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[PATCH v2 1/2] perf probe: add test for regression introduced by switch to die_get_decl_file

Georg Müller posted 2 patches 2 years, 7 months ago
There is a newer version of this series
[PATCH v2 1/2] perf probe: add test for regression introduced by switch to die_get_decl_file
Posted by Georg Müller 2 years, 7 months ago 
This patch adds a test to validate that perf probe works for binaries
where DWARF info is split into multiple CUs

Signed-off-by: Georg Müller <georgmueller@gmx.net>
Link: https://lore.kernel.org/r/5a00d5a5-7be7-ef8a-4044-9a16249fff25@gmx.net/
---
 .../shell/test_uprobe_from_different_cu.sh    | 77 +++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100755 tools/perf/tests/shell/test_uprobe_from_different_cu.sh

diff --git a/tools/perf/tests/shell/test_uprobe_from_different_cu.sh b/tools/perf/tests/shell/test_uprobe_from_different_cu.sh
new file mode 100755
index 000000000000..00d2e0e2e0c2
--- /dev/null
+++ b/tools/perf/tests/shell/test_uprobe_from_different_cu.sh
@@ -0,0 +1,77 @@
+#!/bin/bash
+# test perf probe of function from different CU
+# SPDX-License-Identifier: GPL-2.0
+
+set -e
+
+temp_dir=$(mktemp -d /tmp/perf-uprobe-different-cu-sh.XXXXXXXXXX)
+
+cleanup()
+{
+	trap - EXIT TERM INT
+	if [[ "${temp_dir}" =~ ^/tmp/perf-uprobe-different-cu-sh.*$ ]]; then
+		echo "--- Cleaning up ---"
+		perf probe -x ${temp_dir}/testfile -d foo
+		rm -f "${temp_dir}/"*
+		rmdir "${temp_dir}"
+	fi
+}
+
+trap_cleanup()
+{
+        cleanup
+        exit 1
+}
+
+trap trap_cleanup EXIT TERM INT
+
+cat > ${temp_dir}/testfile-foo.h << EOF
+struct t
+{
+  int *p;
+  int c;
+};
+
+extern int foo (int i, struct t *t);
+EOF
+
+cat > ${temp_dir}/testfile-foo.c << EOF
+#include "testfile-foo.h"
+
+int
+foo (int i, struct t *t)
+{
+  int j, res = 0;
+  for (j = 0; j < i && j < t->c; j++)
+    res += t->p[j];
+
+  return res;
+}
+EOF
+
+cat > ${temp_dir}/testfile-main.c << EOF
+#include "testfile-foo.h"
+
+static struct t g;
+
+int
+main (int argc, char **argv)
+{
+  int i;
+  int j[argc];
+  g.c = argc;
+  g.p = j;
+  for (i = 0; i < argc; i++)
+    j[i] = (int) argv[i][0];
+  return foo (3, &g);
+}
+EOF
+
+gcc -g -Og -flto -c ${temp_dir}/testfile-foo.c -o ${temp_dir}/testfile-foo.o
+gcc -g -Og -c ${temp_dir}/testfile-main.c -o ${temp_dir}/testfile-main.o
+gcc -g -Og -o ${temp_dir}/testfile ${temp_dir}/testfile-foo.o ${temp_dir}/testfile-main.o
+
+perf probe -x ${temp_dir}/testfile --funcs foo
+perf probe -x ${temp_dir}/testfile foo
+
+cleanup
--
2.41.0
Re: [PATCH v2 1/2] perf probe: add test for regression introduced by switch to die_get_decl_file
Posted by Ian Rogers 2 years, 6 months ago 
On Wed, Jun 28, 2023 at 1:25 AM Georg Müller <georgmueller@gmx.net> wrote:
>
> This patch adds a test to validate that perf probe works for binaries
> where DWARF info is split into multiple CUs
>
> Signed-off-by: Georg Müller <georgmueller@gmx.net>
> Link: https://lore.kernel.org/r/5a00d5a5-7be7-ef8a-4044-9a16249fff25@gmx.net/
> ---
>  .../shell/test_uprobe_from_different_cu.sh    | 77 +++++++++++++++++++
>  1 file changed, 77 insertions(+)
>  create mode 100755 tools/perf/tests/shell/test_uprobe_from_different_cu.sh
>
> diff --git a/tools/perf/tests/shell/test_uprobe_from_different_cu.sh b/tools/perf/tests/shell/test_uprobe_from_different_cu.sh
> new file mode 100755
> index 000000000000..00d2e0e2e0c2
> --- /dev/null
> +++ b/tools/perf/tests/shell/test_uprobe_from_different_cu.sh
> @@ -0,0 +1,77 @@
> +#!/bin/bash
> +# test perf probe of function from different CU
> +# SPDX-License-Identifier: GPL-2.0
> +
> +set -e
> +
> +temp_dir=$(mktemp -d /tmp/perf-uprobe-different-cu-sh.XXXXXXXXXX)
> +
> +cleanup()
> +{
> +       trap - EXIT TERM INT
> +       if [[ "${temp_dir}" =~ ^/tmp/perf-uprobe-different-cu-sh.*$ ]]; then
> +               echo "--- Cleaning up ---"
> +               perf probe -x ${temp_dir}/testfile -d foo
> +               rm -f "${temp_dir}/"*
> +               rmdir "${temp_dir}"
> +       fi
> +}
> +
> +trap_cleanup()
> +{
> +        cleanup
> +        exit 1
> +}
> +
> +trap trap_cleanup EXIT TERM INT
> +
> +cat > ${temp_dir}/testfile-foo.h << EOF
> +struct t
> +{
> +  int *p;
> +  int c;
> +};
> +
> +extern int foo (int i, struct t *t);
> +EOF
> +
> +cat > ${temp_dir}/testfile-foo.c << EOF
> +#include "testfile-foo.h"
> +
> +int
> +foo (int i, struct t *t)
> +{
> +  int j, res = 0;
> +  for (j = 0; j < i && j < t->c; j++)
> +    res += t->p[j];
> +
> +  return res;
> +}
> +EOF
> +
> +cat > ${temp_dir}/testfile-main.c << EOF
> +#include "testfile-foo.h"
> +
> +static struct t g;
> +
> +int
> +main (int argc, char **argv)
> +{
> +  int i;
> +  int j[argc];
> +  g.c = argc;
> +  g.p = j;
> +  for (i = 0; i < argc; i++)
> +    j[i] = (int) argv[i][0];
> +  return foo (3, &g);
> +}
> +EOF
> +
> +gcc -g -Og -flto -c ${temp_dir}/testfile-foo.c -o ${temp_dir}/testfile-foo.o
> +gcc -g -Og -c ${temp_dir}/testfile-main.c -o ${temp_dir}/testfile-main.o
> +gcc -g -Og -o ${temp_dir}/testfile ${temp_dir}/testfile-foo.o ${temp_dir}/testfile-main.o

