Merge branches 'x86/paravirt', 'x86/pat', 'x86/setup-v2', 'x86/subarch', 'x86/uaccess...

[linux-2.6-omap-h63xx.git] / arch / x86 / kernel / ptrace.c

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 508b6b57d0c313812262ccb34fc4432d3a7806a8..d2f7cd5b2c8378e057152846a98dedde59535086 100644 (file)
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -75,10 +75,7 @@ static inline bool invalid_selector(u16 value)
 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 {
        BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
-       regno >>= 2;
-       if (regno > FS)
-               --regno;
-       return &regs->bx + regno;
+       return &regs->bx + (regno >> 2);
 }
 
 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
@@ -808,12 +805,16 @@ static void ptrace_bts_untrace(struct task_struct *child)
 
 static void ptrace_bts_detach(struct task_struct *child)
 {
-       if (unlikely(child->bts)) {
-               ds_release_bts(child->bts);
-               child->bts = NULL;
-
-               ptrace_bts_free_buffer(child);
-       }
+       /*
+        * Ptrace_detach() races with ptrace_untrace() in case
+        * the child dies and is reaped by another thread.
+        *
+        * We only do the memory accounting at this point and
+        * leave the buffer deallocation and the bts tracer
+        * release to ptrace_bts_untrace() which will be called
+        * later on with tasklist_lock held.
+        */
+       release_locked_buffer(child->bts_buffer, child->bts_size);
 }
 #else
 static inline void ptrace_bts_fork(struct task_struct *tsk) {}