[commit: ghc] ghc-8.0: Pass -no-pie to GCC (fefe02c)

git at git.haskell.org git at git.haskell.org
Fri Nov 11 19:29:25 UTC 2016


Repository : ssh://git@git.haskell.org/ghc

On branch  : ghc-8.0
Link       : http://ghc.haskell.org/trac/ghc/changeset/fefe02c0324a25a52455a61f7f6e48be6d82d1ab/ghc

>---------------------------------------------------------------

commit fefe02c0324a25a52455a61f7f6e48be6d82d1ab
Author: Ben Gamari <ben at smart-cactus.org>
Date:   Fri Nov 11 13:20:03 2016 -0500

    Pass -no-pie to GCC
    
    Certain distributions (e.g. Debian and Ubuntu) have enabled PIE be
    default in their GCC packaging. This breaks our abuse of GCC as a linker
    which requires that we pass -Wl,-r, which is incompatible with
    PIE (since the former implies that we are generating a relocatable
    object file and the latter an executable).
    
    This is a second attempt at D2691. This attempt constrasts with D2691 in that
    it preserves the "does gcc support -no-pie" flag in settings, allowing this to
    be reconfigured by `configure` during installation of a binary distribution.
    Thanks for @rwbarton for drawing attention to this issue.
    
    Test Plan: Validate
    
    Reviewers: austin, hvr, erikd
    
    Reviewed By: erikd
    
    Subscribers: thomie, rwbarton, erikd
    
    Differential Revision: https://phabricator.haskell.org/D2693
    
    GHC Trac Issues: #12759


>---------------------------------------------------------------

fefe02c0324a25a52455a61f7f6e48be6d82d1ab
 aclocal.m4                      | 21 +++++++++++++++++++++
 compiler/main/DriverPipeline.hs | 10 ++++++++++
 compiler/main/DynFlags.hs       |  1 +
 compiler/main/SysTools.hs       | 17 ++++++++++++++++-
 configure.ac                    |  3 +++
 distrib/configure.ac.in         |  1 +
 settings.in                     |  1 +
 7 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/aclocal.m4 b/aclocal.m4
index 0c842d5..08ae2e5 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -499,12 +499,14 @@ AC_DEFUN([FP_SETTINGS],
     fi
     SettingsCCompilerFlags="$CONF_CC_OPTS_STAGE2"
     SettingsCCompilerLinkFlags="$CONF_GCC_LINKER_OPTS_STAGE2"
+    SettingsCCompilerSupportsNoPie="$CONF_GCC_SUPPORTS_NO_PIE"
     SettingsLdFlags="$CONF_LD_LINKER_OPTS_STAGE2"
     AC_SUBST(SettingsCCompilerCommand)
     AC_SUBST(SettingsHaskellCPPCommand)
     AC_SUBST(SettingsHaskellCPPFlags)
     AC_SUBST(SettingsCCompilerFlags)
     AC_SUBST(SettingsCCompilerLinkFlags)
+    AC_SUBST(SettingsCCompilerSupportsNoPie)
     AC_SUBST(SettingsLdCommand)
     AC_SUBST(SettingsLdFlags)
     AC_SUBST(SettingsArCommand)
@@ -1258,6 +1260,25 @@ AC_SUBST(GccIsClang)
 rm -f conftest.txt
 ])
 
+# FP_GCC_SUPPORTS_NO_PIE
+# ----------------------
+# Does gcc support the -no-pie option? If so we should pass it to gcc when
+# joining objects since -pie may be enabled by default.
+AC_DEFUN([FP_GCC_SUPPORTS_NO_PIE],
+[
+   AC_REQUIRE([AC_PROG_CC])
+   AC_MSG_CHECKING([whether GCC supports -no-pie])
+   echo 'int main() { return 0; }' > conftest.c
+   if ${CC-cc} -o conftest -no-pie conftest.c > /dev/null 2>&1; then
+       CONF_GCC_SUPPORTS_NO_PIE=YES
+       AC_MSG_RESULT([yes])
+   else
+       CONF_GCC_SUPPORTS_NO_PIE=NO
+       AC_MSG_RESULT([no])
+   fi
+   rm -f conftest.c conftest.o conftest
+])
+
 dnl Small feature test for perl version. Assumes PerlCmd
 dnl contains path to perl binary.
 dnl
diff --git a/compiler/main/DriverPipeline.hs b/compiler/main/DriverPipeline.hs
index f6e5b8b..acd0d61 100644
--- a/compiler/main/DriverPipeline.hs
+++ b/compiler/main/DriverPipeline.hs
@@ -1850,6 +1850,11 @@ linkBinary' staticLink dflags o_files dep_packages = do
                       ++ map SysTools.Option (
                          []
 
