* Licensed under the GPL
*/
-#include "linux/config.h"
-#include "linux/kernel.h"
+#include "linux/percpu.h"
#include "linux/sched.h"
-#include "linux/slab.h"
-#include "linux/types.h"
#include "asm/uaccess.h"
-#include "asm/ptrace.h"
-#include "asm/segment.h"
-#include "asm/smp.h"
-#include "asm/desc.h"
-#include "choose-mode.h"
-#include "kern.h"
-#include "kern_util.h"
-#include "mode_kern.h"
#include "os.h"
-#include "mode.h"
-
-#ifdef CONFIG_MODE_SKAS
#include "skas.h"
-#endif
+#include "sysdep/tls.h"
-/* If needed we can detect when it's uninitialized. */
+/*
+ * If needed we can detect when it's uninitialized.
+ *
+ * These are initialized in an initcall and unchanged thereafter.
+ */
static int host_supports_tls = -1;
-int host_gdt_entry_tls_min = -1;
+int host_gdt_entry_tls_min;
-#ifdef CONFIG_MODE_SKAS
-int do_set_thread_area_skas(struct user_desc *info)
+int do_set_thread_area(struct user_desc *info)
{
int ret;
u32 cpu;
cpu = get_cpu();
ret = os_set_thread_area(info, userspace_pid[cpu]);
put_cpu();
+
+ if (ret)
+ printk(KERN_ERR "PTRACE_SET_THREAD_AREA failed, err = %d, "
+ "index = %d\n", ret, info->entry_number);
+
return ret;
}
-int do_get_thread_area_skas(struct user_desc *info)
+int do_get_thread_area(struct user_desc *info)
{
int ret;
u32 cpu;
cpu = get_cpu();
ret = os_get_thread_area(info, userspace_pid[cpu]);
put_cpu();
+
+ if (ret)
+ printk(KERN_ERR "PTRACE_GET_THREAD_AREA failed, err = %d, "
+ "index = %d\n", ret, info->entry_number);
+
return ret;
}
-#endif
/*
* sys_get_thread_area: get a yet unused TLS descriptor index.
* XXX: Consider leaving one free slot for glibc usage at first place. This must
* be done here (and by changing GDT_ENTRY_TLS_* macros) and nowhere else.
*
- * Also, this must be tested when compiling in SKAS mode with dinamic linking
+ * Also, this must be tested when compiling in SKAS mode with dynamic linking
* and running against NPTL.
*/
static int get_free_idx(struct task_struct* task)
/* Postcondition: LDT_empty(info) returns true. */
memset(info, 0, sizeof(*info));
- /* Check the LDT_empty or the i386 sys_get_thread_area code - we obtain
+ /*
+ * Check the LDT_empty or the i386 sys_get_thread_area code - we obtain
* indeed an empty user_desc.
*/
info->read_exec_only = 1;
int idx;
for (idx = GDT_ENTRY_TLS_MIN; idx < GDT_ENTRY_TLS_MAX; idx++) {
- struct uml_tls_struct* curr = &to->thread.arch.tls_array[idx - GDT_ENTRY_TLS_MIN];
+ struct uml_tls_struct* curr =
+ &to->thread.arch.tls_array[idx - GDT_ENTRY_TLS_MIN];
- /* Actually, now if it wasn't flushed it gets cleared and
- * flushed to the host, which will clear it.*/
+ /*
+ * Actually, now if it wasn't flushed it gets cleared and
+ * flushed to the host, which will clear it.
+ */
if (!curr->present) {
if (!curr->flushed) {
clear_user_desc(&curr->tls);
return ret;
}
-/* Verify if we need to do a flush for the new process, i.e. if there are any
+/*
+ * Verify if we need to do a flush for the new process, i.e. if there are any
* present desc's, only if they haven't been flushed.
*/
static inline int needs_TLS_update(struct task_struct *task)
int ret = 0;
for (i = GDT_ENTRY_TLS_MIN; i < GDT_ENTRY_TLS_MAX; i++) {
- struct uml_tls_struct* curr = &task->thread.arch.tls_array[i - GDT_ENTRY_TLS_MIN];
+ struct uml_tls_struct* curr =
+ &task->thread.arch.tls_array[i - GDT_ENTRY_TLS_MIN];
- /* Can't test curr->present, we may need to clear a descriptor
- * which had a value. */
+ /*
+ * Can't test curr->present, we may need to clear a descriptor
+ * which had a value.
+ */
if (curr->flushed)
continue;
ret = 1;
return ret;
}
-/* On a newly forked process, the TLS descriptors haven't yet been flushed. So
+/*
+ * On a newly forked process, the TLS descriptors haven't yet been flushed. So
* we mark them as such and the first switch_to will do the job.
*/
void clear_flushed_tls(struct task_struct *task)
int i;
for (i = GDT_ENTRY_TLS_MIN; i < GDT_ENTRY_TLS_MAX; i++) {
- struct uml_tls_struct* curr = &task->thread.arch.tls_array[i - GDT_ENTRY_TLS_MIN];
+ struct uml_tls_struct* curr =
+ &task->thread.arch.tls_array[i - GDT_ENTRY_TLS_MIN];
- /* Still correct to do this, if it wasn't present on the host it
- * will remain as flushed as it was. */
+ /*
+ * Still correct to do this, if it wasn't present on the host it
+ * will remain as flushed as it was.
+ */
if (!curr->present)
continue;
}
}
-/* In SKAS0 mode, currently, multiple guest threads sharing the same ->mm have a
+/*
+ * In SKAS0 mode, currently, multiple guest threads sharing the same ->mm have a
* common host process. So this is needed in SKAS0 too.
*
* However, if each thread had a different host process (and this was discussed
* for SMP support) this won't be needed.
*
* And this will not need be used when (and if) we'll add support to the host
- * SKAS patch. */
+ * SKAS patch.
+ */
-int arch_switch_tls_skas(struct task_struct *from, struct task_struct *to)
+int arch_switch_tls(struct task_struct *to)
{
if (!host_supports_tls)
return 0;
- /* We have no need whatsoever to switch TLS for kernel threads; beyond
+ /*
+ * We have no need whatsoever to switch TLS for kernel threads; beyond
* that, that would also result in us calling os_set_thread_area with
- * userspace_pid[cpu] == 0, which gives an error. */
+ * userspace_pid[cpu] == 0, which gives an error.
+ */
if (likely(to->mm))
return load_TLS(O_FORCE, to);
return 0;
}
-int arch_switch_tls_tt(struct task_struct *from, struct task_struct *to)
-{
- if (!host_supports_tls)
- return 0;
-
- if (needs_TLS_update(to))
- return load_TLS(0, to);
-
- return 0;
-}
-
static int set_tls_entry(struct task_struct* task, struct user_desc *info,
int idx, int flushed)
{
}
/* XXX: use do_get_thread_area to read the host value? I'm not at all sure! */
-static int get_tls_entry(struct task_struct* task, struct user_desc *info, int idx)
+static int get_tls_entry(struct task_struct *task, struct user_desc *info,
+ int idx)
{
struct thread_struct *t = &task->thread;
*info = t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].tls;
out:
- /* Temporary debugging check, to make sure that things have been
+ /*
+ * Temporary debugging check, to make sure that things have been
* flushed. This could be triggered if load_TLS() failed.
*/
- if (unlikely(task == current && !t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].flushed)) {
+ if (unlikely(task == current &&
+ !t->arch.tls_array[idx - GDT_ENTRY_TLS_MIN].flushed)) {
printk(KERN_ERR "get_tls_entry: task with pid %d got here "
"without flushed TLS.", current->pid);
}
return 0;
clear:
- /* When the TLS entry has not been set, the values read to user in the
+ /*
+ * When the TLS entry has not been set, the values read to user in the
* tls_array are 0 (because it's cleared at boot, see
* arch/i386/kernel/head.S:cpu_gdt_table). Emulate that.
*/
goto out;
}
-asmlinkage int sys_set_thread_area(struct user_desc __user *user_desc)
+int sys_set_thread_area(struct user_desc __user *user_desc)
{
struct user_desc info;
int idx, ret;
return -EFAULT;
}
- ret = CHOOSE_MODE_PROC(do_set_thread_area_tt, do_set_thread_area_skas, &info);
+ ret = do_set_thread_area(&info);
if (ret)
return ret;
return set_tls_entry(current, &info, idx, 1);
* i386. However the only possible error are caused by bugs.
*/
int ptrace_set_thread_area(struct task_struct *child, int idx,
- struct user_desc __user *user_desc)
+ struct user_desc __user *user_desc)
{
struct user_desc info;
return set_tls_entry(child, &info, idx, 0);
}
-asmlinkage int sys_get_thread_area(struct user_desc __user *user_desc)
+int sys_get_thread_area(struct user_desc __user *user_desc)
{
struct user_desc info;
int idx, ret;
return ret;
}
-
-/* XXX: This part is probably common to i386 and x86-64. Don't create a common
- * file for now, do that when implementing x86-64 support.*/
-static int __init __setup_host_supports_tls(void) {
+/*
+ * This code is really i386-only, but it detects and logs x86_64 GDT indexes
+ * if a 32-bit UML is running on a 64-bit host.
+ */
+static int __init __setup_host_supports_tls(void)
+{
check_host_supports_tls(&host_supports_tls, &host_gdt_entry_tls_min);
if (host_supports_tls) {
printk(KERN_INFO "Host TLS support detected\n");
printk(KERN_INFO "Detected host type: ");
switch (host_gdt_entry_tls_min) {
- case GDT_ENTRY_TLS_MIN_I386:
- printk("i386\n");
- break;
- case GDT_ENTRY_TLS_MIN_X86_64:
- printk("x86_64\n");
- break;
+ case GDT_ENTRY_TLS_MIN_I386:
+ printk(KERN_CONT "i386");
+ break;
+ case GDT_ENTRY_TLS_MIN_X86_64:
+ printk(KERN_CONT "x86_64");
+ break;
}
+ printk(KERN_CONT " (GDT indexes %d to %d)\n",
+ host_gdt_entry_tls_min,
+ host_gdt_entry_tls_min + GDT_ENTRY_TLS_ENTRIES);
} else
printk(KERN_ERR " Host TLS support NOT detected! "
"TLS support inside UML will not work\n");
git.openpandora.org / pandora-kernel.git / blobdiff