sh: add loglvl to dump_mem()

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.

Add log level argument to dump_mem() as a preparation to introduce
show_stack_loglvl().

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

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200418201944.482088-30-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/sh/include/asm/kdebug.h b/arch/sh/include/asm/kdebug.h
index 5212f5fcd7520125b899f3b1d2e0cad83ce48ddd..de8693fabb1d95b563dcde35ef43d7f0487c2261 100644 (file)
--- a/arch/sh/include/asm/kdebug.h
+++ b/arch/sh/include/asm/kdebug.h
@@ -13,6 +13,7 @@ enum die_val {
 
 /* arch/sh/kernel/dumpstack.c */
 extern void printk_address(unsigned long address, int reliable);
-extern void dump_mem(const char *str, unsigned long bottom, unsigned long top);
+extern void dump_mem(const char *str, const char *loglvl,
+                    unsigned long bottom, unsigned long top);
 
 #endif /* __ASM_SH_KDEBUG_H */

diff --git a/arch/sh/kernel/dumpstack.c b/arch/sh/kernel/dumpstack.c
index 9f1c9c11d62df46a8e7ace2f54663f0e076e799b..6784b914fba010981cf289d1d8305af7b9be6d77 100644 (file)
--- a/arch/sh/kernel/dumpstack.c
+++ b/arch/sh/kernel/dumpstack.c
@@ -16,30 +16,31 @@
 #include <asm/unwinder.h>
 #include <asm/stacktrace.h>
 
-void dump_mem(const char *str, unsigned long bottom, unsigned long top)
+void dump_mem(const char *str, const char *loglvl,
+             unsigned long bottom, unsigned long top)
 {
        unsigned long p;
        int i;
 
-       printk("%s(0x%08lx to 0x%08lx)\n", str, bottom, top);
+       printk("%s%s(0x%08lx to 0x%08lx)\n", loglvl, str, bottom, top);
 
        for (p = bottom & ~31; p < top; ) {
-               printk("%04lx: ", p & 0xffff);
+               printk("%s%04lx: ", loglvl,  p & 0xffff);
 
                for (i = 0; i < 8; i++, p += 4) {
                        unsigned int val;
 
                        if (p < bottom || p >= top)
-                               printk("         ");
+                               printk("%s         ", loglvl);
                        else {
                                if (__get_user(val, (unsigned int __user *)p)) {
-                                       printk("\n");
+                                       printk("%s\n", loglvl);
                                        return;
                                }
-                               printk("%08x ", val);
+                               printk("%s%08x ", loglvl, val);
                        }
                }
-               printk("\n");
+               printk("%s\n", loglvl);
        }
 }
 
@@ -156,7 +157,7 @@ void show_stack(struct task_struct *tsk, unsigned long *sp)
                sp = (unsigned long *)tsk->thread.sp;
 
        stack = (unsigned long)sp;
-       dump_mem("Stack: ", stack, THREAD_SIZE +
+       dump_mem("Stack: ", KERN_DEFAULT, stack, THREAD_SIZE +
                 (unsigned long)task_stack_page(tsk));
        show_trace(tsk, sp, NULL);
 }

diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c
index 2130381c9d5749ae2d22eadbc279ac84c92b60cf..a33025451fcd095a6a575cc4735c07b2bc4dc4ce 100644 (file)
--- a/arch/sh/kernel/traps.c
+++ b/arch/sh/kernel/traps.c
@@ -38,8 +38,8 @@ void die(const char *str, struct pt_regs *regs, long err)
                        task_pid_nr(current), task_stack_page(current) + 1);
 
        if (!user_mode(regs) || in_interrupt())
-               dump_mem("Stack: ", regs->regs[15], THREAD_SIZE +
-                        (unsigned long)task_stack_page(current));
+               dump_mem("Stack: ", KERN_DEFAULT, regs->regs[15],
+                       THREAD_SIZE + (unsigned long)task_stack_page(current));
 
        notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV);