat_argvp_envp_on_stack()		1
-#define	flat_old_ram_flag(flags)		(flags)
-#define	flat_reloc_valid(reloc, size)		((reloc) <= (size))
-static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
-					u32 *addr, u32 *persistent)
-{
-#ifdef CONFIG_CPU_HAS_NO_UNALIGNED
-	return copy_from_user(addr, rp, 4) ? -EFAULT : 0;
-#else
-	return get_user(*addr, rp);
-#endif
-}
-
-static inline int flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 rel)
-{
-#ifdef CONFIG_CPU_HAS_NO_UNALIGNED
-	return copy_to_user(rp, &addr, 4) ? -EFAULT : 0;
-#else
-	return put_user(addr, rp);
-#endif
-}
-#define	flat_get_relocate_addr(rel)		(rel)
-
-static inline int flat_set_persistent(u32 relval, u32 *persistent)
-{
-	return 0;
-}
+#include <asm-generic/flat.h>
 
 #define FLAT_PLAT_INIT(regs) \
 	do { \
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index f11433daab4a..d411de05b628 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -3,6 +3,7 @@ config MICROBLAZE
 	def_bool y
 	select ARCH_32BIT_OFF_T
 	select ARCH_NO_SWAP
+	select ARCH_HAS_BINFMT_FLAT if !MMU
 	select ARCH_HAS_DMA_COHERENT_TO_PFN if MMU
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
diff --git a/arch/microblaze/include/asm/flat.h b/arch/microblaze/include/asm/flat.h
index 3d2747d4c967..1ab86770eaee 100644
--- a/arch/microblaze/include/asm/flat.h
+++ b/arch/microblaze/include/asm/flat.h
@@ -13,11 +13,6 @@
 
 #include <asm/unaligned.h>
 
-#define	flat_argvp_envp_on_stack()	0
-#define	flat_old_ram_flag(flags)	(flags)
-#define	flat_reloc_valid(reloc, size)	((reloc) <= (size))
-#define	flat_set_persistent(relval, p)		0
-
 /*
  * Microblaze works a little differently from other arches, because
  * of the MICROBLAZE_64 reloc type. Here, a 32 bit address is split
@@ -33,7 +28,7 @@
  */
 
 static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
-					u32 *addr, u32 *persistent)
+					u32 *addr)
 {
 	u32 *p = (__force u32 *)rp;
 
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 376bc759b9ab..13a1c0d04e9e 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -17,6 +17,7 @@ config RISCV
 	select OF
 	select OF_EARLY_FLATTREE
 	select OF_IRQ
+	select ARCH_HAS_BINFMT_FLAT
 	select ARCH_WANT_FRAME_POINTERS
 	select CLONE_BACKWARDS
 	select COMMON_CLK
diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild
index 5ee646619cc3..1efaeddf1e4b 100644
--- a/arch/riscv/include/asm/Kbuild
+++ b/arch/riscv/include/asm/Kbuild
@@ -5,6 +5,7 @@ generic-y += compat.h
 generic-y += device.h
 generic-y += div64.h
 generic-y += extable.h
+generic-y += flat.h
 generic-y += dma.h
 generic-y += dma-contiguous.h
 generic-y += dma-mapping.h
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index ce1a28654507..c7c99e18d5ff 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 config SUPERH
 	def_bool y
+	select ARCH_HAS_BINFMT_FLAT if !MMU
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_MIGHT_HAVE_PC_PARPORT
diff --git a/arch/sh/include/asm/flat.h b/arch/sh/include/asm/flat.h
index 843d458b8329..fee4f25555cb 100644
--- a/arch/sh/include/asm/flat.h
+++ b/arch/sh/include/asm/flat.h
@@ -11,11 +11,8 @@
 
