From fc2d625c4fac18e672a3b7c61af5de22d7ab7d87 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 30 Jan 2008 13:30:13 +0100 Subject: [PATCH] x86: introduce ldt_write accessor Create a ldt write accessor like the 32 bit one. Preparatory patch for merging ldt.c and anyway necessary for 64bit paravirt ops. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/kernel/ldt_64.c | 8 +++----- include/asm-x86/desc_64.h | 9 +++++++++ 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/ldt_64.c b/arch/x86/kernel/ldt_64.c index 6c41db367d..d72dc7a063 100644 --- a/arch/x86/kernel/ldt_64.c +++ b/arch/x86/kernel/ldt_64.c @@ -172,7 +172,7 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode) { struct task_struct *me = current; struct mm_struct *mm = me->mm; - __u32 entry_1, entry_2, *lp; + __u32 entry_1, entry_2; int error; struct user_desc ldt_info; @@ -202,8 +202,6 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode) goto out_unlock; } - lp = (__u32 *)((ldt_info.entry_number << 3) + (char *)mm->context.ldt); - /* Allow LDTs to be cleared by the user. */ if (ldt_info.base_addr == 0 && ldt_info.limit == 0) { if (oldmode || LDT_empty(&ldt_info)) { @@ -220,8 +218,8 @@ static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode) /* Install the new entry ... */ install: - *lp = entry_1; - *(lp+1) = entry_2; + write_ldt_entry(mm->context.ldt, ldt_info.entry_number, entry_1, + entry_2); error = 0; out_unlock: diff --git a/include/asm-x86/desc_64.h b/include/asm-x86/desc_64.h index bb2009ecbb..7d48df72ae 100644 --- a/include/asm-x86/desc_64.h +++ b/include/asm-x86/desc_64.h @@ -38,6 +38,15 @@ extern struct desc_struct default_ldt[]; extern struct gate_struct idt_table[]; extern struct desc_ptr cpu_gdt_descr[]; +static inline void write_ldt_entry(struct desc_struct *ldt, + int entry, u32 entry_low, u32 entry_high) +{ + __u32 *lp = (__u32 *)((entry << 3) + (char *)ldt); + + lp[0] = entry_low; + lp[1] = entry_high; +} + /* the cpu gdt accessor */ #define cpu_gdt(_cpu) ((struct desc_struct *)cpu_gdt_descr[_cpu].address) -- 2.20.1