On Fri, Feb 10, 2017 at 4:36 PM, Luis R. Rodriguez <mcg...@kernel.org> wrote: > Although we have had tools/testing/selftests/sysctl/ with two > test cases these use existing kernel sysctl interfaces. We want > to expand test coverage, we can't just be looking for random > safe production values to poke at, instead just dedicate a test > driver for debugging purposes and port the existing scripts to > use it. This will make it easier for further tests to be added. > > Signed-off-by: Luis R. Rodriguez <mcg...@kernel.org>
Yes please! Acked-by: Kees Cook <keesc...@chromium.org> > --- > lib/Kconfig.debug | 11 +++ > lib/Makefile | 1 + > lib/test_sysctl.c | 106 > ++++++++++++++++++++++++ > tools/testing/selftests/sysctl/config | 1 + > tools/testing/selftests/sysctl/run_numerictests | 4 +- > tools/testing/selftests/sysctl/run_stringtests | 4 +- > 6 files changed, 123 insertions(+), 4 deletions(-) > create mode 100644 lib/test_sysctl.c > create mode 100644 tools/testing/selftests/sysctl/config > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 64c03b07ad2f..d753fac41f78 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -1975,6 +1975,17 @@ config TEST_FIRMWARE > > If unsure, say N. > > +config TEST_SYSCTL > + tristate "sysctl test driver" > + default n > + depends on PROC_SYSCTL > + help > + This builds the "test_sysctl" module. This driver enables to test > the > + proc sysctl interfaces available to drivers safely without affecting > + production knobs which might alter system functionality. > + > + If unsure, say N. > + > config TEST_UDELAY > tristate "udelay test driver" > default n > diff --git a/lib/Makefile b/lib/Makefile > index 445a39c21f46..ac832c440d41 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -45,6 +45,7 @@ obj-$(CONFIG_TEST_HEXDUMP) += test_hexdump.o > obj-y += kstrtox.o > obj-$(CONFIG_TEST_BPF) += test_bpf.o > obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o > +obj-$(CONFIG_TEST_SYSCTL) += test_sysctl.o > obj-$(CONFIG_TEST_HASH) += test_hash.o test_siphash.o > obj-$(CONFIG_TEST_KASAN) += test_kasan.o > obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o > diff --git a/lib/test_sysctl.c b/lib/test_sysctl.c > new file mode 100644 > index 000000000000..9b9ae1a95ab3 > --- /dev/null > +++ b/lib/test_sysctl.c > @@ -0,0 +1,106 @@ > +/* > + * proc sysctl test driver > + * > + * Copyright (C) 2017 Luis R. Rodriguez <mcg...@kernel.org> > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms of copyleft-next (version 0.3.1 or later) as published > + * at http://copyleft-next.org/. > + */ > + > +/* > + * This module provides an interface to the the proc sysctl interfaces. This > + * driver requires CONFIG_PROC_SYSCTL. It will not normally be loaded by the > + * system unless explicitly requested by name. You can also build this driver > + * into your kernel. > + */ > + > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > + > +#include <linux/init.h> > +#include <linux/list.h> > +#include <linux/module.h> > +#include <linux/printk.h> > +#include <linux/fs.h> > +#include <linux/miscdevice.h> > +#include <linux/slab.h> > +#include <linux/uaccess.h> > +#include <linux/async.h> > +#include <linux/delay.h> > +#include <linux/vmalloc.h> > + > +static int i_zero; > +static int i_one_hundred = 100; > + > +struct test_sysctl_data { > + int int_0001; > + char string_0001[65]; I wonder if it's worth adding a comment here that "65" is tied to the sysctl string self-test. > +}; > + > +static struct test_sysctl_data test_data = { > + .int_0001 = 60, > + .string_0001 = "(none)", > +}; > + > +/* These are all under /proc/sys/debug/test_sysctl/ */ > +static struct ctl_table test_table[] = { > + { > + .procname = "int_0001", > + .data = &test_data.int_0001, > + .maxlen = sizeof(int), > + .mode = 0644, > + .proc_handler = proc_dointvec_minmax, > + .extra1 = &i_zero, > + .extra2 = &i_one_hundred, > + }, > + { > + .procname = "string_0001", > + .data = &test_data.string_0001, > + .maxlen = sizeof(test_data.string_0001), > + .mode = 0644, > + .proc_handler = proc_dostring, > + }, > + { } > +}; > + > +static struct ctl_table test_sysctl_table[] = { > + { > + .procname = "test_sysctl", > + .maxlen = 0, > + .mode = 0555, > + .child = test_table, > + }, > + { } > +}; > + > +static struct ctl_table test_sysctl_root_table[] = { > + { > + .procname = "debug", > + .maxlen = 0, > + .mode = 0555, > + .child = test_sysctl_table, > + }, > + { } > +}; > + > +static struct ctl_table_header *test_sysctl_header; > + > +static int __init test_sysctl_init(void) > +{ > + test_sysctl_header = register_sysctl_table(test_sysctl_root_table); > + if (!test_sysctl_header) > + return -ENOMEM; > + return 0; > +} > +late_initcall(test_sysctl_init); > + > +static void __exit test_sysctl_exit(void) > +{ > + if (test_sysctl_header) > + unregister_sysctl_table(test_sysctl_header); > +} > + > +module_exit(test_sysctl_exit); > + > +MODULE_AUTHOR("Luis R. Rodriguez <mcg...@kernel.org>"); > +MODULE_LICENSE("GPL"); > diff --git a/tools/testing/selftests/sysctl/config > b/tools/testing/selftests/sysctl/config > new file mode 100644 > index 000000000000..6ca14800d755 > --- /dev/null > +++ b/tools/testing/selftests/sysctl/config > @@ -0,0 +1 @@ > +CONFIG_TEST_SYSCTL=y Technically, this works with =m too, but whatever reads "config" would need to know to load it first... > diff --git a/tools/testing/selftests/sysctl/run_numerictests > b/tools/testing/selftests/sysctl/run_numerictests > index 8510f93f2d14..cdfeef96568c 100755 > --- a/tools/testing/selftests/sysctl/run_numerictests > +++ b/tools/testing/selftests/sysctl/run_numerictests > @@ -1,7 +1,7 @@ > #!/bin/sh > > -SYSCTL="/proc/sys" > -TARGET="${SYSCTL}/vm/swappiness" > +SYSCTL="/proc/sys/debug/test_sysctl/" > +TARGET="${SYSCTL}/int_0001" > ORIG=$(cat "${TARGET}") > TEST_STR=$(( $ORIG + 1 )) > > diff --git a/tools/testing/selftests/sysctl/run_stringtests > b/tools/testing/selftests/sysctl/run_stringtests > index 90a9293d520c..15a646b2c527 100755 > --- a/tools/testing/selftests/sysctl/run_stringtests > +++ b/tools/testing/selftests/sysctl/run_stringtests > @@ -1,7 +1,7 @@ > #!/bin/sh > > -SYSCTL="/proc/sys" > -TARGET="${SYSCTL}/kernel/domainname" > +SYSCTL="/proc/sys/debug/test_sysctl/" > +TARGET="${SYSCTL}/string_0001" > ORIG=$(cat "${TARGET}") > TEST_STR="Testing sysctl" > > -- > 2.11.0 > Acked-by: Kees Cook <keesc...@chromium.org> -Kees -- Kees Cook Pixel Security
