From: Thomas Gleixner <[email protected]>
While looking at the TSS io bitmap it turned out that any change in that
area would require identical changes to copy_thread_tls(). The 32 and 64
bit variants share sufficient code to consolidate them into a common
function to avoid duplication of upcoming modifications.
Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Andy Lutomirski <[email protected]>
---
arch/x86/include/asm/ptrace.h | 6 ++
arch/x86/include/asm/switch_to.h | 10 ++++
arch/x86/kernel/process.c | 94 +++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/process_32.c | 68 ----------------------------
arch/x86/kernel/process_64.c | 75 -------------------------------
5 files changed, 110 insertions(+), 143 deletions(-)
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -361,5 +361,11 @@ extern int do_get_thread_area(struct tas
extern int do_set_thread_area(struct task_struct *p, int idx,
struct user_desc __user *info, int can_allocate);
+#ifdef CONFIG_X86_64
+# define do_set_thread_area_64(p, s, t) do_arch_prctl_64(p, s, t)
+#else
+# define do_set_thread_area_64(p, s, t) (0)
+#endif
+
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_X86_PTRACE_H */
--- a/arch/x86/include/asm/switch_to.h
+++ b/arch/x86/include/asm/switch_to.h
@@ -103,7 +103,17 @@ static inline void update_task_stack(str
if (static_cpu_has(X86_FEATURE_XENPV))
load_sp0(task_top_of_stack(task));
#endif
+}
+static inline void kthread_frame_init(struct inactive_task_frame *frame,
+ unsigned long fun, unsigned long arg)
+{
+ frame->bx = fun;
+#ifdef CONFIG_X86_32
+ frame->di = arg;
+#else
+ frame->r12 = arg;
+#endif
}
#endif /* _ASM_X86_SWITCH_TO_H */
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -132,6 +132,100 @@ void exit_thread(struct task_struct *tsk
fpu__drop(fpu);
}
+static int set_new_tls(struct task_struct *p, unsigned long tls)
+{
+ struct user_desc __user *utls = (struct user_desc __user *)tls;
+
+ if (in_ia32_syscall())
+ return do_set_thread_area(p, -1, utls, 0);
+ else
+ return do_set_thread_area_64(p, ARCH_SET_FS, tls);
+}
+
+static inline int copy_io_bitmap(struct task_struct *tsk)
+{
+ if (likely(!test_tsk_thread_flag(current, TIF_IO_BITMAP)))
+ return 0;
+
+ tsk->thread.io_bitmap_ptr = kmemdup(current->thread.io_bitmap_ptr,
+ IO_BITMAP_BYTES, GFP_KERNEL);
+ if (!tsk->thread.io_bitmap_ptr) {
+ tsk->thread.io_bitmap_max = 0;
+ return -ENOMEM;
+ }
+ set_tsk_thread_flag(tsk, TIF_IO_BITMAP);
+ return 0;
+}
+
+static inline void free_io_bitmap(struct task_struct *tsk)
+{
+ if (tsk->thread.io_bitmap_ptr) {
+ kfree(tsk->thread.io_bitmap_ptr);
+ tsk->thread.io_bitmap_ptr = NULL;
+ tsk->thread.io_bitmap_max = 0;
+ }
+}
+
+int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
+ unsigned long arg, struct task_struct *p, unsigned long tls)
+{
+ struct inactive_task_frame *frame;
+ struct fork_frame *fork_frame;
+ struct pt_regs *childregs;
+ int ret;
+
+ childregs = task_pt_regs(p);
+ fork_frame = container_of(childregs, struct fork_frame, regs);
+ frame = &fork_frame->frame;
+
+ frame->bp = 0;
+ frame->ret_addr = (unsigned long) ret_from_fork;
+ p->thread.sp = (unsigned long) fork_frame;
+ p->thread.io_bitmap_ptr = NULL;
+ memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
+
+#ifdef CONFIG_X86_64
+ savesegment(gs, p->thread.gsindex);
+ p->thread.gsbase = p->thread.gsindex ? 0 : current->thread.gsbase;
+ savesegment(fs, p->thread.fsindex);
+ p->thread.fsbase = p->thread.fsindex ? 0 : current->thread.fsbase;
+ savesegment(es, p->thread.es);
+ savesegment(ds, p->thread.ds);
+#else
+ /* Clear all status flags including IF and set fixed bit. */
+ frame->flags = X86_EFLAGS_FIXED;
+#endif
+
+ /* Kernel thread ? */
+ if (unlikely(p->flags & PF_KTHREAD)) {
+ memset(childregs, 0, sizeof(struct pt_regs));
+ kthread_frame_init(frame, sp, arg);
+ return 0;
+ }
+
+ frame->bx = 0;
