[PATCH] riscv: Define __riscv_copy_{,vec_}{words,bytes}_unaligned() using SYM_TYPED_FUNC_START

[PATCH] riscv: Define __riscv_copy_{,vec_}{words,bytes}_unaligned() using SYM_TYPED_FUNC_START

[Nathan Chancellor]

After commit 67bdd7b01387 ("riscv: Split out measure_cycles() for
reuse") and commit c03ad15f7cf6 ("riscv: Reuse measure_cycles() in
check_vector_unaligned_access()"), there are CFI failure when booting
kernels with CONFIG_CFI=y:

  CFI failure at measure_cycles+0x38/0xe0 (target: __riscv_copy_words_unaligned+0x0/0x50; expected type: ...)
  CFI failure at measure_cycles+0x38/0xe0 (target: __riscv_copy_vec_words_unaligned+0x0/0x24; expected type: ...)

The __riscv_copy_*_unaligned() functions are now called indirectly but
they are not defined with SYM_TYPED_FUNC_START, which is required for
assembly functions called indirectly from C to pass CFI checking. Switch
to SYM_TYPED_FUNC_START to clear up the CFI failures.

Fixes: 67bdd7b01387 ("riscv: Split out measure_cycles() for reuse")
Fixes: c03ad15f7cf6 ("riscv: Reuse measure_cycles() in check_vector_unaligned_access()")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 arch/riscv/kernel/copy-unaligned.S     | 5 +++--
 arch/riscv/kernel/vec-copy-unaligned.S | 5 +++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/kernel/copy-unaligned.S b/arch/riscv/kernel/copy-unaligned.S
index 2b3d9398c113..90f3549621f7 100644
--- a/arch/riscv/kernel/copy-unaligned.S
+++ b/arch/riscv/kernel/copy-unaligned.S
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 /* Copyright (C) 2023 Rivos Inc. */
 
+#include <linux/cfi_types.h>
 #include <linux/linkage.h>
 #include <asm/asm.h>
 
@@ -9,7 +10,7 @@
 /* void __riscv_copy_words_unaligned(void *, const void *, size_t) */
 /* Performs a memcpy without aligning buffers, using word loads and stores. */
 /* Note: The size is truncated to a multiple of 8 * SZREG */
-SYM_FUNC_START(__riscv_copy_words_unaligned)
+SYM_TYPED_FUNC_START(__riscv_copy_words_unaligned)
 	andi  a4, a2, ~((8*SZREG)-1)
 	beqz  a4, 2f
 	add   a3, a1, a4
@@ -41,7 +42,7 @@ SYM_FUNC_END(__riscv_copy_words_unaligned)
 /* void __riscv_copy_bytes_unaligned(void *, const void *, size_t) */
 /* Performs a memcpy without aligning buffers, using only byte accesses. */
 /* Note: The size is truncated to a multiple of 8 */
-SYM_FUNC_START(__riscv_copy_bytes_unaligned)
+SYM_TYPED_FUNC_START(__riscv_copy_bytes_unaligned)
 	andi a4, a2, ~(8-1)
 	beqz a4, 2f
 	add  a3, a1, a4
diff --git a/arch/riscv/kernel/vec-copy-unaligned.S b/arch/riscv/kernel/vec-copy-unaligned.S
index 7ce4de6f6e69..361039f7b944 100644
--- a/arch/riscv/kernel/vec-copy-unaligned.S
+++ b/arch/riscv/kernel/vec-copy-unaligned.S
@@ -2,6 +2,7 @@
 /* Copyright (C) 2024 Rivos Inc. */
 
 #include <linux/args.h>
+#include <linux/cfi_types.h>
 #include <linux/linkage.h>
 #include <asm/asm.h>
 
@@ -16,7 +17,7 @@
 /* void __riscv_copy_vec_words_unaligned(void *, const void *, size_t) */
 /* Performs a memcpy without aligning buffers, using word loads and stores. */
 /* Note: The size is truncated to a multiple of WORD_EEW */
-SYM_FUNC_START(__riscv_copy_vec_words_unaligned)
+SYM_TYPED_FUNC_START(__riscv_copy_vec_words_unaligned)
 	andi  a4, a2, ~(WORD_EEW-1)
 	beqz  a4, 2f
 	add   a3, a1, a4
@@ -38,7 +39,7 @@ SYM_FUNC_END(__riscv_copy_vec_words_unaligned)
 /* void __riscv_copy_vec_bytes_unaligned(void *, const void *, size_t) */
 /* Performs a memcpy without aligning buffers, using only byte accesses. */
 /* Note: The size is truncated to a multiple of 8 */
-SYM_FUNC_START(__riscv_copy_vec_bytes_unaligned)
+SYM_TYPED_FUNC_START(__riscv_copy_vec_bytes_unaligned)
 	andi a4, a2, ~(8-1)
 	beqz a4, 2f
 	add  a3, a1, a4

---
base-commit: 9b3a2be84803cf18c4b4d1efc695991f0daa153c
change-id: 20260406-measure_cycles-cfi-failure-d24a02297493

Best regards,
--  
Nathan Chancellor <nathan@kernel.org>

Re: [PATCH] riscv: Define __riscv_copy_{,vec_}{words,bytes}_unaligned() using SYM_TYPED_FUNC_START

[Nam Cao]

Nathan Chancellor <nathan@kernel.org> writes:

> After commit 67bdd7b01387 ("riscv: Split out measure_cycles() for
> reuse") and commit c03ad15f7cf6 ("riscv: Reuse measure_cycles() in
> check_vector_unaligned_access()"), there are CFI failure when booting
> kernels with CONFIG_CFI=y:
>
>   CFI failure at measure_cycles+0x38/0xe0 (target: __riscv_copy_words_unaligned+0x0/0x50; expected type: ...)
>   CFI failure at measure_cycles+0x38/0xe0 (target: __riscv_copy_vec_words_unaligned+0x0/0x24; expected type: ...)
>
> The __riscv_copy_*_unaligned() functions are now called indirectly but
> they are not defined with SYM_TYPED_FUNC_START, which is required for
> assembly functions called indirectly from C to pass CFI checking. Switch
> to SYM_TYPED_FUNC_START to clear up the CFI failures.
>
> Fixes: 67bdd7b01387 ("riscv: Split out measure_cycles() for reuse")
> Fixes: c03ad15f7cf6 ("riscv: Reuse measure_cycles() in check_vector_unaligned_access()")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Reviewed-by: Nam Cao <namcao@linutronix.de>