1 files changed, 28 insertions, 3 deletions

diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h
index a66359ef4ece..d4144056e928 100644
--- a/arch/mips/include/asm/elf.h
+++ b/arch/mips/include/asm/elf.h
@@ -36,6 +36,7 @@
 #define EF_MIPS_ABI2            0x00000020
 #define EF_MIPS_OPTIONS_FIRST   0x00000080
 #define EF_MIPS_32BITMODE       0x00000100
+#define EF_MIPS_FP64            0x00000200
 #define EF_MIPS_ABI             0x0000f000
 #define EF_MIPS_ARCH            0xf0000000
 
@@ -176,6 +177,18 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
 #ifdef CONFIG_32BIT
 
 /*
+ * In order to be sure that we don't attempt to execute an O32 binary which
+ * requires 64 bit FP (FR=1) on a system which does not support it we refuse
+ * to execute any binary which has bits specified by the following macro set
+ * in its ELF header flags.
+ */
+#ifdef CONFIG_MIPS_O32_FP64_SUPPORT
+# define __MIPS_O32_FP64_MUST_BE_ZERO   0
+#else
+# define __MIPS_O32_FP64_MUST_BE_ZERO   EF_MIPS_FP64
+#endif
+
+/*
  * This is used to ensure we don't load something for the wrong architecture.
  */
 #define elf_check_arch(hdr)                                             \
@@ -192,6 +205,8 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
         if (((__h->e_flags & EF_MIPS_ABI) != 0) &&                      \
             ((__h->e_flags & EF_MIPS_ABI) != EF_MIPS_ABI_O32))          \
                 __res = 0;                                              \
+        if (__h->e_flags & __MIPS_O32_FP64_MUST_BE_ZERO)                \
+                __res = 0;                                              \
                                                                         \
         __res;                                                          \
 })
@@ -249,6 +264,11 @@ extern struct mips_abi mips_abi_n32;
 
 #define SET_PERSONALITY(ex)                                             \
 do {                                                                    \
+        if ((ex).e_flags & EF_MIPS_FP64)                                \
+                clear_thread_flag(TIF_32BIT_FPREGS);                    \
+        else                                                            \
+                set_thread_flag(TIF_32BIT_FPREGS);                      \
+                                                                        \
         if (personality(current->personality) != PER_LINUX)             \
                 set_personality(PER_LINUX);                             \
                                                                         \
@@ -271,14 +291,18 @@ do {									\
 #endif
 
 #ifdef CONFIG_MIPS32_O32
-#define __SET_PERSONALITY32_O32()                                       \
+#define __SET_PERSONALITY32_O32(ex)                                     \
         do {                                                            \
                 set_thread_flag(TIF_32BIT_REGS);                        \
                 set_thread_flag(TIF_32BIT_ADDR);                        \
+                                                                        \
+                if (!((ex).e_flags & EF_MIPS_FP64))                     \
+                        set_thread_flag(TIF_32BIT_FPREGS);              \
+                                                                        \
                 current->thread.abi = &mips_abi_32;                     \
         } while (0)
 #else
-#define __SET_PERSONALITY32_O32()                                       \
+#define __SET_PERSONALITY32_O32(ex)                                     \
         do { } while (0)
 #endif
 
@@ -289,7 +313,7 @@ do {									\
              ((ex).e_flags & EF_MIPS_ABI) == 0)                         \
                 __SET_PERSONALITY32_N32();                              \
         else                                                            \
-                __SET_PERSONALITY32_O32();                              \
+                __SET_PERSONALITY32_O32(ex);                            \
 } while (0)
 #else
 #define __SET_PERSONALITY32(ex) do { } while (0)
@@ -300,6 +324,7 @@ do {									\
         unsigned int p;                                                 \
                                                                         \
         clear_thread_flag(TIF_32BIT_REGS);                              \
+        clear_thread_flag(TIF_32BIT_FPREGS);                            \
         clear_thread_flag(TIF_32BIT_ADDR);                              \
                                                                         \
         if ((ex).e_ident[EI_CLASS] == ELFCLASS32)                       \