27985b2a64
On powerpc, watchpoint match range is double-word granular. On a watchpoint hit, DAR is set to the first byte of overlap between actual access and watched range. And thus it's quite possible that DAR does not point inside user specified range. Ex, say user creates a watchpoint with address range 0x1004 to 0x1007. So hw would be configured to watch from 0x1000 to 0x1007. If there is a 4 byte access from 0x1002 to 0x1005, DAR will point to 0x1002 and thus interrupt handler considers it as extraneous, but it's actually not, because part of the access belongs to what user has asked. Instead of blindly ignoring the exception, get actual address range by analysing an instruction, and ignore only if actual range does not overlap with user specified range. Note: The behavior is unchanged for 8xx. Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191017093204.7511-5-ravi.bangoria@linux.ibm.com
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.