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Steven Rostedt (Google) a970174d7a x86/mm: Do not verify W^X at boot up 
Adding on the kernel command line "ftrace=function" triggered:

  CPA detected W^X violation: 8000000000000063 -> 0000000000000063 range: 0xffffffffc0013000 - 0xffffffffc0013fff PFN 10031b
  WARNING: CPU: 0 PID: 0 at arch/x86/mm/pat/set_memory.c:609
  verify_rwx+0x61/0x6d
  Call Trace:
     __change_page_attr_set_clr+0x146/0x8a6
     change_page_attr_set_clr+0x135/0x268
     change_page_attr_clear.constprop.0+0x16/0x1c
     set_memory_x+0x2c/0x32
     arch_ftrace_update_trampoline+0x218/0x2db
     ftrace_update_trampoline+0x16/0xa1
     __register_ftrace_function+0x93/0xb2
     ftrace_startup+0x21/0xf0
     register_ftrace_function_nolock+0x26/0x40
     register_ftrace_function+0x4e/0x143
     function_trace_init+0x7d/0xc3
     tracer_init+0x23/0x2c
     tracing_set_tracer+0x1d5/0x206
     register_tracer+0x1c0/0x1e4
     init_function_trace+0x90/0x96
     early_trace_init+0x25c/0x352
     start_kernel+0x424/0x6e4
     x86_64_start_reservations+0x24/0x2a
     x86_64_start_kernel+0x8c/0x95
     secondary_startup_64_no_verify+0xe0/0xeb

This is because at boot up, kernel text is writable, and there's no
reason to do tricks to updated it.  But the verifier does not
distinguish updates at boot up and at run time, and causes a warning at
time of boot.

Add a check for system_state == SYSTEM_BOOTING and allow it if that is
the case.

[ These SYSTEM_BOOTING special cases are all pretty horrid, but the x86
  text_poke() code does some odd things at bootup, forcing this for now
    - Linus ]

Link: https://lore.kernel.org/r/20221024112730.180916b3@gandalf.local.home
Fixes: 652c5bf380 ("x86/mm: Refuse W^X violations")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-10-24 18:05:27 -07:00
arch x86/mm: Do not verify W^X at boot up 2022-10-24 18:05:27 -07:00
block block-6.1-2022-10-20 2022-10-21 15:14:14 -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 Including fixes from bpf. 2022-10-24 12:43:51 -07:00
drivers Including fixes from bpf. 2022-10-24 12:43:51 -07:00
fs First batch of EFI fixes for v6.1 2022-10-21 18:02:36 -07:00
include Including fixes from bpf. 2022-10-24 12:43:51 -07:00
init init: Kconfig: fix spelling mistake "satify" -> "satisfy" 2022-10-20 21:27:22 -07:00
io_uring io_uring/net: fail zc sendmsg when unsupported by socket 2022-10-22 08:43:03 -06:00
ipc - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
kernel Including fixes from bpf. 2022-10-24 12:43:51 -07:00
lib kunit: update NULL vs IS_ERR() tests 2022-10-18 15:08:42 -06:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm/huge_memory: do not clobber swp_entry_t during THP split 2022-10-20 21:27:24 -07:00
net Including fixes from bpf. 2022-10-24 12:43:51 -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 Kbuild fixes for v6.1 2022-10-16 11:12:22 -07:00
security selinux: enable use of both GFP_KERNEL and GFP_ATOMIC in convert_context() 2022-10-19 09:55:53 -04:00
sound sound fixes for 6.1-rc1 2022-10-14 13:22:14 -07:00
tools Including fixes from bpf. 2022-10-24 12:43:51 -07:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt kvm: Add support for arch compat vm ioctls 2022-10-22 05:15:23 -04:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig
.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 mailmap: update email for Qais Yousef 2022-10-20 21:27:21 -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 Including fixes from bpf. 2022-10-24 12:43:51 -07:00
Makefile Linux 6.1-rc2 2022-10-23 15:27:33 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

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.