 #include <asm/unaligned.h>
 
-#define	flat_argvp_envp_on_stack()		0
-#define	flat_old_ram_flag(flags)		(flags)
-#define	flat_reloc_valid(reloc, size)		((reloc) <= (size))
 static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
-					u32 *addr, u32 *persistent)
+					u32 *addr)
 {
 	*addr = get_unaligned((__force u32 *)rp);
 	return 0;
@@ -25,8 +22,6 @@ static inline int flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 rel)
 	put_unaligned(addr, (__force u32 *)rp);
 	return 0;
 }
-#define	flat_get_relocate_addr(rel)		(rel)
-#define	flat_set_persistent(relval, p)		({ (void)p; 0; })
 
 #define FLAT_PLAT_INIT(_r) \
   do { _r->regs[0]=0; _r->regs[1]=0; _r->regs[2]=0; _r->regs[3]=0; \
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 6ec1b75eabc5..ebc135bda921 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -2,6 +2,7 @@
 config XTENSA
 	def_bool y
 	select ARCH_32BIT_OFF_T
+	select ARCH_HAS_BINFMT_FLAT if !MMU
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_NO_COHERENT_DMA_MMAP if !MMU
diff --git a/arch/xtensa/include/asm/flat.h b/arch/xtensa/include/asm/flat.h
index b8532d7877b3..ed5870c779f9 100644
--- a/arch/xtensa/include/asm/flat.h
+++ b/arch/xtensa/include/asm/flat.h
@@ -4,11 +4,8 @@
 
 #include <asm/unaligned.h>
 
-#define flat_argvp_envp_on_stack()			0
-#define flat_old_ram_flag(flags)			(flags)
-#define flat_reloc_valid(reloc, size)			((reloc) <= (size))
 static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
-					u32 *addr, u32 *persistent)
+					u32 *addr)
 {
 	*addr = get_unaligned((__force u32 *)rp);
 	return 0;
@@ -18,7 +15,5 @@ static inline int flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 rel)
 	put_unaligned(addr, (__force u32 *)rp);
 	return 0;
 }
-#define flat_get_relocate_addr(rel)			(rel)
-#define flat_set_persistent(relval, p)			0
 
 #endif /* __ASM_XTENSA_FLAT_H */
diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
index f87ddd1b6d72..62dc4f577ba1 100644
--- a/fs/Kconfig.binfmt
+++ b/fs/Kconfig.binfmt
@@ -91,12 +91,28 @@ config BINFMT_SCRIPT
 
 	  Most systems will not boot if you say M or N here.  If unsure, say Y.
 
+config ARCH_HAS_BINFMT_FLAT
+	bool
+
 config BINFMT_FLAT
 	bool "Kernel support for flat binaries"
-	depends on !MMU || ARM || M68K
+	depends on ARCH_HAS_BINFMT_FLAT
 	help
 	  Support uClinux FLAT format binaries.
 
+config BINFMT_FLAT_ARGVP_ENVP_ON_STACK
+	bool
+
+config BINFMT_FLAT_OLD_ALWAYS_RAM
+	bool
+
+config BINFMT_FLAT_OLD
+	bool "Enable support for very old legacy flat binaries"
+	depends on BINFMT_FLAT
+	help
+	  Support decade old uClinux FLAT format binaries.  Unless you know
+	  you have some of those say N here.
+
 config BINFMT_ZFLAT
 	bool "Enable ZFLAT support"
 	depends on BINFMT_FLAT
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index e4b59e76afb0..8c6b50f34466 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -42,6 +42,11 @@
 #include <asm/unaligned.h>
 #include <asm/cacheflush.h>
 #include <asm/page.h>
+#include <asm/flat.h>
+
+#ifndef flat_get_relocate_addr
+#define flat_get_relocate_addr(rel)	(rel)
+#endif
 
 /****************************************************************************/
 
@@ -63,6 +68,12 @@
 #define RELOC_FAILED 0xff00ff01		/* Relocation incorrect somewhere */
 #define UNLOADED_LIB 0x7ff000ff		/* Placeholder for unused library */
 
+#ifdef CONFIG_BINFMT_SHARED_FLAT
+#define	MAX_SHARED_LIBS			(4)
+#else
+#define	MAX_SHARED_LIBS			(1)
+#endif
+
 struct lib_info {
 	struct {
 		unsigned long start_code;		/* Start of text segment */
@@ -120,14 +131,15 @@ 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);
@@ -345,7 +357,7 @@ calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
 	start_code = p->lib_list[id].start_code;
 	text_len = p->lib_list[id].text_len;
 
