2023-12-18 08:24:33

by Tong Tiangen

[permalink] [raw]
Subject: [PATCH -next v3 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 <[email protected]>
---
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 faef7ceed746..dbea0c395c56 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1597,7 +1597,7 @@ 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