2db3a8f541
[ Upstream commit 15eb77f873255cf9f4d703b63cfbd23c46579654 ]
Boot memory area is setup as separate PT_LOAD segment in the vmcore
as it is moved by f/w, on crash, to a destination address provided by
the kernel. Having separate PT_LOAD segment helps in handling the
different physical address and offset for boot memory area in the
vmcore.
Commit ced1bf52f477 ("powerpc/fadump: merge adjacent memory ranges to
reduce PT_LOAD segements") inadvertly broke this pre-condition for
cases where some of the first kernel memory is available adjacent to
boot memory area. This scenario is rare but possible when memory for
fadump could not be reserved adjacent to boot memory area owing to
memory hole or such. Reading memory from a vmcore exported in such
scenario provides incorrect data. Fix it by ensuring no other region
is folded into boot memory area.
Fixes: ced1bf52f477 ("powerpc/fadump: merge adjacent memory ranges to reduce PT_LOAD segements")
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220406093839.206608-2-hbathini@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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.