Bug #6790

mingw-w64: rb_libruby_handle and libruby changes when extensions are loaded

Added by Luis Lavena over 1 year ago. Updated over 1 year ago.

[ruby-core:46743]
Status:Closed
Priority:Normal
Assignee:Nobuyoshi Nakada
Category:core
Target version:2.0.0
ruby -v:ruby 2.0.0dev (2012-07-25 trunk 36527) [x64-mingw32] Backport:

Description

=begin
Hello,

I started to look into this failure when running dl/handle tests:

testinitializenoargs(DL::TestHandle):
DL::DLError: unknown symbol "rbstrnew"
C:/Users/Worker/Jenkins/workspace/git-ruby-trunk/test/dl/testhandle.rb:110:in []'
C:/Users/Worker/Jenkins/workspace/git-ruby-trunk/test/dl/test_handle.rb:110:in
test
initialize_noargs'

Above error only happens with compiled 64bits ruby.

After looking a bit more closer, it seems DllMain from libruby gets called several times when (({x64-msvcrt-ruby200.dll})) is loaded but also when extensions are loaded.

Adding some debug strings into DllMain like the following:

diff --git a/ruby.c b/ruby.c
index ab4b674..6d1a715 100644
--- a/ruby.c
+++ b/ruby.c
@@ -315,8 +315,22 @@ static HMODULE libruby;
BOOL WINAPI
DllMain(HINSTANCE dll, DWORD reason, LPVOID reserved)
{
+ HMODULE self;
+ char filename[MAXPATH];
+
if (reason == DLL
PROCESSATTACH)
- libruby = dll;
+ {
+ printf("DLL
PROCESSATTACH\n");
+
+ self = GetModuleHandle(NULL);
+ GetModuleFileName(self, filename, MAX
PATH);
+ printf("self: %#x (%s)\n", self, filename);
+
+ GetModuleFileName(dll, filename, MAX_PATH);
+ printf("dll: %#x (%s)\n", dll, filename);
+
+ libruby = dll;
+ }
return TRUE;
}

Produces the following:

32bits compilation:

C:\Users\Luis\Code\ruby\ruby\x86-installed>ruby -v -rdl -e "puts :ok"
DLLPROCESSATTACH
self: 0x400000 (C:\Users\Luis\Code\ruby\ruby\x86-installed\bin\ruby.exe)
dll: 0x66780000 (C:\Users\Luis\Code\ruby\ruby\x86-installed\bin\msvcrt-ruby200.dll)
ruby 2.0.0dev (2012-07-25 trunk 36527) [i386-mingw32]
ok

64bits (mingw-w64):

C:\Users\Luis\Code\ruby\ruby\x64-installed>ruby -v -rdl -e "puts :ok"
DLLPROCESSATTACH
self: 0x400000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\bin\ruby.exe)
dll: 0x6f100000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\bin\x64-msvcrt-ruby200.dll)
ruby 2.0.0dev (2012-07-25 trunk 36527) [x64-mingw32]
DLLPROCESSATTACH
self: 0x400000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\bin\ruby.exe)
dll: 0x1ee0000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\lib\ruby\2.0.0\x64-mingw32\enc\encdb.so)
DLLPROCESSATTACH
self: 0x400000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\bin\ruby.exe)
dll: 0x6aa00000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\lib\ruby\2.0.0\x64-mingw32\enc\iso88591.so)
DLLPROCESSATTACH
self: 0x400000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\bin\ruby.exe)
dll: 0x68080000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\lib\ruby\2.0.0\x64-mingw32\enc\trans\transdb.so)
DLLPROCESSATTACH
self: 0x400000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\bin\ruby.exe)
dll: 0x623c0000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\lib\ruby\2.0.0\x64-mingw32\dl.so)
DLLPROCESSATTACH
self: 0x400000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\bin\ruby.exe)
dll: 0x63d80000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\lib\ruby\2.0.0\x64-mingw32\fiddle.so)
DLLPROCESSATTACH
self: 0x400000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\bin\ruby.exe)
dll: 0x6e6c0000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\lib\ruby\2.0.0\x64-mingw32\enc\utf16le.so)
DLL
PROCESSATTACH
self: 0x400000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\bin\ruby.exe)
dll: 0x6a340000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\lib\ruby\2.0.0\x64-mingw32\enc\trans\single
byte.so)
DLLPROCESSATTACH
self: 0x400000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\bin\ruby.exe)
dll: 0x1f10000 (C:\Users\Luis\Code\ruby\ruby\x64-installed\lib\ruby\2.0.0\x64-mingw32\enc\trans\utf1632.so)
ok

I just tested a simple project which loads multiple DLLs and DllMain of each DLL do not get invoked several times.

