From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 21B8B1A06FA for ; Wed, 24 Sep 2014 17:00:02 +1000 (EST) From: Anton Blanchard To: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, amodra@gmail.com, torvalds@linux-foundation.org, sfr@canb.auug.org.au Subject: [PATCH 2/3] powerpc: Add VM_FAULT_HWPOISON handling to powerpc page fault handler Date: Wed, 24 Sep 2014 16:59:57 +1000 Message-Id: <1411541999-21457-2-git-send-email-anton@samba.org> In-Reply-To: <1411541999-21457-1-git-send-email-anton@samba.org> References: <1411541999-21457-1-git-send-email-anton@samba.org> Cc: linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , do_page_fault was missing knowledge of HWPOISON, and we would oops if userspace tried to access a poisoned page: kernel BUG at arch/powerpc/mm/fault.c:180! Signed-off-by: Anton Blanchard --- arch/powerpc/mm/fault.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index abc8c81..588b6cc 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -114,7 +114,8 @@ static int store_updates_sp(struct pt_regs *regs) #define MM_FAULT_CONTINUE -1 #define MM_FAULT_ERR(sig) (sig) -static int do_sigbus(struct pt_regs *regs, unsigned long address) +static int do_sigbus(struct pt_regs *regs, unsigned long address, + unsigned int fault) { siginfo_t info; @@ -128,6 +129,13 @@ static int do_sigbus(struct pt_regs *regs, unsigned long address) info.si_errno = 0; info.si_code = BUS_ADRERR; info.si_addr = (void __user *)address; +#ifdef CONFIG_MEMORY_FAILURE + if (fault & (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) { + pr_err("MCE: Killing %s:%d due to hardware memory corruption fault at %lx\n", + current->comm, current->pid, address); + info.si_code = BUS_MCEERR_AR; + } +#endif force_sig_info(SIGBUS, &info, current); return MM_FAULT_RETURN; } @@ -170,11 +178,8 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault) return MM_FAULT_RETURN; } - /* Bus error. x86 handles HWPOISON here, we'll add this if/when - * we support the feature in HW - */ - if (fault & VM_FAULT_SIGBUS) - return do_sigbus(regs, addr); + if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) + return do_sigbus(regs, addr, fault); /* We don't understand the fault code, this is fatal */ BUG(); -- 1.9.1