[Devel] [PATCH RHEL7 COMMIT] ms/x86/process: Unify 32bit and 64bit implementations of get_wchan()
Konstantin Khorenko
khorenko at virtuozzo.com
Wed Nov 18 01:23:15 PST 2015
The commit is pushed to "branch-rh7-3.10.0-229.7.2.vz7.9.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-229.7.2.vz7.9.10
------>
commit 85583522d8aab897c25cecf72cf9c8b61a51ebc9
Author: Thomas Gleixner <tglx at linutronix.de>
Date: Wed Nov 18 13:23:15 2015 +0400
ms/x86/process: Unify 32bit and 64bit implementations of get_wchan()
The stack layout and the functionality is identical. Use the 64bit
version for all of x86.
Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
Reviewed-by: Borislav Petkov <bp at alien8.de>
Reviewed-by: Dmitry Vyukov <dvyukov at google.com>
Cc: Andrey Ryabinin <ryabinin.a.a at gmail.com>
Cc: Andy Lutomirski <luto at amacapital.net>
Cc: Andrey Konovalov <andreyknvl at google.com>
Cc: Kostya Serebryany <kcc at google.com>
Cc: Alexander Potapenko <glider at google.com>
Cc: kasan-dev <kasan-dev at googlegroups.com>
Cc: Denys Vlasenko <dvlasenk at redhat.com>
Cc: Andi Kleen <ak at linux.intel.com>
Cc: Sasha Levin <sasha.levin at oracle.com>
Cc: Wolfram Gloger <wmglo at dent.med.uni-muenchen.de>
Link: http://lkml.kernel.org/r/20150930083302.779694618@linutronix.de
Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
(cherry picked from commit 7ba78053aacb89998a052843e3c56983c31d57f0)
Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
arch/x86/kernel/process.c | 55 +++++++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/process_32.c | 28 ----------------------
arch/x86/kernel/process_64.c | 56 --------------------------------------------
3 files changed, 55 insertions(+), 84 deletions(-)
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 5111a56..ee3666a 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -470,3 +470,58 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
}
+/*
+ * Called from fs/proc with a reference on @p to find the function
+ * which called into schedule(). This needs to be done carefully
+ * because the task might wake up and we might look at a stack
+ * changing under us.
+ */
+unsigned long get_wchan(struct task_struct *p)
+{
+ unsigned long start, bottom, top, sp, fp, ip;
+ int count = 0;
+
+ if (!p || p == current || p->state == TASK_RUNNING)
+ return 0;
+
+ start = (unsigned long)task_stack_page(p);
+ if (!start)
+ return 0;
+
+ /*
+ * Layout of the stack page:
+ *
+ * ----------- topmax = start + THREAD_SIZE - sizeof(unsigned long)
+ * PADDING
+ * ----------- top = topmax - TOP_OF_KERNEL_STACK_PADDING
+ * stack
+ * ----------- bottom = start + sizeof(thread_info)
+ * thread_info
+ * ----------- start
+ *
+ * The tasks stack pointer points at the location where the
+ * framepointer is stored. The data on the stack is:
+ * ... IP FP ... IP FP
+ *
+ * We need to read FP and IP, so we need to adjust the upper
+ * bound by another unsigned long.
+ */
+ top = start + THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING;
+ top -= 2 * sizeof(unsigned long);
+ bottom = start + sizeof(struct thread_info);
+
+ sp = READ_ONCE(p->thread.sp);
+ if (sp < bottom || sp > top)
+ return 0;
+
+ fp = READ_ONCE(*(unsigned long *)sp);
+ do {
+ if (fp < bottom || fp > top)
+ return 0;
+ ip = READ_ONCE(*(unsigned long *)(fp + sizeof(unsigned long)));
+ if (!in_sched_functions(ip))
+ return ip;
+ fp = READ_ONCE(*(unsigned long *)fp);
+ } while (count++ < 16 && p->state != TASK_RUNNING);
+ return 0;
+}
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index dd02d27..ca615af 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -313,31 +313,3 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
return prev_p;
}
-
-#define top_esp (THREAD_SIZE - sizeof(unsigned long))
-#define top_ebp (THREAD_SIZE - 2*sizeof(unsigned long))
-
-unsigned long get_wchan(struct task_struct *p)
-{
- unsigned long bp, sp, ip;
- unsigned long stack_page;
- int count = 0;
- if (!p || p == current || p->state == TASK_RUNNING)
- return 0;
- stack_page = (unsigned long)task_stack_page(p);
- sp = p->thread.sp;
- if (!stack_page || sp < stack_page || sp > top_esp+stack_page)
- return 0;
- /* include/asm-i386/system.h:switch_to() pushes bp last. */
- bp = *(unsigned long *) sp;
- do {
- if (bp < stack_page || bp > top_ebp+stack_page)
- return 0;
- ip = *(unsigned long *) (bp+4);
- if (!in_sched_functions(ip))
- return ip;
- bp = *(unsigned long *) bp;
- } while (count++ < 16);
- return 0;
-}
-
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 6970509..d9a542f 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -422,62 +422,6 @@ void set_personality_ia32(bool x32)
}
EXPORT_SYMBOL_GPL(set_personality_ia32);
-/*
- * Called from fs/proc with a reference on @p to find the function
- * which called into schedule(). This needs to be done carefully
- * because the task might wake up and we might look at a stack
- * changing under us.
- */
-unsigned long get_wchan(struct task_struct *p)
-{
- unsigned long start, bottom, top, sp, fp, ip;
- int count = 0;
-
- if (!p || p == current || p->state == TASK_RUNNING)
- return 0;
-
- start = (unsigned long)task_stack_page(p);
- if (!start)
- return 0;
-
- /*
- * Layout of the stack page:
- *
- * ----------- topmax = start + THREAD_SIZE - sizeof(unsigned long)
- * PADDING
- * ----------- top = topmax - TOP_OF_KERNEL_STACK_PADDING
- * stack
- * ----------- bottom = start + sizeof(thread_info)
- * thread_info
- * ----------- start
- *
- * The tasks stack pointer points at the location where the
- * framepointer is stored. The data on the stack is:
- * ... IP FP ... IP FP
- *
- * We need to read FP and IP, so we need to adjust the upper
- * bound by another unsigned long.
- */
- top = start + THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING;
- top -= 2 * sizeof(unsigned long);
- bottom = start + sizeof(struct thread_info);
-
- sp = READ_ONCE(p->thread.sp);
- if (sp < bottom || sp > top)
- return 0;
-
- fp = READ_ONCE(*(unsigned long *)sp);
- do {
- if (fp < bottom || fp > top)
- return 0;
- ip = READ_ONCE(*(unsigned long *)(fp + sizeof(unsigned long)));
- if (!in_sched_functions(ip))
- return ip;
- fp = READ_ONCE(*(unsigned long *)fp);
- } while (count++ < 16 && p->state != TASK_RUNNING);
- return 0;
-}
-
long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
{
int ret = 0;
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