mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-09 06:41:06 -04:00
73aca179d7
If you build the kernel with CONFIG_RELOCATABLE=n, then install the modules, rebuild the kernel with CONFIG_RELOCATABLE=y and leave the old modules installed, we crash something like: Unable to handle kernel paging request for data at address 0xd000000018d66cef Faulting instruction address: 0xc0000000021ddd08 Oops: Kernel access of bad area, sig: 11 [#1] Modules linked in: x_tables autofs4 CPU: 2 PID: 1 Comm: systemd Not tainted 4.16.0-rc6-gcc_ubuntu_le-g99fec39 #1 ... NIP check_version.isra.22+0x118/0x170 Call Trace: __ksymtab_xt_unregister_table+0x58/0xfffffffffffffcb8 [x_tables] (unreliable) resolve_symbol+0xb4/0x150 load_module+0x10e8/0x29a0 SyS_finit_module+0x110/0x140 system_call+0x58/0x6c This happens because since commit71810db27c("modversions: treat symbol CRCs as 32 bit quantities"), a relocatable kernel encodes and handles symbol CRCs differently from a non-relocatable kernel. Although it's possible we could try and detect this situation and handle it, it's much more robust to simply make the state of CONFIG_RELOCATABLE part of the module vermagic. Fixes:71810db27c("modversions: treat symbol CRCs as 32 bit quantities") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.