MIPS: lib: strlen_user: Add EVA support

In non-EVA mode, strlen_user* aliases are used for the
strlen_kernel* symbols since the code is identical. In EVA
mode, new strlen_user* symbols are used which use the EVA
specific instructions to load values from userspace.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>

arch/mips/kernel/mips_ksyms.c

@@ -20,6 +20,8 @@ extern long __strncpy_from_user_nocheck_asm(char *__to,
 					    const char *__from, long __len);
 extern long __strncpy_from_user_asm(char *__to, const char *__from,
 				    long __len);
+extern long __strlen_kernel_nocheck_asm(const char *s);
+extern long __strlen_kernel_asm(const char *s);
 extern long __strlen_user_nocheck_asm(const char *s);
 extern long __strlen_user_asm(const char *s);
 extern long __strnlen_kernel_nocheck_asm(const char *s);
@@ -48,6 +50,8 @@ EXPORT_SYMBOL(__copy_user_inatomic);
 EXPORT_SYMBOL(__bzero);
 EXPORT_SYMBOL(__strncpy_from_user_nocheck_asm);
 EXPORT_SYMBOL(__strncpy_from_user_asm);
+EXPORT_SYMBOL(__strlen_kernel_nocheck_asm);
+EXPORT_SYMBOL(__strlen_kernel_asm);
 EXPORT_SYMBOL(__strlen_user_nocheck_asm);
 EXPORT_SYMBOL(__strlen_user_asm);
 EXPORT_SYMBOL(__strnlen_kernel_nocheck_asm);

arch/mips/lib/strlen_user.S

@@ -30,7 +30,11 @@ LEAF(__strlen_\func\()_asm)
 
 FEXPORT(__strlen_\func\()_nocheck_asm)
 	move		v0, a0
+.ifeqs "\func", "kernel"
 1:	EX(lbu, v1, (v0), .Lfault\@)
+.else
+1:	EX(lbue, v1, (v0), .Lfault\@)
+.endif
 	PTR_ADDIU	v0, 1
 	bnez		v1, 1b
 	PTR_SUBU	v0, a0
@@ -41,4 +45,20 @@ FEXPORT(__strlen_\func\()_nocheck_asm)
 	jr		ra
 	.endm
 
+#ifndef CONFIG_EVA
+	/* Set aliases */
+	.global __strlen_user_asm
+	.global __strlen_user_nocheck_asm
+	.set __strlen_user_asm, __strlen_kernel_asm
+	.set __strlen_user_nocheck_asm, __strlen_kernel_nocheck_asm
+#endif
+
+__BUILD_STRLEN_ASM kernel
+
+#ifdef CONFIG_EVA
+
+	.set push
+	.set eva
 __BUILD_STRLEN_ASM user
+	.set pop
+#endif