From: Thomas Gleixner Date: Thu, 11 Oct 2007 09:15:06 +0000 (+0200) Subject: x86_64: prepare shared kernel/ldt.c X-Git-Tag: firefly_0821_release~26180 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=c76e79e010a8c48a95cfa947e192c40cdae23f7e;p=firefly-linux-kernel-4.4.55.git x86_64: prepare shared kernel/ldt.c Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- diff --git a/arch/x86_64/kernel/Makefile b/arch/x86_64/kernel/Makefile index 71e90bb88e42..ddc3154b7c29 100644 --- a/arch/x86_64/kernel/Makefile +++ b/arch/x86_64/kernel/Makefile @@ -5,7 +5,7 @@ extra-y := head.o head64.o init_task.o vmlinux.lds EXTRA_AFLAGS := -traditional obj-y := process.o signal_64.o entry.o traps_64.o irq_64.o \ - ptrace_64.o time_64.o ioport_64.o ldt.o setup_64.o i8259_64.o sys_x86_64.o \ + ptrace_64.o time_64.o ioport_64.o ldt_64.o setup_64.o i8259_64.o sys_x86_64.o \ x8664_ksyms.o i387_64.o syscall.o vsyscall_64.o \ setup64.o bootflag.o e820_64.o reboot_64.o quirks.o i8237.o \ pci-dma_64.o pci-nommu_64.o alternative.o hpet_64.o tsc.o bugs_64.o \ diff --git a/arch/x86_64/kernel/ldt.c b/arch/x86_64/kernel/ldt.c deleted file mode 100644 index bc9ffd5c19cc..000000000000 --- a/arch/x86_64/kernel/ldt.c +++ /dev/null @@ -1,252 +0,0 @@ -/* - * linux/arch/x86_64/kernel/ldt.c - * - * Copyright (C) 1992 Krishna Balasubramanian and Linus Torvalds - * Copyright (C) 1999 Ingo Molnar - * Copyright (C) 2002 Andi Kleen - * - * This handles calls from both 32bit and 64bit mode. - */ - -#include -#include -#include -#include -#include -#include -#include - -#include -#include -#include -#include -#include - -#ifdef CONFIG_SMP /* avoids "defined but not used" warnig */ -static void flush_ldt(void *null) -{ - if (current->active_mm) - load_LDT(¤t->active_mm->context); -} -#endif - -static int alloc_ldt(mm_context_t *pc, unsigned mincount, int reload) -{ - void *oldldt; - void *newldt; - unsigned oldsize; - - if (mincount <= (unsigned)pc->size) - return 0; - oldsize = pc->size; - mincount = (mincount+511)&(~511); - if (mincount*LDT_ENTRY_SIZE > PAGE_SIZE) - newldt = vmalloc(mincount*LDT_ENTRY_SIZE); - else - newldt = kmalloc(mincount*LDT_ENTRY_SIZE, GFP_KERNEL); - - if (!newldt) - return -ENOMEM; - - if (oldsize) - memcpy(newldt, pc->ldt, oldsize*LDT_ENTRY_SIZE); - oldldt = pc->ldt; - memset(newldt+oldsize*LDT_ENTRY_SIZE, 0, (mincount-oldsize)*LDT_ENTRY_SIZE); - wmb(); - pc->ldt = newldt; - wmb(); - pc->size = mincount; - wmb(); - if (reload) { -#ifdef CONFIG_SMP - cpumask_t mask; - - preempt_disable(); - mask = cpumask_of_cpu(smp_processor_id()); - load_LDT(pc); - if (!cpus_equal(current->mm->cpu_vm_mask, mask)) - smp_call_function(flush_ldt, NULL, 1, 1); - preempt_enable(); -#else - load_LDT(pc); -#endif - } - if (oldsize) { - if (oldsize*LDT_ENTRY_SIZE > PAGE_SIZE) - vfree(oldldt); - else - kfree(oldldt); - } - return 0; -} - -static inline int copy_ldt(mm_context_t *new, mm_context_t *old) -{ - int err = alloc_ldt(new, old->size, 0); - if (err < 0) - return err; - memcpy(new->ldt, old->ldt, old->size*LDT_ENTRY_SIZE); - return 0; -} - -/* - * we do not have to muck with descriptors here, that is - * done in switch_mm() as needed. - */ -int init_new_context(struct task_struct *tsk, struct mm_struct *mm) -{ - struct mm_struct * old_mm; - int retval = 0; - - init_MUTEX(&mm->context.sem); - mm->context.size = 0; - old_mm = current->mm; - if (old_mm && old_mm->context.size > 0) { - down(&old_mm->context.sem); - retval = copy_ldt(&mm->context, &old_mm->context); - up(&old_mm->context.sem); - } - return retval; -} - -/* - * - * Don't touch the LDT register - we're already in the next thread. - */ -void destroy_context(struct mm_struct *mm) -{ - if (mm->context.size) { - if ((unsigned)mm->context.size*LDT_ENTRY_SIZE > PAGE_SIZE) - vfree(mm->context.ldt); - else - kfree(mm->context.ldt); - mm->context.size = 0; - } -} - -static int read_ldt(void __user * ptr, unsigned long bytecount) -{ - int err; - unsigned long size; - struct mm_struct * mm = current->mm; - - if (!mm->context.size) - return 0; - if (bytecount > LDT_ENTRY_SIZE*LDT_ENTRIES) - bytecount = LDT_ENTRY_SIZE*LDT_ENTRIES; - - down(&mm->context.sem); - size = mm->context.size*LDT_ENTRY_SIZE; - if (size > bytecount) - size = bytecount; - - err = 0; - if (copy_to_user(ptr, mm->context.ldt, size)) - err = -EFAULT; - up(&mm->context.sem); - if (err < 0) - goto error_return; - if (size != bytecount) { - /* zero-fill the rest */ - if (clear_user(ptr+size, bytecount-size) != 0) { - err = -EFAULT; - goto error_return; - } - } - return bytecount; -error_return: - return err; -} - -static int read_default_ldt(void __user * ptr, unsigned long bytecount) -{ - /* Arbitrary number */ - /* x86-64 default LDT is all zeros */ - if (bytecount > 128) - bytecount = 128; - if (clear_user(ptr, bytecount)) - return -EFAULT; - return bytecount; -} - -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; - int error; - struct user_desc ldt_info; - - error = -EINVAL; - - if (bytecount != sizeof(ldt_info)) - goto out; - error = -EFAULT; - if (copy_from_user(&ldt_info, ptr, bytecount)) - goto out; - - error = -EINVAL; - if (ldt_info.entry_number >= LDT_ENTRIES) - goto out; - if (ldt_info.contents == 3) { - if (oldmode) - goto out; - if (ldt_info.seg_not_present == 0) - goto out; - } - - down(&mm->context.sem); - if (ldt_info.entry_number >= (unsigned)mm->context.size) { - error = alloc_ldt(¤t->mm->context, ldt_info.entry_number+1, 1); - if (error < 0) - 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)) { - entry_1 = 0; - entry_2 = 0; - goto install; - } - } - - entry_1 = LDT_entry_a(&ldt_info); - entry_2 = LDT_entry_b(&ldt_info); - if (oldmode) - entry_2 &= ~(1 << 20); - - /* Install the new entry ... */ -install: - *lp = entry_1; - *(lp+1) = entry_2; - error = 0; - -out_unlock: - up(&mm->context.sem); -out: - return error; -} - -asmlinkage int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount) -{ - int ret = -ENOSYS; - - switch (func) { - case 0: - ret = read_ldt(ptr, bytecount); - break; - case 1: - ret = write_ldt(ptr, bytecount, 1); - break; - case 2: - ret = read_default_ldt(ptr, bytecount); - break; - case 0x11: - ret = write_ldt(ptr, bytecount, 0); - break; - } - return ret; -} diff --git a/arch/x86_64/kernel/ldt_64.c b/arch/x86_64/kernel/ldt_64.c new file mode 100644 index 000000000000..bc9ffd5c19cc --- /dev/null +++ b/arch/x86_64/kernel/ldt_64.c @@ -0,0 +1,252 @@ +/* + * linux/arch/x86_64/kernel/ldt.c + * + * Copyright (C) 1992 Krishna Balasubramanian and Linus Torvalds + * Copyright (C) 1999 Ingo Molnar + * Copyright (C) 2002 Andi Kleen + * + * This handles calls from both 32bit and 64bit mode. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +#ifdef CONFIG_SMP /* avoids "defined but not used" warnig */ +static void flush_ldt(void *null) +{ + if (current->active_mm) + load_LDT(¤t->active_mm->context); +} +#endif + +static int alloc_ldt(mm_context_t *pc, unsigned mincount, int reload) +{ + void *oldldt; + void *newldt; + unsigned oldsize; + + if (mincount <= (unsigned)pc->size) + return 0; + oldsize = pc->size; + mincount = (mincount+511)&(~511); + if (mincount*LDT_ENTRY_SIZE > PAGE_SIZE) + newldt = vmalloc(mincount*LDT_ENTRY_SIZE); + else + newldt = kmalloc(mincount*LDT_ENTRY_SIZE, GFP_KERNEL); + + if (!newldt) + return -ENOMEM; + + if (oldsize) + memcpy(newldt, pc->ldt, oldsize*LDT_ENTRY_SIZE); + oldldt = pc->ldt; + memset(newldt+oldsize*LDT_ENTRY_SIZE, 0, (mincount-oldsize)*LDT_ENTRY_SIZE); + wmb(); + pc->ldt = newldt; + wmb(); + pc->size = mincount; + wmb(); + if (reload) { +#ifdef CONFIG_SMP + cpumask_t mask; + + preempt_disable(); + mask = cpumask_of_cpu(smp_processor_id()); + load_LDT(pc); + if (!cpus_equal(current->mm->cpu_vm_mask, mask)) + smp_call_function(flush_ldt, NULL, 1, 1); + preempt_enable(); +#else + load_LDT(pc); +#endif + } + if (oldsize) { + if (oldsize*LDT_ENTRY_SIZE > PAGE_SIZE) + vfree(oldldt); + else + kfree(oldldt); + } + return 0; +} + +static inline int copy_ldt(mm_context_t *new, mm_context_t *old) +{ + int err = alloc_ldt(new, old->size, 0); + if (err < 0) + return err; + memcpy(new->ldt, old->ldt, old->size*LDT_ENTRY_SIZE); + return 0; +} + +/* + * we do not have to muck with descriptors here, that is + * done in switch_mm() as needed. + */ +int init_new_context(struct task_struct *tsk, struct mm_struct *mm) +{ + struct mm_struct * old_mm; + int retval = 0; + + init_MUTEX(&mm->context.sem); + mm->context.size = 0; + old_mm = current->mm; + if (old_mm && old_mm->context.size > 0) { + down(&old_mm->context.sem); + retval = copy_ldt(&mm->context, &old_mm->context); + up(&old_mm->context.sem); + } + return retval; +} + +/* + * + * Don't touch the LDT register - we're already in the next thread. + */ +void destroy_context(struct mm_struct *mm) +{ + if (mm->context.size) { + if ((unsigned)mm->context.size*LDT_ENTRY_SIZE > PAGE_SIZE) + vfree(mm->context.ldt); + else + kfree(mm->context.ldt); + mm->context.size = 0; + } +} + +static int read_ldt(void __user * ptr, unsigned long bytecount) +{ + int err; + unsigned long size; + struct mm_struct * mm = current->mm; + + if (!mm->context.size) + return 0; + if (bytecount > LDT_ENTRY_SIZE*LDT_ENTRIES) + bytecount = LDT_ENTRY_SIZE*LDT_ENTRIES; + + down(&mm->context.sem); + size = mm->context.size*LDT_ENTRY_SIZE; + if (size > bytecount) + size = bytecount; + + err = 0; + if (copy_to_user(ptr, mm->context.ldt, size)) + err = -EFAULT; + up(&mm->context.sem); + if (err < 0) + goto error_return; + if (size != bytecount) { + /* zero-fill the rest */ + if (clear_user(ptr+size, bytecount-size) != 0) { + err = -EFAULT; + goto error_return; + } + } + return bytecount; +error_return: + return err; +} + +static int read_default_ldt(void __user * ptr, unsigned long bytecount) +{ + /* Arbitrary number */ + /* x86-64 default LDT is all zeros */ + if (bytecount > 128) + bytecount = 128; + if (clear_user(ptr, bytecount)) + return -EFAULT; + return bytecount; +} + +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; + int error; + struct user_desc ldt_info; + + error = -EINVAL; + + if (bytecount != sizeof(ldt_info)) + goto out; + error = -EFAULT; + if (copy_from_user(&ldt_info, ptr, bytecount)) + goto out; + + error = -EINVAL; + if (ldt_info.entry_number >= LDT_ENTRIES) + goto out; + if (ldt_info.contents == 3) { + if (oldmode) + goto out; + if (ldt_info.seg_not_present == 0) + goto out; + } + + down(&mm->context.sem); + if (ldt_info.entry_number >= (unsigned)mm->context.size) { + error = alloc_ldt(¤t->mm->context, ldt_info.entry_number+1, 1); + if (error < 0) + 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)) { + entry_1 = 0; + entry_2 = 0; + goto install; + } + } + + entry_1 = LDT_entry_a(&ldt_info); + entry_2 = LDT_entry_b(&ldt_info); + if (oldmode) + entry_2 &= ~(1 << 20); + + /* Install the new entry ... */ +install: + *lp = entry_1; + *(lp+1) = entry_2; + error = 0; + +out_unlock: + up(&mm->context.sem); +out: + return error; +} + +asmlinkage int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount) +{ + int ret = -ENOSYS; + + switch (func) { + case 0: + ret = read_ldt(ptr, bytecount); + break; + case 1: + ret = write_ldt(ptr, bytecount, 1); + break; + case 2: + ret = read_default_ldt(ptr, bytecount); + break; + case 0x11: + ret = write_ldt(ptr, bytecount, 0); + break; + } + return ret; +}