Commit-ID: bd574f0c83c4288f9f6a639e92ae5d9061289eec Gitweb: http://git.kernel.org/tip/bd574f0c83c4288f9f6a639e92ae5d9061289eec Author: Ingo Molnar <mingo@xxxxxxxxxx> AuthorDate: Thu, 26 Jan 2017 10:16:13 +0100 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Thu, 26 Jan 2017 11:06:30 +0100 x86/fpu: Clarify parameter names in the copy_xstate_to_*() methods Right now there's a confusing mixture of 'offset' and 'size' parameters: - __copy_xstate_to_*() input parameter 'end_pos' not not really an offset, but the full size of the copy to be performed. - input parameter 'count' to copy_xstate_to_*() shadows that of __copy_xstate_to_*()'s 'count' parameter name - but the roles are different: the first one is the total number of bytes to be copied, while the second one is a partial copy size. To unconfuse all this, use a consistent set of parameter names: - 'size' is the partial copy size within a single xstate component - 'size_total' is the total copy requested - 'offset_start' is the requested starting offset. - 'offset' is the offset within an xstate component. No change in functionality. Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/include/asm/fpu/xstate.h | 4 ++-- arch/x86/kernel/fpu/xstate.c | 44 +++++++++++++++++++-------------------- 2 files changed, 24 insertions(+), 24 deletions(-) diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index e4430b8..fed6617 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -48,8 +48,8 @@ void fpu__xstate_clear_all_cpu_caps(void); 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(void *kbuf, struct xregs_state *xsave, unsigned int pos, unsigned int count); -int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int pos, unsigned int count); +int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int offset, unsigned int size); +int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int offset, unsigned int size); int copy_user_to_xstate(const void *kbuf, const void __user *ubuf, struct xregs_state *xsave); #endif diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 28cc540..8f9da89 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -926,15 +926,15 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, static inline int __copy_xstate_to_kernel(void *kbuf, const void *data, - unsigned int pos, unsigned int count, int end_pos) + unsigned int offset, unsigned int size, int size_total) { - if (!count) + if (!size) return 0; - if (end_pos < 0 || pos < end_pos) { - unsigned int copy = end_pos < 0 ? count : min(count, end_pos - pos); + if (size_total < 0 || offset < size_total) { + unsigned int copy = size_total < 0 ? size : min(size, size_total - offset); - memcpy(kbuf + pos, data, copy); + memcpy(kbuf + offset, data, copy); } return 0; } @@ -946,7 +946,7 @@ __copy_xstate_to_kernel(void *kbuf, * It supports partial copy but pos always starts from zero. This is called * from xstateregs_get() and there we check the CPU has XSAVES. */ -int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int pos, unsigned int count) +int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int offset_start, unsigned int size_total) { unsigned int offset, size; int ret, i; @@ -955,7 +955,7 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int po /* * Currently copy_regset_to_user() starts from pos 0: */ - if (unlikely(pos != 0)) + if (unlikely(offset_start != 0)) return -EFAULT; /* @@ -971,7 +971,7 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int po offset = offsetof(struct xregs_state, header); size = sizeof(header); - ret = __copy_xstate_to_kernel(kbuf, &header, offset, size, count); + ret = __copy_xstate_to_kernel(kbuf, &header, offset, size, size_total); if (ret) return ret; @@ -985,11 +985,11 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int po offset = xstate_offsets[i]; size = xstate_sizes[i]; - ret = __copy_xstate_to_kernel(kbuf, src, offset, size, count); + ret = __copy_xstate_to_kernel(kbuf, src, offset, size, size_total); if (ret) return ret; - if (offset + size >= count) + if (offset + size >= size_total) break; } @@ -1001,7 +1001,7 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int po offset = offsetof(struct fxregs_state, sw_reserved); size = sizeof(xstate_fx_sw_bytes); - ret = __copy_xstate_to_kernel(kbuf, xstate_fx_sw_bytes, offset, size, count); + ret = __copy_xstate_to_kernel(kbuf, xstate_fx_sw_bytes, offset, size, size_total); if (ret) return ret; @@ -1009,15 +1009,15 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int po } static inline int -__copy_xstate_to_user(void __user *ubuf, const void *data, unsigned int pos, unsigned int count, int end_pos) +__copy_xstate_to_user(void __user *ubuf, const void *data, unsigned int offset, unsigned int size, int size_total) { - if (!count) + if (!size) return 0; - if (end_pos < 0 || pos < end_pos) { - unsigned int copy = end_pos < 0 ? count : min(count, end_pos - pos); + if (size_total < 0 || offset < size_total) { + unsigned int copy = size_total < 0 ? size : min(size, size_total - offset); - if (__copy_to_user(ubuf + pos, data, copy)) + if (__copy_to_user(ubuf + offset, data, copy)) return -EFAULT; } return 0; @@ -1029,7 +1029,7 @@ __copy_xstate_to_user(void __user *ubuf, const void *data, unsigned int pos, uns * zero. This is called from xstateregs_get() and there we check the CPU * has XSAVES. */ -int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int pos, unsigned int count) +int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int offset_start, unsigned int size_total) { unsigned int offset, size; int ret, i; @@ -1038,7 +1038,7 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i /* * Currently copy_regset_to_user() starts from pos 0: */ - if (unlikely(pos != 0)) + if (unlikely(offset_start != 0)) return -EFAULT; /* @@ -1054,7 +1054,7 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i offset = offsetof(struct xregs_state, header); size = sizeof(header); - ret = __copy_xstate_to_user(ubuf, &header, offset, size, count); + ret = __copy_xstate_to_user(ubuf, &header, offset, size, size_total); if (ret) return ret; @@ -1068,11 +1068,11 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i offset = xstate_offsets[i]; size = xstate_sizes[i]; - ret = __copy_xstate_to_user(ubuf, src, offset, size, count); + ret = __copy_xstate_to_user(ubuf, src, offset, size, size_total); if (ret) return ret; - if (offset + size >= count) + if (offset + size >= size_total) break; } @@ -1084,7 +1084,7 @@ int copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned i offset = offsetof(struct fxregs_state, sw_reserved); size = sizeof(xstate_fx_sw_bytes); - ret = __copy_xstate_to_user(ubuf, xstate_fx_sw_bytes, offset, size, count); + ret = __copy_xstate_to_user(ubuf, xstate_fx_sw_bytes, offset, size, size_total); if (ret) return ret; -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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