-	if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
+	if (r > start_brk - start_data + text_len) {
 		pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
 		       r, start_brk-start_data+text_len, text_len);
 		goto failed;
@@ -368,6 +380,7 @@ failed:
 
 /****************************************************************************/
 
+#ifdef CONFIG_BINFMT_FLAT_OLD
 static void old_reloc(unsigned long rl)
 {
 	static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
@@ -405,6 +418,7 @@ static void old_reloc(unsigned long rl)
 
 	pr_debug("Relocation became %lx\n", val);
 }
+#endif /* CONFIG_BINFMT_FLAT_OLD */
 
 /****************************************************************************/
 
@@ -415,7 +429,8 @@ static int load_flat_file(struct linux_binprm *bprm,
 	unsigned long textpos, datapos, realdatastart;
 	u32 text_len, data_len, bss_len, stack_len, full_data, flags;
 	unsigned long len, memp, memp_size, extra, rlim;
-	u32 __user *reloc, *rp;
+	__be32 __user *reloc;
+	u32 __user *rp;
 	struct inode *inode;
 	int i, rev, relocs;
 	loff_t fpos;
@@ -454,6 +469,7 @@ static int load_flat_file(struct linux_binprm *bprm,
 	if (flags & FLAT_FLAG_KTRACE)
 		pr_info("Loading file: %s\n", bprm->filename);
 
+#ifdef CONFIG_BINFMT_FLAT_OLD
 	if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
 		pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
 		       rev, FLAT_VERSION, OLD_FLAT_VERSION);
@@ -470,6 +486,23 @@ static int load_flat_file(struct linux_binprm *bprm,
 	}
 
 	/*
+	 * fix up the flags for the older format,  there were all kinds
+	 * of endian hacks,  this only works for the simple cases
+	 */
+	if (rev == OLD_FLAT_VERSION &&
+	   (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM)))
+		flags = FLAT_FLAG_RAM;
+
+#else /* CONFIG_BINFMT_FLAT_OLD */
+	if (rev != FLAT_VERSION) {
+		pr_err("bad flat file version 0x%x (supported 0x%lx)\n",
+		       rev, FLAT_VERSION);
+		ret = -ENOEXEC;
+		goto err;
+	}
+#endif /* !CONFIG_BINFMT_FLAT_OLD */
+
+	/*
 	 * Make sure the header params are sane.
 	 * 28 bits (256 MB) is way more than reasonable in this case.
 	 * If some top bits are set we have probable binary corruption.
@@ -480,13 +513,6 @@ static int load_flat_file(struct linux_binprm *bprm,
 		goto err;
 	}
 
-	/*
-	 * fix up the flags for the older format,  there were all kinds
-	 * of endian hacks,  this only works for the simple cases
-	 */
-	if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
-		flags = FLAT_FLAG_RAM;
-
 #ifndef CONFIG_BINFMT_ZFLAT
 	if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
 		pr_err("Support for ZFLAT executables is not enabled.\n");
@@ -547,7 +573,7 @@ static int load_flat_file(struct linux_binprm *bprm,
 			goto err;
 		}
 
-		len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
+		len = data_len + extra;
 		len = PAGE_ALIGN(len);
 		realdatastart = vm_mmap(NULL, 0, len,
 			PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
@@ -561,9 +587,7 @@ static int load_flat_file(struct linux_binprm *bprm,
 			vm_munmap(textpos, text_len);
 			goto err;
 		}
-		datapos = ALIGN(realdatastart +
-				MAX_SHARED_LIBS * sizeof(unsigned long),
-				FLAT_DATA_ALIGN);
+		datapos = ALIGN(realdatastart, FLAT_DATA_ALIGN);
 
 		pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
 			 data_len + bss_len + stack_len, datapos);
@@ -587,13 +611,13 @@ static int load_flat_file(struct linux_binprm *bprm,
 			goto err;
 		}
 
