[SRU,Groovy,1/1] UBUNTU: SAUCE: partially revert "bpf: Zero-fill re-used per-cpu map element"

BugLink: https://bugs.launchpad.net/bugs/1917609

Upstream commit d3bec0138bfbe58606fc1d6f57a4cdc1a20218db (bpf: Zero-fill
re-used per-cpu map element) applied to Groovy via upstream stable
update adds new bpf selftests which can't be built on the 5.8 kernel due
to missing helper functions which were added later.

Partially revert this commit to remove the selftests changes but keeping
the actual bpf changes made to kernel/bpf/hashtab.c.

Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
---
 .../selftests/bpf/prog_tests/map_init.c       | 214 ------------------
 .../selftests/bpf/progs/test_map_init.c       |  33 ---
 2 files changed, 247 deletions(-)
 delete mode 100644 tools/testing/selftests/bpf/prog_tests/map_init.c
 delete mode 100644 tools/testing/selftests/bpf/progs/test_map_init.c

On 04.03.21 18:50, Kleber Sacilotto de Souza wrote:
> BugLink: https://bugs.launchpad.net/bugs/1917609
> 
> Upstream commit d3bec0138bfbe58606fc1d6f57a4cdc1a20218db (bpf: Zero-fill
> re-used per-cpu map element) applied to Groovy via upstream stable
> update adds new bpf selftests which can't be built on the 5.8 kernel due
> to missing helper functions which were added later.
> 
> Partially revert this commit to remove the selftests changes but keeping
> the actual bpf changes made to kernel/bpf/hashtab.c.
> 
> Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
> ---
>   .../selftests/bpf/prog_tests/map_init.c       | 214 ------------------
>   .../selftests/bpf/progs/test_map_init.c       |  33 ---
>   2 files changed, 247 deletions(-)
>   delete mode 100644 tools/testing/selftests/bpf/prog_tests/map_init.c
>   delete mode 100644 tools/testing/selftests/bpf/progs/test_map_init.c
> 
> diff --git a/tools/testing/selftests/bpf/prog_tests/map_init.c b/tools/testing/selftests/bpf/prog_tests/map_init.c
> deleted file mode 100644
> index 14a31109dd0e..000000000000
> --- a/tools/testing/selftests/bpf/prog_tests/map_init.c
> +++ /dev/null
> @@ -1,214 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0-only
> -/* Copyright (c) 2020 Tessares SA <http://www.tessares.net> */
> -
> -#include <test_progs.h>
> -#include "test_map_init.skel.h"
> -
> -#define TEST_VALUE 0x1234
> -#define FILL_VALUE 0xdeadbeef
> -
> -static int nr_cpus;
> -static int duration;
> -
> -typedef unsigned long long map_key_t;
> -typedef unsigned long long map_value_t;
> -typedef struct {
> -	map_value_t v; /* padding */
> -} __bpf_percpu_val_align pcpu_map_value_t;
> -
> -
> -static int map_populate(int map_fd, int num)
> -{
> -	pcpu_map_value_t value[nr_cpus];
> -	int i, err;
> -	map_key_t key;
> -
> -	for (i = 0; i < nr_cpus; i++)
> -		bpf_percpu(value, i) = FILL_VALUE;
> -
> -	for (key = 1; key <= num; key++) {
> -		err = bpf_map_update_elem(map_fd, &key, value, BPF_NOEXIST);
> -		if (!ASSERT_OK(err, "bpf_map_update_elem"))
> -			return -1;
> -	}
> -
> -	return 0;
> -}
> -
> -static struct test_map_init *setup(enum bpf_map_type map_type, int map_sz,
> -			    int *map_fd, int populate)
> -{
> -	struct test_map_init *skel;
> -	int err;
> -
> -	skel = test_map_init__open();
> -	if (!ASSERT_OK_PTR(skel, "skel_open"))
> -		return NULL;
> -
> -	err = bpf_map__set_type(skel->maps.hashmap1, map_type);
> -	if (!ASSERT_OK(err, "bpf_map__set_type"))
> -		goto error;
> -
> -	err = bpf_map__set_max_entries(skel->maps.hashmap1, map_sz);
> -	if (!ASSERT_OK(err, "bpf_map__set_max_entries"))
> -		goto error;
> -
> -	err = test_map_init__load(skel);
> -	if (!ASSERT_OK(err, "skel_load"))
> -		goto error;
> -
> -	*map_fd = bpf_map__fd(skel->maps.hashmap1);
> -	if (CHECK(*map_fd < 0, "bpf_map__fd", "failed\n"))
> -		goto error;
> -
> -	err = map_populate(*map_fd, populate);
> -	if (!ASSERT_OK(err, "map_populate"))
> -		goto error_map;
> -
> -	return skel;
> -
> -error_map:
> -	close(*map_fd);
> -error:
> -	test_map_init__destroy(skel);
> -	return NULL;
> -}
> -
> -/* executes bpf program that updates map with key, value */
> -static int prog_run_insert_elem(struct test_map_init *skel, map_key_t key,
> -				map_value_t value)
> -{
> -	struct test_map_init__bss *bss;
> -
> -	bss = skel->bss;
> -
> -	bss->inKey = key;
> -	bss->inValue = value;
> -	bss->inPid = getpid();
> -
> -	if (!ASSERT_OK(test_map_init__attach(skel), "skel_attach"))
> -		return -1;
> -
> -	/* Let tracepoint trigger */
> -	syscall(__NR_getpgid);
> -
> -	test_map_init__detach(skel);
> -
> -	return 0;
> -}
> -
> -static int check_values_one_cpu(pcpu_map_value_t *value, map_value_t expected)
