Thread (2 messages) 2 messages, 2 authors, 2025-12-04

Re: [PATCH 2/2] net: smc: SMC_HS_CTRL_BPF should depend on BPF_JIT

From: Martin KaFai Lau <martin.lau@linux.dev>
Date: 2025-12-04 19:16:01
Also in: bpf, linux-rdma, linux-s390, lkml

On 12/4/25 2:29 AM, Geert Uytterhoeven wrote:
quoted hunk ↗ jump to hunk
If CONFIG_BPF_SYSCALL=y, but CONFIG_BPF_JIT=n:

     net/smc/smc_hs_bpf.c: In function ‘bpf_smc_hs_ctrl_init’:
     include/linux/bpf.h:2068:50: error: statement with no effect [-Werror=unused-value]
      2068 | #define register_bpf_struct_ops(st_ops, type) ({ (void *)(st_ops); 0; })
	  |                                                  ^~~~~~~~~~~~~~~~
     net/smc/smc_hs_bpf.c:139:16: note: in expansion of macro ‘register_bpf_struct_ops’
       139 |         return register_bpf_struct_ops(&bpf_smc_hs_ctrl_ops, smc_hs_ctrl);
	  |                ^~~~~~~~~~~~~~~~~~~~~~~

While this compile error is caused by a bug in <linux/bpf.h>, none of
the code in net/smc/smc_hs_bpf.c becomes effective if CONFIG_BPF_JIT is
not enabled.  Hence add a dependency on BPF_JIT.

While at it, add the missing newline at the end of the file.

Fixes: 15f295f55656658e ("net/smc: bpf: Introduce generic hook for handshake flow")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
  net/smc/Kconfig | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/smc/Kconfig b/net/smc/Kconfig
index 325addf83cc69f6c..277ef504bc26ef89 100644
--- a/net/smc/Kconfig
+++ b/net/smc/Kconfig
@@ -22,10 +22,10 @@ config SMC_DIAG
  
  config SMC_HS_CTRL_BPF
  	bool "Generic eBPF hook for SMC handshake flow"
-	depends on SMC && BPF_SYSCALL
+	depends on SMC && BPF_JIT && BPF_SYSCALL
  	default y
  	help
  	  SMC_HS_CTRL_BPF enables support to register generic eBPF hook for SMC
  	  handshake flow, which offer much greater flexibility in modifying the behavior
  	  of the SMC protocol stack compared to a complete kernel-based approach. Select
-	  this option if you want filtring the handshake process via eBPF programs.
\ No newline at end of file
+	  this option if you want filtring the handshake process via eBPF programs.
I have applied patch 2 to the bpf tree. Thanks.
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