-		reloc = (u32 __user *)
+		reloc = (__be32 __user *)
 			(datapos + (ntohl(hdr->reloc_start) - text_len));
 		memp = realdatastart;
 		memp_size = len;
 	} else {
 
-		len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32);
+		len = text_len + data_len + extra;
 		len = PAGE_ALIGN(len);
 		textpos = vm_mmap(NULL, 0, len,
 			PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
@@ -608,11 +632,9 @@ static int load_flat_file(struct linux_binprm *bprm,
 		}
 
 		realdatastart = textpos + ntohl(hdr->data_start);
-		datapos = ALIGN(realdatastart +
-				MAX_SHARED_LIBS * sizeof(u32),
-				FLAT_DATA_ALIGN);
+		datapos = ALIGN(realdatastart, FLAT_DATA_ALIGN);
 
-		reloc = (u32 __user *)
+		reloc = (__be32 __user *)
 			(datapos + (ntohl(hdr->reloc_start) - text_len));
 		memp = textpos;
 		memp_size = len;
@@ -627,8 +649,9 @@ static int load_flat_file(struct linux_binprm *bprm,
 					 (text_len + full_data
 						  - sizeof(struct flat_hdr)),
 					 0);
-			memmove((void *) datapos, (void *) realdatastart,
-					full_data);
+			if (datapos != realdatastart)
+				memmove((void *)datapos, (void *)realdatastart,
+						full_data);
 #else
 			/*
 			 * This is used on MMU systems mainly for testing.
@@ -684,8 +707,7 @@ static int load_flat_file(struct linux_binprm *bprm,
 		if (IS_ERR_VALUE(result)) {
 			ret = result;
 			pr_err("Unable to read code+data+bss, errno %d\n", ret);
-			vm_munmap(textpos, text_len + data_len + extra +
-				MAX_SHARED_LIBS * sizeof(u32));
+			vm_munmap(textpos, text_len + data_len + extra);
 			goto err;
 		}
 	}
@@ -775,20 +797,18 @@ static int load_flat_file(struct linux_binprm *bprm,
 	 * __start to address 4 so that is okay).
 	 */
 	if (rev > OLD_FLAT_VERSION) {
-		u32 __maybe_unused persistent = 0;
 		for (i = 0; i < relocs; i++) {
 			u32 addr, relval;
+			__be32 tmp;
 
 			/*
 			 * Get the address of the pointer to be
 			 * relocated (of course, the address has to be
 			 * relocated first).
 			 */
-			if (get_user(relval, reloc + i))
+			if (get_user(tmp, reloc + i))
 				return -EFAULT;
-			relval = ntohl(relval);
-			if (flat_set_persistent(relval, &persistent))
-				continue;
+			relval = ntohl(tmp);
 			addr = flat_get_relocate_addr(relval);
 			rp = (u32 __user *)calc_reloc(addr, libinfo, id, 1);
 			if (rp == (u32 __user *)RELOC_FAILED) {
@@ -797,8 +817,7 @@ static int load_flat_file(struct linux_binprm *bprm,
 			}
 
 			/* Get the pointer's value.  */
-			ret = flat_get_addr_from_rp(rp, relval, flags,
-							&addr, &persistent);
+			ret = flat_get_addr_from_rp(rp, relval, flags, &addr);
 			if (unlikely(ret))
 				goto err;
 
@@ -807,8 +826,13 @@ static int load_flat_file(struct linux_binprm *bprm,
 				 * Do the relocation.  PIC relocs in the data section are
 				 * already in target order
 				 */
-				if ((flags & FLAT_FLAG_GOTPIC) == 0)
-					addr = ntohl(addr);
+				if ((flags & FLAT_FLAG_GOTPIC) == 0) {
+					/*
+					 * Meh, the same value can have a different
+					 * byte order based on a flag..
+					 */
+					addr = ntohl((__force __be32)addr);
+				}
 				addr = calc_reloc(addr, libinfo, id, 0);
 				if (addr == RELOC_FAILED) {
 					ret = -ENOEXEC;
@@ -821,14 +845,15 @@ static int load_flat_file(struct linux_binprm *bprm,
 					goto err;
 			}
 		}
+#ifdef CONFIG_BINFMT_FLAT_OLD
 	} else {
 		for (i = 0; i < relocs; i++) {
-			u32 relval;
+			__be32 relval;
 			if (get_user(relval, reloc + i))
 				return -EFAULT;
-			relval = ntohl(relval);
-			old_reloc(relval);
+			old_reloc(ntohl(relval));
 		}
+#endif /* CONFIG_BINFMT_FLAT_OLD */
 	}
 
