X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=arch%2Fx86%2Fkernel%2Ftls.c;h=ab6bf375a3077e0e6052f07bff9c5c6a93742e45;hb=5d47a271f38cf2ba7299047ad0bf3ac7e4c4a214;hp=74d2b65a82eb8e975e83e73f6ee86220bdaa7e78;hpb=80fbb69a8d1268ef48dfe21da80e68cb01922f31;p=linux-2.6 diff --git a/arch/x86/kernel/tls.c b/arch/x86/kernel/tls.c index 74d2b65a82..ab6bf375a3 100644 --- a/arch/x86/kernel/tls.c +++ b/arch/x86/kernel/tls.c @@ -2,6 +2,7 @@ #include #include #include +#include #include #include @@ -10,6 +11,8 @@ #include #include +#include "tls.h" + /* * sys_alloc_thread_area: get a yet unused TLS descriptor index. */ @@ -24,6 +27,33 @@ static int get_free_idx(void) return -ESRCH; } +static void set_tls_desc(struct task_struct *p, int idx, + const struct user_desc *info, int n) +{ + struct thread_struct *t = &p->thread; + struct desc_struct *desc = &t->tls_array[idx - GDT_ENTRY_TLS_MIN]; + int cpu; + + /* + * We must not get preempted while modifying the TLS. + */ + cpu = get_cpu(); + + while (n-- > 0) { + if (LDT_empty(info)) + desc->a = desc->b = 0; + else + fill_ldt(desc, info); + ++info; + ++desc; + } + + if (t == ¤t->thread) + load_TLS(t, cpu); + + put_cpu(); +} + /* * Set a given TLS descriptor: */ @@ -31,10 +61,7 @@ int do_set_thread_area(struct task_struct *p, int idx, struct user_desc __user *u_info, int can_allocate) { - struct thread_struct *t = &p->thread; struct user_desc info; - u32 *desc; - int cpu; if (copy_from_user(&info, u_info, sizeof(info))) return -EFAULT; @@ -57,29 +84,16 @@ int do_set_thread_area(struct task_struct *p, int idx, if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) return -EINVAL; - desc = (u32 *) &t->tls_array[idx - GDT_ENTRY_TLS_MIN]; + set_tls_desc(p, idx, &info, 1); - /* - * We must not get preempted while modifying the TLS. - */ - cpu = get_cpu(); - - if (LDT_empty(&info)) { - desc[0] = 0; - desc[1] = 0; - } else - fill_ldt((struct desc_struct *)desc, &info); - - if (t == ¤t->thread) - load_TLS(t, cpu); - - put_cpu(); return 0; } asmlinkage int sys_set_thread_area(struct user_desc __user *u_info) { - return do_set_thread_area(current, -1, u_info, 1); + int ret = do_set_thread_area(current, -1, u_info, 1); + asmlinkage_protect(1, ret, u_info); + return ret; } @@ -87,42 +101,38 @@ asmlinkage int sys_set_thread_area(struct user_desc __user *u_info) * Get the current Thread-Local Storage area: */ -#define GET_LIMIT(desc) (((desc)[0] & 0x0ffff) | ((desc)[1] & 0xf0000)) -#define GET_32BIT(desc) (((desc)[1] >> 22) & 1) -#define GET_CONTENTS(desc) (((desc)[1] >> 10) & 3) -#define GET_WRITABLE(desc) (((desc)[1] >> 9) & 1) -#define GET_LIMIT_PAGES(desc) (((desc)[1] >> 23) & 1) -#define GET_PRESENT(desc) (((desc)[1] >> 15) & 1) -#define GET_USEABLE(desc) (((desc)[1] >> 20) & 1) -#define GET_LONGMODE(desc) (((desc)[1] >> 21) & 1) +static void fill_user_desc(struct user_desc *info, int idx, + const struct desc_struct *desc) + +{ + memset(info, 0, sizeof(*info)); + info->entry_number = idx; + info->base_addr = get_desc_base(desc); + info->limit = get_desc_limit(desc); + info->seg_32bit = desc->d; + info->contents = desc->type >> 2; + info->read_exec_only = !(desc->type & 2); + info->limit_in_pages = desc->g; + info->seg_not_present = !desc->p; + info->useable = desc->avl; +#ifdef CONFIG_X86_64 + info->lm = desc->l; +#endif +} int do_get_thread_area(struct task_struct *p, int idx, struct user_desc __user *u_info) { - struct thread_struct *t = &p->thread; struct user_desc info; - u32 *desc; if (idx == -1 && get_user(idx, &u_info->entry_number)) return -EFAULT; + if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX) return -EINVAL; - desc = (u32 *) &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((void *)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); -#ifdef CONFIG_X86_64 - info.lm = GET_LONGMODE(desc); -#endif + fill_user_desc(&info, idx, + &p->thread.tls_array[idx - GDT_ENTRY_TLS_MIN]); if (copy_to_user(u_info, &info, sizeof(info))) return -EFAULT; @@ -131,5 +141,77 @@ int do_get_thread_area(struct task_struct *p, int idx, asmlinkage int sys_get_thread_area(struct user_desc __user *u_info) { - return do_get_thread_area(current, -1, u_info); + int ret = do_get_thread_area(current, -1, u_info); + asmlinkage_protect(1, ret, u_info); + return ret; +} + +int regset_tls_active(struct task_struct *target, + const struct user_regset *regset) +{ + struct thread_struct *t = &target->thread; + int n = GDT_ENTRY_TLS_ENTRIES; + while (n > 0 && desc_empty(&t->tls_array[n - 1])) + --n; + return n; +} + +int regset_tls_get(struct task_struct *target, const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + const struct desc_struct *tls; + + if (pos > GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) || + (pos % sizeof(struct user_desc)) != 0 || + (count % sizeof(struct user_desc)) != 0) + return -EINVAL; + + pos /= sizeof(struct user_desc); + count /= sizeof(struct user_desc); + + tls = &target->thread.tls_array[pos]; + + if (kbuf) { + struct user_desc *info = kbuf; + while (count-- > 0) + fill_user_desc(info++, GDT_ENTRY_TLS_MIN + pos++, + tls++); + } else { + struct user_desc __user *u_info = ubuf; + while (count-- > 0) { + struct user_desc info; + fill_user_desc(&info, GDT_ENTRY_TLS_MIN + pos++, tls++); + if (__copy_to_user(u_info++, &info, sizeof(info))) + return -EFAULT; + } + } + + return 0; +} + +int regset_tls_set(struct task_struct *target, const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + struct user_desc infobuf[GDT_ENTRY_TLS_ENTRIES]; + const struct user_desc *info; + + if (pos > GDT_ENTRY_TLS_ENTRIES * sizeof(struct user_desc) || + (pos % sizeof(struct user_desc)) != 0 || + (count % sizeof(struct user_desc)) != 0) + return -EINVAL; + + if (kbuf) + info = kbuf; + else if (__copy_from_user(infobuf, ubuf, count)) + return -EFAULT; + else + info = infobuf; + + set_tls_desc(target, + GDT_ENTRY_TLS_MIN + (pos / sizeof(struct user_desc)), + info, count / sizeof(struct user_desc)); + + return 0; }