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Modify the SAVE_SOME macro to look more like a standard function, doing the arithmetic for the frame on the SP register instead of copying it from K1, and by saving the stored EPC from the RA. This lets the get_frame_info() function process this function like any other. It also remove an instruction or two from the kernel entry, making it more efficient. unwind_stack_by_address() has special handling for the top of the interrupt stack, but without this change unwinding will still fail if you get an interrupt while handling an interrupt and try to do a traceback from the second interrupt. This change modifies the get_saved_sp macro to optionally store the fetched value right into sp and store the old SP value into K0. Then it's just a matter of subtracting the frame from SP and storing the old SP from K0. This required changing the DADDI workaround a bit, since K0 holds the SP, we had to use K1 for AT. But it eliminated some of the special handling for the DADDI workaround. Saving the RA register was moved up to before fetching the CP0_EPC register, so the CP0_EPC register could be stored into RA and the saved. This lets the traceback code know where RA is actually stored. Signed-off-by: Corey Minyard <cminyard@mvista.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16991/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.