[1/2] bpf: hide unused bpf_patch_call_args

Message ID 20230517125617.931437-1-arnd@kernel.org
State New
Headers
Series [1/2] bpf: hide unused bpf_patch_call_args |

Commit Message

Arnd Bergmann May 17, 2023, 12:56 p.m. UTC
  From: Arnd Bergmann <arnd@arndb.de>

This function has no callers and no declaration when CONFIG_BPF_JIT_ALWAYS_ON
is enabled:

kernel/bpf/core.c:2075:6: error: no previous prototype for 'bpf_patch_call_args' [-Werror=missing-prototypes]

Hide the definition as well.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 kernel/bpf/core.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
  

Comments

Daniel Borkmann May 22, 2023, 2:26 p.m. UTC | #1
On 5/17/23 2:56 PM, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> This function has no callers and no declaration when CONFIG_BPF_JIT_ALWAYS_ON
> is enabled:
> 
> kernel/bpf/core.c:2075:6: error: no previous prototype for 'bpf_patch_call_args' [-Werror=missing-prototypes]
> 
> Hide the definition as well.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>   kernel/bpf/core.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index 7421487422d4..6f5ede31e471 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -2064,7 +2064,7 @@ EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
>   };
>   #undef PROG_NAME_LIST
>   #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
> -static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
> +static __maybe_unused u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
>   				  const struct bpf_insn *insn) = {

Patch 2 lgtm, small nit above: could you fix up indent?

>   EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
>   EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
> @@ -2072,6 +2072,7 @@ EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
>   };
>   #undef PROG_NAME_LIST
>   
> +#ifdef CONFIG_BPF_SYSCALL
>   void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
>   {
>   	stack_depth = max_t(u32, stack_depth, 1);
> @@ -2080,6 +2081,7 @@ void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
>   		__bpf_call_base_args;
>   	insn->code = BPF_JMP | BPF_CALL_ARGS;
>   }
> +#endif
>   
>   #else
>   static unsigned int __bpf_prog_ret0_warn(const void *ctx,

Thanks,
Daniel
  

Patch

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 7421487422d4..6f5ede31e471 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -2064,7 +2064,7 @@  EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
 };
 #undef PROG_NAME_LIST
 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
-static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
+static __maybe_unused u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
 				  const struct bpf_insn *insn) = {
 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
@@ -2072,6 +2072,7 @@  EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
 };
 #undef PROG_NAME_LIST
 
+#ifdef CONFIG_BPF_SYSCALL
 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
 {
 	stack_depth = max_t(u32, stack_depth, 1);
@@ -2080,6 +2081,7 @@  void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
 		__bpf_call_base_args;
 	insn->code = BPF_JMP | BPF_CALL_ARGS;
 }
+#endif
 
 #else
 static unsigned int __bpf_prog_ret0_warn(const void *ctx,