linux.git/kernel/sysctl-test.c, branch v6.18.21

sysctl: move u8 register test to lib/test_sysctl.c

2025-04-14T12:13:41+00:00

If the test added in commit b5ffbd139688 ("sysctl: move the extra1/2
boundary check of u8 to sysctl_check_table_array") is run as a module, a
lingering reference to the module is left behind, and a 'sysctl -a'
leads to a panic.

To reproduce
    CONFIG_KUNIT=y
    CONFIG_SYSCTL_KUNIT_TEST=m

Then run these commands:
    modprobe sysctl-test
    rmmod sysctl-test
    sysctl -a

The panic varies but generally looks something like this:

    BUG: unable to handle page fault for address: ffffa4571c0c7db4
    #PF: supervisor read access in kernel mode
    #PF: error_code(0x0000) - not-present page
    PGD 100000067 P4D 100000067 PUD 100351067 PMD 114f5e067 PTE 0
    Oops: Oops: 0000 [#1] SMP NOPTI
    ... ... ...
    RIP: 0010:proc_sys_readdir+0x166/0x2c0
    ... ... ...
    Call Trace:
     
     iterate_dir+0x6e/0x140
     __se_sys_getdents+0x6e/0x100
     do_syscall_64+0x70/0x150
     entry_SYSCALL_64_after_hwframe+0x76/0x7e

Move the test to lib/test_sysctl.c where the registration reference is
handled on module exit

Fixes: b5ffbd139688 ("sysctl: move the extra1/2 boundary check of u8 to sysctl_check_table_array")

Reviewed-by: Kees Cook 
Signed-off-by: Joel Granados

treewide: const qualify ctl_tables where applicable

2025-01-28T12:48:37+00:00

Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.

Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit 78eb4ea25cd5 ("sysctl: treewide:
constify the ctl_table argument of proc_handlers") constified all the
proc_handlers.

Created this by running an spatch followed by a sed command:
Spatch:
    virtual patch

    @
    depends on !(file in "net")
    disable optional_qualifier
    @

    identifier table_name != {
      watchdog_hardlockup_sysctl,
      iwcm_ctl_table,
      ucma_ctl_table,
      memory_allocation_profiling_sysctls,
      loadpin_sysctl_table
    };
    @@

    + const
    struct ctl_table table_name [] = { ... };

sed:
    sed --in-place \
      -e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \
      kernel/utsname_sysctl.c

Reviewed-by: Song Liu 
Acked-by: Steven Rostedt (Google)  # for kernel/trace/
Reviewed-by: Martin K. Petersen  # SCSI
Reviewed-by: Darrick J. Wong  # xfs
Acked-by: Jani Nikula 
Acked-by: Corey Minyard 
Acked-by: Wei Liu 
Acked-by: Thomas Gleixner 
Reviewed-by: Bill O'Donnell 
Acked-by: Baoquan He 
Acked-by: Ashutosh Dixit 
Acked-by: Anna Schumaker 
Signed-off-by: Joel Granados

sysctl: Add module description to sysctl-testing

2024-06-03T13:20:37+00:00

Added a module description to sysctl Kunit self test module to fix the
'make W=1' warning (" WARNING: modpost: missing MODULE_DESCRIPTION() in
kernel/sysctl-test.o")

Signed-off-by: Jeff Johnson 
Signed-off-by: Joel Granados

sysctl: move the extra1/2 boundary check of u8 to sysctl_check_table_array

2024-06-03T13:14:34+00:00

Move boundary checking for proc_dou8ved_minmax into module loading, thereby
reporting errors in advance. And add a kunit test case ensuring the
boundary check is done correctly.

The boundary check in proc_dou8vec_minmax done to the extra elements in
the ctl_table struct is currently performed at runtime. This allows buggy
kernel modules to be loaded normally without any errors only to fail
when used.

