Jinjie Ruan 28926daf73 fpga: Fix memory leak for fpga_region_test_class_find()
fpga_region_class_find() in fpga_region_test_class_find() will call
get_device() if the data is matched, which will increment refcount for
dev->kobj, so it should call put_device() to decrement refcount for
dev->kobj to free the region, because fpga_region_unregister() will call
fpga_region_dev_release() only when the refcount for dev->kobj is zero
but fpga_region_test_init() call device_register() in
fpga_region_register_full(), which also increment refcount.

So call put_device() after calling fpga_region_class_find() in
fpga_region_test_class_find(). After applying this patch, the following
memory leak is never detected.

unreferenced object 0xffff88810c8ef000 (size 1024):
  comm "kunit_try_catch", pid 1875, jiffies 4294715298 (age 836.836s)
  hex dump (first 32 bytes):
    b8 d1 fb 05 81 88 ff ff 08 f0 8e 0c 81 88 ff ff  ................
    08 f0 8e 0c 81 88 ff ff 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff817ebad7>] kmalloc_trace+0x27/0xa0
    [<ffffffffa02385e1>] fpga_region_register_full+0x51/0x430 [fpga_region]
    [<ffffffffa0228e47>] 0xffffffffa0228e47
    [<ffffffff829c479d>] kunit_try_run_case+0xdd/0x250
    [<ffffffff829c9f2a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81238b85>] kthread+0x2b5/0x380
    [<ffffffff81097ded>] ret_from_fork+0x2d/0x70
    [<ffffffff810034d1>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff888105fbd1b8 (size 8):
  comm "kunit_try_catch", pid 1875, jiffies 4294715298 (age 836.836s)
  hex dump (first 8 bytes):
    72 65 67 69 6f 6e 30 00                          region0.
  backtrace:
    [<ffffffff817ec023>] __kmalloc_node_track_caller+0x53/0x150
    [<ffffffff82995590>] kvasprintf+0xb0/0x130
    [<ffffffff83f713b1>] kobject_set_name_vargs+0x41/0x110
    [<ffffffff8304ac1b>] dev_set_name+0xab/0xe0
    [<ffffffffa02388a2>] fpga_region_register_full+0x312/0x430 [fpga_region]
    [<ffffffffa0228e47>] 0xffffffffa0228e47
    [<ffffffff829c479d>] kunit_try_run_case+0xdd/0x250
    [<ffffffff829c9f2a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81238b85>] kthread+0x2b5/0x380
    [<ffffffff81097ded>] ret_from_fork+0x2d/0x70
    [<ffffffff810034d1>] ret_from_fork_asm+0x11/0x20
unreferenced object 0xffff88810b3b8a00 (size 256):
  comm "kunit_try_catch", pid 1875, jiffies 4294715298 (age 836.836s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 08 8a 3b 0b 81 88 ff ff  ..........;.....
    08 8a 3b 0b 81 88 ff ff e0 ac 04 83 ff ff ff ff  ..;.............
  backtrace:
    [<ffffffff817ebad7>] kmalloc_trace+0x27/0xa0
    [<ffffffff83056d7a>] device_add+0xa2a/0x15e0
    [<ffffffffa02388b1>] fpga_region_register_full+0x321/0x430 [fpga_region]
    [<ffffffffa0228e47>] 0xffffffffa0228e47
    [<ffffffff829c479d>] kunit_try_run_case+0xdd/0x250
    [<ffffffff829c9f2a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
    [<ffffffff81238b85>] kthread+0x2b5/0x380
    [<ffffffff81097ded>] ret_from_fork+0x2d/0x70
    [<ffffffff810034d1>] ret_from_fork_asm+0x11/0x20

Fixes: 64a5f972c9 ("fpga: add an initial KUnit suite for the FPGA Region")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Marco Pagani <marpagan@redhat.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20231007094321.3447084-1-ruanjinjie@huawei.com
[yilun.xu@intel.com: slightly changes the commit message]
Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>
Link: https://lore.kernel.org/r/20231023032857.902699-3-yilun.xu@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-24 19:32:39 +02:00
2022-09-28 09:02:20 +02:00
2023-10-15 13:34:39 -07:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%