Mark Mossberg 238c91115c x86/dumpstack: Fix misleading instruction pointer error message
Printing "Bad RIP value" if copy_code() fails can be misleading for
userspace pointers, since copy_code() can fail if the instruction
pointer is valid but the code is paged out. This is because copy_code()
calls copy_from_user_nmi() for userspace pointers, which disables page
fault handling.

This is reproducible in OOM situations, where it's plausible that the
code may be reclaimed in the time between entry into the kernel and when
this message is printed. This leaves a misleading log in dmesg that
suggests instruction pointer corruption has occurred, which may alarm
users.

Change the message to state the error condition more precisely.

 [ bp: Massage a bit. ]

Signed-off-by: Mark Mossberg <mark.mossberg@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201002042915.403558-1-mark.mossberg@gmail.com
2020-10-02 11:33:55 +02:00
2020-09-26 10:33:57 -07:00
2020-09-27 14:38:10 -07:00

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.
Description
No description provided
Readme 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%