Pull lameter-spinlock-optimization into release branch

[linux-2.6] / arch / i386 / kernel / process.c

diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index ba243a4cc119fd35774bfc26e3fb3587bb31c741..e3f362e8af5b33e194ac5b7bad3a9ec294f0a030 100644 (file)
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -700,23 +700,27 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas
 
        /*
         * Restore %fs and %gs if needed.
+        *
+        * Glibc normally makes %fs be zero, and %gs is one of
+        * the TLS segments.
         */
-       if (unlikely(prev->fs | prev->gs | next->fs | next->gs)) {
+       if (unlikely(prev->fs | next->fs))
                loadsegment(fs, next->fs);
+
+       if (prev->gs | next->gs)
                loadsegment(gs, next->gs);
-       }
 
        /*
         * Now maybe reload the debug registers
         */
        if (unlikely(next->debugreg[7])) {
-               set_debugreg(current->thread.debugreg[0], 0);
-               set_debugreg(current->thread.debugreg[1], 1);
-               set_debugreg(current->thread.debugreg[2], 2);
-               set_debugreg(current->thread.debugreg[3], 3);
+               set_debugreg(next->debugreg[0], 0);
+               set_debugreg(next->debugreg[1], 1);
+               set_debugreg(next->debugreg[2], 2);
+               set_debugreg(next->debugreg[3], 3);
                /* no 4 and 5 */
-               set_debugreg(current->thread.debugreg[6], 6);
-               set_debugreg(current->thread.debugreg[7], 7);
+               set_debugreg(next->debugreg[6], 6);
+               set_debugreg(next->debugreg[7], 7);
        }
 
        if (unlikely(prev->io_bitmap_ptr || next->io_bitmap_ptr))
@@ -913,6 +917,8 @@ asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
        if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
                return -EINVAL;
 
+       memset(&info, 0, sizeof(info));
+
        desc = current->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
 
        info.entry_number = idx;