MIPS: ELF: Set FP mode according to .MIPS.abiflags

This patch reads the .MIPS.abiflags section when it is present, and sets
the FP mode of the task accordingly. Any loaded ELF files which do not
contain a .MIPS.abiflags section will continue to observe the previous
behaviour, that is FR=1 if EF_MIPS_FP64 is set else FR=0.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7681/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 33 insertions, 17 deletions

diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h
index bfa4bbd42c6c..eb4d95de619c 100644
--- a/arch/mips/include/asm/elf.h
+++ b/arch/mips/include/asm/elf.h
@@ -8,6 +8,8 @@
 #ifndef _ASM_ELF_H
 #define _ASM_ELF_H
 
+#include <linux/fs.h>
+#include <uapi/linux/elf.h>
 
 /* ELF header e_flags defines. */
 /* MIPS architecture level. */
@@ -287,18 +289,13 @@ extern struct mips_abi mips_abi_n32;
 
 #ifdef CONFIG_32BIT
 
-#define SET_PERSONALITY(ex)						\
+#define SET_PERSONALITY2(ex, state)					\
 do {									\
-	if ((ex).e_flags & EF_MIPS_FP64)				\
-		clear_thread_flag(TIF_32BIT_FPREGS);			\
-	else								\
-		set_thread_flag(TIF_32BIT_FPREGS);			\
-									\
-	clear_thread_flag(TIF_HYBRID_FPREGS);				\
-									\
 	if (personality(current->personality) != PER_LINUX)		\
 		set_personality(PER_LINUX);				\
 									\
+	mips_set_personality_fp(state);					\
+									\
 	current->thread.abi = &mips_abi;				\
 } while (0)
 
@@ -318,35 +315,34 @@ do {									\
 #endif
 
 #ifdef CONFIG_MIPS32_O32
-#define __SET_PERSONALITY32_O32(ex)					\
+#define __SET_PERSONALITY32_O32(ex, state)				\
 	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);		\
+		mips_set_personality_fp(state);				\
 									\
 		current->thread.abi = &mips_abi_32;			\
 	} while (0)
 #else
-#define __SET_PERSONALITY32_O32(ex)					\
+#define __SET_PERSONALITY32_O32(ex, state)				\
 	do { } while (0)
 #endif
 
 #ifdef CONFIG_MIPS32_COMPAT
-#define __SET_PERSONALITY32(ex)						\
+#define __SET_PERSONALITY32(ex, state)					\
 do {									\
 	if ((((ex).e_flags & EF_MIPS_ABI2) != 0) &&			\
 	     ((ex).e_flags & EF_MIPS_ABI) == 0)				\
 		__SET_PERSONALITY32_N32();				\
 	else								\
-		__SET_PERSONALITY32_O32(ex);                            \
+		__SET_PERSONALITY32_O32(ex, state);			\
 } while (0)
 #else
-#define __SET_PERSONALITY32(ex) do { } while (0)
+#define __SET_PERSONALITY32(ex, state) do { } while (0)
 #endif
 
-#define SET_PERSONALITY(ex)						\
+#define SET_PERSONALITY2(ex, state)					\
 do {									\
 	unsigned int p;							\
 									\
@@ -356,7 +352,7 @@ do {									\
 	clear_thread_flag(TIF_32BIT_ADDR);				\
 									\
 	if ((ex).e_ident[EI_CLASS] == ELFCLASS32)			\
-		__SET_PERSONALITY32(ex);				\
+		__SET_PERSONALITY32(ex, state);				\
 	else								\
 		current->thread.abi = &mips_abi;			\
 									\
@@ -418,4 +414,24 @@ struct mm_struct;
 extern unsigned long arch_randomize_brk(struct mm_struct *mm);
 #define arch_randomize_brk arch_randomize_brk
 
+struct arch_elf_state {
+	int fp_abi;
+	int interp_fp_abi;
+	int overall_abi;
+};
+
+#define INIT_ARCH_ELF_STATE {			\
+	.fp_abi = -1,				\
+	.interp_fp_abi = -1,			\
+	.overall_abi = -1,			\
+}
+
+extern int arch_elf_pt_proc(void *ehdr, void *phdr, struct file *elf,
+			    bool is_interp, struct arch_elf_state *state);
+
+extern int arch_check_elf(void *ehdr, bool has_interpreter,
+			  struct arch_elf_state *state);
+
+extern void mips_set_personality_fp(struct arch_elf_state *state);
+
 #endif /* _ASM_ELF_H */