+ *childregs = *current_pt_regs();
+ childregs->ax = 0;
+ if (sp)
+ childregs->sp = sp;
+
+#ifdef CONFIG_X86_32
+ task_user_gs(p) = get_user_gs(current_pt_regs());
+#endif
+
+ ret = copy_io_bitmap(p);
+ if (ret)
+ return ret;
+
+ /* Set a new TLS for the child thread? */
+ if (clone_flags & CLONE_SETTLS) {
+ ret = set_new_tls(p, tls);
+ if (ret)
+ free_io_bitmap(p);
+ }
+ return ret;
+}
+
void flush_thread(void)
{
struct task_struct *tsk = current;
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -112,74 +112,6 @@ void release_thread(struct task_struct *
release_vm86_irqs(dead_task);
}
-int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
- unsigned long arg, struct task_struct *p, unsigned long tls)
-{
- struct pt_regs *childregs = task_pt_regs(p);
- struct fork_frame *fork_frame = container_of(childregs, struct fork_frame, regs);
- struct inactive_task_frame *frame = &fork_frame->frame;
- 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;
- p->thread.sp0 = (unsigned long) (childregs+1);
- memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
-
- if (unlikely(p->flags & PF_KTHREAD)) {
- /* kernel thread */
- memset(childregs, 0, sizeof(struct pt_regs));
- frame->bx = sp; /* function */
- frame->di = arg;
- p->thread.io_bitmap_ptr = NULL;
- return 0;
- }
- frame->bx = 0;
- *childregs = *current_pt_regs();
- childregs->ax = 0;
- if (sp)
- childregs->sp = sp;
-
- task_user_gs(p) = get_user_gs(current_pt_regs());
-
- p->thread.io_bitmap_ptr = NULL;
- tsk = current;
- err = -ENOMEM;
-
- if (unlikely(test_tsk_thread_flag(tsk, TIF_IO_BITMAP))) {
- p->thread.io_bitmap_ptr = kmemdup(tsk->thread.io_bitmap_ptr,
- IO_BITMAP_BYTES, GFP_KERNEL);
- if (!p->thread.io_bitmap_ptr) {
- p->thread.io_bitmap_max = 0;
- return -ENOMEM;
- }
- set_tsk_thread_flag(p, TIF_IO_BITMAP);
- }
-
- err = 0;
-
- /*
- * Set a new TLS for the child thread?
- */
- if (clone_flags & CLONE_SETTLS)
- err = do_set_thread_area(p, -1,
- (struct user_desc __user *)tls, 0);
-
- if (err && p->thread.io_bitmap_ptr) {
- kfree(p->thread.io_bitmap_ptr);
- p->thread.io_bitmap_max = 0;
- }
- return err;
-}
-
void
start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
{
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -371,81 +371,6 @@ void x86_gsbase_write_task(struct task_s
task->thread.gsbase = gsbase;
}
-int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
- unsigned long arg, struct task_struct *p, unsigned long tls)
-{
- int err;
- struct pt_regs *childregs;
- struct fork_frame *fork_frame;
- struct inactive_task_frame *frame;
- struct task_struct *me = current;
-
- childregs = task_pt_regs(p);
- fork_frame = container_of(childregs, struct fork_frame, regs);
- frame = &fork_frame->frame;
-
- frame->bp = 0;
- frame->ret_addr = (unsigned long) ret_from_fork;
- p->thread.sp = (unsigned long) fork_frame;
- p->thread.io_bitmap_ptr = NULL;
-
- savesegment(gs, p->thread.gsindex);
- p->thread.gsbase = p->thread.gsindex ? 0 : me->thread.gsbase;
- savesegment(fs, p->thread.fsindex);
- p->thread.fsbase = p->thread.fsindex ? 0 : me->thread.fsbase;
- savesegment(es, p->thread.es);
- savesegment(ds, p->thread.ds);
- memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
-
- if (unlikely(p->flags & PF_KTHREAD)) {
- /* kernel thread */
- memset(childregs, 0, sizeof(struct pt_regs));
- frame->bx = sp; /* function */
- frame->r12 = arg;
- return 0;
- }
- frame->bx = 0;
- *childregs = *current_pt_regs();
-
- childregs->ax = 0;
- if (sp)
- childregs->sp = sp;
-
- err = -ENOMEM;
- if (unlikely(test_tsk_thread_flag(me, TIF_IO_BITMAP))) {
- p->thread.io_bitmap_ptr = kmemdup(me->thread.io_bitmap_ptr,
- IO_BITMAP_BYTES, GFP_KERNEL);
- if (!p->thread.io_bitmap_ptr) {
- p->thread.io_bitmap_max = 0;
- return -ENOMEM;
- }
- set_tsk_thread_flag(p, TIF_IO_BITMAP);
- }
-
- /*
- * Set a new TLS for the child thread?
