+ proc-wchan-use-printk-format-instead-of-lookup_symbol_name.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     Subject: proc/wchan: use printk format instead of lookup_symbol_name()
has been added to the -mm tree.  Its filename is
     proc-wchan-use-printk-format-instead-of-lookup_symbol_name.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/proc-wchan-use-printk-format-instead-of-lookup_symbol_name.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/proc-wchan-use-printk-format-instead-of-lookup_symbol_name.patch

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------------------------------------------------------
From: Helge Deller <deller@gmx.de>
Subject: proc/wchan: use printk format instead of lookup_symbol_name()

To resolve the symbol fuction name for wchan, use the printk format
specifier %ps instead of manually looking up the symbol function name
via lookup_symbol_name().

Link: https://lkml.kernel.org/r/20201217165413.GA1959@ls3530.fritz.box
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/proc/base.c |   21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

--- a/fs/proc/base.c~proc-wchan-use-printk-format-instead-of-lookup_symbol_name
+++ a/fs/proc/base.c
@@ -67,7 +67,6 @@
 #include <linux/mm.h>
 #include <linux/swap.h>
 #include <linux/rcupdate.h>
-#include <linux/kallsyms.h>
 #include <linux/stacktrace.h>
 #include <linux/resource.h>
 #include <linux/module.h>
@@ -386,19 +385,17 @@ static int proc_pid_wchan(struct seq_fil
 			  struct pid *pid, struct task_struct *task)
 {
 	unsigned long wchan;
-	char symname[KSYM_NAME_LEN];
 
-	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
-		goto print0;
+	if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
+		wchan = get_wchan(task);
+	else
+		wchan = 0;
+
+	if (wchan)
+		seq_printf(m, "%ps", (void *) wchan);
+	else
+		seq_putc(m, '0');
 
-	wchan = get_wchan(task);
-	if (wchan && !lookup_symbol_name(wchan, symname)) {
-		seq_puts(m, symname);
-		return 0;
-	}
-
-print0:
-	seq_putc(m, '0');
 	return 0;
 }
 #endif /* CONFIG_KALLSYMS */
_

Patches currently in -mm which might be from deller@gmx.de are

proc-wchan-use-printk-format-instead-of-lookup_symbol_name.patch