mirror of
https://github.com/torvalds/linux.git
synced 2025-12-07 20:06:24 +00:00
d181d2da01
H.J. reported that post 5.7 a segfault of a user space task does not longer
dump the Code bytes when /proc/sys/debug/exception-trace is enabled. It
prints 'Code: Bad RIP value.' instead.
This was broken by a recent change which made probe_kernel_read() reject
non-kernel addresses.
Update show_opcodes() so it retrieves user space opcodes via
copy_from_user_nmi().
Fixes: 98a23609b1 ("maccess: always use strict semantics for probe_kernel_read")
Reported-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87h7tz306w.fsf@nanos.tec.linutronix.de
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.