- */
- if (clone_flags & CLONE_SETTLS) {
-#ifdef CONFIG_IA32_EMULATION
- if (in_ia32_syscall())
- err = do_set_thread_area(p, -1,
- (struct user_desc __user *)tls, 0);
- else
-#endif
- err = do_arch_prctl_64(p, ARCH_SET_FS, tls);
- if (err)
- goto out;
- }
- err = 0;
-out:
- if (err && p->thread.io_bitmap_ptr) {
- kfree(p->thread.io_bitmap_ptr);
- p->thread.io_bitmap_max = 0;
- }
-
- return err;
-}
-
static void
start_thread_common(struct pt_regs *regs, unsigned long new_ip,
unsigned long new_sp,
On Wed, Nov 13, 2019 at 1:02 PM Thomas Gleixner <[email protected]> wrote:
>
> +int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
> + unsigned long arg, struct task_struct *p, unsigned long tls)
...
> +#ifdef CONFIG_X86_64
..
> +#else
> + /* Clear all status flags including IF and set fixed bit. */
> + frame->flags = X86_EFLAGS_FIXED;
> +#endif
Hmm. The unification I like, but it also shows these differences that
I don't remember the reason for.
Remind me why __switch_to_asm() on 32-bit safes eflags, but we don't
do it on x86-64?
The comment just talks about callee-saved registers, but flags isn't
callee-saved, so there's something else going on.
This patch clearly doesn't change anything, I'm not complaining about
the patch at all. I'm just wondering about the odd difference that the
patch exposes.
Linus
On Wed, 13 Nov 2019, Linus Torvalds wrote:
> On Wed, Nov 13, 2019 at 1:02 PM Thomas Gleixner <[email protected]> wrote:
> >
> > +int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
> > + unsigned long arg, struct task_struct *p, unsigned long tls)
> ...
> > +#ifdef CONFIG_X86_64
> ..
> > +#else
> > + /* Clear all status flags including IF and set fixed bit. */
> > + frame->flags = X86_EFLAGS_FIXED;
> > +#endif
>
> Hmm. The unification I like, but it also shows these differences that
> I don't remember the reason for.
>
> Remind me why __switch_to_asm() on 32-bit safes eflags, but we don't
> do it on x86-64?
>
> The comment just talks about callee-saved registers, but flags isn't
> callee-saved, so there's something else going on.
>
> This patch clearly doesn't change anything, I'm not complaining about
> the patch at all. I'm just wondering about the odd difference that the
> patch exposes.
See commit: 64604d54d311 ("sched/x86_64: Don't save flags on context switch")
We need "only" make objtool support 32bit :)
Thanks,
tglx
On Wed, Nov 13, 2019 at 4:14 PM Linus Torvalds
<[email protected]> wrote:
>
> On Wed, Nov 13, 2019 at 1:02 PM Thomas Gleixner <[email protected]> wrote:
> >
> > +int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
> > + unsigned long arg, struct task_struct *p, unsigned long tls)
> ...
> > +#ifdef CONFIG_X86_64
> ..
> > +#else
> > + /* Clear all status flags including IF and set fixed bit. */
> > + frame->flags = X86_EFLAGS_FIXED;
> > +#endif
>
> Hmm. The unification I like, but it also shows these differences that
> I don't remember the reason for.
>
> Remind me why __switch_to_asm() on 32-bit safes eflags, but we don't
> do it on x86-64?
