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From: Dave Young <dyoung@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Baoquan He <bhe@redhat.com>, Borislav Petkov <bp@alien8.de>,
	j-nomura@ce.jp.nec.com, kasong@redhat.com,
	fanc.fnst@cn.fujitsu.com, x86@kernel.org,
	kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
	hpa@zytor.com, tglx@linutronix.de
Subject: Re: [PATCH v6 1/2] x86/kexec: Build identity mapping for EFI systab and ACPI tables
Date: Tue, 14 May 2019 20:58:35 +0800	[thread overview]
Message-ID: <20190514125835.GA29045@dhcp-128-65.nay.redhat.com> (raw)
In-Reply-To: <20190514113826.GM2589@hirez.programming.kicks-ass.net>

On 05/14/19 at 01:38pm, Peter Zijlstra wrote:
> On Tue, May 14, 2019 at 04:48:41PM +0800, Dave Young wrote:
> 
> > > I did some tests on the laptop,  thing is:
> > > 1. apply the 3 patches (two you posted + Boris's revert commit 52b922c3d49c)
> > >    on latest Linus master branch, everything works fine.
> > > 
> > > 2. build and test the tip/next-merge-window branch, kernel hangs early
> > > without output, (both 1st boot and kexec boot)
> > 
> > Update about 2.  It should be not early rsdp related, I got the boot log
> > Since can not reproduce with Linus master branch it may have been fixed.
> 
> Nothing was changed here since PTI.
> 
> > [    0.685374][    T1] rcu: Hierarchical SRCU implementation.
> > [    0.686414][    T1] general protection fault: 0000 [#1] SMP PTI
> > [    0.687328][    T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.1.0-rc6+ #877
> > [    0.687328][    T1] Hardware name: LENOVO 4236NUC/4236NUC, BIOS 83ET82WW (1.52 ) 06/04/2018
> > [    0.687328][    T1] RIP: 0010:reserve_ds_buffers+0x34e/0x450
> 
> > [    0.687328][    T1] Call Trace:
> > [    0.687328][    T1]  ? hardlockup_detector_event_create+0x50/0x50
> > [    0.687328][    T1]  x86_reserve_hardware+0x173/0x180
> > [    0.687328][    T1]  x86_pmu_event_init+0x39/0x220
> 
> The DS buffers are special in that they're part of cpu_entrt_area. If
> this comes apart it might mean your pagetables are dodgy.

Hmm, it seems caused by some WIP branch patches, I suspect below:
commit 124d6af5a5f559e516ed2c6ea857e889ed293b43
x86/paravirt: Standardize 'insn_buff' variable names

The suspicious line is "per_cpu(insn_buff, cpu) = insn_buff;"

I can help to test if need to try anything, eg. debug patch.

I do not know anything of the pti and ds buffer logic, but below chunk
make the next-merge-window branch booting fine on the laptop.
---
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index ad47f6415b17..fa254c576032 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -337,7 +337,7 @@ static int alloc_pebs_buffer(int cpu)
 	struct debug_store *ds = hwev->ds;
 	size_t bsiz = x86_pmu.pebs_buffer_size;
 	int max, node = cpu_to_node(cpu);
-	void *buffer, *insn_buff, *cea;
+	void *buffer, *ibuff, *cea;
 
 	if (!x86_pmu.pebs)
 		return 0;
@@ -351,12 +351,12 @@ static int alloc_pebs_buffer(int cpu)
 	 * buffer then.
 	 */
 	if (x86_pmu.intel_cap.pebs_format < 2) {
-		insn_buff = kzalloc_node(PEBS_FIXUP_SIZE, GFP_KERNEL, node);
-		if (!insn_buff) {
+		ibuff = kzalloc_node(PEBS_FIXUP_SIZE, GFP_KERNEL, node);
+		if (!ibuff) {
 			dsfree_pages(buffer, bsiz);
 			return -ENOMEM;
 		}
-		per_cpu(insn_buff, cpu) = insn_buff;
+		per_cpu(insn_buff, cpu) = ibuff;
 	}
 	hwev->ds_pebs_vaddr = buffer;
 	/* Update the cpu entry area mapping */

  reply	other threads:[~2019-05-14 12:58 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-24  9:29 [PATCH v5 0/2] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Baoquan He
2019-04-24  9:29 ` [PATCH v5 1/2] x86/kexec: Build identity mapping for EFI systab and ACPI tables Baoquan He
2019-04-27 16:11   ` Borislav Petkov
2019-04-28  5:41     ` Baoquan He
2019-04-29 12:50       ` Borislav Petkov
2019-04-29  0:23   ` [PATCH v6 " Baoquan He
2019-04-29 13:55     ` Borislav Petkov
2019-04-29 14:16       ` Baoquan He
2019-05-13  1:43       ` Baoquan He
2019-05-13  7:07         ` Borislav Petkov
2019-05-13  7:32           ` Baoquan He
2019-05-13  7:50             ` Borislav Petkov
2019-05-13  8:02               ` Baoquan He
2019-05-15  5:17                 ` Junichi Nomura
2019-05-15  6:58                   ` Borislav Petkov
2019-05-15  7:09                     ` Junichi Nomura
2019-05-21  9:02                       ` Kairui Song
2019-05-21 10:43                         ` Junichi Nomura
2019-05-21 18:09                         ` Borislav Petkov
2019-05-28  2:49                           ` Kairui Song
2019-06-06 19:20                             ` Borislav Petkov
2019-05-13  8:06               ` Baoquan He
2019-05-14  3:22                 ` Dave Young
2019-05-14  3:33                   ` Baoquan He
2019-05-21 21:53                     ` Dirk van der Merwe
2019-05-21 23:04                       ` Borislav Petkov
2019-05-14  8:48                   ` Dave Young
2019-05-14 11:18                     ` Kairui Song
2019-05-14 11:38                     ` Peter Zijlstra
2019-05-14 12:58                       ` Dave Young [this message]
2019-05-14 13:54                         ` Peter Zijlstra
2019-05-14 14:09                         ` Ingo Molnar
2019-05-15  1:08                           ` Dave Young
2019-05-15  6:43                             ` Junichi Nomura
2019-05-17 13:41                   ` Borislav Petkov
2019-05-17 13:50                     ` [PATCH] x86/boot: Call get_rsdp_addr() after console_init() Borislav Petkov
2019-05-21  9:28                       ` Baoquan He
2019-06-06 19:22     ` [tip:x86/boot] x86/kexec: Add the EFI system tables and ACPI tables to the ident map tip-bot for Kairui Song
2019-04-24  9:29 ` [PATCH v5 2/2] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernels Baoquan He
2019-04-24  9:33   ` Baoquan He
2019-04-24  9:38 ` [PATCH v5 0/2] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Borislav Petkov
2019-04-24 10:00   ` Baoquan He

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