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-rw-r--r--arch/x86/entry/entry_32.S2
-rw-r--r--arch/x86/entry/entry_64.S2
-rw-r--r--arch/x86/include/asm/switch_to.h1
-rw-r--r--arch/x86/kernel/process_32.c7
-rw-r--r--arch/x86/kernel/process_64.c8
5 files changed, 20 insertions, 0 deletions
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index a76dc738ec61..1cf16760f5e3 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -219,6 +219,7 @@ ENTRY(__switch_to_asm)
pushl %ebx
pushl %edi
pushl %esi
+ pushfl
/* switch stack */
movl %esp, TASK_threadsp(%eax)
@@ -241,6 +242,7 @@ ENTRY(__switch_to_asm)
#endif
/* restore callee-saved registers */
+ popfl
popl %esi
popl %edi
popl %ebx
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 870e941c1947..8252d9dc48eb 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -313,6 +313,7 @@ ENTRY(__switch_to_asm)
pushq %r13
pushq %r14
pushq %r15
+ pushfq
/* switch stack */
movq %rsp, TASK_threadsp(%rdi)
@@ -335,6 +336,7 @@ ENTRY(__switch_to_asm)
#endif
/* restore callee-saved registers */
+ popfq
popq %r15
popq %r14
popq %r13
diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h
index 676e84f521ba..e959b8d40473 100644
--- a/arch/x86/include/asm/switch_to.h
+++ b/arch/x86/include/asm/switch_to.h
@@ -35,6 +35,7 @@ asmlinkage void ret_from_fork(void);
/* data that is pointed to by thread.sp */
struct inactive_task_frame {
+ unsigned long flags;
#ifdef CONFIG_X86_64
unsigned long r15;
unsigned long r14;
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 912246fd6cd9..4ca26fc7aa89 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -129,6 +129,13 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
struct task_struct *tsk;
int err;
+ /*
+ * For a new task use the RESET flags value since there is no before.
+ * All the status flags are zero; DF and all the system flags must also
+ * be 0, specifically IF must be 0 because we context switch to the new
+ * task with interrupts disabled.
+ */
+ frame->flags = X86_EFLAGS_FIXED;
frame->bp = 0;
frame->ret_addr = (unsigned long) ret_from_fork;
p->thread.sp = (unsigned long) fork_frame;
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 81eec65fe053..6d6c15cd9b9a 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -268,6 +268,14 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
childregs = task_pt_regs(p);
fork_frame = container_of(childregs, struct fork_frame, regs);
frame = &fork_frame->frame;
+
+ /*
+ * For a new task use the RESET flags value since there is no before.
+ * All the status flags are zero; DF and all the system flags must also
+ * be 0, specifically IF must be 0 because we context switch to the new
+ * task with interrupts disabled.
+ */
+ frame->flags = X86_EFLAGS_FIXED;
frame->bp = 0;
frame->ret_addr = (unsigned long) ret_from_fork;
p->thread.sp = (unsigned long) fork_frame;