This is a buggy example module:
	#include 
	#include 
	#include 

	static struct ctl_table_header *_table_header = NULL;
	static unsigned char _data = 0;
	struct ctl_table table[] = {
		{
			.procname       = "foo",
			.data           = &_data,
			.maxlen         = sizeof(u8),
			.mode           = 0644,
			.proc_handler   = proc_dou8vec_minmax,
			.extra1         = SYSCTL_ZERO,
			.extra2         = SYSCTL_ONE_THOUSAND,
		},
	};

	static int init_demo(void) {
		_table_header = register_sysctl("kernel", table);
		if (!_table_header)
			return -ENOMEM;

		return 0;
	}

	module_init(init_demo);
	MODULE_LICENSE("GPL");

And this is the result:
        # insmod test.ko
        # cat /proc/sys/kernel/foo
        cat: /proc/sys/kernel/foo: Invalid argument

Suggested-by: Joel Granados 
Signed-off-by: Wen Yang 
Cc: Luis Chamberlain 
Cc: Kees Cook 
Cc: Joel Granados 
Cc: Eric W. Biederman 
Cc: Christian Brauner 
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Joel Granados 
Signed-off-by: Joel Granados

kernel/sysctl-test: use SYSCTL_{ZERO/ONE_HUNDRED} instead of i_{zero/one_hundred}

2022-09-08T23:56:45+00:00

It is better to use SYSCTL_ZERO and SYSCTL_ONE_HUNDRED instead of &i_zero
and &i_one_hundred, and then we can remove these two local variable.

No functional change.

Signed-off-by: Liu Shixin 
Signed-off-by: Luis Chamberlain

kernel/sysctl-test: Remove some casts which are no-longer required

2021-06-23T22:41:24+00:00

With some of the stricter type checking in KUnit's EXPECT macros
removed, several casts in sysctl-test are no longer required.

Remove the unnecessary casts, making the conditions clearer.

Signed-off-by: David Gow 
Reviewed-by: Brendan Higgins 
Signed-off-by: Shuah Khan

kunit: allow kunit tests to be loaded as a module

2020-01-09T23:42:29+00:00

As tests are added to kunit, it will become less feasible to execute
all built tests together.  By supporting modular tests we provide
a simple way to do selective execution on a running system; specifying

CONFIG_KUNIT=y
CONFIG_KUNIT_EXAMPLE_TEST=m

...means we can simply "insmod example-test.ko" to run the tests.

To achieve this we need to do the following:

o export the required symbols in kunit
o string-stream tests utilize non-exported symbols so for now we skip
  building them when CONFIG_KUNIT_TEST=m.
o drivers/base/power/qos-test.c contains a few unexported interface
  references, namely freq_qos_read_value() and freq_constraints_init().
  Both of these could be potentially defined as static inline functions
  in include/linux/pm_qos.h, but for now we simply avoid supporting
  module build for that test suite.
o support a new way of declaring test suites.  Because a module cannot
  do multiple late_initcall()s, we provide a kunit_test_suites() macro
  to declare multiple suites within the same module at once.
o some test module names would have been too general ("test-test"
  and "example-test" for kunit tests, "inode-test" for ext4 tests);
  rename these as appropriate ("kunit-test", "kunit-example-test"
  and "ext4-inode-test" respectively).

Also define kunit_test_suite() via kunit_test_suites()
as callers in other trees may need the old definition.

Co-developed-by: Knut Omang 
Signed-off-by: Knut Omang 
Signed-off-by: Alan Maguire 
Reviewed-by: Brendan Higgins 
Acked-by: Theodore Ts'o  # for ext4 bits
Acked-by: David Gow  # For list-test
Reported-by: kbuild test robot 
Signed-off-by: Shuah Khan

kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec()

2019-09-30T23:35:01+00:00

KUnit tests for initialized data behavior of proc_dointvec that is
explicitly checked in the code. Includes basic parsing tests including
int min/max overflow.

Signed-off-by: Iurii Zaikin 
Signed-off-by: Brendan Higgins 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Logan Gunthorpe 
Acked-by: Luis Chamberlain 
Reviewed-by: Stephen Boyd 
Signed-off-by: Shuah Khan