From 28244039a5ca469bfdd1103dd5ef933680f52ebd Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Tue, 30 Apr 2019 14:47:22 +0200
Subject: [PATCH] Kernel: Don't symbolicate symbol+offset for obvious
 non-kernel addresses.

---
 Kernel/FileSystem/ProcFS.cpp | 19 +++++++++++++------
 Kernel/KSyms.cpp             | 18 ++++++++++++++----
 Kernel/mkmap.sh              |  2 +-
 3 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/Kernel/FileSystem/ProcFS.cpp b/Kernel/FileSystem/ProcFS.cpp
index 5ca1d4dc8a..1397872f5d 100644
--- a/Kernel/FileSystem/ProcFS.cpp
+++ b/Kernel/FileSystem/ProcFS.cpp
@@ -304,18 +304,25 @@ ByteBuffer procfs$pid_stack(InodeIdentifier identifier)
     StringBuilder builder;
     process.for_each_thread([&] (Thread& thread) {
         builder.appendf("Thread %d:\n", thread.tid());
-        Vector<RecognizedSymbol> recognized_symbols;
-        if (auto* eip_ksym = ksymbolicate(thread.tss().eip))
-            recognized_symbols.append({ thread.tss().eip, eip_ksym });
+        Vector<RecognizedSymbol, 64> recognized_symbols;
+        recognized_symbols.append({ thread.tss().eip, ksymbolicate(thread.tss().eip) });
         for (dword* stack_ptr = (dword*)thread.frame_ptr(); process.validate_read_from_kernel(LinearAddress((dword)stack_ptr)); stack_ptr = (dword*)*stack_ptr) {
             dword retaddr = stack_ptr[1];
-            if (auto* ksym = ksymbolicate(retaddr))
-                recognized_symbols.append({ retaddr, ksym });
+            recognized_symbols.append({ retaddr, ksymbolicate(retaddr) });
         }
 
         for (auto& symbol : recognized_symbols) {
+            if (!symbol.address)
+                break;
+            if (!symbol.ksym) {
+                builder.appendf("%p\n", symbol.address);
+                continue;
+            }
             unsigned offset = symbol.address - symbol.ksym->address;
-            builder.appendf("%p  %s +%u\n", symbol.address, symbol.ksym->name, offset);
+            if (symbol.ksym->address == ksym_highest_address && offset > 4096)
+                builder.appendf("%p\n", symbol.address);
+            else
+                builder.appendf("%p  %s +%u\n", symbol.address, symbol.ksym->name, offset);
         }
         return IterationDecision::Continue;
     });
diff --git a/Kernel/KSyms.cpp b/Kernel/KSyms.cpp
index 92ad15d785..95d2feca21 100644
--- a/Kernel/KSyms.cpp
+++ b/Kernel/KSyms.cpp
@@ -30,6 +30,8 @@ const KSym* ksymbolicate(dword address)
 
 static void load_ksyms_from_data(const ByteBuffer& buffer)
 {
+    ksym_lowest_address = 0xffffffff;
+    ksym_highest_address = 0;
     auto* bufptr = (const char*)buffer.pointer();
     auto* start_of_name = bufptr;
     dword address = 0;
@@ -92,8 +94,7 @@ static void load_ksyms_from_data(const ByteBuffer& buffer)
     if (use_ksyms) {
         for (dword* stack_ptr = (dword*)ebp; current->process().validate_read_from_kernel(LinearAddress((dword)stack_ptr)); stack_ptr = (dword*)*stack_ptr) {
             dword retaddr = stack_ptr[1];
-            if (auto* ksym = ksymbolicate(retaddr))
-                recognized_symbols[recognized_symbol_count++] = { retaddr, ksym };
+            recognized_symbols[recognized_symbol_count++] = { retaddr, ksymbolicate(retaddr) };
         }
     } else {
         for (dword* stack_ptr = (dword*)ebp; current->process().validate_read_from_kernel(LinearAddress((dword)stack_ptr)); stack_ptr = (dword*)*stack_ptr) {
@@ -106,12 +107,21 @@ static void load_ksyms_from_data(const ByteBuffer& buffer)
     size_t bytes_needed = 0;
     for (int i = 0; i < recognized_symbol_count; ++i) {
         auto& symbol = recognized_symbols[i];
-        bytes_needed += strlen(symbol.ksym->name) + 8 + 16;
+        bytes_needed += (symbol.ksym ? strlen(symbol.ksym->name) : 0) + 8 + 16;
     }
     for (int i = 0; i < recognized_symbol_count; ++i) {
         auto& symbol = recognized_symbols[i];
+        if (!symbol.address)
+            break;
+        if (!symbol.ksym) {
+            dbgprintf("%p\n", symbol.address);
+            continue;
+        }
         unsigned offset = symbol.address - symbol.ksym->address;
-        dbgprintf("%p  %s +%u\n", symbol.address, symbol.ksym->name, offset);
+        if (symbol.ksym->address == ksym_highest_address && offset > 4096)
+            dbgprintf("%p\n", symbol.address);
+        else
+            dbgprintf("%p  %s +%u\n", symbol.address, symbol.ksym->name, offset);
     }
 }
 
diff --git a/Kernel/mkmap.sh b/Kernel/mkmap.sh
index b554769a68..3c2d7b5cff 100644
--- a/Kernel/mkmap.sh
+++ b/Kernel/mkmap.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 tmp=$(mktemp)
-nm -nC kernel | uniq > $tmp
+nm -nC kernel | awk '{ if ($2 != "a") print; }' | uniq > $tmp
 printf "%08x\n" $(wc -l $tmp | cut -f1 -d' ') > kernel.map
 cat $tmp >> kernel.map
 rm -f $tmp