Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755897AbZFCSrg (ORCPT ); Wed, 3 Jun 2009 14:47:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755115AbZFCSqr (ORCPT ); Wed, 3 Jun 2009 14:46:47 -0400 Received: from one.firstfloor.org ([213.235.205.2]:37810 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754732AbZFCSqq (ORCPT ); Wed, 3 Jun 2009 14:46:46 -0400 From: Andi Kleen References: <20090603846.816684333@firstfloor.org> In-Reply-To: <20090603846.816684333@firstfloor.org> To: akpm@linux-foundation.org, npiggin@suse.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org, fengguang.wu@intel.com Subject: [PATCH] [4/16] HWPOISON: Add new SIGBUS error codes for hardware poison signals Message-Id: <20090603184636.9F9DE1D0286@basil.firstfloor.org> Date: Wed, 3 Jun 2009 20:46:36 +0200 (CEST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2955 Lines: 72 Add new SIGBUS codes for reporting machine checks as signals. When the hardware detects an uncorrected ECC error it can trigger these signals. This is needed for telling KVM's qemu about machine checks that happen to guests, so that it can inject them, but might be also useful for other programs. I find it useful in my test programs. This patch merely defines the new types. - Define two new si_codes for SIGBUS. BUS_MCEERR_AO and BUS_MCEERR_AR * BUS_MCEERR_AO is for "Action Optional" machine checks, which means that some corruption has been detected in the background, but nothing has been consumed so far. The program can ignore those if it wants (but most programs would already get killed) * BUS_MCEERR_AR is for "Action Required" machine checks. This happens when corrupted data is consumed or the application ran into an area which has been known to be corrupted earlier. These require immediate action and cannot just returned to. Most programs would kill themselves. - They report the address of the corruption in the user address space in si_addr. - Define a new si_addr_lsb field that reports the extent of the corruption to user space. That's currently always a (small) page. The user application cannot tell where in this page the corruption happened. AK: I plan to write a man page update before anyone asks. Signed-off-by: Andi Kleen --- include/asm-generic/siginfo.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) Index: linux/include/asm-generic/siginfo.h =================================================================== --- linux.orig/include/asm-generic/siginfo.h 2009-06-03 19:36:22.000000000 +0200 +++ linux/include/asm-generic/siginfo.h 2009-06-03 19:36:23.000000000 +0200 @@ -82,6 +82,7 @@ #ifdef __ARCH_SI_TRAPNO int _trapno; /* TRAP # which caused the signal */ #endif + short _addr_lsb; /* LSB of the reported address */ } _sigfault; /* SIGPOLL */ @@ -112,6 +113,7 @@ #ifdef __ARCH_SI_TRAPNO #define si_trapno _sifields._sigfault._trapno #endif +#define si_addr_lsb _sifields._sigfault._addr_lsb #define si_band _sifields._sigpoll._band #define si_fd _sifields._sigpoll._fd @@ -192,7 +194,11 @@ #define BUS_ADRALN (__SI_FAULT|1) /* invalid address alignment */ #define BUS_ADRERR (__SI_FAULT|2) /* non-existant physical address */ #define BUS_OBJERR (__SI_FAULT|3) /* object specific hardware error */ -#define NSIGBUS 3 +/* hardware memory error consumed on a machine check: action required */ +#define BUS_MCEERR_AR (__SI_FAULT|4) +/* hardware memory error detected in process but not consumed: action optional*/ +#define BUS_MCEERR_AO (__SI_FAULT|5) +#define NSIGBUS 5 /* * SIGTRAP si_codes -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/