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Diffstat (limited to 'arch/x86/kernel/process_32.c')
-rw-r--r--arch/x86/kernel/process_32.c241
1 files changed, 29 insertions, 212 deletions
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index bd4da2af08ae..14014d766cad 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -11,6 +11,7 @@
#include <stdarg.h>
+#include <linux/stackprotector.h>
#include <linux/cpu.h>
#include <linux/errno.h>
#include <linux/sched.h>
@@ -66,9 +67,6 @@ asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
EXPORT_PER_CPU_SYMBOL(current_task);
-DEFINE_PER_CPU(int, cpu_number);
-EXPORT_PER_CPU_SYMBOL(cpu_number);
-
/*
* Return saved PC of a blocked thread.
*/
@@ -94,6 +92,15 @@ void cpu_idle(void)
{
int cpu = smp_processor_id();
+ /*
+ * If we're the non-boot CPU, nothing set the stack canary up
+ * for us. CPU0 already has it initialized but no harm in
+ * doing it again. This is a good place for updating it, as
+ * we wont ever return from this function (so the invalid
+ * canaries already on the stack wont ever trigger).
+ */
+ boot_init_stack_canary();
+
current_thread_info()->status |= TS_POLLING;
/* endless idle loop with no priority at all */
@@ -108,7 +115,6 @@ void cpu_idle(void)
play_dead();
local_irq_disable();
- __get_cpu_var(irq_stat).idle_timestamp = jiffies;
/* Don't trace irqs off for idle */
stop_critical_timings();
pm_idle();
@@ -132,7 +138,7 @@ void __show_regs(struct pt_regs *regs, int all)
if (user_mode_vm(regs)) {
sp = regs->sp;
ss = regs->ss & 0xffff;
- savesegment(gs, gs);
+ gs = get_user_gs(regs);
} else {
sp = (unsigned long) (&regs->sp);
savesegment(ss, ss);
@@ -213,6 +219,7 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
regs.ds = __USER_DS;
regs.es = __USER_DS;
regs.fs = __KERNEL_PERCPU;
+ regs.gs = __KERNEL_STACK_CANARY;
regs.orig_ax = -1;
regs.ip = (unsigned long) kernel_thread_helper;
regs.cs = __KERNEL_CS | get_kernel_rpl();
@@ -223,55 +230,6 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
}
EXPORT_SYMBOL(kernel_thread);
-/*
- * Free current thread data structures etc..
- */
-void exit_thread(void)
-{
- /* The process may have allocated an io port bitmap... nuke it. */
- if (unlikely(test_thread_flag(TIF_IO_BITMAP))) {
- struct task_struct *tsk = current;
- struct thread_struct *t = &tsk->thread;
- int cpu = get_cpu();
- struct tss_struct *tss = &per_cpu(init_tss, cpu);
-
- kfree(t->io_bitmap_ptr);
- t->io_bitmap_ptr = NULL;
- clear_thread_flag(TIF_IO_BITMAP);
- /*
- * Careful, clear this in the TSS too:
- */
- memset(tss->io_bitmap, 0xff, tss->io_bitmap_max);
- t->io_bitmap_max = 0;
- tss->io_bitmap_owner = NULL;
- tss->io_bitmap_max = 0;
- tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
- put_cpu();
- }
-
- ds_exit_thread(current);
-}
-
-void flush_thread(void)
-{
- struct task_struct *tsk = current;
-
- tsk->thread.debugreg0 = 0;
- tsk->thread.debugreg1 = 0;
- tsk->thread.debugreg2 = 0;
- tsk->thread.debugreg3 = 0;
- tsk->thread.debugreg6 = 0;
- tsk->thread.debugreg7 = 0;
- memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
- clear_tsk_thread_flag(tsk, TIF_DEBUG);
- /*
- * Forget coprocessor state..
- */
- tsk->fpu_counter = 0;
- clear_fpu(tsk);
- clear_used_math();
-}
-
void release_thread(struct task_struct *dead_task)
{
BUG_ON(dead_task->mm);
@@ -305,7 +263,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
p->thread.ip = (unsigned long) ret_from_fork;
- savesegment(gs, p->thread.gs);
+ task_user_gs(p) = get_user_gs(regs);
tsk = current;
if (unlikely(test_tsk_thread_flag(tsk, TIF_IO_BITMAP))) {
@@ -343,7 +301,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
void
start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
{
- __asm__("movl %0, %%gs" : : "r"(0));
+ set_user_gs(regs, 0);
regs->fs = 0;
set_fs(USER_DS);
regs->ds = __USER_DS;
@@ -359,127 +317,6 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
}
EXPORT_SYMBOL_GPL(start_thread);
-static void hard_disable_TSC(void)
-{
- write_cr4(read_cr4() | X86_CR4_TSD);
-}
-
-void disable_TSC(void)
-{
- preempt_disable();
- if (!test_and_set_thread_flag(TIF_NOTSC))
- /*
- * Must flip the CPU state synchronously with
- * TIF_NOTSC in the current running context.
- */
- hard_disable_TSC();
- preempt_enable();
-}
-
-static void hard_enable_TSC(void)
-{
- write_cr4(read_cr4() & ~X86_CR4_TSD);
-}
-
-static void enable_TSC(void)
-{
- preempt_disable();
- if (test_and_clear_thread_flag(TIF_NOTSC))
- /*
- * Must flip the CPU state synchronously with
- * TIF_NOTSC in the current running context.
