From nobody Sat Apr 11 12:44:14 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99C64C25B0D for ; Thu, 11 Aug 2022 07:42:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234445AbiHKHmG (ORCPT ); Thu, 11 Aug 2022 03:42:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47052 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234431AbiHKHmC (ORCPT ); Thu, 11 Aug 2022 03:42:02 -0400 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E9B08E0DC; Thu, 11 Aug 2022 00:42:00 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R191e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045192;MF=xianting.tian@linux.alibaba.com;NM=1;PH=DS;RN=23;SR=0;TI=SMTPD_---0VLyMVg9_1660203714; Received: from localhost(mailfrom:xianting.tian@linux.alibaba.com fp:SMTPD_---0VLyMVg9_1660203714) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 15:41:55 +0800 From: Xianting Tian To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, anup@brainfault.org, heiko@sntech.de, guoren@kernel.org, mick@ics.forth.gr, alexandre.ghiti@canonical.com, bhe@redhat.com, vgoyal@redhat.com, dyoung@redhat.com, corbet@lwn.net, Conor.Dooley@microchip.com Cc: kexec@lists.infradead.org, linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, crash-utility@redhat.com, heinrich.schuchardt@canonical.com, k-hagio-ab@nec.com, hschauhan@nulltrace.org, yixun.lan@gmail.com, Xianting Tian Subject: [PATCH V6 1/6] RISC-V: kexec: Fixup use of smp_processor_id() in preemptible context Date: Thu, 11 Aug 2022 15:41:45 +0800 Message-Id: <20220811074150.3020189-2-xianting.tian@linux.alibaba.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220811074150.3020189-1-xianting.tian@linux.alibaba.com> References: <20220811074150.3020189-1-xianting.tian@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Use __smp_processor_id() to avoid check the preemption context when CONFIG_DEBUG_PREEMPT enabled, as we will enter crash kernel and no return. Without the patch, [ 103.781044] sysrq: Trigger a crash [ 103.784625] Kernel panic - not syncing: sysrq triggered crash [ 103.837634] CPU1: off [ 103.889668] CPU2: off [ 103.933479] CPU3: off [ 103.939424] Starting crashdump kernel... [ 103.943442] BUG: using smp_processor_id() in preemptible [00000000] code= : sh/346 [ 103.950884] caller is debug_smp_processor_id+0x1c/0x26 [ 103.956051] CPU: 0 PID: 346 Comm: sh Kdump: loaded Not tainted 5.10.113-= 00002-gce03f03bf4ec-dirty #149 [ 103.965355] Call Trace: [ 103.967805] [] walk_stackframe+0x0/0xa2 [ 103.973206] [] show_stack+0x32/0x3e [ 103.978258] [] dump_stack_lvl+0x72/0x8e [ 103.983655] [] dump_stack+0x14/0x1c [ 103.988705] [] check_preemption_disabled+0x9e/0xaa [ 103.995057] [] debug_smp_processor_id+0x1c/0x26 [ 104.001150] [] machine_kexec+0x22/0xd0 [ 104.006463] [] __crash_kexec+0x6a/0xa4 [ 104.011774] [] panic+0xfc/0x2b0 [ 104.016480] [] sysrq_reset_seq_param_set+0x0/0x70 [ 104.022745] [] __handle_sysrq+0x8c/0x154 [ 104.028229] [] write_sysrq_trigger+0x5a/0x6a [ 104.034061] [] proc_reg_write+0x58/0xd4 [ 104.039459] [] vfs_write+0x7e/0x254 [ 104.044509] [] ksys_write+0x58/0xbe [ 104.049558] [] sys_write+0xe/0x16 [ 104.054434] [] ret_from_syscall+0x0/0x2 [ 104.067863] Will call new kernel at ecc00000 from hart id 0 [ 104.074939] FDT image at fc5ee000 [ 104.079523] Bye... With the patch we can got clear output, [ 67.740553] sysrq: Trigger a crash [ 67.744166] Kernel panic - not syncing: sysrq triggered crash [ 67.809123] CPU1: off [ 67.865210] CPU2: off [ 67.909075] CPU3: off [ 