Fork of alistair23 Linux kernel for reMarkable from https://github.com/alistair23/linux
ea0eada456
Currently, if a section has a relocation to '_mcount' symbol, a new
__mcount_loc entry will be added whatever the relocation type is.
This is problematic when a relocation to '_mcount' is in the middle of a
section and is not a call for ftrace use.
Such relocation could be generated with below code for example:
bool is_mcount(unsigned long addr)
{
return (target == (unsigned long) &_mcount);
}
With this snippet of code, ftrace will try to patch the mcount location
generated by this code on module load and fail with:
Call trace:
ftrace_bug+0xa0/0x28c
ftrace_process_locs+0x2f4/0x430
ftrace_module_init+0x30/0x38
load_module+0x14f0/0x1e78
__do_sys_finit_module+0x100/0x11c
__arm64_sys_finit_module+0x28/0x34
el0_svc_common+0x88/0x194
el0_svc_handler+0x38/0x8c
el0_svc+0x8/0xc
---[ end trace d828d06b36ad9d59 ]---
ftrace failed to modify
[<ffffa2dbf3a3a41c>] 0xffffa2dbf3a3a41c
actual: 66:a9:3c:90
Initializing ftrace call sites
ftrace record flags: 2000000
(0)
expected tramp: ffffa2dc6cf66724
So Limit the relocation type to R_AARCH64_CALL26 as in perl version of
recordmcount.
Fixes:
|
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.