From 3a838494fc769f1ae39adf20325869331f0c300d Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Fri, 15 Jul 2016 13:07:09 +0200 Subject: [PATCH] Emacs should work with glibc 2.24 on ppc64 This patch, backported from upstream by Aurelien Jarno , has been added: Port to glibc 2.24 (pre-release) + ppc64 Inspired by a suggestion by Florian Weimer in: https://sourceware.org/ml/libc-alpha/2016-07/msg00425.html * configure.ac (HAVE_PERSONALITY_ADDR_NO_RANDOMIZE): Rename from HAVE_PERSONALITY_LINUX32, and check for ADDR_NO_RANDOMIZE (the crucial thing) instead of for LINUX32. All uses changed. * src/emacs.c (main) [HAVE_PERSONALITY_ADDR_NO_RANDOMIZE]: Use ADDR_NO_RANDOMIZE from personality.h rather than inventing the flag ourselves. Just set that flag, rather than also setting the persona. When doing it, avoid functions like putenv that may allocate memory. Origin: backport, commit: e95b023163e96538b15f030b7176b7ec59cf86f5 Bug-Debian: http://bugs.debian.org/833727 Added-by: Rob Browning --- admin/CPP-DEFINES | 2 +- configure.ac | 20 +++++++++++--------- src/emacs.c | 30 ++++++++++++++---------------- 3 files changed, 26 insertions(+), 26 deletions(-) diff --git a/admin/CPP-DEFINES b/admin/CPP-DEFINES index e475b422500..ef355135d8a 100644 --- a/admin/CPP-DEFINES +++ b/admin/CPP-DEFINES @@ -244,7 +244,7 @@ HAVE_NET_IF_DL_H HAVE_NET_IF_H HAVE_NLIST_H HAVE_OTF_GET_VARIATION_GLYPHS -HAVE_PERSONALITY_LINUX32 +HAVE_PERSONALITY_ADDR_NO_RANDOMIZE HAVE_PNG HAVE_PNG_H HAVE_POSIX_MEMALIGN diff --git a/configure.ac b/configure.ac index bdc76bca3db..18387d84ec5 100644 --- a/configure.ac +++ b/configure.ac @@ -1478,15 +1478,17 @@ AC_CHECK_HEADERS_ONCE( sys/resource.h sys/utsname.h pwd.h utmp.h util.h) -AC_MSG_CHECKING(if personality LINUX32 can be set) -AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include ]], [[personality (PER_LINUX32)]])], - emacs_cv_personality_linux32=yes, - emacs_cv_personality_linux32=no) -AC_MSG_RESULT($emacs_cv_personality_linux32) - -if test $emacs_cv_personality_linux32 = yes; then - AC_DEFINE(HAVE_PERSONALITY_LINUX32, 1, - [Define to 1 if personality LINUX32 can be set.]) +AC_CACHE_CHECK([for ADDR_NO_RANDOMIZE], + [emacs_cv_personality_addr_no_randomize], + [AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM([[#include ]], + [[personality (personality (0xffffffff) + | ADDR_NO_RANDOMIZE)]])], + [emacs_cv_personality_addr_no_randomize=yes], + [emacs_cv_personality_addr_no_randomize=no])]) +if test $emacs_cv_personality_addr_no_randomize = yes; then + AC_DEFINE([HAVE_PERSONALITY_ADDR_NO_RANDOMIZE], [1], + [Define to 1 if personality flag ADDR_NO_RANDOMIZE exists.]) fi dnl On Solaris 8 there's a compilation warning for term.h because diff --git a/src/emacs.c b/src/emacs.c index b5d3ab46a00..eda439ac6b1 100644 --- a/src/emacs.c +++ b/src/emacs.c @@ -99,7 +99,7 @@ extern void moncontrol (int mode); #include #endif -#ifdef HAVE_PERSONALITY_LINUX32 +#ifdef HAVE_PERSONALITY_ADDR_NO_RANDOMIZE #include #endif @@ -833,24 +833,22 @@ main (int argc, char **argv) dumping = !initialized && (strcmp (argv[argc - 1], "dump") == 0 || strcmp (argv[argc - 1], "bootstrap") == 0); -#ifdef HAVE_PERSONALITY_LINUX32 - if (dumping && ! getenv ("EMACS_HEAP_EXEC")) +#ifdef HAVE_PERSONALITY_ADDR_NO_RANDOMIZE + if (dumping) { - /* Set this so we only do this once. */ - xputenv ("EMACS_HEAP_EXEC=true"); - - /* A flag to turn off address randomization which is introduced - in linux kernel shipped with fedora core 4 */ -#define ADD_NO_RANDOMIZE 0x0040000 - personality (PER_LINUX32 | ADD_NO_RANDOMIZE); -#undef ADD_NO_RANDOMIZE - - execvp (argv[0], argv); + int pers = personality (0xffffffff); + if (! (pers & ADDR_NO_RANDOMIZE) + && 0 <= personality (pers | ADDR_NO_RANDOMIZE)) + { + /* Address randomization was enabled, but is now disabled. + Re-execute Emacs to get a clean slate. */ + execvp (argv[0], argv); - /* If the exec fails, try to dump anyway. */ - emacs_perror (argv[0]); + /* If the exec fails, warn and then try without a clean slate. */ + perror (argv[0]); + } } -#endif /* HAVE_PERSONALITY_LINUX32 */ +#endif #if defined (HAVE_SETRLIMIT) && defined (RLIMIT_STACK) /* Extend the stack space available. -- 2.30.2