x86/mce: Rename kill_it to kill_current_task

Currently, if an MCE happens in user-mode or while the kernel is copying
data from user space, 'kill_it' is used to check if execution of the
interrupted task can be recovered or not; the flag name however is not
very meaningful, hence rename it to match its goal.

 [ bp: Massage commit message, rename the queue_task_work() arg too. ]
Signed-off-by: Gabriele Paoloni <gabriele.paoloni@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201127161819.3106432-6-gabriele.paoloni@intel.com

arch/x86/kernel/cpu/mce/core.c

@@ -1266,14 +1266,14 @@ static void kill_me_maybe(struct callback_head *cb)
 	}
 }
 
-static void queue_task_work(struct mce *m, int kill_it)
+static void queue_task_work(struct mce *m, int kill_current_task)
 {
 	current->mce_addr = m->addr;
 	current->mce_kflags = m->kflags;
 	current->mce_ripv = !!(m->mcgstatus & MCG_STATUS_RIPV);
 	current->mce_whole_page = whole_page(m);
 
-	if (kill_it)
+	if (kill_current_task)
 		current->mce_kill_me.func = kill_me_now;
 	else
 		current->mce_kill_me.func = kill_me_maybe;
@@ -1321,10 +1321,10 @@ noinstr void do_machine_check(struct pt_regs *regs)
 	int no_way_out = 0;
 
 	/*
-	 * If kill_it gets set, there might be a way to recover from this
+	 * If kill_current_task is not set, there might be a way to recover from this
 	 * error.
 	 */
-	int kill_it = 0;
+	int kill_current_task = 0;
 
 	/*
 	 * MCEs are always local on AMD. Same is determined by MCG_STATUS_LMCES
@@ -1351,7 +1351,7 @@ noinstr void do_machine_check(struct pt_regs *regs)
 	 * severity is MCE_AR_SEVERITY we have other options.
 	 */
 	if (!(m.mcgstatus & MCG_STATUS_RIPV))
-		kill_it = (cfg->tolerant == 3) ? 0 : 1;
+		kill_current_task = (cfg->tolerant == 3) ? 0 : 1;
 	/*
 	 * Check if this MCE is signaled to only this logical processor,
 	 * on Intel, Zhaoxin only.
@@ -1406,7 +1406,7 @@ noinstr void do_machine_check(struct pt_regs *regs)
 		}
 	}
 
-	if (worst != MCE_AR_SEVERITY && !kill_it)
+	if (worst != MCE_AR_SEVERITY && !kill_current_task)
 		goto out;
 
 	/* Fault was in user mode and we need to take some action */
@@ -1414,7 +1414,7 @@ noinstr void do_machine_check(struct pt_regs *regs)
 		/* If this triggers there is no way to recover. Die hard. */
 		BUG_ON(!on_thread_stack() || !user_mode(regs));
 
-		queue_task_work(&m, kill_it);
+		queue_task_work(&m, kill_current_task);
 
 	} else {
 		/*
@@ -1432,7 +1432,7 @@ noinstr void do_machine_check(struct pt_regs *regs)
 		}
 
 		if (m.kflags & MCE_IN_KERNEL_COPYIN)
-			queue_task_work(&m, kill_it);
+			queue_task_work(&m, kill_current_task);
 	}
 out:
 	mce_wrmsrl(MSR_IA32_MCG_STATUS, 0);