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Kees Cook bdc77507fe um: virt-pci: Avoid GCC non-NULL warning
GCC gets confused about the return value of get_cpu_var() possibly
being NULL, so explicitly test for it before calls to memcpy() and
memset(). Avoids warnings like this:

   arch/um/drivers/virt-pci.c: In function 'um_pci_send_cmd':
   include/linux/fortify-string.h:48:33: warning: argument 1 null where non-null expected [-Wnonnull]
      48 | #define __underlying_memcpy     __builtin_memcpy
         |                                 ^
   include/linux/fortify-string.h:438:9: note: in expansion of macro '__underlying_memcpy'
     438 |         __underlying_##op(p, q, __fortify_size);                        \
         |         ^~~~~~~~~~~~~
   include/linux/fortify-string.h:483:26: note: in expansion of macro '__fortify_memcpy_chk'
     483 | #define memcpy(p, q, s)  __fortify_memcpy_chk(p, q, s,                  \
         |                          ^~~~~~~~~~~~~~~~~~~~
   arch/um/drivers/virt-pci.c💯9: note: in expansion of macro 'memcpy'
     100 |         memcpy(buf, cmd, cmd_size);
         |         ^~~~~~

While at it, avoid literal "8" and use stored sizeof(buf->data) in
memset() and um_pci_send_cmd().

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/202211271212.SUZSC9f9-lkp@intel.com
Fixes: ba38961a06 ("um: Enable FORTIFY_SOURCE")
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Xiu Jianfeng <xiujianfeng@huawei.com>
Cc: Vincent Whitchurch <vincent.whitchurch@axis.com>
Cc: linux-um@lists.infradead.org
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-12-02 13:04:44 -08:00
arch um: virt-pci: Avoid GCC non-NULL warning 2022-12-02 13:04:44 -08:00
block Random number generator fixes for Linux 6.1-rc1. 2022-10-16 15:27:07 -07:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto treewide: use get_random_bytes() when possible 2022-10-11 17:42:58 -06:00
Documentation panic: Expose "warn_count" to sysfs 2022-12-02 13:04:44 -08:00
drivers drm/sti: Fix return type of sti_{dvo,hda,hdmi}_connector_mode_valid() 2022-11-18 09:17:13 -08:00
fs coredump: Proactively round up to kmalloc bucket size 2022-11-01 10:04:52 -07:00
include panic: Consolidate open-coded panic_on_warn checks 2022-12-02 13:04:44 -08:00
init kbuild: upgrade the orphan section warning to an error if CONFIG_WERROR is set 2022-11-01 10:04:52 -07:00
io_uring io_uring/rw: ensure kiocb_end_write() is always called 2022-10-12 16:30:56 -06:00
ipc - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
kernel signal: Initialize the info in ksignal 2022-12-02 13:04:44 -08:00
lib lib: fortify_kunit: build without structleak plugin 2022-12-02 13:04:44 -08:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm panic: Consolidate open-coded panic_on_warn checks 2022-12-02 13:04:44 -08:00
net cred: Do not default to init_cred in prepare_kernel_cred() 2022-11-01 10:04:52 -07:00
rust Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
samples VFIO updates for v6.1-rc1 2022-10-12 14:46:48 -07:00
scripts string: Rewrite and add more kern-doc for the str*() functions 2022-10-28 16:07:57 -07:00
security - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
sound sound fixes for 6.1-rc1 2022-10-14 13:22:14 -07:00
tools perf tools changes for v6.1: 2nd batch 2022-10-16 15:14:29 -07:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt VFIO updates for v6.1-rc1 2022-10-12 14:46:48 -07:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS panic: Expose "warn_count" to sysfs 2022-12-02 13:04:44 -08:00
Makefile kbuild: upgrade the orphan section warning to an error if CONFIG_WERROR is set 2022-11-01 10:04:52 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.