67.919123] Starting crashdump kernel... [ 67.924900] Will call new kernel at ecc00000 from hart id 0 [ 67.932045] FDT image at fc5ee000 [ 67.935560] Bye... Fixes: 0e105f1d0037 ("riscv: use hart id instead of cpu id on machine_kexec= ") Reviewed-by: Guo Ren Reviewed-by: Heiko Stuebner Reviewed-by: Atish Patra Signed-off-by: Xianting Tian Reviewed-by: Conor Dooley --- arch/riscv/kernel/machine_kexec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_= kexec.c index df8e24559035..86d1b5f9dfb5 100644 --- a/arch/riscv/kernel/machine_kexec.c +++ b/arch/riscv/kernel/machine_kexec.c @@ -171,7 +171,7 @@ machine_kexec(struct kimage *image) struct kimage_arch *internal =3D &image->arch; unsigned long jump_addr =3D (unsigned long) image->start; unsigned long first_ind_entry =3D (unsigned long) &image->head; - unsigned long this_cpu_id =3D smp_processor_id(); + unsigned long this_cpu_id =3D __smp_processor_id(); unsigned long this_hart_id =3D cpuid_to_hartid_map(this_cpu_id); unsigned long fdt_addr =3D internal->fdt_addr; void *control_code_buffer =3D page_address(image->control_code_page); --=20 2.17.1 From nobody Sat Apr 11 12:44:14 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1FF28C19F2D for ; Thu, 11 Aug 2022 07:42:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234384AbiHKHmM (ORCPT ); Thu, 11 Aug 2022 03:42:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234439AbiHKHmE (ORCPT ); Thu, 11 Aug 2022 03:42:04 -0400 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3826F8E44E; Thu, 11 Aug 2022 00:42:01 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R501e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046051;MF=xianting.tian@linux.alibaba.com;NM=1;PH=DS;RN=23;SR=0;TI=SMTPD_---0VLyDALP_1660203715; Received: from localhost(mailfrom:xianting.tian@linux.alibaba.com fp:SMTPD_---0VLyDALP_1660203715) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 15:41:56 +0800 From: Xianting Tian To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, anup@brainfault.org, heiko@sntech.de, guoren@kernel.org, mick@ics.forth.gr, alexandre.ghiti@canonical.com, bhe@redhat.com, vgoyal@redhat.com, dyoung@redhat.com, corbet@lwn.net, Conor.Dooley@microchip.com Cc: kexec@lists.infradead.org, linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, crash-utility@redhat.com, heinrich.schuchardt@canonical.com, k-hagio-ab@nec.com, hschauhan@nulltrace.org, yixun.lan@gmail.com, Xianting Tian Subject: [PATCH V6 2/6] RISC-V: Fixup get incorrect user mode PC for kernel mode regs Date: Thu, 11 Aug 2022 15:41:46 +0800 Message-Id: <20220811074150.3020189-3-xianting.tian@linux.alibaba.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220811074150.3020189-1-xianting.tian@linux.alibaba.com> References: <20220811074150.3020189-1-xianting.tian@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" When use 'echo c > /proc/sysrq-trigger' to trigger kdump, riscv_crash_save_= regs() will be called to save regs for vmcore, we found "epc" value 00ffffffa55374= 00 is not a valid kernel virtual address, but is a user virtual address. Other regs(eg, ra, sp, gp...) are correct kernel virtual address. Actually 0x00ffffffb0dd9400 is the user mode PC of 'PID: 113 Comm: sh', whi= ch is saved in the task's stack. [ 21.201701] CPU: 0 PID: 113 Comm: sh Kdump: loaded Not tainted 5.18.9 #45 [ 21.201979] Hardware name: riscv-virtio,qemu (DT) [ 21.202160] epc : 00ffffffa5537400 ra : ffffffff80088640 sp : ff20000010= 333b90 [ 21.202435] gp : ffffffff810dde38 tp : ff6000000226c200 t0 : ffffffff80= 32be7c [ 21.202707] t1 : 0720072007200720 t2 : 30203a7375746174 s0 : ff20000010= 333cf0 [ 21.202973] s1 : 0000000000000000 a0 : ff20000010333b98 a1 : 0000000000= 000001 [ 21.203243] a2 : 0000000000000010 a3 : 0000000000000000 a4 : 28c8f0aeff= ea4e00 [ 21.203519] a5 : 28c8f0aeffea4e00 a6 : 0000000000000009 a7 : ffffffff80= 35c9b8 [ 21.203794] s2 : ffffffff810df0a8 s3 : ffffffff810df718 s4 : ff20000010= 333b98 [ 21.204062] s5 : 0000000000000000 s6 : 0000000000000007 s7 : ffffffff80= c4a468 [ 21.204331] s8 : 00ffffffef451410 s9 : 0000000000000007 s10: 00aaaaaac0= 510700 [ 21.204606] s11: 0000000000000001 t3 : ff60000001218f00 t4 : ff60000001= 218f00 [ 21.204876] t5 : ff60000001218000 t6 : ff200000103338b8 [ 21.205079] status: 0000000200000020 badaddr: 0000000000000000 cause: 00= 00000000000008 With the incorrect PC, the backtrace showed by crash tool as below, the fir= st stack frame is abnormal, crash> bt PID: 113 TASK: ff60000002269600 CPU: 0 COMMAND: "sh" #0 [ff2000001039bb90] __efistub_.Ldebug_info0 at 00ffffffa5537400 <-- Abno= rmal #1 [ff2000001039bcf0] panic at ffffffff806578ba #2 [ff2000001039bd50] sysrq_reset_seq_param_set at ffffffff8038c030 #3 [ff2000001039bda0] __handle_sysrq at ffffffff8038c5f8 #4 [ff2000001039be00] write_sysrq_trigger at ffffffff8038cad8 #5 [ff2000001039be20] proc_reg_write at ffffffff801b7edc #6 [ff2000001039be40] vfs_write at ffffffff80152ba6 #7 [ff2000001039be80] ksys_write at ffffffff80152ece #8 [ff2000001039bed0] sys_write at ffffffff80152f46 With the patch, we can get current kernel mode PC, the output as below, [ 17.607658] CPU: 0 PID: 113 Comm: sh Kdump: loaded Not tainted 5.18.9 #42 [ 17.607937] Hardware name: riscv-virtio,qemu (DT) [ 17.608150] epc : ffffffff800078f8 ra : ffffffff8008862c sp : ff20000010= 333b90 [ 17.608441] gp : ffffffff810dde38 tp : ff6000000226c200 t0 : ffffffff80= 32be68 [ 17.608741] t1 : 0720072007200720 t2 : 666666666666663c s0 : ff20000010= 333cf0 [ 17.609025] s1 : 0000000000000000 a0 : ff20000010333b98 a1 : 0000000000= 000001 [ 17.609320] a2 : 0000000000000010 a3 : 0000000000000000 a4 : 0000000000= 000000 [ 17.609601] a5 : ff60000001c78000 a6 : 000000000000003c a7 : ffffffff80= 35c9a4 [ 17.609894] s2 : ffffffff810df0a8 s3 : ffffffff810df718 s4 : ff20000010= 333b98 [ 17.610186] s5 : 0000000000000000 s6 : 0000000000000007 s7 : ffffffff80= c4a468 [ 17.610469] s8 : 00ffffffca281410 s9 : 0000000000000007 s10: 00aaaaaab5= bb6700 [ 17.610755] s11: 0000000000000001 t3 : ff60000001218f00 t4 : ff60000001= 218f00 [ 17.611041] t5 : ff60000001218000 t6 : ff20000010333988 [ 17.611255] status: 0000000200000020 badaddr: 0000000000000000 cause: 00= 00000000000008 With the correct PC, the backtrace showed by crash tool as below, crash> bt PID: 113 TASK: ff6000000226c200 CPU: 0 COMMAND: "sh" #0 [ff20000010333b90] riscv_crash_save_regs at ffffffff800078f8 <--- Normal #1 [ff20000010333cf0] panic at ffffffff806578c6 #2 [ff20000010333d50] sysrq_reset_seq_param_set at ffffffff8038c03c #3 [ff20000010333da0] __handle_sysrq at ffffffff8038c604 #4 [ff20000010333e00] write_sysrq_trigger at ffffffff8038cae4 #5 [ff20000010333e20] proc_reg_write at ffffffff801b7ee8 #6 [ff20000010333e40] vfs_write at ffffffff80152bb2 #7 [ff20000010333e80] ksys_write at ffffffff80152eda #8 [ff20000010333ed0] sys_write at ffffffff80152f52 Fixes: e53d28180d4d ("RISC-V: Add kdump support") Co-developed-by: Guo Ren Signed-off-by: Xianting Tian Reviewed-by: Conor Dooley --- arch/riscv/kernel/crash_save_regs.