[patch] X86: add sysctl for kstack_depth_to_print

From: Chuck Ebbert
Date: Sat Nov 25 2006 - 12:46:54 EST


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@xxxxxxxxxxxxxx>
---
Tested on i386; compiled on x86_64.

Documentation/sysctl/kernel.txt | 8 ++++++++
arch/i386/kernel/traps.c | 2 +-
arch/x86_64/kernel/traps.c | 2 +-
include/asm-x86_64/stacktrace.h | 2 ++
include/linux/sysctl.h | 1 +
kernel/sysctl.c | 9 +++++++++
6 files changed, 22 insertions(+), 2 deletions(-)

--- 2.6.19-rc6-32smp.orig/kernel/sysctl.c
+++ 2.6.19-rc6-32smp/kernel/sysctl.c
@@ -54,6 +54,7 @@ extern int proc_nr_files(ctl_table *tabl

#ifdef CONFIG_X86
#include <asm/nmi.h>
+#include <asm/stacktrace.h>
#endif

#if defined(CONFIG_SYSCTL)
@@ -707,6 +708,14 @@ static ctl_table kern_table[] = {
.mode = 0444,
.proc_handler = &proc_dointvec,
},
+ {
+ .ctl_name = KERN_KSTACK_DEPTH_TO_PRINT,
+ .procname = "kstack_depth_to_print",
+ .data = &kstack_depth_to_print,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
#endif
#if defined(CONFIG_MMU)
{
--- 2.6.19-rc6-32smp.orig/arch/i386/kernel/traps.c
+++ 2.6.19-rc6-32smp/arch/i386/kernel/traps.c
@@ -94,7 +94,7 @@ asmlinkage void alignment_check(void);
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
--- 2.6.19-rc6-32smp.orig/include/asm-x86_64/stacktrace.h
+++ 2.6.19-rc6-32smp/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 {
--- 2.6.19-rc6-32smp.orig/include/linux/sysctl.h
+++ 2.6.19-rc6-32smp/include/linux/sysctl.h
@@ -160,6 +160,7 @@ enum
KERN_MAX_LOCK_DEPTH=74,
KERN_NMI_WATCHDOG=75, /* int: enable/disable nmi watchdog */
KERN_PANIC_ON_NMI=76, /* int: whether we will panic on an unrecovered */
+ KERN_KSTACK_DEPTH_TO_PRINT=78, /* int: # words to print in show_stack() */
};


--- 2.6.19-rc6-32smp.orig/Documentation/sysctl/kernel.txt
+++ 2.6.19-rc6-32smp/Documentation/sysctl/kernel.txt
@@ -27,6 +27,7 @@ show up in /proc/sys/kernel:
- 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 @@ This flag controls the L2 cache of G3 pr

==============================================================

+kstack_depth_to_print: (X86 only)
+
+Controls the number of words to print when dumping the raw
+kernel stack.
+
+==============================================================
+
osrelease, ostype & version:

# cat osrelease
--- 2.6.19-rc6-32smp.orig/arch/x86_64/kernel/traps.c
+++ 2.6.19-rc6-32smp/arch/x86_64/kernel/traps.c
@@ -108,7 +108,7 @@ static inline void preempt_conditional_c
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
--
Chuck
"Even supernovas have their duller moments."
-
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