linux-kernel - [PATCH 4.13 02/53] MIPS: math-emu: Remove pr_err() calls from fpu

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 16 Oct 2017 18:15:59 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Paul Burton <paul.burton@...tec.com>,
        linux-mips@...ux-mips.org, Ralf Baechle <ralf@...ux-mips.org>
Subject: [PATCH 4.13 02/53] MIPS: math-emu: Remove pr_err() calls from fpu_emu()

4.13-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Paul Burton <paul.burton@...tec.com>

commit ca8eb05b5f332a9e1ab3e2ece498d49f4d683470 upstream.

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@...tec.com>
Fixes: f8c3c6717a71 ("MIPS: math-emu: Add support for the CMP.condn.fmt R6 instruction")
Cc: linux-mips@...ux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17253/
Signed-off-by: Ralf Baechle <ralf@...ux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 arch/mips/math-emu/cp1emu.c |    2 --
 1 file changed, 2 deletions(-)

--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -2387,7 +2387,6 @@ dcopuop:
 					break;
 				default:
 					/* Reserved R6 ops */
-					pr_err("Reserved MIPS R6 CMP.condn.S operation\n");
 					return SIGILL;
 				}
 			}
@@ -2461,7 +2460,6 @@ dcopuop:
 					break;
 				default:
 					/* Reserved R6 ops */
-					pr_err("Reserved MIPS R6 CMP.condn.D operation\n");
 					return SIGILL;
 				}
 			}