linux-kernel - [PATCH -next v4 2/3] x86/mce: rename MCE_IN_KERNEL_COPYIN to MCE_IN_KERNEL_COPY

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Date: Thu, 11 Jan 2024 21:55:47 +0800
From: Tong Tiangen <tongtiangen@...wei.com>
To: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>, <wangkefeng.wang@...wei.com>, Dave Hansen
	<dave.hansen@...ux.intel.com>, <x86@...nel.org>, "H. Peter Anvin"
	<hpa@...or.com>, Tony Luck <tony.luck@...el.com>, Andy Lutomirski
	<luto@...nel.org>, Peter Zijlstra <peterz@...radead.org>, Andrew Morton
	<akpm@...ux-foundation.org>, Naoya Horiguchi <naoya.horiguchi@....com>
CC: <linux-kernel@...r.kernel.org>, <linux-edac@...r.kernel.org>,
	<linux-mm@...ck.org>, Tong Tiangen <tongtiangen@...wei.com>, Guohanjun
	<guohanjun@...wei.com>
Subject: [PATCH -next v4 2/3] x86/mce: rename MCE_IN_KERNEL_COPYIN to MCE_IN_KERNEL_COPY_MC

In the x86 mce processing, macro MCE_IN_KERNEL_COPYIN is used to identify
copied from user. do_machine_check() uses this flag to isolate posion
page in memory_failure(). there's nothing wrong but we can expand the use
of this macro.

Currently, there are some kernel memory copy scenarios is also mc safe
which use copy_mc_to_kernel() or copy_mc_user_highpage(). In these
scenarios, posion pages need to be isolated too. Therefore, a macro similar
to MCE_IN_KERNEL_COPYIN is required. For this reason, we can rename
MCE_IN_KERNEL_COPYIN to MCE_IN_KERNEL_COPY_MC, the new macro can be applied
to both user-to-kernel mc safe copy and kernel-to-kernel mc safe copy.

Signed-off-by: Tong Tiangen <tongtiangen@...wei.com>
---
 arch/x86/include/asm/mce.h         | 8 ++++----
 arch/x86/kernel/cpu/mce/core.c     | 2 +-
 arch/x86/kernel/cpu/mce/severity.c | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index de3118305838..cb628ab2f32f 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -151,11 +151,11 @@
 
 /*
  * Indicates an MCE that happened in kernel space while copying data
- * from user. In this case fixup_exception() gets the kernel to the
- * error exit for the copy function. Machine check handler can then
- * treat it like a fault taken in user mode.
+ * from user or kernel. In this case fixup_exception() gets the kernel
+ * to the error exit for the copy function. Machine check handler can
+ * then treat it like a fault taken in user or kernel mode.
  */
-#define MCE_IN_KERNEL_COPYIN	BIT_ULL(7)
+#define MCE_IN_KERNEL_COPY_MC	BIT_ULL(7)
 
 /*
  * This structure contains all data related to the MCE log.  Also
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 2bfd0e3c62e4..bd1a31ed148b 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1607,7 +1607,7 @@ noinstr void do_machine_check(struct pt_regs *regs)
 				mce_panic("Failed kernel mode recovery", &m, msg);
 		}
 
-		if (m.kflags & MCE_IN_KERNEL_COPYIN)
+		if (m.kflags & MCE_IN_KERNEL_COPY_MC)
 			queue_task_work(&m, msg, kill_me_never);
 	}
 
diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c
index bca780fa5e57..df67a7a13034 100644
--- a/arch/x86/kernel/cpu/mce/severity.c
+++ b/arch/x86/kernel/cpu/mce/severity.c
@@ -292,7 +292,7 @@ static noinstr int error_context(struct mce *m, struct pt_regs *regs)
 	case EX_TYPE_UACCESS:
 		if (!copy_user)
 			return IN_KERNEL;
-		m->kflags |= MCE_IN_KERNEL_COPYIN;
+		m->kflags |= MCE_IN_KERNEL_COPY_MC;
 		fallthrough;
 
 	case EX_TYPE_FAULT_MCE_SAFE:
-- 
2.25.1