This facility is used in a few places so let's introduce
a helper function to improve readability.

Signed-off-by: Aaron Tomlin <atom...@redhat.com>
---
 arch/powerpc/mm/fault.c    | 6 ++----
 arch/x86/mm/fault.c        | 5 +----
 include/linux/sched.h      | 3 +++
 kernel/trace/trace_stack.c | 5 ++---
 4 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 51ab9e7..5cffc7c 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -30,7 +30,6 @@
 #include <linux/kprobes.h>
 #include <linux/kdebug.h>
 #include <linux/perf_event.h>
-#include <linux/magic.h>
 #include <linux/ratelimit.h>
 #include <linux/context_tracking.h>
 
@@ -508,7 +507,6 @@ bail:
 void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
 {
        const struct exception_table_entry *entry;
-       unsigned long *stackend;
 
        /* Are we prepared to handle this fault?  */
        if ((entry = search_exception_tables(regs->nip)) != NULL) {
@@ -537,8 +535,8 @@ void bad_page_fault(struct pt_regs *regs, unsigned long 
address, int sig)
        printk(KERN_ALERT "Faulting instruction address: 0x%08lx\n",
                regs->nip);
 
-       stackend = end_of_stack(current);
-       if (current != &init_task && *stackend != STACK_END_MAGIC)
+       if (current != &init_task &&
+               task_stack_end_corrupted(current))
                printk(KERN_ALERT "Thread overran stack, or stack corrupted\n");
 
        die("Kernel access of bad area", regs, sig);
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index a241946..b5b9c09 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -3,7 +3,6 @@
  *  Copyright (C) 2001, 2002 Andi Kleen, SuSE Labs.
  *  Copyright (C) 2008-2009, Red Hat Inc., Ingo Molnar
  */
-#include <linux/magic.h>               /* STACK_END_MAGIC              */
 #include <linux/sched.h>               /* test_thread_flag(), ...      */
 #include <linux/kdebug.h>              /* oops_begin/end, ...          */
 #include <linux/module.h>              /* search_exception_table       */
@@ -649,7 +648,6 @@ no_context(struct pt_regs *regs, unsigned long error_code,
           unsigned long address, int signal, int si_code)
 {
        struct task_struct *tsk = current;
-       unsigned long *stackend;
        unsigned long flags;
        int sig;
 
@@ -709,8 +707,7 @@ no_context(struct pt_regs *regs, unsigned long error_code,
 
        show_fault_oops(regs, error_code, address);
 
-       stackend = end_of_stack(tsk);
-       if (tsk != &init_task && *stackend != STACK_END_MAGIC)
+       if (tsk != &init_task && task_stack_end_corrupted(tsk))
                printk(KERN_EMERG "Thread overran stack, or stack corrupted\n");
 
        tsk->thread.cr2         = address;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 5c2c885..36d93aa 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -57,6 +57,7 @@ struct sched_param {
 #include <linux/llist.h>
 #include <linux/uidgid.h>
 #include <linux/gfp.h>
+#include <linux/magic.h>
 
 #include <asm/processor.h>
 
@@ -2614,6 +2615,8 @@ static inline unsigned long *end_of_stack(struct 
task_struct *p)
 }
 
 #endif
+#define task_stack_end_corrupted(task) \
+               (*(end_of_stack(task)) != STACK_END_MAGIC)
 
 static inline int object_is_on_stack(void *obj)
 {
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 8a4e5cb..06c7390 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -13,7 +13,6 @@
 #include <linux/sysctl.h>
 #include <linux/init.h>
 #include <linux/fs.h>
-#include <linux/magic.h>
 
 #include <asm/setup.h>
 
@@ -171,8 +170,8 @@ check_stack(unsigned long ip, unsigned long *stack)
                        i++;
        }
 
-       if ((current != &init_task &&
-               *(end_of_stack(current)) != STACK_END_MAGIC)) {
+       if (current != &init_task &&
+               task_stack_end_corrupted(current)) {
                print_max_stack();
                BUG();
        }
-- 
1.9.3

_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Reply via email to