debian/patches/0008-SIMD-FPU-register-save-restore-is-also-required-on-5.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Thomas Lamprecht <t.lamprecht@proxmox.com>
   3 Date: Wed, 25 Sep 2019 10:48:48 +0200
   4 Subject: [PATCH] [SIMD]: FPU register save/restore is also required on 5.0
   5  kernels
   6
   7 NOTE: the kernel needs to have the copy_kernel_to_xregs_err,
   8 copy_kernel_to_fxregs_err and copy_kernel_to_fregs_err functions
   9 backported for this to work.
  10
  11 Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
  12 ---
  13  include/linux/simd_x86.h | 11 ++++-------
  14  1 file changed, 4 insertions(+), 7 deletions(-)
  15
  16 diff --git a/include/linux/simd_x86.h b/include/linux/simd_x86.h
  17 index edd456098..98503a29e 100644
  18 --- a/include/linux/simd_x86.h
  19 +++ b/include/linux/simd_x86.h
  20 @@ -181,7 +181,6 @@ kfpu_begin(void)
  21         preempt_disable();
  22         local_irq_disable();
  23
  24 -#if defined(HAVE_KERNEL_TIF_NEED_FPU_LOAD)
  25         /*
  26          * The current FPU registers need to be preserved by kfpu_begin()
  27          * and restored by kfpu_end().  This is required because we can
  28 @@ -190,11 +189,11 @@ kfpu_begin(void)
  29          * context switch.
  30          */
  31         copy_fpregs_to_fpstate(&current->thread.fpu);
  32 -#elif defined(HAVE_KERNEL_FPU_INITIALIZED)
  33 +
  34 +
  35 +#if defined(HAVE_KERNEL_FPU_INITIALIZED)
  36         /*
  37 -        * There is no need to preserve and restore the FPU registers.
  38 -        * They will always be restored from the task's stored FPU state
  39 -        * when switching contexts.
  40 +        * Was removed with 5.2 as it was always set to 1 there
  41          */
  42         WARN_ON_ONCE(current->thread.fpu.initialized == 0);
  43  #endif
  44 @@ -203,7 +202,6 @@ kfpu_begin(void)
  45  static inline void
  46  kfpu_end(void)
  47  {
  48 -#if defined(HAVE_KERNEL_TIF_NEED_FPU_LOAD)
  49         union fpregs_state *state = &current->thread.fpu.state;
  50         int error;
  51
  52 @@ -215,7 +213,6 @@ kfpu_end(void)
  53                 error = copy_kernel_to_fregs_err(&state->fsave);
  54         }
  55         WARN_ON_ONCE(error);
  56 -#endif
  57
  58         local_irq_enable();
  59         preempt_enable();