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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 56bf143..3851bfc 100644 (file)
--- a/fs/proc/base.c
+++ b/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_file *m, struct pid_namespace *ns,
                          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;
 
-       wchan = get_wchan(task);
-       if (wchan && !lookup_symbol_name(wchan, symname)) {
-               seq_puts(m, symname);
-               return 0;
-       }
+       if (wchan)
+               seq_printf(m, "%ps", (void *) wchan);
+       else
+               seq_putc(m, '0');
 
-print0:
-       seq_putc(m, '0');
        return 0;
 }
 #endif /* CONFIG_KALLSYMS */