Since each extension depends on (({x86-msvcrt-ruby200.dll})), perhaps that is the reason why (({DllMain})) is invoked multiple times.

Maybe there is something I'm missing? Perhaps a workaround will be set (({libruby})) only once?
=end

Associated revisions

Revision 36544
Added by Usaku NAKAMURA over 1 year ago

  • win32/mkexports.rb: should not export DllMain(). reported by luis at [Bug #6790], solved by Heesob Park, and confirmed by nobu.

History

#1 Updated by Nobuyoshi Nakada over 1 year ago

Seems it occurs only in x64-mingw; and does not occur when loading the DLL by x64-mswin ruby.exe.
Needs more investigation.

#2 Updated by Luis Lavena over 1 year ago

nobu (Nobuyoshi Nakada) wrote:

Seems it occurs only in x64-mingw; and does not occur when loading the DLL by x64-mswin ruby.exe.
Needs more investigation.

Do you think this simplification is good enough?

https://github.com/luislavena/experiments/tree/master/dll-handles

DllMain is only invoked once on this example, which might indicate something going on on Ruby.

After a GDB session, seems that dln.c line 1271 (LoadLibrary) is causing x64-msvcrt-ruby200.dll be loaded again.

Will keep investigating on this.

#3 Updated by Heesob Park over 1 year ago

After some investigating, I found this bug is due to exporting "DllMain" symbol of x64-msvcrt-ruby200.dll.

You can see the following line in the x64-msvcrt-ruby200.def.

VERSION 2.0
EXPORTS
DllMain
FDCLR=rbw32fdclr
FD
ISSET=rbw32fdisset
...

I think that DllMain should not be exported.

Here is a simple workaround for win32/mkexports.rb

diff --git a/mkexports.rb b/mkexports.rb.new
index 3a1a91a..9dc8a19 100644
--- a/mkexports.rb
+++ b/mkexports.rb.new
@@ -38,6 +38,7 @@ class Exports
winapis = {}
syms["rubysysinitreal"] = "rubysysinit"
each
export(objs) do |internal, export|
+ next if internal == 'DllMain'
syms[internal] = export
winapis[$1] = internal if /?(rbw32_\w+)(?:@\d+)?$/ =~ internal
end

With the patched and rebuilt version, I confirmed this bug is solved.

#4 Updated by Usaku NAKAMURA over 1 year ago

=begin
Hmm, I see.

Is this patch OK?

Index: win32/mkexports.rb
===================================================================
--- win32/mkexports.rb (revision 36541)
+++ win32/mkexports.rb (working copy)
@@ -116,7 +116,7 @@ class Exports::Mswin < Exports
isdata = !$1
if noprefix or /[@
]/ =~ l
next if /(?!)@.*@/ =~ l || /@:xdigit:{8,16}$/ =~ l ||
- /(?:Init|.*threadptr|DllMain@)/ =~ l
+ /?(?:Init|.*threadptr|DllMain\b)/ =~ l
l.sub!(/[@_]/, '') if /@\d+$/ !~ l
elsif !l.sub!(/\+) ([@?`\']*)$/, '\1')
next
@@ -150,7 +150,7 @@ class Exports::Cygwin < Exports
def eachexport(objs)
symprefix = RbConfig::CONFIG["SYMBOL
PREFIX"]
symprefix.strip! if symprefix
- re = /\s(?:(T)|:upper:)\s#{symprefix}((?!Init|.*threadptr|DllMain@).*)$/
+ re = /\s(?:(T)|:upper:)\s#{symprefix}((?!Init
|.threadptr|DllMain\b).)$/
objdump(objs) do |l|
next if /@.*@/ =~ l
yield $2, !$1 if re =~ l

=end

#5 Updated by Usaku NAKAMURA over 1 year ago

  • Status changed from Assigned to Closed
  • % Done changed from 0 to 100

This issue was solved with changeset r36544.
Luis, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.


  • win32/mkexports.rb: should not export DllMain(). reported by luis at [Bug #6790], solved by Heesob Park, and confirmed by nobu.

#6 Updated by Luis Lavena over 1 year ago

Thank you Heesob Park, Usaku Nakamura and Nobu for fixing this!

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