From a69c158fb3e7a91220f55029bf222a4e678d16e9 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sat, 23 Sep 2017 14:59:47 +0200 Subject: [PATCH] x86/fpu: Remove 'kbuf' parameter from the copy_xstate_to_user() APIs The 'kbuf' parameter is unused in the _user() side of the API, remove it. This simplifies the code and makes it easier to think about. Cc: Andrew Morton Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: Eric Biggers Cc: Fenghua Yu Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: Yu-cheng Yu Link: http://lkml.kernel.org/r/20170923130016.21448-5-mingo@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/include/asm/fpu/xstate.h | 2 +- arch/x86/kernel/fpu/regset.c | 2 +- arch/x86/kernel/fpu/xstate.c | 25 +++++++------------------ 3 files changed, 9 insertions(+), 20 deletions(-) diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index c762574a245f..65bd68c30cd0 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -49,7 +49,7 @@ void *get_xsave_addr(struct xregs_state *xsave, int xstate); const void *get_xsave_field_ptr(int xstate_field); int using_compacted_format(void); int copy_xstate_to_kernel(unsigned int pos, unsigned int count, void *kbuf, struct xregs_state *xsave); -int copy_xstate_to_user(unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf, struct xregs_state *xsave); +int copy_xstate_to_user(unsigned int pos, unsigned int count, void __user *ubuf, struct xregs_state *xsave); int copy_user_to_xstate(const void *kbuf, const void __user *ubuf, struct xregs_state *xsave); #endif diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c index 34e74adf9d5d..fd6dbdd8fde6 100644 --- a/arch/x86/kernel/fpu/regset.c +++ b/arch/x86/kernel/fpu/regset.c @@ -95,7 +95,7 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset, if (kbuf) ret = copy_xstate_to_kernel(pos, count, kbuf, xsave); else - ret = copy_xstate_to_user(pos, count, kbuf, ubuf, xsave); + ret = copy_xstate_to_user(pos, count, ubuf, xsave); } else { fpstate_sanitize_xstate(fpu); /* diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 71d3bda2b898..2d8f3344875d 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1011,10 +1011,7 @@ int copy_xstate_to_kernel(unsigned int pos, unsigned int count, void *kbuf, stru } static inline int -__copy_xstate_to_user(unsigned int pos, unsigned int count, - void *kbuf, void __user *ubuf, - const void *data, const int start_pos, - const int end_pos) +__copy_xstate_to_user(unsigned int pos, unsigned int count, void __user *ubuf, const void *data, const int start_pos, const int end_pos) { if ((count == 0) || (pos < start_pos)) return 0; @@ -1022,12 +1019,8 @@ __copy_xstate_to_user(unsigned int pos, unsigned int count, if (end_pos < 0 || pos < end_pos) { unsigned int copy = (end_pos < 0 ? count : min(count, end_pos - pos)); - if (kbuf) { - memcpy(kbuf + pos, data, copy); - } else { - if (__copy_to_user(ubuf + pos, data, copy)) - return -EFAULT; - } + if (__copy_to_user(ubuf + pos, data, copy)) + return -EFAULT; } return 0; } @@ -1038,8 +1031,7 @@ __copy_xstate_to_user(unsigned int pos, unsigned int count, * zero. This is called from xstateregs_get() and there we check the CPU * has XSAVES. */ -int copy_xstate_to_user(unsigned int pos, unsigned int count, void *kbuf, - void __user *ubuf, struct xregs_state *xsave) +int copy_xstate_to_user(unsigned int pos, unsigned int count, void __user *ubuf, struct xregs_state *xsave) { unsigned int offset, size; int ret, i; @@ -1064,8 +1056,7 @@ int copy_xstate_to_user(unsigned int pos, unsigned int count, void *kbuf, offset = offsetof(struct xregs_state, header); size = sizeof(header); - ret = __copy_xstate_to_user(offset, size, kbuf, ubuf, &header, 0, count); - + ret = __copy_xstate_to_user(offset, size, ubuf, &header, 0, count); if (ret) return ret; @@ -1079,8 +1070,7 @@ int copy_xstate_to_user(unsigned int pos, unsigned int count, void *kbuf, offset = xstate_offsets[i]; size = xstate_sizes[i]; - ret = __copy_xstate_to_user(offset, size, kbuf, ubuf, src, 0, count); - + ret = __copy_xstate_to_user(offset, size, ubuf, src, 0, count); if (ret) return ret; @@ -1096,8 +1086,7 @@ int copy_xstate_to_user(unsigned int pos, unsigned int count, void *kbuf, offset = offsetof(struct fxregs_state, sw_reserved); size = sizeof(xstate_fx_sw_bytes); - ret = __copy_xstate_to_user(offset, size, kbuf, ubuf, xstate_fx_sw_bytes, 0, count); - + ret = __copy_xstate_to_user(offset, size, ubuf, xstate_fx_sw_bytes, 0, count); if (ret) return ret; -- 2.20.1