>
> The comment just talks about callee-saved registers, but flags isn't
> callee-saved, so there's something else going on.
>
> This patch clearly doesn't change anything, I'm not complaining about
> the patch at all. I'm just wondering about the odd difference that the
> patch exposes.
It's to prevent AC from leaking into the next task. objtool can
verify that 64-bit code doesn't schedule when AC is set, but it
doesn't work on 32-bit. We could probably just do a CLAC on switch
and when it switches back to that task you would get an oops and it
would get noticed. It's likely though that the 64-bit coverage has
fixed most of the places where this happened.
--
Brian Gerst
On Wed, Nov 13, 2019 at 1:41 PM Thomas Gleixner <[email protected]> wrote:
>
> See commit: 64604d54d311 ("sched/x86_64: Don't save flags on context switch")
>
> We need "only" make objtool support 32bit :)
Duh, I knew that.
Maybe just a comment in the structure and/or the __switch_to_asm() so
that next time I forget I won't look like such a tool.
The "Save callee-saved registers" comment we have now in the 32-bit
__switch_to_asm() really is misleading and incorrect wrt the pushfl.
Linus
On Wed, 13 Nov 2019, Linus Torvalds wrote:
> On Wed, Nov 13, 2019 at 1:41 PM Thomas Gleixner <[email protected]> wrote:
> >
> > See commit: 64604d54d311 ("sched/x86_64: Don't save flags on context switch")
> >
> > We need "only" make objtool support 32bit :)
>
> Duh, I knew that.
>
> Maybe just a comment in the structure and/or the __switch_to_asm() so
> that next time I forget I won't look like such a tool.
>
> The "Save callee-saved registers" comment we have now in the 32-bit
> __switch_to_asm() really is misleading and incorrect wrt the pushfl.
Yeah. Let me fix that.
Thanks,
tglx
The following commit has been merged into the x86/iopl branch of tip:
Commit-ID: 320044006807464e3e80c11b3afbc08a57767f29
Gitweb: https://git.kernel.org/tip/320044006807464e3e80c11b3afbc08a57767f29
Author: Thomas Gleixner <[email protected]>
AuthorDate: Wed, 13 Nov 2019 21:42:42 +01:00
Committer: Thomas Gleixner <[email protected]>
CommitterDate: Thu, 14 Nov 2019 20:14:59 +01:00
x86/process: Unify copy_thread_tls()
While looking at the TSS io bitmap it turned out that any change in that
area would require identical changes to copy_thread_tls(). The 32 and 64
bit variants share sufficient code to consolidate them into a common
function to avoid duplication of upcoming modifications.
Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Andy Lutomirski <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
---
arch/x86/include/asm/ptrace.h | 6 ++-
arch/x86/include/asm/switch_to.h | 10 +++-
arch/x86/kernel/process.c | 94 +++++++++++++++++++++++++++++++-
arch/x86/kernel/process_32.c | 68 +----------------------
arch/x86/kernel/process_64.c | 75 +-------------------------
5 files changed, 110 insertions(+), 143 deletions(-)
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 332eb35..5057a8e 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -361,5 +361,11 @@ extern int do_get_thread_area(struct task_struct *p, int idx,
extern int do_set_thread_area(struct task_struct *p, int idx,
struct user_desc __user *info, int can_allocate);
+#ifdef CONFIG_X86_64
+# define do_set_thread_area_64(p, s, t) do_arch_prctl_64(p, s, t)
+#else
+# define do_set_thread_area_64(p, s, t) (0)
+#endif
+
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_X86_PTRACE_H */
diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h
index 18a4b68..0e059b7 100644
--- a/arch/x86/include/asm/switch_to.h
+++ b/arch/x86/include/asm/switch_to.h
@@ -103,7 +103,17 @@ static inline void update_task_stack(struct task_struct *task)
if (static_cpu_has(X86_FEATURE_XENPV))
load_sp0(task_top_of_stack(task));
#endif
+}
+static inline void kthread_frame_init(struct inactive_task_frame *frame,
+ unsigned long fun, unsigned long arg)
+{
+ frame->bx = fun;
+#ifdef CONFIG_X86_32
+ frame->di = arg;
+#else
+ frame->r12 = arg;
+#endif
}
#endif /* _ASM_X86_SWITCH_TO_H */
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 5e94c43..c09130a 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -132,6 +132,100 @@ void exit_thread(struct task_struct *tsk)
