[PATCH] kselftest/arm64: signal: copy each test binary only once

[PATCH] kselftest/arm64: signal: copy each test binary only once

[Sasha Levin]

The signal tests are built in testcases/ and then copied to the output
directory. The copy rule lists every generated program as a target and
copies all of them in each recipe:

  $(TEST_GEN_PROGS): $(PROGS)
          cp $(PROGS) $(OUTPUT)/

In a parallel build make runs that recipe once for each program, so
several cp processes write the same destination files at the same time.
cp then fails with "cannot create regular file ...: File exists", which
fails the arm64 build even though every test compiled. A cross build of
the arm64 signal tests at -j8 hit this in all of 8 runs.

Use a static pattern rule so that each output depends on, and copies,
only its own binary.

Fixes: f96bf4340316 ("kselftest: arm64: mangle_pstate_invalid_compat_toggle and common utils")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/arm64/signal/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/arm64/signal/Makefile b/tools/testing/selftests/arm64/signal/Makefile
index 1381039fb36f9..c4df4be41636c 100644
--- a/tools/testing/selftests/arm64/signal/Makefile
+++ b/tools/testing/selftests/arm64/signal/Makefile
@@ -17,8 +17,8 @@ TEST_GEN_PROGS := $(notdir $(PROGS))
 # the toplevel makefile
 include ../../lib.mk
 
-$(TEST_GEN_PROGS): $(PROGS)
-	cp $(PROGS) $(OUTPUT)/
+$(TEST_GEN_PROGS): $(OUTPUT)/%: testcases/%
+	cp $< $@
 
 # Common test-unit targets to build common-layout test-cases executables
 # Needs secondary expansion to properly include the testcase c-file in pre-reqs

base-commit: 4eb2586bd40db27d77cc5b724ca9386ed0c71d53
-- 
2.53.0

Re: [PATCH] kselftest/arm64: signal: copy each test binary only once

[Catalin Marinas]

On Wed, 14 Oct 2026 16:01:40 -0400, Sasha Levin wrote:
> The signal tests are built in testcases/ and then copied to the output
> directory. The copy rule lists every generated program as a target and
> copies all of them in each recipe:
> 
>   $(TEST_GEN_PROGS): $(PROGS)
>           cp $(PROGS) $(OUTPUT)/
> 
> [...]

Applied to arm64 (for-next/kselftest), thanks!

[1/1] kselftest/arm64: signal: copy each test binary only once
      https://git.kernel.org/arm64/c/7b3b147c4104

Re: [PATCH] kselftest/arm64: signal: copy each test binary only once

[Mark Brown]

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On Wed, Oct 14, 2026 at 04:01:40PM -0400, Sasha Levin wrote:
> The signal tests are built in testcases/ and then copied to the output
> directory. The copy rule lists every generated program as a target and
> copies all of them in each recipe:

The build stuff for the signal testcases is a menance, it's being far
too cute.

> -$(TEST_GEN_PROGS): $(PROGS)
> -	cp $(PROGS) $(OUTPUT)/
> +$(TEST_GEN_PROGS): $(OUTPUT)/%: testcases/%
> +	cp $< $@

You'd have thought that'd be clearer with two separate rules but the
obvious doesn't work and we're already being so clever I think this is
fine:

Reviewed-by: Mark Brown <broonie@kernel.org>

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