From 0557d64d983e3dedead2d4b4e8abc49620d5f5d2 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 18 Feb 2020 12:14:34 -0500 Subject: x86: switch to ->regset_get() All instances of ->get() in arch/x86 switched; that might or might not be worth splitting up. Notes: * for xstateregs_get() the amount we want to store is determined at the boot time; see init_xstate_size() and update_regset_xstate_info() for details. task->thread.fpu.state.xsave ends with a flexible array member and the amount of data in it depends upon the FPU features supported/enabled. * fpregs_get() writes slightly less than full ->thread.fpu.state.fsave (the last word is not copied); we pass the full size of state.fsave and let membuf_write() trim to the amount declared by regset - __regset_get() will make sure that the space in buffer is no more than that. * copy_xstate_to_user() and its helpers are gone now. * fpregs_soft_get() was getting user_regset_copyout() arguments wrong. Since "x86: x86 user_regset math_emu" back in 2008... I really doubt that it's worth splitting out for -stable, though - you need a 486SX box for that to trigger... [Kevin's braino fix for copy_xstate_to_kernel() essentially duplicated here] Signed-off-by: Al Viro --- arch/x86/math-emu/fpu_entry.c | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-) (limited to 'arch/x86/math-emu') diff --git a/arch/x86/math-emu/fpu_entry.c b/arch/x86/math-emu/fpu_entry.c index a873da6b46d6..8679a9d6c47f 100644 --- a/arch/x86/math-emu/fpu_entry.c +++ b/arch/x86/math-emu/fpu_entry.c @@ -689,12 +689,10 @@ int fpregs_soft_set(struct task_struct *target, int fpregs_soft_get(struct task_struct *target, const struct user_regset *regset, - unsigned int pos, unsigned int count, - void *kbuf, void __user *ubuf) + struct membuf to) { struct swregs_state *s387 = &target->thread.fpu.state.soft; const void *space = s387->st_space; - int ret; int offset = (S387->ftop & 7) * 10, other = 80 - offset; RE_ENTRANT_CHECK_OFF; @@ -709,18 +707,11 @@ int fpregs_soft_get(struct task_struct *target, S387->fos |= 0xffff0000; #endif /* PECULIAR_486 */ - ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, s387, 0, - offsetof(struct swregs_state, st_space)); - - /* Copy all registers in stack order. */ - if (!ret) - ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, - space + offset, 0, other); - if (!ret) - ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, - space, 0, offset); + membuf_write(&to, s387, offsetof(struct swregs_state, st_space)); + membuf_write(&to, space + offset, other); + membuf_write(&to, space, offset); RE_ENTRANT_CHECK_ON; - return ret; + return 0; } -- cgit v1.2.3