Commit ca8eb05b authored Sep 08, 2017 by Paul Burton Committed by Ralf Baechle Oct 09, 2017

MIPS: math-emu: Remove pr_err() calls from fpu_emu()



The FPU emulator includes 2 calls to pr_err() which are triggered by
invalid instruction encodings for MIPSr6 cmp.cond.fmt instructions.
These cases are not kernel errors, merely invalid instructions which are
already handled by delivering a SIGILL which will provide notification
that something failed in cases where that makes sense.

In cases where that SIGILL is somewhat expected & being handled, for
example when crashme happens to generate one of the affected bad
encodings, the message is printed with no useful context about what
triggered it & spams the kernel log for no good reason.

Remove the pr_err() calls to make crashme run silently & treat the bad
encodings the same way we do others, with a SIGILL & no further kernel
log output.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: f8c3c671 ("MIPS: math-emu: Add support for the CMP.condn.fmt R6 instruction")
Cc: linux-mips@linux-mips.org
Cc: stable <stable@vger.kernel.org> # v4.3+
Patchwork: https://patchwork.linux-mips.org/patch/17253/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

parent e1270575

arch/mips/math-emu/cp1emu.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -2558,7 +2558,6 @@ static int fpu_emu(struct pt_regs xcp, struct mips_fpu_struct ctx,
		break;
		default:
		/* Reserved R6 ops */
		pr_err("Reserved MIPS R6 CMP.condn.S operation\n");
		return SIGILL;
		}
		}
		@@ -2719,7 +2718,6 @@ static int fpu_emu(struct pt_regs xcp, struct mips_fpu_struct ctx,
		break;
		default:
		/* Reserved R6 ops */
		pr_err("Reserved MIPS R6 CMP.condn.D operation\n");
		return SIGILL;
		}
		}