From af8d27bf15c8d68c60d830552055fcdba5b5f045 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Fri, 22 Mar 2024 14:49:36 +0100 Subject: selftests/bpf: Mark uprobe trigger functions with nocf_check attribute Some distros seem to enable the -fcf-protection=branch by default, which breaks our setup on first instruction of uprobe trigger functions and place there endbr64 instruction. Marking them with nocf_check attribute to skip that. Ignoring unknown attribute warning in gcc for bench objects, because nocf_check can be used only when -fcf-protection=branch is enabled, otherwise we get a warning and break compilation. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20240322134936.1075395-1-jolsa@kernel.org --- tools/include/linux/compiler.h | 4 ++++ tools/testing/selftests/bpf/benchs/bench_trigger.c | 8 +++++--- 2 files changed, 9 insertions(+), 3 deletions(-) (limited to 'tools') diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h index 7b65566f3e42..8a63a9913495 100644 --- a/tools/include/linux/compiler.h +++ b/tools/include/linux/compiler.h @@ -58,6 +58,10 @@ #define noinline #endif +#ifndef __nocf_check +#define __nocf_check __attribute__((nocf_check)) +#endif + /* Are two types/vars the same type (ignoring qualifiers)? */ #ifndef __same_type # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) diff --git a/tools/testing/selftests/bpf/benchs/bench_trigger.c b/tools/testing/selftests/bpf/benchs/bench_trigger.c index 9c50412f72e9..d66eddacd642 100644 --- a/tools/testing/selftests/bpf/benchs/bench_trigger.c +++ b/tools/testing/selftests/bpf/benchs/bench_trigger.c @@ -9,6 +9,8 @@ /* adjust slot shift in inc_hits() if changing */ #define MAX_BUCKETS 256 +#pragma GCC diagnostic ignored "-Wattributes" + /* BPF triggering benchmarks */ static struct trigger_ctx { struct trigger_bench *skel; @@ -167,7 +169,7 @@ static void trigger_fmodret_setup(void) * GCC doesn't generate stack setup preample for these functions due to them * having no input arguments and doing nothing in the body. */ -__weak void uprobe_target_nop(void) +__nocf_check __weak void uprobe_target_nop(void) { asm volatile ("nop"); } @@ -176,7 +178,7 @@ __weak void opaque_noop_func(void) { } -__weak int uprobe_target_push(void) +__nocf_check __weak int uprobe_target_push(void) { /* overhead of function call is negligible compared to uprobe * triggering, so this shouldn't affect benchmark results much @@ -185,7 +187,7 @@ __weak int uprobe_target_push(void) return 1; } -__weak void uprobe_target_ret(void) +__nocf_check __weak void uprobe_target_ret(void) { asm volatile (""); } -- cgit v1.2.3