+                      -- See Note [No PIE eating when linking]
+                      ++ (if sGccSupportsNoPie mySettings
+                             then ["-no-pie"]
+                             else [])
+
                       -- Permit the linker to auto link _symbol to _imp_symbol.
                       -- This lets us link against DLLs without needing an "import library".
                       ++ (if platformOS platform == OSMinGW32
@@ -2151,6 +2156,11 @@ joinObjectFiles dflags o_files output_fn = do
                        SysTools.Option "-nostdlib",
                        SysTools.Option "-Wl,-r"
                      ]
+                        -- See Note [No PIE eating while linking] in SysTools
+                     ++ (if sGccSupportsNoPie mySettings
+                          then [SysTools.Option "-no-pie"]
+                          else [])
+
                      ++ (if any (cc ==) [Clang, AppleClang, AppleClang51]
                           then []
                           else [SysTools.Option "-nodefaultlibs"])
diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs
index 93c0ee8..e1a271a 100644
--- a/compiler/main/DynFlags.hs
+++ b/compiler/main/DynFlags.hs
@@ -947,6 +947,7 @@ data Settings = Settings {
   sLdSupportsBuildId       :: Bool,
   sLdSupportsFilelist      :: Bool,
   sLdIsGnuLd               :: Bool,
+  sGccSupportsNoPie        :: Bool,
   -- commands for particular phases
   sPgm_L                 :: String,
   sPgm_P                 :: (String,[Option]),
diff --git a/compiler/main/SysTools.hs b/compiler/main/SysTools.hs
index 236bcfd..1ab5b13 100644
--- a/compiler/main/SysTools.hs
+++ b/compiler/main/SysTools.hs
@@ -251,6 +251,7 @@ initSysTools mbMinusB
        -- to make that possible, so for now you can't.
        gcc_prog <- getSetting "C compiler command"
        gcc_args_str <- getSetting "C compiler flags"
+       gccSupportsNoPie <- getBooleanSetting "C compiler supports -no-pie"
        cpp_prog <- getSetting "Haskell CPP command"
        cpp_args_str <- getSetting "Haskell CPP flags"
        let unreg_gcc_args = if targetUnregisterised
@@ -343,6 +344,7 @@ initSysTools mbMinusB
                     sLdSupportsBuildId       = ldSupportsBuildId,
                     sLdSupportsFilelist      = ldSupportsFilelist,
                     sLdIsGnuLd               = ldIsGnuLd,
+                    sGccSupportsNoPie        = gccSupportsNoPie,
                     sProgramName             = "ghc",
                     sProjectVersion          = cProjectVersion,
                     sPgm_L   = unlit_path,
@@ -858,7 +860,7 @@ getLinkerInfo' dflags = do
                      -- Note [Windows stack usage]
                      -- Force static linking of libGCC
                      -- Note [Windows static libGCC]
-                   , "-Xlinker", "--stack=0x800000,0x800000", "-static-libgcc" ]
+                   , "-static-libgcc" ]
                _ -> do
                  -- In practice, we use the compiler as the linker here. Pass
                  -- -Wl,--version to get linker version info.
@@ -1578,6 +1580,15 @@ linesPlatform xs =
 
 #endif
 
+{-
+Note [No PIE eating while linking]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+As of 2016 some Linux distributions (e.g. Debian) have started enabling -pie by
+default in their gcc builds. This is incompatible with -r as it implies that we
+are producing an executable. Consequently, we must manually pass -no-pie to gcc
+when joining object files or linking dynamic libraries. See #12759.
+-}
+
 linkDynLib :: DynFlags -> [String] -> [UnitId] -> IO ()
 linkDynLib dflags0 o_files dep_packages
  = do
@@ -1743,6 +1754,10 @@ linkDynLib dflags0 o_files dep_packages
                  ++ [ Option "-o"
                     , FileOption "" output_fn
                     ]
+                    -- See Note [No PIE eating when linking]
+                 ++ (if sGccSupportsNoPie (settings dflags)
+                     then [Option "-no-pie"]
+                     else [])
                  ++ map Option o_files
                  ++ [ Option "-shared" ]
                  ++ map Option bsymbolicFlag
diff --git a/configure.ac b/configure.ac
index 57726d6..bbb39eb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -647,6 +647,9 @@ dnl     If gcc, make sure it's at least 3.0
 dnl
 FP_GCC_VERSION
 
+dnl ** See whether gcc supports -no-pie
+FP_GCC_SUPPORTS_NO_PIE
+
 dnl ** look to see if we have a C compiler using an llvm back end.
 dnl
 FP_CC_LLVM_BACKEND
diff --git a/distrib/configure.ac.in b/distrib/configure.ac.in
index d50ce86..fa6a177 100644
--- a/distrib/configure.ac.in
+++ b/distrib/configure.ac.in
@@ -92,6 +92,7 @@ FIND_LD([LdCmd])
 AC_SUBST([LdCmd])
 
 FP_GCC_VERSION
+FP_GCC_SUPPORTS_NO_PIE
 AC_PROG_CPP
 
 FP_PROG_LD_IS_GNU
diff --git a/settings.in b/settings.in
index e8cdad3..7ec1c26 100644
--- a/settings.in
+++ b/settings.in
@@ -2,6 +2,7 @@
  ("C compiler command", "@SettingsCCompilerCommand@"),
  ("C compiler flags", "@SettingsCCompilerFlags@"),
  ("C compiler link flags", "@SettingsCCompilerLinkFlags@"),
+ ("C compiler supports -no-pie", "@SettingsCCompilerSupportsNoPie@"),
  ("Haskell CPP command","@SettingsHaskellCPPCommand@"),
  ("Haskell CPP flags","@SettingsHaskellCPPFlags@"),
  ("ld command", "@SettingsLdCommand@"),



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