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kernel/crash_save_regs.S b/arch/riscv/kernel/crash_= save_regs.S index 7832fb763aba..b2a1908c0463 100644 --- a/arch/riscv/kernel/crash_save_regs.S +++ b/arch/riscv/kernel/crash_save_regs.S @@ -44,7 +44,7 @@ SYM_CODE_START(riscv_crash_save_regs) REG_S t6, PT_T6(a0) /* x31 */ =20 csrr t1, CSR_STATUS - csrr t2, CSR_EPC + auipc t2, 0x0 csrr t3, CSR_TVAL csrr t4, CSR_CAUSE =20 --=20 2.17.1 From nobody Sat Apr 11 12:44:14 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C848C19F2D for ; Thu, 11 Aug 2022 07:42:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234459AbiHKHmP (ORCPT ); Thu, 11 Aug 2022 03:42:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234321AbiHKHmG (ORCPT ); Thu, 11 Aug 2022 03:42:06 -0400 Received: from out30-131.freemail.mail.aliyun.com (out30-131.freemail.mail.aliyun.com [115.124.30.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 659778E0DC; Thu, 11 Aug 2022 00:42:03 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R801e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045192;MF=xianting.tian@linux.alibaba.com;NM=1;PH=DS;RN=23;SR=0;TI=SMTPD_---0VLyDALq_1660203717; Received: from localhost(mailfrom:xianting.tian@linux.alibaba.com fp:SMTPD_---0VLyDALq_1660203717) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 15:41:58 +0800 From: Xianting Tian To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, anup@brainfault.org, heiko@sntech.de, guoren@kernel.org, mick@ics.forth.gr, alexandre.ghiti@canonical.com, bhe@redhat.com, vgoyal@redhat.com, dyoung@redhat.com, corbet@lwn.net, Conor.Dooley@microchip.com Cc: kexec@lists.infradead.org, linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, crash-utility@redhat.com, heinrich.schuchardt@canonical.com, k-hagio-ab@nec.com, hschauhan@nulltrace.org, yixun.lan@gmail.com, Xianting Tian Subject: [PATCH V6 3/6] RISC-V: Fixup schedule out issue in machine_crash_shutdown() Date: Thu, 11 Aug 2022 15:41:47 +0800 Message-Id: <20220811074150.3020189-4-xianting.tian@linux.alibaba.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220811074150.3020189-1-xianting.tian@linux.alibaba.com> References: <20220811074150.3020189-1-xianting.tian@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Current task of executing crash kexec will be schedule out when panic is triggered by RCU Stall, as it needs to wait rcu completion. It lead to inability to enter the crash system. The implementation of machine_crash_shutdown() is non-standard for RISC-V according to other Arch's implementation(eg, x86, arm64), we need to send IPI to stop secondary harts. [224521.877268] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: [224521.883471] rcu: 0-...0: (3 GPs behind) idle=3Dcfa/0/0x1 softirq=3D396= 8793/3968793 fqs=3D2495 [224521.891742] (detected by 2, t=3D5255 jiffies, g=3D60855593, q=3D328) [224521.897754] Task dump for CPU 0: [224521.901074] task:swapper/0 state:R running task stack: 0 pid: = 0 ppid: 0 flags:0x00000008 [224521.911090] Call Trace: [224521.913638] [] __schedule+0x208/0x5ea [224521.918957] Kernel panic - not syncing: RCU Stall [224521.923773] bad: scheduling from the idle thread! [224521.928571] CPU: 2 PID: 0 Comm: swapper/2 Kdump: loaded Tainted: G O = 5.10.113-yocto-standard #1 [224521.938658] Call Trace: [224521.941200] [] walk_stackframe+0x0/0xaa [224521.946689] [] show_stack+0x32/0x3e [224521.951830] [] dump_stack_lvl+0x7e/0xa2 [224521.957317] [] dump_stack+0x14/0x1c [224521.962459] [] dequeue_task_idle+0x2c/0x40 [224521.968207] [] __schedule+0x41e/0x5ea [224521.973520] [] schedule+0x34/0xe4 [224521.978487] [] schedule_timeout+0xc6/0x170 [224521.984234] [] wait_for_completion+0x98/0xf2 [224521.990157] [] __wait_rcu_gp+0x148/0x14a [224521.995733] [] synchronize_rcu+0x5c/0x66 [224522.001307] [] rcu_sync_enter+0x54/0xe6 [224522.006795] [] percpu_down_write+0x32/0x11c [224522.012629] [] _cpu_down+0x92/0x21a [224522.017771] [] smp_shutdown_nonboot_cpus+0x90/0x118 [224522.024299] [] machine_crash_shutdown+0x30/0x4a [224522.030483] [] __crash_kexec+0x62/0xa6 [224522.035884] [] panic+0xfa/0x2b6 [224522.040678] [] rcu_sched_clock_irq+0xc26/0xcb8 [224522.046774] [] update_process_times+0x62/0x8a [224522.052785] [] tick_sched_timer+0x9e/0x102 [224522.058533] [] __hrtimer_run_queues+0x16a/0x318 [224522.064716] [] hrtimer_interrupt+0xd4/0x228 [224522.070551] [] riscv_timer_interrupt+0x3c/0x48 [224522.076646] [] handle_percpu_devid_irq+0xb0/0x24c [224522.083004] [] __handle_domain_irq+0xa8/0x122 [224522.089014] [] riscv_intc_irq+0x38/0x60 [224522.094501] [] ret_from_exception+0x0/0xc [224522.100161] [] rcu_eqs_enter.constprop.0+0x8c/0xb8 With the patch, it can enter crash system when RCU Stall occur. Fixes: e53d28180d4d ("RISC-V: Add kdump support") Signed-off-by: Xianting Tian Reviewed-by: Conor Dooley --- arch/riscv/kernel/machine_kexec.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_= kexec.c index 86d1b5f9dfb5..ee79e6839b86 100644 --- a/arch/riscv/kernel/machine_kexec.c +++ b/arch/riscv/kernel/machine_kexec.c @@ -138,19 +138,37 @@ void machine_shutdown(void) #endif } =20 +/* Override the weak function in kernel/panic.c */ +void crash_smp_send_stop(void) +{ + static int cpus_stopped; + + /* + * This function can be called twice in panic path, but obviously + * we execute this only once. + */ + if (cpus_stopped) + return; + + smp_send_stop(); + cpus_stopped =3D 1; +} + /* * machine_crash_shutdown - Prepare to kexec after a kernel crash * * This function is called by crash_kexec just before machine_kexec - * below and its goal is similar to machine_shutdown, but in case of - * a kernel crash. Since we don't handle such cases yet, this function - * is empty. + * and its goal is to shutdown non-crashing cpus and save registers. */ void machine_crash_shutdown(struct pt_regs *regs) { + local_irq_disable(); + + /* shutdown non-crashing cpus */ + crash_smp_send_stop(); + crash_save_cpu(regs, smp_processor_id()); - machine_shutdown(); pr_info("Starting crashdump kernel...\n"); } =20 --=20 2.17.1 From nobody Sat Apr 11 12:44:14 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AD7ADC19F2D for ; Thu, 11 Aug 2022 07:42:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234455AbiHKHmS (ORCPT ); Thu, 11 Aug 2022 03:42:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47182 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234431AbiHKHmH (ORCPT ); Thu, 11 Aug 2022 03:42:07 -0400 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D77691D25; Thu, 11 Aug 2022 00:42:05 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R951e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045170;MF=xianting.tian@linux.alibaba.com;NM=1;PH=DS;RN=23;SR=0;TI=SMTPD_---0VLyDZ0M_1660203718; Received: from localhost(mailfrom:xianting.tian@linux.alibaba.com fp:SMTPD_---0VLyDZ0M_1660203718) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 15:41:59 +0800 From: Xianting Tian