[PATCH v4 06/10] x86: process: Introduce helper to clear a thread's IO bitmap

From: Josh Triplett
Date: Sun Nov 02 2014 - 12:32:53 EST


This will make it easier to make the io_bitmap_ptr field optional later.

Signed-off-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
---
arch/x86/kernel/process-io.h | 5 +++++
arch/x86/kernel/process_32.c | 4 ++--
arch/x86/kernel/process_64.c | 2 +-
3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/process-io.h b/arch/x86/kernel/process-io.h
index d884444..ffa65e8 100644
--- a/arch/x86/kernel/process-io.h
+++ b/arch/x86/kernel/process-io.h
@@ -1,6 +1,11 @@
#ifndef _X86_KERNEL_PROCESS_IO_H
#define _X86_KERNEL_PROCESS_IO_H

+static inline void clear_thread_io_bitmap(struct task_struct *p)
+{
+ p->thread.io_bitmap_ptr = NULL;
+}
+
static inline int copy_io_bitmap(struct task_struct *me,
struct task_struct *p)
{
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 07550ff..b55f78e 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -154,7 +154,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
childregs->orig_ax = -1;
childregs->cs = __KERNEL_CS | get_kernel_rpl();
childregs->flags = X86_EFLAGS_IF | X86_EFLAGS_FIXED;
- p->thread.io_bitmap_ptr = NULL;
+ clear_thread_io_bitmap(p);
return 0;
}
*childregs = *current_pt_regs();
@@ -165,7 +165,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
p->thread.ip = (unsigned long) ret_from_fork;
task_user_gs(p) = get_user_gs(current_pt_regs());

- p->thread.io_bitmap_ptr = NULL;
+ clear_thread_io_bitmap(p);
tsk = current;

/*
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index b1babb4..d18f3fc 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -164,7 +164,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
p->thread.sp = (unsigned long) childregs;
p->thread.usersp = me->thread.usersp;
set_tsk_thread_flag(p, TIF_FORK);
- p->thread.io_bitmap_ptr = NULL;
+ clear_thread_io_bitmap(p);

savesegment(gs, p->thread.gsindex);
p->thread.gs = p->thread.gsindex ? 0 : me->thread.gs;
--
2.1.1

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