> -{
> -	int i, nzCnt = 0;
> -	map_value_t val;
> -
> -	for (i = 0; i < nr_cpus; i++) {
> -		val = bpf_percpu(value, i);
> -		if (val) {
> -			if (CHECK(val != expected, "map value",
> -				  "unexpected for cpu %d: 0x%llx\n", i, val))
> -				return -1;
> -			nzCnt++;
> -		}
> -	}
> -
> -	if (CHECK(nzCnt != 1, "map value", "set for %d CPUs instead of 1!\n",
> -		  nzCnt))
> -		return -1;
> -
> -	return 0;
> -}
> -
> -/* Add key=1 elem with values set for all CPUs
> - * Delete elem key=1
> - * Run bpf prog that inserts new key=1 elem with value=0x1234
> - *   (bpf prog can only set value for current CPU)
> - * Lookup Key=1 and check value is as expected for all CPUs:
> - *   value set by bpf prog for one CPU, 0 for all others
> - */
> -static void test_pcpu_map_init(void)
> -{
> -	pcpu_map_value_t value[nr_cpus];
> -	struct test_map_init *skel;
> -	int map_fd, err;
> -	map_key_t key;
> -
> -	/* max 1 elem in map so insertion is forced to reuse freed entry */
> -	skel = setup(BPF_MAP_TYPE_PERCPU_HASH, 1, &map_fd, 1);
> -	if (!ASSERT_OK_PTR(skel, "prog_setup"))
> -		return;
> -
> -	/* delete element so the entry can be re-used*/
> -	key = 1;
> -	err = bpf_map_delete_elem(map_fd, &key);
> -	if (!ASSERT_OK(err, "bpf_map_delete_elem"))
> -		goto cleanup;
> -
> -	/* run bpf prog that inserts new elem, re-using the slot just freed */
> -	err = prog_run_insert_elem(skel, key, TEST_VALUE);
> -	if (!ASSERT_OK(err, "prog_run_insert_elem"))
> -		goto cleanup;
> -
> -	/* check that key=1 was re-created by bpf prog */
> -	err = bpf_map_lookup_elem(map_fd, &key, value);
> -	if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
> -		goto cleanup;
> -
> -	/* and has expected values */
> -	check_values_one_cpu(value, TEST_VALUE);
> -
> -cleanup:
> -	test_map_init__destroy(skel);
> -}
> -
> -/* Add key=1 and key=2 elems with values set for all CPUs
> - * Run bpf prog that inserts new key=3 elem
> - *   (only for current cpu; other cpus should have initial value = 0)
> - * Lookup Key=1 and check value is as expected for all CPUs
> - */
> -static void test_pcpu_lru_map_init(void)
> -{
> -	pcpu_map_value_t value[nr_cpus];
> -	struct test_map_init *skel;
> -	int map_fd, err;
> -	map_key_t key;
> -
> -	/* Set up LRU map with 2 elements, values filled for all CPUs.
> -	 * With these 2 elements, the LRU map is full
> -	 */
> -	skel = setup(BPF_MAP_TYPE_LRU_PERCPU_HASH, 2, &map_fd, 2);
> -	if (!ASSERT_OK_PTR(skel, "prog_setup"))
> -		return;
> -
> -	/* run bpf prog that inserts new key=3 element, re-using LRU slot */
> -	key = 3;
> -	err = prog_run_insert_elem(skel, key, TEST_VALUE);
> -	if (!ASSERT_OK(err, "prog_run_insert_elem"))
> -		goto cleanup;
> -
> -	/* check that key=3 replaced one of earlier elements */
> -	err = bpf_map_lookup_elem(map_fd, &key, value);
> -	if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
> -		goto cleanup;
> -
> -	/* and has expected values */
> -	check_values_one_cpu(value, TEST_VALUE);
> -
> -cleanup:
> -	test_map_init__destroy(skel);
> -}
> -
> -void test_map_init(void)
> -{
> -	nr_cpus = bpf_num_possible_cpus();
> -	if (nr_cpus <= 1) {
> -		printf("%s:SKIP: >1 cpu needed for this test\n", __func__);
> -		test__skip();
> -		return;
> -	}
> -
> -	if (test__start_subtest("pcpu_map_init"))
> -		test_pcpu_map_init();
> -	if (test__start_subtest("pcpu_lru_map_init"))
> -		test_pcpu_lru_map_init();
> -}
> diff --git a/tools/testing/selftests/bpf/progs/test_map_init.c b/tools/testing/selftests/bpf/progs/test_map_init.c
> deleted file mode 100644
> index c89d28ead673..000000000000
> --- a/tools/testing/selftests/bpf/progs/test_map_init.c
> +++ /dev/null
> @@ -1,33 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -/* Copyright (c) 2020 Tessares SA <http://www.tessares.net> */
> -
> -#include "vmlinux.h"
> -#include <bpf/bpf_helpers.h>
> -
> -__u64 inKey = 0;
> -__u64 inValue = 0;
> -__u32 inPid = 0;
> -
> -struct {
> -	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
> -	__uint(max_entries, 2);
> -	__type(key, __u64);
> -	__type(value, __u64);
> -} hashmap1 SEC(".maps");
> -
> -
> -SEC("tp/syscalls/sys_enter_getpgid")
> -int sysenter_getpgid(const void *ctx)
> -{
> -	/* Just do it for once, when called from our own test prog. This
> -	 * ensures the map value is only updated for a single CPU.
> -	 */
> -	int cur_pid = bpf_get_current_pid_tgid() >> 32;
> -
> -	if (cur_pid == inPid)
> -		bpf_map_update_elem(&hashmap1, &inKey, &inValue, BPF_NOEXIST);
> -
> -	return 0;
> -}
> -
> -char _license[] SEC("license") = "GPL";
>