To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, anup@brainfault.org, heiko@sntech.de, guoren@kernel.org, mick@ics.forth.gr, alexandre.ghiti@canonical.com, bhe@redhat.com, vgoyal@redhat.com, dyoung@redhat.com, corbet@lwn.net, Conor.Dooley@microchip.com Cc: kexec@lists.infradead.org, linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, crash-utility@redhat.com, heinrich.schuchardt@canonical.com, k-hagio-ab@nec.com, hschauhan@nulltrace.org, yixun.lan@gmail.com, Xianting Tian Subject: [PATCH V6 4/6] RISC-V: Add modules to virtual kernel memory layout dump Date: Thu, 11 Aug 2022 15:41:48 +0800 Message-Id: <20220811074150.3020189-5-xianting.tian@linux.alibaba.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220811074150.3020189-1-xianting.tian@linux.alibaba.com> References: <20220811074150.3020189-1-xianting.tian@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Modules always live before the kernel, MODULES_END is fixed but MODULES_VADDR isn't fixed, it depends on the kernel size. Let's add it to virtual kernel memory layout dump. As MODULES is only defined for CONFIG_64BIT, so we dump it when CONFIG_64BIT=3Dy. eg, MODULES_VADDR - MODULES_END 0xffffffff01133000 - 0xffffffff80000000 Reviewed-by: Guo Ren Reviewed-by: Heiko Stuebner Signed-off-by: Xianting Tian Reviewed-by: Conor Dooley --- arch/riscv/mm/init.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index a88b7dc31a68..b56a0a75533f 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -135,6 +135,10 @@ static void __init print_vm_layout(void) (unsigned long)VMEMMAP_END); print_ml("vmalloc", (unsigned long)VMALLOC_START, (unsigned long)VMALLOC_END); +#ifdef CONFIG_64BIT + print_ml("modules", (unsigned long)MODULES_VADDR, + (unsigned long)MODULES_END); +#endif print_ml("lowmem", (unsigned long)PAGE_OFFSET, (unsigned long)high_memory); if (IS_ENABLED(CONFIG_64BIT)) { --=20 2.17.1 From nobody Sat Apr 11 12:44:14 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40553C19F2D for ; Thu, 11 Aug 2022 07:42:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234467AbiHKHmY (ORCPT ); Thu, 11 Aug 2022 03:42:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47206 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234141AbiHKHmI (ORCPT ); Thu, 11 Aug 2022 03:42:08 -0400 Received: from out30-57.freemail.mail.aliyun.com (out30-57.freemail.mail.aliyun.com [115.124.30.57]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8804E91D2F; Thu, 11 Aug 2022 00:42:06 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R111e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045170;MF=xianting.tian@linux.alibaba.com;NM=1;PH=DS;RN=23;SR=0;TI=SMTPD_---0VLyMVhz_1660203719; Received: from localhost(mailfrom:xianting.tian@linux.alibaba.com fp:SMTPD_---0VLyMVhz_1660203719) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 15:42:00 +0800 From: Xianting Tian To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, anup@brainfault.org, heiko@sntech.de, guoren@kernel.org, mick@ics.forth.gr, alexandre.ghiti@canonical.com, bhe@redhat.com, vgoyal@redhat.com, dyoung@redhat.com, corbet@lwn.net, Conor.Dooley@microchip.com Cc: kexec@lists.infradead.org, linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, crash-utility@redhat.com, heinrich.schuchardt@canonical.com, k-hagio-ab@nec.com, hschauhan@nulltrace.org, yixun.lan@gmail.com, Xianting Tian Subject: [PATCH V6 5/6] RISC-V: Add arch_crash_save_vmcoreinfo support Date: Thu, 11 Aug 2022 15:41:49 +0800 Message-Id: <20220811074150.3020189-6-xianting.tian@linux.alibaba.