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Patch "MIPS: Send SIGILL for BPOSGE32 in `__compute_return_epc_for_insn'" has been added to the 4.4-stable tree

PATCH [email protected] 1 participant 1 message Jul 25, 2017

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

MIPS: Send SIGILL for BPOSGE32 in `__compute_return_epc_for_insn'

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-send-sigill-for-bposge32-in-__compute_return_epc_for_insn.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.

Quoted 1 line

From 7b82c1058ac1f8f8b9f2b8786b1f710a57a870a8 Mon Sep 17 00:00:00 2001

From: "Maciej W. Rozycki" <[email protected]>
Date: Fri, 16 Jun 2017 00:08:29 +0100
Subject: MIPS: Send SIGILL for BPOSGE32 in `__compute_return_epc_for_insn'

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

commit 7b82c1058ac1f8f8b9f2b8786b1f710a57a870a8 upstream.

Fix commit e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE.") and send SIGILL rather than SIGBUS whenever an unimplemented BPOSGE32 DSP ASE instruction has been encountered in `__compute_return_epc_for_insn' as our Reserved Instruction exception handler would in response to an attempt to actually execute the instruction. Sending SIGBUS only makes sense for the unaligned PC case, since moved to __compute_return_epc'. Adjust function documentation accordingly, correct formatting and use pr_info' rather than `printk' as the other exit path already does.

Fixes e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE.")
Cc James Hogan <[email protected]>

Patchwork: https://patchwork.linux-mips.org/patch/16396/

---
 arch/mips/kernel/branch.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
arch/mips/kernel/branch.c +4 -3
@@ -399,7 +399,7 @@ int __MIPS16e_compute_return_epc(struct
  *
  * @regs:	Pointer to pt_regs
  * @insn:	branch instruction to decode
- * @returns:	-EFAULT on error and forces SIGBUS, and on success
+ * @returns:	-EFAULT on error and forces SIGILL, and on success
  *		returns 0 or BRANCH_LIKELY_TAKEN as appropriate after
  *		evaluating the branch.
  *
@@ -844,8 +844,9 @@ int __compute_return_epc_for_insn(struct
 	return ret;
 
 sigill_dsp:
-	printk("%s: DSP branch but not DSP ASE - sending SIGBUS.\n", current->comm);
-	force_sig(SIGBUS, current);
+	pr_info("%s: DSP branch but not DSP ASE - sending SIGILL.\n",
+		current->comm);
+	force_sig(SIGILL, current);
 	return -EFAULT;
 sigill_r6:
 	pr_info("%s: R2 branch but r2-to-r6 emulator is not preset - sending SIGILL.\n",

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