Re: libbpf error: unknown register name 'r0' in asm

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 10/9/20 6:56 PM, Yaniv Agman wrote:
‫בתאריך יום ו׳, 9 באוק׳ 2020 ב-19:27 מאת ‪Daniel Borkmann‬‏
<‪daniel@xxxxxxxxxxxxx‬‏>:‬

[ Cc +Yonghong ]

On 10/9/20 6:05 PM, Yaniv Agman wrote:
Pulling the latest changes of libbpf and compiling my application with it,
I see the following error:

../libbpf/src//root/usr/include/bpf/bpf_helpers.h:99:10: error:
unknown register name 'r0' in asm
                       : "r0", "r1", "r2", "r3", "r4", "r5");

The commit which introduced this change is:
80c7838600d39891f274e2f7508b95a75e4227c1

I'm not sure if I'm doing something wrong (missing include?), or this
is a genuine error

Seems like your clang/llvm version might be too old.

I'm using clang 10.0.1

Ah, okay, I see. Would this diff do the trick for you?

diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index 2bdb7d6dbad2..31e356831fcf 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -72,6 +72,7 @@
 /*
  * Helper function to perform a tail call with a constant/immediate map slot.
  */
+#if __clang_major__ >= 10 && defined(__bpf__)
 static __always_inline void
 bpf_tail_call_static(void *ctx, const void *map, const __u32 slot)
 {
@@ -98,6 +99,9 @@ bpf_tail_call_static(void *ctx, const void *map, const __u32 slot)
 		     :: [ctx]"r"(ctx), [map]"r"(map), [slot]"i"(slot)
 		     : "r0", "r1", "r2", "r3", "r4", "r5");
 }
+#else
+# define bpf_tail_call_static	bpf_tail_call
+#endif /* __clang_major__ >= 10 && __bpf__ */

 /*
  * Helper structure used by eBPF C program



[Index of Archives]     [Linux Samsung SoC]     [Linux Rockchip SoC]     [Linux Actions SoC]     [Linux for Synopsys ARC Processors]     [Linux NFS]     [Linux NILFS]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]


  Powered by Linux