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220811074150.3020189-1-xianting.tian@linux.alibaba.com> References: <20220811074150.3020189-1-xianting.tian@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Add arch_crash_save_vmcoreinfo(), which exports VM layout(MODULES, VMALLOC, VMEMMAP and KERNEL_LINK_ADDR ranges), va bits and ram base for vmcore. Default pagetable levels and PAGE_OFFSET aren't same for different kernel version as below. For default pagetable levels, it sets sv57 on defaultly in latest kernel and do fallback to try to set sv48 on boot time if sv57 is not supported in current hardware. For ram base, the default value is 0x80200000 for qemu riscv64 env, 0x200000 for riscv64 SoC platform(eg, SoC platform of RISC-V XuanTie 910 CPU). * Linux Kernel 5.18 ~ * PGTABLE_LEVELS =3D 5 * PAGE_OFFSET =3D 0xff60000000000000 * Linux Kernel 5.17 ~ * PGTABLE_LEVELS =3D 4 * PAGE_OFFSET =3D 0xffffaf8000000000 * Linux Kernel 4.19 ~ * PGTABLE_LEVELS =3D 3 * PAGE_OFFSET =3D 0xffffffe000000000 Since these configurations change from time to time and version to version, it is preferable to export them via vmcoreinfo than to change the crash's code frequently, it can simplify the development of crash tool. Signed-off-by: Xianting Tian Reviewed-by: Conor Dooley --- arch/riscv/kernel/Makefile | 1 + arch/riscv/kernel/crash_core.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) create mode 100644 arch/riscv/kernel/crash_core.c diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index 33bb60a354cd..5e149df58176 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -81,6 +81,7 @@ obj-$(CONFIG_KGDB) +=3D kgdb.o obj-$(CONFIG_KEXEC_CORE) +=3D kexec_relocate.o crash_save_regs.o machine_k= exec.o obj-$(CONFIG_KEXEC_FILE) +=3D elf_kexec.o machine_kexec_file.o obj-$(CONFIG_CRASH_DUMP) +=3D crash_dump.o +obj-$(CONFIG_CRASH_CORE) +=3D crash_core.o =20 obj-$(CONFIG_JUMP_LABEL) +=3D jump_label.o =20 diff --git a/arch/riscv/kernel/crash_core.c b/arch/riscv/kernel/crash_core.c new file mode 100644 index 000000000000..8d7f5ff108da --- /dev/null +++ b/arch/riscv/kernel/crash_core.c @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include +#include + +void arch_crash_save_vmcoreinfo(void) +{ + VMCOREINFO_NUMBER(VA_BITS); + VMCOREINFO_NUMBER(phys_ram_base); + + vmcoreinfo_append_str("NUMBER(PAGE_OFFSET)=3D0x%lx\n", PAGE_OFFSET); + vmcoreinfo_append_str("NUMBER(VMALLOC_START)=3D0x%lx\n", VMALLOC_START); + vmcoreinfo_append_str("NUMBER(VMALLOC_END)=3D0x%lx\n", VMALLOC_END); + vmcoreinfo_append_str("NUMBER(VMEMMAP_START)=3D0x%lx\n", VMEMMAP_START); + vmcoreinfo_append_str("NUMBER(VMEMMAP_END)=3D0x%lx\n", VMEMMAP_END); +#ifdef CONFIG_64BIT + vmcoreinfo_append_str("NUMBER(MODULES_VADDR)=3D0x%lx\n", MODULES_VADDR); + vmcoreinfo_append_str("NUMBER(MODULES_END)=3D0x%lx\n", MODULES_END); +#endif + + if (IS_ENABLED(CONFIG_64BIT)) { +#ifdef CONFIG_KASAN + vmcoreinfo_append_str("NUMBER(KASAN_SHADOW_START)=3D0x%lx\n", KASAN_SHAD= OW_START); + vmcoreinfo_append_str("NUMBER(KASAN_SHADOW_END)=3D0x%lx\n", KASAN_SHADOW= _END); +#endif + vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=3D0x%lx\n", KERNEL_LINK_= ADDR); + vmcoreinfo_append_str("NUMBER(ADDRESS_SPACE_END)=3D0x%lx\n", ADDRESS_SPA= CE_END); + } +} --=20 2.17.1 From nobody Sat Apr 11 12:44:14 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BB9F1C25B07 for ; Thu, 11 Aug 2022 07:42:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234168AbiHKHm1 (ORCPT ); Thu, 11 Aug 2022 03:42:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234460AbiHKHmQ (ORCPT ); Thu, 11 Aug 2022 03:42:16 -0400 Received: from out30-56.freemail.mail.aliyun.com (out30-56.freemail.mail.aliyun.com [115.124.30.