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-rw-r--r--kernel/exit.c5
-rw-r--r--kernel/fork.c5
-rw-r--r--kernel/panic.c12
-rw-r--r--kernel/sched.c7
4 files changed, 18 insertions, 11 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index 85a83c8..c8d0485 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -968,12 +968,9 @@ static void check_stack_usage(void)
{
static DEFINE_SPINLOCK(low_water_lock);
static int lowest_to_date = THREAD_SIZE;
- unsigned long *n = end_of_stack(current);
unsigned long free;
- while (*n == 0)
- n++;
- free = (unsigned long)n - (unsigned long)end_of_stack(current);
+ free = stack_not_used(current);
if (free >= lowest_to_date)
return;
diff --git a/kernel/fork.c b/kernel/fork.c
index 30de644..99c5c65 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -58,6 +58,7 @@
#include <linux/tty.h>
#include <linux/proc_fs.h>
#include <linux/blkdev.h>
+#include <linux/magic.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -207,6 +208,8 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
{
struct task_struct *tsk;
struct thread_info *ti;
+ unsigned long *stackend;
+
int err;
prepare_to_copy(orig);
@@ -232,6 +235,8 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
goto out;
setup_thread_stack(tsk, orig);
+ stackend = end_of_stack(tsk);
+ *stackend = STACK_END_MAGIC; /* for overflow detection */
#ifdef CONFIG_CC_STACKPROTECTOR
tsk->stack_canary = get_random_int();
diff --git a/kernel/panic.c b/kernel/panic.c
index 12c5a0a..e0a87bb 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -80,6 +80,9 @@ NORET_TYPE void panic(const char * fmt, ...)
vsnprintf(buf, sizeof(buf), fmt, args);
va_end(args);
printk(KERN_EMERG "Kernel panic - not syncing: %s\n",buf);
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+ dump_stack();
+#endif
bust_spinlocks(0);
/*
@@ -343,13 +346,20 @@ EXPORT_SYMBOL(warn_slowpath);
#endif
#ifdef CONFIG_CC_STACKPROTECTOR
+
+#ifndef GCC_HAS_SP
+#warning You have selected the CONFIG_CC_STACKPROTECTOR option, but the gcc used does not support this.
+#endif
+
/*
* Called when gcc's -fstack-protector feature is used, and
* gcc detects corruption of the on-stack canary value
*/
void __stack_chk_fail(void)
{
- panic("stack-protector: Kernel stack is corrupted");
+ panic("stack-protector: Kernel stack is corrupted in: %p\n",
+ __builtin_return_address(0));
}
EXPORT_SYMBOL(__stack_chk_fail);
+
#endif
diff --git a/kernel/sched.c b/kernel/sched.c
index 6f23059..d897a52 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5790,12 +5790,7 @@ void sched_show_task(struct task_struct *p)
printk(KERN_CONT " %016lx ", thread_saved_pc(p));
#endif
#ifdef CONFIG_DEBUG_STACK_USAGE
- {
- unsigned long *n = end_of_stack(p);
- while (!*n)
- n++;
- free = (unsigned long)n - (unsigned long)end_of_stack(p);
- }
+ free = stack_not_used(p);
#endif
printk(KERN_CONT "%5lu %5d %6d\n", free,
task_pid_nr(p), task_pid_nr(p->real_parent));
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