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-rw-r--r--arch/x86/kernel/Makefile_322
-rw-r--r--arch/x86/kernel/Makefile_642
-rw-r--r--arch/x86/kernel/ldt.c (renamed from arch/x86/kernel/ldt_64.c)25
-rw-r--r--arch/x86/kernel/ldt_32.c253
4 files changed, 22 insertions, 260 deletions
diff --git a/arch/x86/kernel/Makefile_32 b/arch/x86/kernel/Makefile_32
index 0cc1981d1e3..31ff982bc26 100644
--- a/arch/x86/kernel/Makefile_32
+++ b/arch/x86/kernel/Makefile_32
@@ -6,7 +6,7 @@ extra-y := head_32.o init_task.o vmlinux.lds
CPPFLAGS_vmlinux.lds += -Ui386
obj-y := process_32.o signal_32.o entry_32.o traps_32.o irq_32.o \
- ptrace_32.o time_32.o ioport_32.o ldt_32.o setup_32.o i8259_32.o sys_i386_32.o \
+ ptrace_32.o time_32.o ioport_32.o ldt.o setup_32.o i8259_32.o sys_i386_32.o \
pci-dma_32.o i386_ksyms_32.o i387_32.o bootflag.o e820_32.o\
quirks.o i8237.o topology.o alternative.o i8253.o tsc_32.o io_delay.o
diff --git a/arch/x86/kernel/Makefile_64 b/arch/x86/kernel/Makefile_64
index 08a68f0d8fd..9cb3df27c41 100644
--- a/arch/x86/kernel/Makefile_64
+++ b/arch/x86/kernel/Makefile_64
@@ -7,7 +7,7 @@ CPPFLAGS_vmlinux.lds += -Ux86_64
EXTRA_AFLAGS := -traditional
obj-y := process_64.o signal_64.o entry_64.o traps_64.o irq_64.o \
- ptrace_64.o time_64.o ioport_64.o ldt_64.o setup_64.o i8259_64.o sys_x86_64.o \
+ ptrace_64.o time_64.o ioport_64.o ldt.o setup_64.o i8259_64.o sys_x86_64.o \
x8664_ksyms_64.o i387_64.o syscall_64.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.o tsc_64.o bugs_64.o \
diff --git a/arch/x86/kernel/ldt_64.c b/arch/x86/kernel/ldt.c
index 95903938e7a..a8cdca3615b 100644
--- a/arch/x86/kernel/ldt_64.c
+++ b/arch/x86/kernel/ldt.c
@@ -50,7 +50,11 @@ static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
oldldt = pc->ldt;
memset(newldt + oldsize * LDT_ENTRY_SIZE, 0,
(mincount - oldsize) * LDT_ENTRY_SIZE);
+
+#ifdef CONFIG_X86_64
+ /* CHECKME: Do we really need this ? */
wmb();
+#endif
pc->ldt = newldt;
wmb();
pc->size = mincount;
@@ -110,11 +114,18 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
}
/*
- * Don't touch the LDT register - we're already in the next thread.
+ * No need to lock the MM as we are the last user
+ *
+ * 64bit: Don't touch the LDT register - we're already in the next thread.
*/
void destroy_context(struct mm_struct *mm)
{
if (mm->context.size) {
+#ifdef CONFIG_X86_32
+ /* CHECKME: Can this ever happen ? */
+ if (mm == current->active_mm)
+ clear_LDT();
+#endif
if (mm->context.size * LDT_ENTRY_SIZE > PAGE_SIZE)
vfree(mm->context.ldt);
else
@@ -159,10 +170,14 @@ error_return:
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;
+ /* CHECKME: Can we use _one_ random number ? */
+#ifdef CONFIG_X86_32
+ unsigned long size = 5 * sizeof(struct desc_struct);
+#else
+ unsigned long size = 128;
+#endif
+ if (bytecount > size)
+ bytecount = size;
if (clear_user(ptr, bytecount))
return -EFAULT;
return bytecount;
diff --git a/arch/x86/kernel/ldt_32.c b/arch/x86/kernel/ldt_32.c
deleted file mode 100644
index bb15753abaf..00000000000
--- a/arch/x86/kernel/ldt_32.c
+++ /dev/null
@@ -1,253 +0,0 @@
-/*
- * Copyright (C) 1992 Krishna Balasubramanian and Linus Torvalds
- * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
- */
-
-#include <linux/errno.h>
-#include <linux/sched.h>
-#include <linux/string.h>
-#include <linux/mm.h>
-#include <linux/smp.h>
-#include <linux/vmalloc.h>
-#include <linux/slab.h>
-
-#include <asm/uaccess.h>
-#include <asm/system.h>
-#include <asm/ldt.h>
-#include <asm/desc.h>
-#include <asm/mmu_context.h>
-
-#ifdef CONFIG_SMP
-static void flush_ldt(void *null)
-{
- if (current->active_mm)
- load_LDT(&current->active_mm->context);
-}
-#endif
-
-static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
-{
- void *oldldt, *newldt;
- int oldsize;
-
- if (mincount <= 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);
- pc->ldt = newldt;
- wmb();
- pc->size = mincount;
- wmb();
-
- if (reload) {
-#ifdef CONFIG_SMP
- cpumask_t mask;
-
- preempt_disable();
- load_LDT(pc);
- mask = cpumask_of_cpu(smp_processor_id());
- 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;
-
- mutex_init(&mm->context.lock);
- mm->context.size = 0;
- old_mm = current->mm;
- if (old_mm && old_mm->context.size > 0) {
- mutex_lock(&old_mm->context.lock);
- retval = copy_ldt(&mm->context, &old_mm->context);
- mutex_unlock(&old_mm->context.lock);
- }
- return retval;
-}
-
-/*
- * No need to lock the MM as we are the last user
- */
-void destroy_context(struct mm_struct *mm)
-{
- if (mm->context.size) {
- if (mm == current->active_mm)
- clear_LDT();
- if (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;
-
- mutex_lock(&mm->context.lock);
- 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;
- mutex_unlock(&mm->context.lock);
- 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)
-{
- int err;
- unsigned long size;
-
- err = 0;
- size = 5 * sizeof(struct desc_struct);
- if (size > bytecount)
- size = bytecount;
-
- err = size;
- if (clear_user(ptr, size))
- err = -EFAULT;
-
- return err;
-}
-
-static int write_ldt(void __user *ptr, unsigned long bytecount, int oldmode)
-{
- struct mm_struct *mm = current->mm;
- __u32 entry_1, entry_2;
- 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, sizeof(ldt_info)))
- 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;
- }
-
- mutex_lock(&mm->context.lock);
- if (ldt_info.entry_number >= mm->context.size) {
- error = alloc_ldt(&current->mm->context,
- ldt_info.entry_number + 1, 1);
- if (error < 0)
- goto out_unlock;
- }
-
- /* 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:
- write_ldt_entry(mm->context.ldt, ldt_info.entry_number, entry_1,
- entry_2);
- error = 0;
-
-out_unlock:
- mutex_unlock(&mm->context.lock);
-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;
-}
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-21 03:33:48 +0000