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

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

[akpm]

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

As a good side-effect die() now prints the stacktrace with KERN_EMERG
aligned with other messages.

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

Link: http://lkml.kernel.org/r/20200418201944.482088-15-dima@arista.com
Signed-off-by: Dmitry Safonov <dima@arista.com>
Acked-by: Brian Cain <bcain@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/hexagon/kernel/traps.c |   31 +++++++++++++++++--------------
 1 file changed, 17 insertions(+), 14 deletions(-)

--- a/arch/hexagon/kernel/traps.c~hexagon-add-show_stack_loglvl
+++ a/arch/hexagon/kernel/traps.c
@@ -79,7 +79,7 @@ static const char *ex_name(int ex)
 }
 
 static void do_show_stack(struct task_struct *task, unsigned long *fp,
-			  unsigned long ip)
+			  unsigned long ip, const char *loglvl)
 {
 	int kstack_depth_to_print = 24;
 	unsigned long offset, size;
@@ -93,9 +93,8 @@ static void do_show_stack(struct task_st
 	if (task == NULL)
 		task = current;
 
-	printk(KERN_INFO "CPU#%d, %s/%d, Call Trace:\n",
-	       raw_smp_processor_id(), task->comm,
-	       task_pid_nr(task));
+	printk("%sCPU#%d, %s/%d, Call Trace:\n", loglvl, raw_smp_processor_id(),
+		task->comm, task_pid_nr(task));
 
 	if (fp == NULL) {
 		if (task == current) {
@@ -108,7 +107,7 @@ static void do_show_stack(struct task_st
 	}
 
 	if ((((unsigned long) fp) & 0x3) || ((unsigned long) fp < 0x1000)) {
-		printk(KERN_INFO "-- Corrupt frame pointer %p\n", fp);
+		printk("%s-- Corrupt frame pointer %p\n", loglvl, fp);
 		return;
 	}
 
@@ -125,8 +124,7 @@ static void do_show_stack(struct task_st
 
 		name = kallsyms_lookup(ip, &size, &offset, &modname, tmpstr);
 
-		printk(KERN_INFO "[%p] 0x%lx: %s + 0x%lx", fp, ip, name,
-			offset);
+		printk("%s[%p] 0x%lx: %s + 0x%lx", loglvl, fp, ip, name, offset);
 		if (((unsigned long) fp < low) || (high < (unsigned long) fp))
 			printk(KERN_CONT " (FP out of bounds!)");
 		if (modname)
@@ -136,8 +134,7 @@ static void do_show_stack(struct task_st
 		newfp = (unsigned long *) *fp;
 
 		if (((unsigned long) newfp) & 0x3) {
-			printk(KERN_INFO "-- Corrupt frame pointer %p\n",
-				newfp);
+			printk("%s-- Corrupt frame pointer %p\n", loglvl, newfp);
 			break;
 		}
 
@@ -147,7 +144,7 @@ static void do_show_stack(struct task_st
 						+ 8);
 
 			if (regs->syscall_nr != -1) {
-				printk(KERN_INFO "-- trap0 -- syscall_nr: %ld",
+				printk("%s-- trap0 -- syscall_nr: %ld", loglvl,
 					regs->syscall_nr);
 				printk(KERN_CONT "  psp: %lx  elr: %lx\n",
 					 pt_psp(regs), pt_elr(regs));
@@ -155,7 +152,7 @@ static void do_show_stack(struct task_st
 			} else {
 				/* really want to see more ... */
 				kstack_depth_to_print += 6;
-				printk(KERN_INFO "-- %s (0x%lx)  badva: %lx\n",
+				printk("%s-- %s (0x%lx)  badva: %lx\n", loglvl,
 					ex_name(pt_cause(regs)), pt_cause(regs),
 					pt_badva(regs));
 			}
@@ -178,10 +175,16 @@ static void do_show_stack(struct task_st
 	}
 }
 
-void show_stack(struct task_struct *task, unsigned long *fp)
+void show_stack_loglvl(struct task_struct *task, unsigned long *fp,
+		       const char *loglvl)
 {
 	/* Saved link reg is one word above FP */
-	do_show_stack(task, fp, 0);
+	do_show_stack(task, fp, 0, loglvl);
+}
+
+void show_stack(struct task_struct *task, unsigned long *fp)
+{
+	show_stack_loglvl(task, fp, 0, KERN_INFO);
 }
 
 int die(const char *str, struct pt_regs *regs, long err)
@@ -207,7 +210,7 @@ int die(const char *str, struct pt_regs
 
 	print_modules();
 	show_regs(regs);
-	do_show_stack(current, &regs->r30, pt_elr(regs));
+	do_show_stack(current, &regs->r30, pt_elr(regs), KERN_EMERG);
 
 	bust_spinlocks(0);
 	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
_

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