diff options
| -rw-r--r-- | arch/arm/vfp/vfpmodule.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index 05872d92fca2..bc683b8219b5 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -564,6 +564,21 @@ int vfp_preserve_user_clear_hwstate(struct user_vfp __user *ufp, if (err) return -EFAULT; + + /* Ensure that VFP is disabled. */ + vfp_flush_hwstate(thread); + + /* + * As per the PCS, clear the length and stride bits for function + * entry. + */ + hwstate->fpscr &= ~(FPSCR_LENGTH_MASK | FPSCR_STRIDE_MASK); + + /* + * Disable VFP in the hwstate so that we can detect if it gets + * used. + */ + hwstate->fpexc &= ~FPEXC_EN; return 0; } @@ -576,7 +591,12 @@ int vfp_restore_user_hwstate(struct user_vfp __user *ufp, unsigned long fpexc; int err = 0; - vfp_flush_hwstate(thread); + /* + * If VFP has been used, then disable it to avoid corrupting + * the new thread state. + */ + if (hwstate->fpexc & FPEXC_EN) + vfp_flush_hwstate(thread); /* * Copy the floating point registers. There can be unused |