Re: [RFC PATCH 1/3] selftests: add rbtree selftests

From: Hev
Date: Tue Dec 24 2019 - 12:00:58 EST


Hi,

On Tue, Dec 24, 2019 at 8:12 PM Heiher <r@xxxxxx> wrote:
>
> This adds the selftest for rbtree. It will reproduce the crash at earsing.
>
> Signed-off-by: hev <r@xxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Michel Lespinasse <walken@xxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> ---
> tools/testing/selftests/Makefile | 1 +
> tools/testing/selftests/lib/rbtree/.gitignore | 1 +
> tools/testing/selftests/lib/rbtree/Makefile | 29 ++++++++
> .../selftests/lib/rbtree/rbtree_test.c | 70 +++++++++++++++++++
> 4 files changed, 101 insertions(+)
> create mode 100644 tools/testing/selftests/lib/rbtree/.gitignore
> create mode 100644 tools/testing/selftests/lib/rbtree/Makefile
> create mode 100644 tools/testing/selftests/lib/rbtree/rbtree_test.c
>
> diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
> index b001c602414b..0e84ca3f207f 100644
> --- a/tools/testing/selftests/Makefile
> +++ b/tools/testing/selftests/Makefile
> @@ -25,6 +25,7 @@ TARGETS += kcmp
> TARGETS += kexec
> TARGETS += kvm
> TARGETS += lib
> +TARGETS += lib/rbtree
> TARGETS += livepatch
> TARGETS += membarrier
> TARGETS += memfd
> diff --git a/tools/testing/selftests/lib/rbtree/.gitignore b/tools/testing/selftests/lib/rbtree/.gitignore
> new file mode 100644
> index 000000000000..4c9f82761fad
> --- /dev/null
> +++ b/tools/testing/selftests/lib/rbtree/.gitignore
> @@ -0,0 +1 @@
> +rbtree_test
> diff --git a/tools/testing/selftests/lib/rbtree/Makefile b/tools/testing/selftests/lib/rbtree/Makefile
> new file mode 100644
> index 000000000000..68fa9dad24a1
> --- /dev/null
> +++ b/tools/testing/selftests/lib/rbtree/Makefile
> @@ -0,0 +1,29 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +CFLAGS += -I../../../../include/
> +
> +include ../../lib.mk
> +
> +# lib.mk TEST_CUSTOM_PROGS var is for custom tests that need special
> +# build rules. lib.mk will run and install them.
> +
> +TEST_CUSTOM_PROGS := $(OUTPUT)/rbtree_test
> +all: $(TEST_CUSTOM_PROGS)
> +
> +OBJS = rbtree_test.o
> +
> +LIBS = ../../../../lib/rbtree.o
> +
> +OBJS := $(patsubst %,$(OUTPUT)/%,$(OBJS))
> +LIBS := $(patsubst %,$(OUTPUT)/%,$(LIBS))
> +
> +$(TEST_CUSTOM_PROGS): $(LIBS) $(OBJS)
> + $(CC) -o $(TEST_CUSTOM_PROGS) $(OBJS) $(LIBS) $(CFLAGS) $(LDFLAGS)
> +
> +$(OBJS): $(OUTPUT)/%.o: %.c
> + $(CC) -c $^ -o $@ $(CFLAGS)
> +
> +$(LIBS): $(OUTPUT)/%.o: %.c
> + $(CC) -c $^ -o $@ $(CFLAGS)
> +
> +EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) $(OBJS) $(LIBS)
> diff --git a/tools/testing/selftests/lib/rbtree/rbtree_test.c b/tools/testing/selftests/lib/rbtree/rbtree_test.c
> new file mode 100644
> index 000000000000..11420541071a
> --- /dev/null
> +++ b/tools/testing/selftests/lib/rbtree/rbtree_test.c
> @@ -0,0 +1,70 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <stdlib.h>
> +#include <linux/rbtree.h>
> +#include "../../kselftest_harness.h"
> +
> +struct node {
> + struct rb_node node;
> + int key;
> +};
> +
> +static int _insert(struct rb_root *tree, int key)
> +{
> + struct rb_node **new = &tree->rb_node, *parent = NULL;
> + struct node *node;
> +
> + while (*new) {
> + struct node *this = container_of(*new, struct node, node);
> +
> + if (key < this->key)
> + new = &((*new)->rb_left);
> + else if (key > this->key)
> + new = &((*new)->rb_right);
> + else
> + return 0;
> + }
> +
> + node = malloc(sizeof(struct node));
> + if (!node)
> + return 0;
> +
> + node->key = key;
> + rb_link_node(&node->node, parent, new);
> + rb_insert_color(&node->node, tree);
> +
> + return 1;
> +}
> +
> +static void _remove(struct rb_root *tree, int key)
> +{
> + struct rb_node **node = &tree->rb_node;
> +
> + while (*node) {
> + struct node *this = container_of(*node, struct node, node);
> +
> + if (key < this->key) {
> + node = &((*node)->rb_left);
> + } else if (key > this->key) {
> + node = &((*node)->rb_right);
> + } else {
> + rb_erase(&this->node, tree);
> + free(this);
> + return;
> + }
> + }
> +}
> +
> +TEST(rbtree)
> +{
> + struct rb_root tree = { 0 };
> +
> + _insert(&tree, 2);
> + _insert(&tree, 1);
> + _insert(&tree, 4);
> + _insert(&tree, 3);
> +
> + _remove(&tree, 2);
> +}
> +
> +TEST_HARNESS_MAIN
> --
> 2.24.1
>

Sorry, recall these patches.
It was my mistake. I forget to update the parent pointer at inserting. :(

--
Best regards!
Hev
https://hev.cc