 	flush_icache_range(start_code, end_code);
diff --git a/arch/arm/include/asm/flat.h b/include/asm-generic/flat.h
index f0c75ddeea23..1928a3596938 100644
--- a/arch/arm/include/asm/flat.h
+++ b/include/asm-generic/flat.h
@@ -1,19 +1,11 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-/*
- * arch/arm/include/asm/flat.h -- uClinux flat-format executables
- */
-
-#ifndef __ARM_FLAT_H__
-#define __ARM_FLAT_H__
+#ifndef _ASM_GENERIC_FLAT_H
+#define _ASM_GENERIC_FLAT_H
 
 #include <linux/uaccess.h>
 
-#define	flat_argvp_envp_on_stack()		1
-#define	flat_old_ram_flag(flags)		(flags)
-#define	flat_reloc_valid(reloc, size)		((reloc) <= (size))
-
 static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
-					u32 *addr, u32 *persistent)
+		u32 *addr)
 {
 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
 	return copy_from_user(addr, rp, 4) ? -EFAULT : 0;
@@ -31,7 +23,4 @@ static inline int flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 rel)
 #endif
 }
 
-#define	flat_get_relocate_addr(rel)		(rel)
-#define	flat_set_persistent(relval, p)		0
-
-#endif /* __ARM_FLAT_H__ */
+#endif /* _ASM_GENERIC_FLAT_H */
diff --git a/include/linux/flat.h b/include/linux/flat.h
index 569b67d64d5c..83977c0ce3de 100644
--- a/include/linux/flat.h
+++ b/include/linux/flat.h
@@ -10,8 +10,41 @@
 #ifndef _LINUX_FLAT_H
 #define _LINUX_FLAT_H
 
-#include <uapi/linux/flat.h>
-#include <asm/flat.h>
+#define	FLAT_VERSION			0x00000004L
+
+/*
+ * To make everything easier to port and manage cross platform
+ * development,  all fields are in network byte order.
+ */
+
+struct flat_hdr {
+	char	magic[4];
+	__be32	rev;          /* version (as above) */
+	__be32	entry;        /* Offset of first executable instruction
+				 with text segment from beginning of file */
+	__be32	data_start;   /* Offset of data segment from beginning of
+				 file */
+	__be32	data_end;     /* Offset of end of data segment from beginning
+				 of file */
+	__be32	bss_end;      /* Offset of end of bss segment from beginning
+				 of file */
+
+	/* (It is assumed that data_end through bss_end forms the bss segment.) */
+
+	__be32	stack_size;   /* Size of stack, in bytes */
+	__be32	reloc_start;  /* Offset of relocation records from beginning of
+				 file */
+	__be32	reloc_count;  /* Number of relocation records */
+	__be32	flags;
+	__be32	build_date;   /* When the program/library was built */
+	__u32	filler[5];    /* Reservered, set to zero */
+};
+
+#define FLAT_FLAG_RAM    0x0001 /* load program entirely into RAM */
+#define FLAT_FLAG_GOTPIC 0x0002 /* program is PIC with GOT */
+#define FLAT_FLAG_GZIP   0x0004 /* all but the header is compressed */
+#define FLAT_FLAG_GZDATA 0x0008 /* only data/relocs are compressed (for XIP) */
+#define FLAT_FLAG_KTRACE 0x0010 /* output useful kernel trace for debugging */
 
 /*
  * While it would be nice to keep this header clean,  users of older
@@ -22,28 +55,21 @@
  *        with the format above,  except to fix bugs with old format support.
  */
 
