From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5A6C0CAC5BE for ; Tue, 30 Sep 2025 08:29:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=RGxlg0S4g6GR+9HkPBC1Uu0i6i9cl1VmWc/ktKnXixE=; b=myIHPqEFceQUJT 72FA4lFd/x+CWfKjCTrLZj67uXNT8PQlZ0/KO+7jMuMhX0vMvE7bdrrvzLU3Uml/JvCs7p774P8MC 531V2ztWv+6hbRvoMw/O8BVSQY6oJDNW4n+VZI+NhO9lkZX5gSfqsgty6z8YDZK9XYgWnFrejvwDe uVr2VvPIjm99XTuyea4+VS+WSa8119HcWB6YBZYOrS2P/NHkyLY7i3WYZcxImKEsvI14PWvSuaWIm gN+gYjZOk7lisT9HucfRQK5UBRBhqqaYoLoAJnix3bg/Iib0N7o3ntnA91qZsR64Be+6YD4NYIHPE H1oir3HGgVWjhpQTnmuA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1v3Vk1-00000004e4x-2bDk; Tue, 30 Sep 2025 08:29:45 +0000 Received: from out30-110.freemail.mail.aliyun.com ([115.124.30.110]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1v3Vjx-00000004e2c-33fZ for linux-riscv@lists.infradead.org; Tue, 30 Sep 2025 08:29:44 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1759220976; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=i7nzeHl2OpvLizjeFtH4Z8hEn2MtSOZC5V4NVsTLCRc=; b=BhyFwamzMAd1bbQ53XUD6MjQPTo8jONNcgR4/lLrcOtVdwn1aujZL8Mi6ZWMpi62PR2YGV4e6ZXLmvT6ZQnkey+QUI9kWb0Cvjg4fg8yib6SHERvkfK+E/OVb2ry5kOHmjaDNd1SIKCSM2Ar2vfM8WHgUcXd6JWYqNJVC340+/k= Received: from localhost(mailfrom:tianruidong@linux.alibaba.com fp:SMTPD_---0WpAl8GN_1759220970 cluster:ay36) by smtp.aliyun-inc.com; Tue, 30 Sep 2025 16:29:34 +0800 From: Ruidong Tian To: xueshuai@linux.alibaba.com, palmer@dabbelt.com, paul.walmsley@sifive.com, aou@eecs.berkeley.edu, alex@ghiti.fr, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: tianruidong@linux.alibaba.com Subject: [PATCH] riscv: mm: Add proper handling for HWPOISON faults Date: Tue, 30 Sep 2025 16:29:27 +0800 Message-Id: <20250930082927.18971-1-tianruidong@linux.alibaba.com> X-Mailer: git-send-email 2.33.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250930_012942_626367_152E28A5 X-CRM114-Status: GOOD ( 13.87 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: winterddd Currently, the RISC-V fault handler treats memory poisoning faults (VM_FAULT_HWPOISON and VM_FAULT_HWPOISON_LARGE) as a generic bus error (BUS_ADRERR). This is incorrect as it loses crucial information about the nature of the error. As for describe in [0], A SIGBUS is sent with the correct machine check error code (BUS_MCEERR_AR) and populates `si_addr_lsb`(log2 of the corruption page size) in siginfo while there is page fault with poison page. The logic is based on the existing arm64 implementation for handling HWPOISON. Testing -------------- ras-tools[0] is used to test. ./einj_mem_uc -j -k single & echo 0x107943b400 > /sys/devices/system/memory/hard_offline_page echo trigger > ./trigger_start before apply this patch: signal 7 code 2 addr 0x7fff95bdc400 after apply this patch: signal 7 code 4 addr 0x7fff95bdc400 [0]: https://www.man7.org/linux/man-pages/man2/sigaction.2.html [1]: https://kernel.googlesource.com/pub/scm/linux/kernel/git/aegl/ras-tools/ Signed-off-by: Ruidong Tian --- arch/riscv/include/asm/bug.h | 1 + arch/riscv/kernel/traps.c | 32 ++++++++++++++++++++++---------- arch/riscv/mm/fault.c | 12 +++++++++++- 3 files changed, 34 insertions(+), 11 deletions(-) diff --git a/arch/riscv/include/asm/bug.h b/arch/riscv/include/asm/bug.h index 4c03e20ad11f..23711f2ffae3 100644 --- a/arch/riscv/include/asm/bug.h +++ b/arch/riscv/include/asm/bug.h @@ -95,5 +95,6 @@ struct task_struct; void __show_regs(struct pt_regs *regs); void die(struct pt_regs *regs, const char *str); void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr); +void riscv_force_sig_mceerr(int code, unsigned long addr, short lsb); #endif /* _ASM_RISCV_BUG_H */ diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index d46347482509..17dad6f8d678 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -113,20 +113,32 @@ void die(struct pt_regs *regs, const char *str) make_task_dead(SIGSEGV); } -void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr) +static void riscv_show_signal(int signo, int code, unsigned long addr) { struct task_struct *tsk = current; + struct pt_regs *regs = task_pt_regs(tsk); - if (show_unhandled_signals && unhandled_signal(tsk, signo) - && printk_ratelimit()) { - pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x" REG_FMT, - tsk->comm, task_pid_nr(tsk), signo, code, addr); - print_vma_addr(KERN_CONT " in ", instruction_pointer(regs)); - pr_cont("\n"); - __show_regs(regs); - dump_instr(KERN_INFO, regs); - } + if (!show_unhandled_signals || !unhandled_signal(tsk, signo) + || !printk_ratelimit()) + return; + + pr_info("%s[%d]: unhandled signal %d code 0x%x at 0x" REG_FMT, + tsk->comm, task_pid_nr(tsk), signo, code, addr); + print_vma_addr(KERN_CONT " in ", instruction_pointer(regs)); + pr_cont("\n"); + __show_regs(regs); + dump_instr(KERN_INFO, regs); +} +void riscv_force_sig_mceerr(int code, unsigned long addr, short lsb) +{ + riscv_show_signal(SIGBUS, code, addr); + force_sig_mceerr(code, (void __user *)addr, lsb); +} + +void do_trap(struct pt_regs *regs, int signo, int code, unsigned long addr) +{ + riscv_show_signal(signo, code, addr); force_sig_fault(signo, code, (void __user *)addr); } diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c index 04ed6f8acae4..a6ccc4ab3a75 100644 --- a/arch/riscv/mm/fault.c +++ b/arch/riscv/mm/fault.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -128,10 +129,19 @@ static inline void mm_fault_error(struct pt_regs *regs, unsigned long addr, vm_f */ pagefault_out_of_memory(); return; - } else if (fault & (VM_FAULT_SIGBUS | VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE)) { + } else if (fault & VM_FAULT_SIGBUS) { /* Kernel mode? Handle exceptions or die */ do_trap(regs, SIGBUS, BUS_ADRERR, addr); return; + } else if (fault & (VM_FAULT_HWPOISON_LARGE | VM_FAULT_HWPOISON)) { + unsigned int lsb; + + lsb = PAGE_SHIFT; + if (fault & VM_FAULT_HWPOISON_LARGE) + lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault)); + + riscv_force_sig_mceerr(BUS_MCEERR_AR, addr, lsb); + return; } else if (fault & VM_FAULT_SIGSEGV) { do_trap(regs, SIGSEGV, SEGV_MAPERR, addr); return; -- 2.43.7 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv