From 3d45e7ffe513fdddce5b9b382e7578617dd44c15 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Francesco=20Potort=C3=AC?= Date: Thu, 17 Feb 2005 12:57:42 +0000 Subject: [PATCH] Segfault during `make bootstrap' under certain recent versions of the Linux kernel. Copied from the trunk PROBLEMS file, with the following part removed, because I am not sure whether it is true for 21.4: Configure can overcome the problem of exec-shield if the architecture is x86 and the program setarch is present. On other architectures no workaround is known. --- etc/ChangeLog | 5 +++++ etc/PROBLEMS | 27 +++++++++++++++++++++++++++ 2 files changed, 32 insertions(+) diff --git a/etc/ChangeLog b/etc/ChangeLog index 17fd31b51c6..c5233d11815 100644 --- a/etc/ChangeLog +++ b/etc/ChangeLog @@ -1,3 +1,8 @@ +2005-02-17 Francesco Potort,Al(B + + * PROBLEMS: Document exec-shield Linux problem. Do not mention + that configure can overcome it on i386: not sure for 21.4. + 2003-05-28 Dave Love * ORDERS.EUROPE, ORDERS.JAPAN: Removed. diff --git a/etc/PROBLEMS b/etc/PROBLEMS index 6f07e886ed7..f09dc2c6cb9 100644 --- a/etc/PROBLEMS +++ b/etc/PROBLEMS @@ -136,6 +136,33 @@ in the `/gnu/emacs/windows' directory a program called `djtarnt.exe' which can be used to unpack `.tar.gz' and `.zip' archives without mangling them. +* Segfault during `make bootstrap' under certain recent versions of the Linux kernel. + +With certain recent Linux kernels (like the one of Redhat Fedora Core +1 and 2), the new "Exec-shield" functionality is enabled by default, which +creates a different memory layout that breaks the emacs dumper. + +You can check the Exec-shield state like this: + + cat /proc/sys/kernel/exec-shield + +It returns non-zero when Exec-shield is enabled, 0 otherwise. Please +read your system documentation for more details on Exec-shield and +associated commands. Exec-shield can be turned off with this command: + + echo "0" > /proc/sys/kernel/exec-shield + +When Exec-shield is enabled, building Emacs will segfault during the +execution of this command: + + ./temacs --batch --load loadup [dump|bootstrap] + +To work around this problem, it is necessary to temporarily disable +Exec-shield while building Emacs, or, on x86, by using the `setarch' +command when running temacs like this: + + setarch i386 ./temacs --batch --load loadup [dump|bootstrap] + * Emacs crashes when dumping itself on Mac PPC running Yellow Dog GNU/Linux. The crashes happen inside the function Fmake_symbol; here's a typical -- 2.39.5