[PATCH] x86: add sysctl for kstack_depth_to_print
Add sysctl for kstack_depth_to_print. This lets users change
the amount of raw stack data printed in dump_stack() without
having to reboot.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andi Kleen <ak@suse.de>
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 0bc7f1e..5922e84 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -27,6 +27,7 @@
- hotplug
- java-appletviewer [ binfmt_java, obsolete ]
- java-interpreter [ binfmt_java, obsolete ]
+- kstack_depth_to_print [ X86 only ]
- l2cr [ PPC only ]
- modprobe ==> Documentation/kmod.txt
- msgmax
@@ -170,6 +171,13 @@
==============================================================
+kstack_depth_to_print: (X86 only)
+
+Controls the number of words to print when dumping the raw
+kernel stack.
+
+==============================================================
+
osrelease, ostype & version:
# cat osrelease
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 7b2f9f0..1d48a75 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -91,7 +91,7 @@
asmlinkage void spurious_interrupt_bug(void);
asmlinkage void machine_check(void);
-static int kstack_depth_to_print = 24;
+int kstack_depth_to_print = 24;
#ifdef CONFIG_STACK_UNWIND
static int call_trace = 1;
#else
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index 264db33..75cecce 100644
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -108,7 +108,7 @@
preempt_enable_no_resched();
}
-static int kstack_depth_to_print = 12;
+int kstack_depth_to_print = 12;
#ifdef CONFIG_STACK_UNWIND
static int call_trace = 1;
#else
diff --git a/include/asm-x86_64/stacktrace.h b/include/asm-x86_64/stacktrace.h
index 5eb9799..6f0b545 100644
--- a/include/asm-x86_64/stacktrace.h
+++ b/include/asm-x86_64/stacktrace.h
@@ -1,6 +1,8 @@
#ifndef _ASM_STACKTRACE_H
#define _ASM_STACKTRACE_H 1
+extern int kstack_depth_to_print;
+
/* Generic stack tracer with callbacks */
struct stacktrace_ops {
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 09e569f4..6fc5e17 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -54,6 +54,7 @@
#ifdef CONFIG_X86
#include <asm/nmi.h>
+#include <asm/stacktrace.h>
#endif
#if defined(CONFIG_SYSCTL)
@@ -707,6 +708,14 @@
.mode = 0444,
.proc_handler = &proc_dointvec,
},
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "kstack_depth_to_print",
+ .data = &kstack_depth_to_print,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
#endif
#if defined(CONFIG_MMU)
{
