2023-06-29 23:51:38

by Sami Tolvanen

Subject: [PATCH 2/6] 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.

Signed-off-by: Sami Tolvanen <[email protected]>
---
arch/riscv/kernel/mcount.S | 5 +++--
arch/riscv/kernel/suspend_entry.S | 5 +++--
2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/kernel/mcount.S b/arch/riscv/kernel/mcount.S
index 30102aadc4d7..712c1d2c2723 100644
--- a/arch/riscv/kernel/mcount.S
+++ b/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)
diff --git a/arch/riscv/kernel/suspend_entry.S b/arch/riscv/kernel/suspend_entry.S
index 12b52afe09a4..f7960c7c5f9e 100644
--- a/arch/riscv/kernel/suspend_entry.S
+++ b/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)
--
2.41.0.255.g8b1d071c50-goog

2023-06-30 18:46:42

by Kees Cook

Subject: Re: [PATCH 2/6] riscv: Add types to indirectly called assembly functions

On Thu, Jun 29, 2023 at 11:42:47PM +0000, Sami Tolvanen wrote:
> 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.
>
> Signed-off-by: Sami Tolvanen <[email protected]>

Reviewed-by: Kees Cook <[email protected]>

--
Kees Cook