Patch "MIPS: Fix unaligned PC interpretation in `compute_return_epc'" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

MIPS: Fix unaligned PC interpretation in `compute_return_epc'

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mips-fix-unaligned-pc-interpretation-in-compute_return_epc.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: "Maciej W. Rozycki" <[email protected]>
Date: Fri, 16 Jun 2017 00:07:34 +0100
Subject: MIPS: Fix unaligned PC interpretation in `compute_return_epc'

From: Maciej W. Rozycki <[email protected]>

commit 11a3799dbeb620bf0400b1fda5cc2c6bea55f20a upstream.

Fix a regression introduced with commit fb6883e5809c ("MIPS: microMIPS:
Support handling of delay slots.") and defer to `__compute_return_epc' if the ISA bit is set in EPC with non-MIPS16, non-microMIPS hardware, which will then arrange for a SIGBUS due to an unaligned instruction reference. Returning EPC here is never correct as the API defines this function's result to be either a negative error code on failure or one of 0 and BRANCH_LIKELY_TAKEN on success.

Patchwork: https://patchwork.linux-mips.org/patch/16395/

---
 arch/mips/include/asm/branch.h |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

@@ -74,10 +74,7 @@ static inline int compute_return_epc(str
 			return __microMIPS_compute_return_epc(regs);
 		if (cpu_has_mips16)
 			return __MIPS16e_compute_return_epc(regs);
-		return regs->cp0_epc;
-	}
-
-	if (!delay_slot(regs)) {
+	} else if (!delay_slot(regs)) {
 		regs->cp0_epc += 4;
 		return 0;
 	}

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/mips-send-sigill-for-bposge32-in-__compute_return_epc_for_insn.patch queue-4.4/mips-actually-decode-jalx-in-__compute_return_epc_for_insn.patch queue-4.4/mips-fix-a-typo-s-preset-present-in-r2-to-r6-emulation-error-message.patch queue-4.4/mips-fix-unaligned-pc-interpretation-in-compute_return_epc.patch queue-4.4/mips-rename-sigill_r6-to-sigill_r2r6-in-__compute_return_epc_for_insn.patch queue-4.4/mips-send-sigill-for-linked-branches-in-__compute_return_epc_for_insn.patch queue-4.4/mips-math-emu-prevent-wrong-isa-mode-instruction-emulation.patch