@@ -103,7 +103,7 @@ static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
* Note that this also saves V16-31, which aren't visible
* in AArch32.
*/
- fpsimd_signal_preserve_current_state();
+ fpsimd_save_and_flush_current_state();
/* Place structure header on the stack */
__put_user_error(magic, &frame->magic, err);
@@ -169,14 +169,17 @@ static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
+ if (err)
+ return -EFAULT;
+
/*
* We don't need to touch the exception register, so
* reload the hardware state.
*/
- if (!err)
- fpsimd_update_current_state(&fpsimd);
+ fpsimd_save_and_flush_current_state();
+ current->thread.uw.fpsimd_state = fpsimd;
- return err ? -EFAULT : 0;
+ return 0;
}
static int compat_restore_sigframe(struct pt_regs *regs,
There are several issues with the way the native signal handling code manipulates FPSIMD/SVE/SME state. To fix those issues, subsequent patches will rework the native signal handling code to always save+flush the current task's FPSIMD/SVE/SME state before manipulating that state. In preparation for those changes, rework the compat signal handling code to save+flush the current task's FPSIMD state before manipulating it. Subsequent patches will remove fpsimd_signal_preserve_current_state() and fpsimd_update_current_state(). Compat tasks can only have FPSIMD state, and cannot have any SVE or SME state. Thus, the SVE state manipulation present in fpsimd_signal_preserve_current_state() and fpsimd_update_current_state() is not necessary, and it is safe to directly manipulate current->thread.uw.fpsimd_state once it has been saved+flushed. Use fpsimd_save_and_flush_current_state() to save+flush the state for both signal delivery and signal return, before the state is manipulated in any way. While it would be safe for compat_restore_vfp_context() to use fpsimd_flush_task_state(current), there are several extant issues in the native signal code resulting from incorrect use of fpsimd_flush_task_state(), and for consistency it is preferable to use fpsimd_save_and_flush_current_state(). Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Will Deacon <will@kernel.org> --- arch/arm64/kernel/signal32.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)