fpu__drop(fpu);
}
+static int set_new_tls(struct task_struct *p, unsigned long tls)
+{
+ struct user_desc __user *utls = (struct user_desc __user *)tls;
+
+ if (in_ia32_syscall())
+ return do_set_thread_area(p, -1, utls, 0);
+ else
+ return do_set_thread_area_64(p, ARCH_SET_FS, tls);
+}
+
+static inline int copy_io_bitmap(struct task_struct *tsk)
+{
+ if (likely(!test_tsk_thread_flag(current, TIF_IO_BITMAP)))
+ return 0;
+
+ tsk->thread.io_bitmap_ptr = kmemdup(current->thread.io_bitmap_ptr,
+ IO_BITMAP_BYTES, GFP_KERNEL);
+ if (!tsk->thread.io_bitmap_ptr) {
+ tsk->thread.io_bitmap_max = 0;
+ return -ENOMEM;
+ }
+ set_tsk_thread_flag(tsk, TIF_IO_BITMAP);
+ return 0;
+}
+
+static inline void free_io_bitmap(struct task_struct *tsk)
+{
+ if (tsk->thread.io_bitmap_ptr) {
+ kfree(tsk->thread.io_bitmap_ptr);
+ tsk->thread.io_bitmap_ptr = NULL;
+ tsk->thread.io_bitmap_max = 0;
+ }
+}
+
+int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
+ unsigned long arg, struct task_struct *p, unsigned long tls)
+{
+ struct inactive_task_frame *frame;
+ struct fork_frame *fork_frame;
+ struct pt_regs *childregs;
+ int ret;
+
+ childregs = task_pt_regs(p);
+ fork_frame = container_of(childregs, struct fork_frame, regs);
+ frame = &fork_frame->frame;
+
+ frame->bp = 0;
+ frame->ret_addr = (unsigned long) ret_from_fork;
+ p->thread.sp = (unsigned long) fork_frame;
+ p->thread.io_bitmap_ptr = NULL;
+ memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
+
+#ifdef CONFIG_X86_64
+ savesegment(gs, p->thread.gsindex);
+ p->thread.gsbase = p->thread.gsindex ? 0 : current->thread.gsbase;
+ savesegment(fs, p->thread.fsindex);
+ p->thread.fsbase = p->thread.fsindex ? 0 : current->thread.fsbase;
+ savesegment(es, p->thread.es);
+ savesegment(ds, p->thread.ds);
+#else
+ /* Clear all status flags including IF and set fixed bit. */
+ frame->flags = X86_EFLAGS_FIXED;
+#endif
+
+ /* Kernel thread ? */
+ if (unlikely(p->flags & PF_KTHREAD)) {
+ memset(childregs, 0, sizeof(struct pt_regs));
+ kthread_frame_init(frame, sp, arg);
+ return 0;
+ }
+
+ frame->bx = 0;
+ *childregs = *current_pt_regs();
+ childregs->ax = 0;
+ if (sp)
+ childregs->sp = sp;
+
+#ifdef CONFIG_X86_32
+ task_user_gs(p) = get_user_gs(current_pt_regs());
+#endif
+
+ ret = copy_io_bitmap(p);
+ if (ret)
+ return ret;
+
+ /* Set a new TLS for the child thread? */
+ if (clone_flags & CLONE_SETTLS) {
+ ret = set_new_tls(p, tls);
+ if (ret)
+ free_io_bitmap(p);
+ }
+ return ret;
+}
+
void flush_thread(void)
{
struct task_struct *tsk = current;
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index b8ceec4..6c7d905 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -112,74 +112,6 @@ void release_thread(struct task_struct *dead_task)
release_vm86_irqs(dead_task);
}
-int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
- unsigned long arg, struct task_struct *p, unsigned long tls)
-{
- struct pt_regs *childregs = task_pt_regs(p);
- struct fork_frame *fork_frame = container_of(childregs, struct fork_frame, regs);
- struct inactive_task_frame *frame = &fork_frame->frame;
- 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;
- p->thread.sp0 = (unsigned long) (childregs+1);
- memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
-
- if (unlikely(p->flags & PF_KTHREAD)) {
- /* kernel thread */
- memset(childregs, 0, sizeof(struct pt_regs));
- frame->bx = sp; /* function */
- frame->di = arg;
- p->thread.io_bitmap_ptr = NULL;
- return 0;
- }
- frame->bx = 0;
- *childregs = *current_pt_regs();
- childregs->ax = 0;
- if (sp)
- childregs->sp = sp;
-
- task_user_gs(p) = get_user_gs(current_pt_regs());
-
- p->thread.io_bitmap_ptr = NULL;
- tsk = current;
- err = -ENOMEM;
-
- if (unlikely(test_tsk_thread_flag(tsk, TIF_IO_BITMAP))) {
- p->thread.io_bitmap_ptr = kmemdup(tsk->thread.io_bitmap_ptr,
- IO_BITMAP_BYTES, GFP_KERNEL);
- if (!p->thread.io_bitmap_ptr) {
- p->thread.io_bitmap_max = 0;
- return -ENOMEM;
- }
- set_tsk_thread_flag(p, TIF_IO_BITMAP);
- }
-
- err = 0;
-
- /*
- * Set a new TLS for the child thread?