- */
- hard_enable_TSC();
- preempt_enable();
-}
-
-int get_tsc_mode(unsigned long adr)
-{
- unsigned int val;
-
- if (test_thread_flag(TIF_NOTSC))
- val = PR_TSC_SIGSEGV;
- else
- val = PR_TSC_ENABLE;
-
- return put_user(val, (unsigned int __user *)adr);
-}
-
-int set_tsc_mode(unsigned int val)
-{
- if (val == PR_TSC_SIGSEGV)
- disable_TSC();
- else if (val == PR_TSC_ENABLE)
- enable_TSC();
- else
- return -EINVAL;
-
- return 0;
-}
-
-static noinline void
-__switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
- struct tss_struct *tss)
-{
- struct thread_struct *prev, *next;
-
- prev = &prev_p->thread;
- next = &next_p->thread;
-
- if (test_tsk_thread_flag(next_p, TIF_DS_AREA_MSR) ||
- test_tsk_thread_flag(prev_p, TIF_DS_AREA_MSR))
- ds_switch_to(prev_p, next_p);
- else if (next->debugctlmsr != prev->debugctlmsr)
- update_debugctlmsr(next->debugctlmsr);
-
- if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
- set_debugreg(next->debugreg0, 0);
- set_debugreg(next->debugreg1, 1);
- set_debugreg(next->debugreg2, 2);
- set_debugreg(next->debugreg3, 3);
- /* no 4 and 5 */
- set_debugreg(next->debugreg6, 6);
- set_debugreg(next->debugreg7, 7);
- }
-
- if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^
- test_tsk_thread_flag(next_p, TIF_NOTSC)) {
- /* prev and next are different */
- if (test_tsk_thread_flag(next_p, TIF_NOTSC))
- hard_disable_TSC();
- else
- hard_enable_TSC();
- }
-
- if (!test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
- /*
- * Disable the bitmap via an invalid offset. We still cache
- * the previous bitmap owner and the IO bitmap contents:
- */
- tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
- return;
- }
-
- if (likely(next == tss->io_bitmap_owner)) {
- /*
- * Previous owner of the bitmap (hence the bitmap content)
- * matches the next task, we dont have to do anything but
- * to set a valid offset in the TSS:
- */
- tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
- return;
- }
- /*
- * Lazy TSS's I/O bitmap copy. We set an invalid offset here
- * and we let the task to get a GPF in case an I/O instruction
- * is performed. The handler of the GPF will verify that the
- * faulting task has a valid I/O bitmap and, it true, does the
- * real copy and restart the instruction. This will save us
- * redundant copies when the currently switched task does not
- * perform any I/O during its timeslice.
- */
- tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET_LAZY;
-}
/*
* switch_to(x,yn) should switch tasks from x to y.
@@ -540,7 +377,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
* used %fs or %gs (it does not today), or if the kernel is
* running inside of a hypervisor layer.
*/
- savesegment(gs, prev->gs);
+ lazy_save_gs(prev->gs);
/*
* Load the per-thread Thread-Local Storage descriptor.
@@ -586,64 +423,44 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
* Restore %gs if needed (which is common)
*/
if (prev->gs | next->gs)
- loadsegment(gs, next->gs);
+ lazy_load_gs(next->gs);
- x86_write_percpu(current_task, next_p);
+ percpu_write(current_task, next_p);
return prev_p;
}
-asmlinkage int sys_fork(struct pt_regs regs)
-{
- return do_fork(SIGCHLD, regs.sp, &regs, 0, NULL, NULL);
-}
-
-asmlinkage int sys_clone(struct pt_regs regs)
+int sys_clone(struct pt_regs *regs)
{
unsigned long clone_flags;
unsigned long newsp;
int __user *parent_tidptr, *child_tidptr;
- clone_flags = regs.bx;
- newsp = regs.cx;
- parent_tidptr = (int __user *)regs.dx;
- child_tidptr = (int __user *)regs.di;
+ clone_flags = regs->bx;
+ newsp = regs->cx;
+ parent_tidptr = (int __user *)regs->dx;
+ child_tidptr = (int __user *)regs->di;
if (!newsp)
- newsp = regs.sp;
- return do_fork(clone_flags, newsp, &regs, 0, parent_tidptr, child_tidptr);
-}
-
-/*
- * This is trivial, and on the face of it looks like it
- * could equally well be done in user mode.
- *
- * Not so, for quite unobvious reasons - register pressure.
- * In user mode vfork() cannot have a stack frame, and if
- * done by calling the "clone()" system call directly, you
- * do not have enough call-clobbered registers to hold all
- * the information you need.
- */
-asmlinkage int sys_vfork(struct pt_regs regs)
-{
- return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.sp, &regs, 0, NULL, NULL);
+ newsp = regs->sp;
+ return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr);
}
/*
* sys_execve() executes a new program.
*/
-asmlinkage int sys_execve(struct pt_regs regs)
+int sys_execve(struct pt_regs *regs)
{
int error;
char *filename;
- filename = getname((char __user *) regs.bx);
+ filename = getname((char __user *) regs->bx);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename,
- (char __user * __user *) regs.cx,
- (char __user * __user *) regs.dx,
- &regs);
+ (char __user * __user *) regs->cx,
+ (char __user * __user *) regs->dx,
+ regs);
if (error == 0) {
/* Make sure we don't return using sysenter.. */
set_thread_flag(TIF_IRET);