1 files changed, 61 insertions, 37 deletions

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 0a6d8c12e10d..2c8ec1ba75e6 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -668,14 +668,14 @@ static int ptrace_bts_read_record(struct task_struct *child, size_t index,
         size_t bts_index, bts_end;
         int error;
 
-        error = ds_get_bts_end(child, &bts_end);
+        error = ds_get_bts_end(child->bts, &bts_end);
         if (error < 0)
                 return error;
 
         if (bts_end <= index)
                 return -EINVAL;
 
-        error = ds_get_bts_index(child, &bts_index);
+        error = ds_get_bts_index(child->bts, &bts_index);
         if (error < 0)
                 return error;
 
@@ -684,7 +684,7 @@ static int ptrace_bts_read_record(struct task_struct *child, size_t index,
         if (bts_end <= bts_index)
                 bts_index -= bts_end;
 
-        error = ds_access_bts(child, bts_index, &bts_record);
+        error = ds_access_bts(child->bts, bts_index, &bts_record);
         if (error < 0)
                 return error;
 
@@ -705,14 +705,14 @@ static int ptrace_bts_drain(struct task_struct *child,
         size_t end, i;
         int error;
 
-        error = ds_get_bts_index(child, &end);
+        error = ds_get_bts_index(child->bts, &end);
         if (error < 0)
                 return error;
 
         if (size < (end * sizeof(struct bts_struct)))
                 return -EIO;
 
-        error = ds_access_bts(child, 0, (const void **)&raw);
+        error = ds_access_bts(child->bts, 0, (const void **)&raw);
         if (error < 0)
                 return error;
 
@@ -723,18 +723,13 @@ static int ptrace_bts_drain(struct task_struct *child,
                         return -EFAULT;
         }
 
-        error = ds_clear_bts(child);
+        error = ds_clear_bts(child->bts);
         if (error < 0)
                 return error;
 
         return end;
 }
 
-static void ptrace_bts_ovfl(struct task_struct *child)
-{
-        send_sig(child->thread.bts_ovfl_signal, child, 0);
-}
-
 static int ptrace_bts_config(struct task_struct *child,
                              long cfg_size,
                              const struct ptrace_bts_config __user *ucfg)
@@ -760,23 +755,45 @@ static int ptrace_bts_config(struct task_struct *child,
                 goto errout;
 
         if (cfg.flags & PTRACE_BTS_O_ALLOC) {
-                ds_ovfl_callback_t ovfl = NULL;
+                bts_ovfl_callback_t ovfl = NULL;
                 unsigned int sig = 0;
 
-                /* we ignore the error in case we were not tracing child */
-                (void)ds_release_bts(child);
+                error = -EINVAL;
+                if (cfg.size < (10 * bts_cfg.sizeof_bts))
+                        goto errout;
 
                 if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
                         if (!cfg.signal)
                                 goto errout;
 
+                        error = -EOPNOTSUPP;
+                        goto errout;
+
                         sig  = cfg.signal;
-                        ovfl = ptrace_bts_ovfl;
                 }
 
-                error = ds_request_bts(child, /* base = */ NULL, cfg.size, ovfl);
-                if (error < 0)
+                if (child->bts) {
+                        (void)ds_release_bts(child->bts);
+                        kfree(child->bts_buffer);
+
+                        child->bts = NULL;
+                        child->bts_buffer = NULL;
+                }
+
+                error = -ENOMEM;
+                child->bts_buffer = kzalloc(cfg.size, GFP_KERNEL);
+                if (!child->bts_buffer)
+                        goto errout;
+
+                child->bts = ds_request_bts(child, child->bts_buffer, cfg.size,
+                                            ovfl, /* th = */ (size_t)-1);
+                if (IS_ERR(child->bts)) {
+                        error = PTR_ERR(child->bts);
+                        kfree(child->bts_buffer);
+                        child->bts = NULL;
+                        child->bts_buffer = NULL;
                         goto errout;
+                }
 
                 child->thread.bts_ovfl_signal = sig;
         }
@@ -823,15 +840,15 @@ static int ptrace_bts_status(struct task_struct *child,
         if (cfg_size < sizeof(cfg))
                 return -EIO;
 
-        error = ds_get_bts_end(child, &end);
+        error = ds_get_bts_end(child->bts, &end);
         if (error < 0)
                 return error;
 
-        error = ds_access_bts(child, /* index = */ 0, &base);
+        error = ds_access_bts(child->bts, /* index = */ 0, &base);
         if (error < 0)
                 return error;
 
-        error = ds_access_bts(child, /* index = */ end, &max);
+        error = ds_access_bts(child->bts, /* index = */ end, &max);
         if (error < 0)
                 return error;
 
@@ -884,10 +901,7 @@ static int ptrace_bts_write_record(struct task_struct *child,
                 return -EINVAL;
         }
 
-        /* The writing task will be the switched-to task on a context
-         * switch. It needs to write into the switched-from task's BTS
-         * buffer. */
-        return ds_unchecked_write_bts(child, bts_record, bts_cfg.sizeof_bts);
+        return ds_write_bts(child->bts, bts_record, bts_cfg.sizeof_bts);
 }
 
 void ptrace_bts_take_timestamp(struct task_struct *tsk,
@@ -929,17 +943,16 @@ void __cpuinit ptrace_bts_init_intel(struct cpuinfo_x86 *c)
         switch (c->x86) {
         case 0x6:
                 switch (c->x86_model) {
+                case 0 ... 0xC:
+                        /* sorry, don't know about them */
+                        break;
                 case 0xD:
                 case 0xE: /* Pentium M */
                         bts_configure(&bts_cfg_pentium_m);
                         break;
-                case 0xF: /* Core2 */
-        case 0x1C: /* Atom */
+                default: /* Core2, Atom, ... */
                         bts_configure(&bts_cfg_core2);
                         break;
-                default:
-                        /* sorry, don't know about them */
-                        break;
                 }
                 break;
         case 0xF:
@@ -973,13 +986,17 @@ void ptrace_disable(struct task_struct *child)
         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
 #endif
 #ifdef CONFIG_X86_PTRACE_BTS
-        (void)ds_release_bts(child);
+        if (child->bts) {
+                (void)ds_release_bts(child->bts);
+                kfree(child->bts_buffer);
+                child->bts_buffer = NULL;
 
-        child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
-        if (!child->thread.debugctlmsr)
-                clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
+                child->thread.debugctlmsr &= ~bts_cfg.debugctl_mask;
+                if (!child->thread.debugctlmsr)
+                        clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
 
-        clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
+                clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
+        }
 #endif /* CONFIG_X86_PTRACE_BTS */
 }
 
@@ -1111,9 +1128,16 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                         (child, data, (struct ptrace_bts_config __user *)addr);
                 break;
 
-        case PTRACE_BTS_SIZE:
-                ret = ds_get_bts_index(child, /* pos = */ NULL);
+        case PTRACE_BTS_SIZE: {
+                size_t size;
+
+                ret = ds_get_bts_index(child->bts, &size);
+                if (ret == 0) {
+                        BUG_ON(size != (int) size);
+                        ret = (int) size;
+                }
                 break;
+        }
 
         case PTRACE_BTS_GET:
                 ret = ptrace_bts_read_record
@@ -1121,7 +1145,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                 break;
 
         case PTRACE_BTS_CLEAR:
-                ret = ds_clear_bts(child);
+                ret = ds_clear_bts(child->bts);
                 break;
 
         case PTRACE_BTS_DRAIN: