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authorRoland McGrath <roland@redhat.com>2008-01-30 13:30:45 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:30:45 +0100
commit13abd0e50433092c41551bc13c32268028b6d663 (patch)
tree25637d680966f6f021cf469614e5838963ead20c /arch/x86/kernel/tls.c
parent12c3cbbb7e3218b1c3ed4c97b3496fc3f94ea967 (diff)
x86: tls32 moved
This renames arch/x86/ia32/tls32.c to arch/x86/kernel/tls.c, which does nothing now but paves the way to consolidate this code for 32-bit too. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Zachary Amsden <zach@vmware.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/tls.c')
-rw-r--r--arch/x86/kernel/tls.c158
1 files changed, 158 insertions, 0 deletions
diff --git a/arch/x86/kernel/tls.c b/arch/x86/kernel/tls.c
new file mode 100644
index 00000000000..5291596f19b
--- /dev/null
+++ b/arch/x86/kernel/tls.c
@@ -0,0 +1,158 @@
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/user.h>
+
+#include <asm/uaccess.h>
+#include <asm/desc.h>
+#include <asm/system.h>
+#include <asm/ldt.h>
+#include <asm/processor.h>
+#include <asm/proto.h>
+
+/*
+ * sys_alloc_thread_area: get a yet unused TLS descriptor index.
+ */
+static int get_free_idx(void)
+{
+ struct thread_struct *t = &current->thread;
+ int idx;
+
+ for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++)
+ if (desc_empty((struct n_desc_struct *)(t->tls_array) + idx))
+ return idx + GDT_ENTRY_TLS_MIN;
+ return -ESRCH;
+}
+
+/*
+ * Set a given TLS descriptor:
+ * When you want addresses > 32bit use arch_prctl()
+ */
+int do_set_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
+{
+ struct user_desc info;
+ struct n_desc_struct *desc;
+ int cpu, idx;
+
+ if (copy_from_user(&info, u_info, sizeof(info)))
+ return -EFAULT;
+
+ idx = info.entry_number;
+
+ /*
+ * index -1 means the kernel should try to find and
+ * allocate an empty descriptor:
+ */
+ if (idx == -1) {
+ idx = get_free_idx();
+ if (idx < 0)
+ return idx;
+ if (put_user(idx, &u_info->entry_number))
+ return -EFAULT;
+ }
+
+ if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
+ return -EINVAL;
+
+ desc = ((struct n_desc_struct *)t->tls_array) + idx - GDT_ENTRY_TLS_MIN;
+
+ /*
+ * We must not get preempted while modifying the TLS.
+ */
+ cpu = get_cpu();
+
+ if (LDT_empty(&info)) {
+ desc->a = 0;
+ desc->b = 0;
+ } else {
+ desc->a = LDT_entry_a(&info);
+ desc->b = LDT_entry_b(&info);
+ }
+ if (t == &current->thread)
+ load_TLS(t, cpu);
+
+ put_cpu();
+ return 0;
+}
+
+asmlinkage long sys32_set_thread_area(struct user_desc __user *u_info)
+{
+ return do_set_thread_area(&current->thread, u_info);
+}
+
+
+/*
+ * Get the current Thread-Local Storage area:
+ */
+
+#define GET_LIMIT(desc) ( \
+ ((desc)->a & 0x0ffff) | \
+ ((desc)->b & 0xf0000) )
+
+#define GET_32BIT(desc) (((desc)->b >> 22) & 1)
+#define GET_CONTENTS(desc) (((desc)->b >> 10) & 3)
+#define GET_WRITABLE(desc) (((desc)->b >> 9) & 1)
+#define GET_LIMIT_PAGES(desc) (((desc)->b >> 23) & 1)
+#define GET_PRESENT(desc) (((desc)->b >> 15) & 1)
+#define GET_USEABLE(desc) (((desc)->b >> 20) & 1)
+#define GET_LONGMODE(desc) (((desc)->b >> 21) & 1)
+
+int do_get_thread_area(struct thread_struct *t, struct user_desc __user *u_info)
+{
+ struct user_desc info;
+ struct n_desc_struct *desc;
+ int idx;
+
+ if (get_user(idx, &u_info->entry_number))
+ return -EFAULT;
+ if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
+ return -EINVAL;
+
+ desc = ((struct n_desc_struct *)t->tls_array) + idx - GDT_ENTRY_TLS_MIN;
+
+ memset(&info, 0, sizeof(struct user_desc));
+ info.entry_number = idx;
+ info.base_addr = get_desc_base(desc);
+ info.limit = GET_LIMIT(desc);
+ info.seg_32bit = GET_32BIT(desc);
+ info.contents = GET_CONTENTS(desc);
+ info.read_exec_only = !GET_WRITABLE(desc);
+ info.limit_in_pages = GET_LIMIT_PAGES(desc);
+ info.seg_not_present = !GET_PRESENT(desc);
+ info.useable = GET_USEABLE(desc);
+ info.lm = GET_LONGMODE(desc);
+
+ if (copy_to_user(u_info, &info, sizeof(info)))
+ return -EFAULT;
+ return 0;
+}
+
+asmlinkage long sys32_get_thread_area(struct user_desc __user *u_info)
+{
+ return do_get_thread_area(&current->thread, u_info);
+}
+
+
+int ia32_child_tls(struct task_struct *p, struct pt_regs *childregs)
+{
+ struct n_desc_struct *desc;
+ struct user_desc info;
+ struct user_desc __user *cp;
+ int idx;
+
+ cp = (void __user *)childregs->rsi;
+ if (copy_from_user(&info, cp, sizeof(info)))
+ return -EFAULT;
+ if (LDT_empty(&info))
+ return -EINVAL;
+
+ idx = info.entry_number;
+ if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
+ return -EINVAL;
+
+ desc = (struct n_desc_struct *)(p->thread.tls_array) + idx - GDT_ENTRY_TLS_MIN;
+ desc->a = LDT_entry_a(&info);
+ desc->b = LDT_entry_b(&info);
+
+ return 0;
+}