-#include <asm/byteorder.h>
-
 #define	OLD_FLAT_VERSION			0x00000002L
 #define OLD_FLAT_RELOC_TYPE_TEXT	0
 #define OLD_FLAT_RELOC_TYPE_DATA	1
 #define OLD_FLAT_RELOC_TYPE_BSS		2
 
 typedef union {
-	unsigned long	value;
+	u32		value;
 	struct {
-# if defined(mc68000) && !defined(CONFIG_COLDFIRE)
-		signed long offset : 30;
-		unsigned long type : 2;
-#   	define OLD_FLAT_FLAG_RAM    0x1 /* load program entirely into RAM */
+#if defined(__LITTLE_ENDIAN_BITFIELD) || \
+    (defined(mc68000) && !defined(CONFIG_COLDFIRE))
+		s32	offset : 30;
+		u32	type : 2;
 # elif defined(__BIG_ENDIAN_BITFIELD)
-		unsigned long type : 2;
-		signed long offset : 30;
-#   	define OLD_FLAT_FLAG_RAM    0x1 /* load program entirely into RAM */
-# elif defined(__LITTLE_ENDIAN_BITFIELD)
-		signed long offset : 30;
-		unsigned long type : 2;
-#   	define OLD_FLAT_FLAG_RAM    0x1 /* load program entirely into RAM */
+		u32	type : 2;
+		s32	offset : 30;
 # else
 #   	error "Unknown bitfield order for flat files."
 # endif
diff --git a/include/uapi/linux/flat.h b/include/uapi/linux/flat.h
deleted file mode 100644
index 27e595e44fb7..000000000000
--- a/include/uapi/linux/flat.h
+++ /dev/null
@@ -1,59 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/*
- * Copyright (C) 2002-2003  David McCullough <davidm@snapgear.com>
- * Copyright (C) 1998       Kenneth Albanowski <kjahds@kjahds.com>
- *                          The Silver Hammer Group, Ltd.
- *
- * This file provides the definitions and structures needed to
- * support uClinux flat-format executables.
- */
-
-#ifndef _UAPI_LINUX_FLAT_H
-#define _UAPI_LINUX_FLAT_H
-
-
-#define	FLAT_VERSION			0x00000004L
-
-#ifdef CONFIG_BINFMT_SHARED_FLAT
-#define	MAX_SHARED_LIBS			(4)
-#else
-#define	MAX_SHARED_LIBS			(1)
-#endif
-
-/*
- * To make everything easier to port and manage cross platform
- * development,  all fields are in network byte order.
- */
-
-struct flat_hdr {
-	char magic[4];
-	unsigned long rev;          /* version (as above) */
-	unsigned long entry;        /* Offset of first executable instruction
-	                               with text segment from beginning of file */
-	unsigned long data_start;   /* Offset of data segment from beginning of
-	                               file */
-	unsigned long data_end;     /* Offset of end of data segment
-	                               from beginning of file */
-	unsigned long bss_end;      /* Offset of end of bss segment from beginning
-	                               of file */
-
-	/* (It is assumed that data_end through bss_end forms the bss segment.) */
-
-	unsigned long stack_size;   /* Size of stack, in bytes */
-	unsigned long reloc_start;  /* Offset of relocation records from
-	                               beginning of file */
-	unsigned long reloc_count;  /* Number of relocation records */
-	unsigned long flags;       
-	unsigned long build_date;   /* When the program/library was built */
-	unsigned long filler[5];    /* Reservered, set to zero */
-};
-
-#define FLAT_FLAG_RAM    0x0001 /* load program entirely into RAM */
-#define FLAT_FLAG_GOTPIC 0x0002 /* program is PIC with GOT */
-#define FLAT_FLAG_GZIP   0x0004 /* all but the header is compressed */
-#define FLAT_FLAG_GZDATA 0x0008 /* only data/relocs are compressed (for XIP) */
-#define FLAT_FLAG_KTRACE 0x0010 /* output useful kernel trace for debugging */
-
-
-
-#endif /* _UAPI_LINUX_FLAT_H */