From 46ce47a98460cc5dba0cbfabce97cdd45f591021 Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Sat, 29 Dec 2018 03:28:55 +0100
Subject: [PATCH] Use the entry point address from the ELF header instead of
 looking up _start.

I love these kind of dumb gotcha moments. Turns out you can find the entry
address right there in the header. :^)
---
 Kernel/ELFImage.h  | 2 ++
 Kernel/ELFLoader.h | 1 +
 Kernel/Process.cpp | 4 ++--
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/Kernel/ELFImage.h b/Kernel/ELFImage.h
index a4decc0ab35..5df7d939e81 100644
--- a/Kernel/ELFImage.h
+++ b/Kernel/ELFImage.h
@@ -155,6 +155,8 @@ public:
     bool is_executable() const { return header().e_type == ET_EXEC; }
     bool is_relocatable() const { return header().e_type == ET_REL; }
 
+    LinearAddress entry() const { return LinearAddress(header().e_entry); }
+
 private:
     bool parseHeader();
     const char* raw_data(unsigned offset) const;
diff --git a/Kernel/ELFLoader.h b/Kernel/ELFLoader.h
index b364ce7299c..8ae46280833 100644
--- a/Kernel/ELFLoader.h
+++ b/Kernel/ELFLoader.h
@@ -17,6 +17,7 @@ public:
     char* symbol_ptr(const char* name);
     bool allocate_section(LinearAddress, size_t, size_t alignment, bool is_readable, bool is_writable);
     bool map_section(LinearAddress, size_t, size_t alignment, size_t offset_in_image, bool is_readable, bool is_writable);
+    LinearAddress entry() const { return m_image.entry(); }
 
 private:
     bool layout();
diff --git a/Kernel/Process.cpp b/Kernel/Process.cpp
index d904cf2d685..c5671e4435a 100644
--- a/Kernel/Process.cpp
+++ b/Kernel/Process.cpp
@@ -344,7 +344,7 @@ int Process::do_exec(const String& path, Vector<String>&& arguments, Vector<Stri
             return -ENOEXEC;
         }
 
-        entry_eip = (dword)loader.symbol_ptr("_start");
+        entry_eip = loader.entry().get();
         if (!entry_eip) {
             m_page_directory = old_page_directory;
             MM.enter_process_paging_scope(*this);
@@ -606,7 +606,7 @@ Process::Process(String&& name, uid_t uid, gid_t gid, pid_t ppid, RingLevel ring
             if (!fork_parent->m_fds[i].descriptor)
                 continue;
 #ifdef FORK_DEBUG
-            dbgprintf("fork: cloning fd %u... (%p) istty? %u\n", i, fork_parent->m_fds[i].ptr(), fork_parent->m_fds[i]->isTTY());
+            dbgprintf("fork: cloning fd %u... (%p) istty? %u\n", i, fork_parent->m_fds[i].descriptor.ptr(), fork_parent->m_fds[i].descriptor->is_tty());
 #endif
             m_fds[i].descriptor = fork_parent->m_fds[i].descriptor->clone();
             m_fds[i].flags = fork_parent->m_fds[i].flags;