[PATCH 6/7] x86 dumpstack: fix printing of stack dump loglevels

From: Alan Jenkins
Date: Wed Oct 07 2009 - 04:42:54 EST


Commit 5fd29d6 "printk: clean up handling of log-levels and newlines"
breaks the log level in the output of the x86 stack dumper:

Pid: 2199, comm: klauncher Not tainted (2.6.32-rc2eeepc-test #483) 701
EFLAGS: 00010296 CPU: 0
EIP is at fget_light+0x39/0x79
...
Stack:
00000020 dbe23e7c dbe23f8c c01a62bd 00000001 d759c400 dbc61840 00000000
<0> 08088728 08088750 00000000 dbe23e74 dbe23ea4 00000000 00000000 00000000
<0> dbe23c18 00c7afc0 c01a6eb1 ffffffff 00000000 dbc61840 00000000 00000000

^ stray loglevel tokens

Those last two lines will also be incorrectly output as KERN_DEFAULT.

In this case the problem is effectively

printk("\n" KERN_EMERG);

Changing printk() to accept loglevels in the middle of the string again
would be non-trivial. Let's accept this limitation and simply split the
above code into two separate calls to printk().

Signed-off-by: Alan Jenkins <alan-jenkins@xxxxxxxxxxxxxx>
---
arch/x86/kernel/dumpstack_32.c | 6 ++++--
arch/x86/kernel/dumpstack_64.c | 6 ++++--
2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index f7dd2a7..8f1fb21 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -88,8 +88,10 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
for (i = 0; i < kstack_depth_to_print; i++) {
if (kstack_end(stack))
break;
- if (i && ((i % STACKSLOTS_PER_LINE) == 0))
- printk("\n%s", log_lvl);
+ if (i && ((i % STACKSLOTS_PER_LINE) == 0)) {
+ printk("\n");
+ printk("%s", log_lvl);
+ }
printk(" %08lx", *stack++);
touch_nmi_watchdog();
}
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index a071e6b..dbe1734 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -235,8 +235,10 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
if (((long) stack & (THREAD_SIZE-1)) == 0)
break;
}
- if (i && ((i % STACKSLOTS_PER_LINE) == 0))
- printk("\n%s", log_lvl);
+ if (i && ((i % STACKSLOTS_PER_LINE) == 0)) {
+ printk("\n");
+ printk("%s", log_lvl);
+ }
printk(" %016lx", *stack++);
touch_nmi_watchdog();
}
--
1.6.3.2

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