[merged] um-add-show_stack_loglvl.patch removed from -mm tree

[merged] um-add-show_stack_loglvl.patch removed from -mm tree

[akpm]

The patch titled
     Subject: um: add show_stack_loglvl()
has been removed from the -mm tree.  Its filename was
     um-add-show_stack_loglvl.patch

This patch was dropped because it was merged into mainline or a subsystem tree

------------------------------------------------------
From: Dmitry Safonov <dima@arista.com>
Subject: um: add show_stack_loglvl()

Currently, the log-level of show_stack() depends on a platform
realization.  It creates situations where the headers are printed with
lower log level or higher than the stacktrace (depending on a platform or
user).

Furthermore, it forces the logic decision from user to an architecture
side.  In result, some users as sysrq/kdb/etc are doing tricks with
temporary rising console_loglevel while printing their messages.  And in
result it not only may print unwanted messages from other CPUs, but also
omit printing at all in the unlucky case where the printk() was deferred.

Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier
approach than introducing more printk buffers.  Also, it will consolidate
printings with headers.

Introduce show_stack_loglvl(), that eventually will substitute
show_stack().

[1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u

Link: http://lkml.kernel.org/r/20200418201944.482088-37-dima@arista.com
Signed-off-by: Dmitry Safonov <dima@arista.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/um/kernel/sysrq.c |   24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

--- a/arch/um/kernel/sysrq.c~um-add-show_stack_loglvl
+++ a/arch/um/kernel/sysrq.c
@@ -17,7 +17,9 @@
 
 static void _print_addr(void *data, unsigned long address, int reliable)
 {
-	pr_info(" [<%08lx>] %s%pS\n", address, reliable ? "" : "? ",
+	const char *loglvl = data;
+
+	printk("%s [<%08lx>] %s%pS\n", loglvl, address, reliable ? "" : "? ",
 		(void *)address);
 }
 
@@ -25,7 +27,8 @@ static const struct stacktrace_ops stack
 	.address = _print_addr
 };
 
-void show_stack(struct task_struct *task, unsigned long *stack)
+void show_stack_loglvl(struct task_struct *task, unsigned long *stack,
+		       const char *loglvl)
 {
 	struct pt_regs *segv_regs = current->thread.segv_regs;
 	int i;
@@ -39,17 +42,22 @@ void show_stack(struct task_struct *task
 	if (!stack)
 		stack = get_stack_pointer(task, segv_regs);
 
-	pr_info("Stack:\n");
+	printk("%sStack:\n", loglvl);
 	for (i = 0; i < 3 * STACKSLOTS_PER_LINE; i++) {
 		if (kstack_end(stack))
 			break;
 		if (i && ((i % STACKSLOTS_PER_LINE) == 0))
-			pr_cont("\n");
+			printk("%s\n", loglvl);
 		pr_cont(" %08lx", *stack++);
 	}
-	pr_cont("\n");
+	printk("%s\n", loglvl);
+
+	printk("%sCall Trace:\n", loglvl);
+	dump_trace(current, &stackops, (void *)loglvl);
+	printk("%s\n", loglvl);
+}
 
-	pr_info("Call Trace:\n");
-	dump_trace(current, &stackops, NULL);
-	pr_info("\n");
+void show_stack(struct task_struct *task, unsigned long *stack)
+{
+	show_stack_loglvl(task, stack, KERN_INFO);
 }
_

Patches currently in -mm which might be from dima@arista.com are