[PATCH 5.15 174/183] bpf: Fix BTF_ID symbol generation collision

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5.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jiri Olsa <jolsa@xxxxxxxxxx>

commit 8f908db77782630c45ba29dac35c434b5ce0b730 upstream.

Marcus and Satya reported an issue where BTF_ID macro generates same
symbol in separate objects and that breaks final vmlinux link.

ld.lld: error: ld-temp.o <inline asm>:14577:1: symbol
'__BTF_ID__struct__cgroup__624' is already defined

This can be triggered under specific configs when __COUNTER__ happens to
be the same for the same symbol in two different translation units,
which is already quite unlikely to happen.

Add __LINE__ number suffix to make BTF_ID symbol more unique, which is
not a complete fix, but it would help for now and meanwhile we can work
on better solution as suggested by Andrii.

Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Satya Durga Srinivasu Prabhala <quic_satyap@xxxxxxxxxxx>
Reported-by: Marcus Seyfarth <m.seyfarth@xxxxxxxxx>
Closes: https://github.com/ClangBuiltLinux/linux/issues/1913
Debugged-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/CAEf4Bzb5KQ2_LmhN769ifMeSJaWfebccUasQOfQKaOd0nQ51tw@xxxxxxxxxxxxxx/
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230915-bpf_collision-v3-1-263fc519c21f@xxxxxxxxxx
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 include/linux/btf_ids.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/linux/btf_ids.h
+++ b/include/linux/btf_ids.h
@@ -38,7 +38,7 @@ asm(							\
 	____BTF_ID(symbol)
 
 #define __ID(prefix) \
-	__PASTE(prefix, __COUNTER__)
+	__PASTE(__PASTE(prefix, __COUNTER__), __LINE__)
 
 /*
  * The BTF_ID defines unique symbol for each ID pointing





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