riscv: Add types to indirectly called assembly functions

With CONFIG_CFI_CLANG, assembly functions indirectly called
from C code must be annotated with type identifiers to pass CFI
checking. Use the SYM_TYPED_START macro to add types to the
relevant functions.

Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20230710183544.999540-10-samitolvanen@google.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Author: samitolvanen

arch/riscv/kernel/mcount.S

@@ -3,6 +3,7 @@
 
 #include <linux/init.h>
 #include <linux/linkage.h>
+#include <linux/cfi_types.h>
 #include <asm/asm.h>
 #include <asm/csr.h>
 #include <asm/unistd.h>
@@ -47,13 +48,13 @@
 	addi	sp, sp, 4*SZREG
 	.endm
 
-ENTRY(ftrace_stub)
+SYM_TYPED_FUNC_START(ftrace_stub)
 #ifdef CONFIG_DYNAMIC_FTRACE
        .global MCOUNT_NAME
        .set    MCOUNT_NAME, ftrace_stub
 #endif
 	ret
-ENDPROC(ftrace_stub)
+SYM_FUNC_END(ftrace_stub)
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 ENTRY(return_to_handler)

arch/riscv/kernel/suspend_entry.S

@@ -5,6 +5,7 @@
  */
 
 #include <linux/linkage.h>
+#include <linux/cfi_types.h>
 #include <asm/asm.h>
 #include <asm/asm-offsets.h>
 #include <asm/assembler.h>
@@ -58,7 +59,7 @@ ENTRY(__cpu_suspend_enter)
 	ret
 END(__cpu_suspend_enter)
 
-ENTRY(__cpu_resume_enter)
+SYM_TYPED_FUNC_START(__cpu_resume_enter)
 	/* Load the global pointer */
 	.option push
 	.option norelax
@@ -94,4 +95,4 @@ ENTRY(__cpu_resume_enter)
 
 	/* Return to C code */
 	ret
-END(__cpu_resume_enter)
+SYM_FUNC_END(__cpu_resume_enter)