Thanks for the test Georg! By directly relying on gcc this test fails
for me in some constrained environments, like containers. I think
there should be a skip if gcc isn't present. A different option is to
just build the test code into the perf binary itself as a test
workload:
https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git/tree/tools/perf/tests/workloads?h=perf-tools-next

Wdyt? Thanks,
Ian

> +
> +perf probe -x ${temp_dir}/testfile --funcs foo
> +perf probe -x ${temp_dir}/testfile foo
> +
> +cleanup
> --
> 2.41.0
>
Re: [PATCH v2 1/2] perf probe: add test for regression introduced by switch to die_get_decl_file
Posted by Georg Müller 2 years, 6 months ago 
Am 27.07.23 um 19:45 schrieb Ian Rogers:
> On Wed, Jun 28, 2023 at 1:25 AM Georg Müller <georgmueller@gmx.net> wrote:
>
> Thanks for the test Georg! By directly relying on gcc this test fails
> for me in some constrained environments, like containers. I think
> there should be a skip if gcc isn't present. A different option is to
> just build the test code into the perf binary itself as a test
> workload:
> https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git/tree/tools/perf/tests/workloads?h=perf-tools-next
>
> Wdyt? Thanks,
> Ian
>

I prepare a commit which checks for gcc and skips the test in this case.

I think building thi test code into the perf binary itself is not an option
here, since the test relies on a special setup of using -flto for one of the
compilation units.

There is also a cleanup issue if anything fails. This will be included in
the patch as well.

Best regards,
Georg

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