- */
- if (clone_flags & CLONE_SETTLS)
- err = do_set_thread_area(p, -1,
- (struct user_desc __user *)tls, 0);
-
- if (err && p->thread.io_bitmap_ptr) {
- kfree(p->thread.io_bitmap_ptr);
- p->thread.io_bitmap_max = 0;
- }
- return err;
-}
-
void
start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
{
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index af64519..e93a1b8 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -371,81 +371,6 @@ void x86_gsbase_write_task(struct task_struct *task, unsigned long gsbase)
task->thread.gsbase = gsbase;
}
-int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
- unsigned long arg, struct task_struct *p, unsigned long tls)
-{
- int err;
- struct pt_regs *childregs;
- struct fork_frame *fork_frame;
- struct inactive_task_frame *frame;
- struct task_struct *me = current;
-
- childregs = task_pt_regs(p);
- fork_frame = container_of(childregs, struct fork_frame, regs);
- frame = &fork_frame->frame;
-
- frame->bp = 0;
- frame->ret_addr = (unsigned long) ret_from_fork;
- p->thread.sp = (unsigned long) fork_frame;
- p->thread.io_bitmap_ptr = NULL;
-
- savesegment(gs, p->thread.gsindex);
- p->thread.gsbase = p->thread.gsindex ? 0 : me->thread.gsbase;
- savesegment(fs, p->thread.fsindex);
- p->thread.fsbase = p->thread.fsindex ? 0 : me->thread.fsbase;
- savesegment(es, p->thread.es);
- savesegment(ds, p->thread.ds);
- memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
-
- if (unlikely(p->flags & PF_KTHREAD)) {
- /* kernel thread */
- memset(childregs, 0, sizeof(struct pt_regs));
- frame->bx = sp; /* function */
- frame->r12 = arg;
- return 0;
- }
- frame->bx = 0;
- *childregs = *current_pt_regs();
-
- childregs->ax = 0;
- if (sp)
- childregs->sp = sp;
-
- err = -ENOMEM;
- if (unlikely(test_tsk_thread_flag(me, TIF_IO_BITMAP))) {
- p->thread.io_bitmap_ptr = kmemdup(me->thread.io_bitmap_ptr,
- IO_BITMAP_BYTES, GFP_KERNEL);
- if (!p->thread.io_bitmap_ptr) {
- p->thread.io_bitmap_max = 0;
- return -ENOMEM;
- }
- set_tsk_thread_flag(p, TIF_IO_BITMAP);
- }
-
- /*
- * Set a new TLS for the child thread?
- */
- if (clone_flags & CLONE_SETTLS) {
-#ifdef CONFIG_IA32_EMULATION
- if (in_ia32_syscall())
- err = do_set_thread_area(p, -1,
- (struct user_desc __user *)tls, 0);
- else
-#endif
- err = do_arch_prctl_64(p, ARCH_SET_FS, tls);
- if (err)
- goto out;
- }
- err = 0;
-out:
- if (err && p->thread.io_bitmap_ptr) {
- kfree(p->thread.io_bitmap_ptr);
- p->thread.io_bitmap_max = 0;
- }
-
- return err;
-}
-
static void
start_thread_common(struct pt_regs *regs, unsigned long new_ip,
unsigned long new_sp,