selftests/bpf: Emit nop,nop5 instructions combo for x86_64 arch

Syncing latest usdt.h change [1].

Now that we have nop5 optimization support in kernel, let's emit
nop,nop5 for usdt probe. We leave it up to the library to use
desirable nop instruction.

[1] https://github.com/libbpf/usdt/commit/c9865d158984fb2b73e3cbbdcdfb4f583ad36a73
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260224103915.1369690-4-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/usdt.h b/tools/testing/selftests/bpf/usdt.h
index 549d1f77481019754070457df3e86ad9f00d0424..c71e21df38b322e7a2056a4efb8317f7ce2cd377 100644 (file)
--- a/tools/testing/selftests/bpf/usdt.h
+++ b/tools/testing/selftests/bpf/usdt.h
@@ -312,6 +312,8 @@ struct usdt_sema { volatile unsigned short active; };
 #ifndef USDT_NOP
 #if defined(__ia64__) || defined(__s390__) || defined(__s390x__)
 #define USDT_NOP                       nop 0
+#elif defined(__x86_64__)
+#define USDT_NOP                       .byte 0x90, 0x0f, 0x1f, 0x44, 0x00, 0x0 /* nop, nop5 */
 #else
 #define USDT_NOP                       nop
 #endif