From: Aaron Tomlin <atomlin@redhat•com>
To: peterz@infradead•org
Cc: dzickus@redhat•com, jcastillo@redhat•com, riel@redhat•com,
x86@kernel•org, akpm@linux-foundation•org, minchan@kernel•org,
bmr@redhat•com, prarit@redhat•com, oleg@redhat•com,
rostedt@goodmis•org, linux-kernel@vger•kernel.org,
hannes@cmpxchg•org, mingo@redhat•com,
aneesh.kumar@linux•vnet.ibm.com, atomlin@redhat•com,
jgh@redhat•com, linuxppc-dev@lists•ozlabs.org,
tglx@linutronix•de, akpm@google•com
Subject: [PATCH v4 2/3] sched: Add helper for task stack page overrun checking
Date: Fri, 12 Sep 2014 14:16:18 +0100 [thread overview]
Message-ID: <1410527779-8133-3-git-send-email-atomlin@redhat.com> (raw)
In-Reply-To: <1410527779-8133-1-git-send-email-atomlin@redhat.com>
This facility is used in a few places so let's introduce
a helper function to improve code readability.
Signed-off-by: Aaron Tomlin <atomlin@redhat•com>
---
arch/powerpc/mm/fault.c | 4 +---
arch/x86/mm/fault.c | 4 +---
include/linux/sched.h | 2 ++
kernel/trace/trace_stack.c | 2 +-
4 files changed, 5 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 35d0760c..99b2f27 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -507,7 +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) {
@@ -536,8 +535,7 @@ 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 (*stackend != STACK_END_MAGIC)
+ if (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 bc23a70..6240bc7 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -648,7 +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;
@@ -708,8 +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 (*stackend != STACK_END_MAGIC)
+ if (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 7ef34b7..a80e35d 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2615,6 +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 1636e41..16eddb3 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -170,7 +170,7 @@ check_stack(unsigned long ip, unsigned long *stack)
i++;
}
- if (*end_of_stack(current) != STACK_END_MAGIC) {
+ if (task_stack_end_corrupted(current)) {
print_max_stack();
BUG();
}
--
1.9.3
next prev parent reply other threads:[~2014-09-12 13:19 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-12 13:16 [PATCH v4 0/3] sched: Always check the integrity of the canary Aaron Tomlin
2014-09-12 13:16 ` [PATCH v4 1/3] init/main.c: Give init_task a canary Aaron Tomlin
2014-09-18 20:27 ` Oleg Nesterov
2014-09-12 13:16 ` Aaron Tomlin [this message]
2014-09-12 13:16 ` [PATCH v4 3/3] sched: BUG when stack end location is over written Aaron Tomlin
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