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-rw-r--r--arch/x86/kernel/fpu/signal.c31
1 files changed, 15 insertions, 16 deletions
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index 7026f1c4e5e3..5a8d118bc423 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -157,11 +157,9 @@ static inline int copy_fpregs_to_sigframe(struct xregs_state __user *buf)
*/
int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
{
- struct fpu *fpu = &current->thread.fpu;
- struct xregs_state *xsave = &fpu->state.xsave;
struct task_struct *tsk = current;
int ia32_fxstate = (buf != buf_fx);
- int ret = -EFAULT;
+ int ret;
ia32_fxstate &= (IS_ENABLED(CONFIG_X86_32) ||
IS_ENABLED(CONFIG_IA32_EMULATION));
@@ -174,11 +172,12 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
sizeof(struct user_i387_ia32_struct), NULL,
(struct _fpstate_32 __user *) buf) ? -1 : 1;
+retry:
/*
* Load the FPU registers if they are not valid for the current task.
* With a valid FPU state we can attempt to save the state directly to
- * userland's stack frame which will likely succeed. If it does not, do
- * the slowpath.
+ * userland's stack frame which will likely succeed. If it does not,
+ * resolve the fault in the user memory and try again.
*/
fpregs_lock();
if (test_thread_flag(TIF_NEED_FPU_LOAD))
@@ -187,20 +186,20 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
pagefault_disable();
ret = copy_fpregs_to_sigframe(buf_fx);
pagefault_enable();
- if (ret && !test_thread_flag(TIF_NEED_FPU_LOAD))
- copy_fpregs_to_fpstate(fpu);
- set_thread_flag(TIF_NEED_FPU_LOAD);
fpregs_unlock();
if (ret) {
- if (using_compacted_format()) {
- if (copy_xstate_to_user(buf_fx, xsave, 0, size))
- return -1;
- } else {
- fpstate_sanitize_xstate(fpu);
- if (__copy_to_user(buf_fx, xsave, fpu_user_xstate_size))
- return -1;
- }
+ int aligned_size;
+ int nr_pages;
+
+ aligned_size = offset_in_page(buf_fx) + fpu_user_xstate_size;
+ nr_pages = DIV_ROUND_UP(aligned_size, PAGE_SIZE);
+
+ ret = get_user_pages_unlocked((unsigned long)buf_fx, nr_pages,
+ NULL, FOLL_WRITE);
+ if (ret == nr_pages)
+ goto retry;
+ return -EFAULT;
}
/* Save the fsave header for the 32-bit frames. */