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BFAA9923E4; Thu, 11 Aug 2022 00:42:13 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045170;MF=xianting.tian@linux.alibaba.com;NM=1;PH=DS;RN=23;SR=0;TI=SMTPD_---0VLyDZ1R_1660203721; Received: from localhost(mailfrom:xianting.tian@linux.alibaba.com fp:SMTPD_---0VLyDZ1R_1660203721) by smtp.aliyun-inc.com; Thu, 11 Aug 2022 15:42:02 +0800 From: Xianting Tian To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, anup@brainfault.org, heiko@sntech.de, guoren@kernel.org, mick@ics.forth.gr, alexandre.ghiti@canonical.com, bhe@redhat.com, vgoyal@redhat.com, dyoung@redhat.com, corbet@lwn.net, Conor.Dooley@microchip.com Cc: kexec@lists.infradead.org, linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, crash-utility@redhat.com, heinrich.schuchardt@canonical.com, k-hagio-ab@nec.com, hschauhan@nulltrace.org, yixun.lan@gmail.com, Xianting Tian Subject: [PATCH V6 6/6] Documentation: kdump: describe VMCOREINFO export for RISCV64 Date: Thu, 11 Aug 2022 15:41:50 +0800 Message-Id: <20220811074150.3020189-7-xianting.tian@linux.alibaba.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220811074150.3020189-1-xianting.tian@linux.alibaba.com> References: <20220811074150.3020189-1-xianting.tian@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The following interrelated definitions and ranges are needed by the kdump crash tool, they are exported by "arch/riscv/kernel/crash_core.c": VA_BITS, PAGE_OFFSET, phys_ram_base MODULES_VADDR ~ MODULES_END, VMALLOC_START ~ VMALLOC_END, VMEMMAP_START ~ VMEMMAP_END KASAN_SHADOW_START ~ KASAN_SHADOW_END, KERNEL_LINK_ADDR ~ ADDRESS_SPACE_END This patch just add the description of VMCOREINFO export for RISCV64. Signed-off-by: Xianting Tian Reviewed-by: Conor Dooley --- .../admin-guide/kdump/vmcoreinfo.rst | 31 +++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation= /admin-guide/kdump/vmcoreinfo.rst index 8419019b6a88..1e71e6710404 100644 --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst @@ -595,3 +595,34 @@ X2TLB ----- =20 Indicates whether the crashed kernel enabled SH extended mode. + +RISCV64 +=3D=3D=3D=3D=3D=3D=3D + +VA_BITS +------- + +The maximum number of bits for virtual addresses. Used to compute the +virtual memory ranges. + +PAGE_OFFSET +----------- + +Indicates the virtual kernel start address of direct-mapped RAM region. + +phys_ram_base +------------- + +Indicates the start physical RAM address. + +--------------------------------------------------------------------------= -------------------------------------------------------------------------- +MODULES_VADDR|MODULES_END|VMALLOC_START|VMALLOC_END|VMEMMAP_START|VMEMMAP_= END|KASAN_SHADOW_START|KASAN_SHADOW_END|KERNEL_LINK_ADDR|ADDRESS_SPACE_END +--------------------------------------------------------------------------= -------------------------------------------------------------------------- + +Used to get the correct ranges: + + * MODULES_VADDR ~ MODULES_END : Kernel module space. + * VMALLOC_START ~ VMALLOC_END : vmalloc() / ioremap() space. + * VMEMMAP_START ~ VMEMMAP_END : vmemmap region, used for struct page arr= ay. + * KASAN_SHADOW_START ~ KASAN_SHADOW_END : kasan shadow space. + * KERNEL_LINK_ADDR ~ ADDRESS_SPACE_END : Kernel link and BPF space. --=20 2.17.1