[PATCH v5 15/15] ARM: enable binfmt_flat on systems with an MMU

From: Nicolas Pitre
Date: Sun Jul 24 2016 - 11:31:25 EST


Now that the generic changes are in place, this can be enabled on ARM
with the use of proper user space accessors in the flat_get_addr_from_rp()
and flat_put_addr_at_rp() handlers as rp actually holds a user space
address.

Signed-off-by: Nicolas Pitre <nico@xxxxxxxxxx>
---
arch/arm/include/asm/flat.h | 5 +++--
fs/Kconfig.binfmt | 2 +-
2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/flat.h b/arch/arm/include/asm/flat.h
index e847d23351..acf1d14b89 100644
--- a/arch/arm/include/asm/flat.h
+++ b/arch/arm/include/asm/flat.h
@@ -8,8 +8,9 @@
#define flat_argvp_envp_on_stack() 1
#define flat_old_ram_flag(flags) (flags)
#define flat_reloc_valid(reloc, size) ((reloc) <= (size))
-#define flat_get_addr_from_rp(rp, relval, flags, persistent) ((void)persistent,get_unaligned(rp))
-#define flat_put_addr_at_rp(rp, val, relval) put_unaligned(val,rp)
+#define flat_get_addr_from_rp(rp, relval, flags, persistent) \
+ ({ unsigned long __val; __get_user_unaligned(__val, rp); __val; })
+#define flat_put_addr_at_rp(rp, val, relval) __put_user_unaligned(val, rp)
#define flat_get_relocate_addr(rel) (rel)
#define flat_set_persistent(relval, p) 0

diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
index c7efddf6e0..4c09d93d95 100644
--- a/fs/Kconfig.binfmt
+++ b/fs/Kconfig.binfmt
@@ -89,7 +89,7 @@ config BINFMT_SCRIPT

config BINFMT_FLAT
bool "Kernel support for flat binaries"
- depends on !MMU || M68K
+ depends on !MMU || ARM || M68K
depends on !FRV || BROKEN
help
Support uClinux FLAT format binaries.
--
2.7.4