Merge remote-tracking branch 'origin/4.6'

Change-Id: Ide7a92f4f331c8df3214dc15a9c8268a74e1420f

2 files changed, 26 insertions, 15 deletions

diff --git a/app/perfunwind.cpp b/app/perfunwind.cpp
index 849b220..94b68ef 100644
--- a/app/perfunwind.cpp
+++ b/app/perfunwind.cpp
@@ -365,8 +365,12 @@ static int frameCallback(Dwfl_Frame *state, void *arg)
     return DWARF_CB_OK;
 }
 
-void PerfUnwind::unwindStack(Dwfl *dwfl)
+void PerfUnwind::unwindStack()
 {
+    Dwfl *dwfl = symbolTable(m_currentUnwind.sample->pid())->attachDwfl(&m_currentUnwind);
+    if (!dwfl)
+        return;
+
     dwfl_getthread_frames(dwfl, m_currentUnwind.sample->pid(), frameCallback, &m_currentUnwind);
     if (m_currentUnwind.isInterworking) {
         QVector<qint32> savedFrames = m_currentUnwind.frames;
@@ -417,12 +421,14 @@ void PerfUnwind::resolveCallchain()
 
         // sometimes it skips the first user frame.
         if (i == 0 && !isKernel && ip != m_currentUnwind.sample->ip()) {
+            symbols->attachDwfl(&m_currentUnwind);
             m_currentUnwind.frames.append(symbols->lookupFrame(
                                               m_currentUnwind.sample->ip(), false,
                                               &m_currentUnwind.isInterworking));
         }
 
         if (ip <= PERF_CONTEXT_MAX) {
+            symbols->attachDwfl(&m_currentUnwind);
             m_currentUnwind.frames.append(symbols->lookupFrame(
                                               ip, isKernel,
                                               &m_currentUnwind.isInterworking));
@@ -508,8 +514,7 @@ void PerfUnwind::analyze(const PerfRecordSample &sample)
     if (m_stats.enabled) // don't do any time intensive work in stats mode
         return;
 
-    const bool isKernel = ipIsInKernelSpace(sample.ip());
-
+    PerfSymbolTable *kernelSymbols = symbolTable(s_kernelPid);
     PerfSymbolTable *userSymbols = symbolTable(sample.pid());
 
     for (int unwindingAttempt = 0; unwindingAttempt < 2; ++unwindingAttempt) {
@@ -519,32 +524,38 @@ void PerfUnwind::analyze(const PerfRecordSample &sample)
         m_currentUnwind.frames.clear();
 
         userSymbols->updatePerfMap();
-
-        Dwfl *userDwfl = userSymbols->attachDwfl(&m_currentUnwind);
         if (sample.callchain().length() > 0)
             resolveCallchain();
 
+        bool userDirty = userSymbols->cacheIsDirty();
+        bool kernelDirty = kernelSymbols->cacheIsDirty();
+
         // only try to unwind when resolveCallchain did not dirty the cache
-        if (!userSymbols->cacheIsDirty()) {
-            if (userDwfl && sample.registerAbi() != 0 && sample.userStack().length() > 0)
-                unwindStack(userDwfl);
-            else
+        if (!userDirty && !kernelDirty) {
+            if (sample.registerAbi() != 0 && sample.userStack().length() > 0) {
+                unwindStack();
+                userDirty = userSymbols->cacheIsDirty();
+            } else {
                 break;
+            }
         }
 
         // when the cache is dirty, we clean it up and try again, otherwise we can
         // stop as unwinding should have succeeded
-        if (userSymbols->cacheIsDirty())
+        if (userDirty)
             userSymbols->clearCache(); // fail, try again
-        else
+        if (kernelDirty)
+            kernelSymbols->clearCache();
+        if (!userDirty && !kernelDirty)
             break; // success
     }
 
     // If nothing was found, at least look up the IP
     if (m_currentUnwind.frames.isEmpty()) {
-        PerfSymbolTable *symbols = isKernel ? symbolTable(s_kernelPid) : userSymbols;
-        m_currentUnwind.frames.append(symbols->lookupFrame(sample.ip(), isKernel,
-                                                           &m_currentUnwind.isInterworking));
+        const bool isKernel = ipIsInKernelSpace(sample.ip());
+        PerfSymbolTable *ipSymbols = isKernel ? kernelSymbols : userSymbols;
+        m_currentUnwind.frames.append(ipSymbols->lookupFrame(sample.ip(), isKernel,
+                                                             &m_currentUnwind.isInterworking));
     }
 
 
diff --git a/app/perfunwind.h b/app/perfunwind.h
index a18d6a0..82713a3 100644
--- a/app/perfunwind.h
+++ b/app/perfunwind.h
@@ -284,7 +284,7 @@ private:
 
     Stats m_stats;
 
-    void unwindStack(Dwfl *dwfl);
+    void unwindStack();
     void resolveCallchain();
     void analyze(const PerfRecordSample &sample);
     void sendBuffer(const QByteArray &buffer);