[binutils-gdb] Disable year 2038 support on 32-bit hosts by default

[Luis Machado <luisgpm@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=e5f2f7d901ee735224b3a657c193f88c7ad79a07

commit e5f2f7d901ee735224b3a657c193f88c7ad79a07
Author: Luis Machado <luis.machado@arm.com>
Date:   Tue Jul 26 00:17:38 2022 +0100

    Disable year 2038 support on 32-bit hosts by default
    
    With a recent import of gnulib, code has been pulled that tests and enables
    64-bit time_t by default on 32-bit hosts that support it.
    
    Although gdb can use the gnulib support, bfd doesn't use gnulib and currently
    doesn't do these checks.
    
    As a consequence, if we have a 32-bit host that supports 64-bit time_t, we'll
    have a mismatch between gdb's notion of time_t and bfd's notion of time_t.
    
    This will lead to mismatches in the struct stat size, leading to memory
    corruption and crashes.
    
    This patch disables the year 2038 check for now, which makes things work
    reliably again.
    
    I'd consider this a temporary fix until we have proper bfd checks for the year
    2038, if it makes sense.  64-bit hosts seems to be more common these days, so
    I'm not sure how important it is to have this support enabled and how soon
    we want to enable it.
    
    Thoughts?

Diff:
---
 configure    | 22 ++++++++++++++++++++++
 configure.ac | 18 ++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/configure b/configure
index be433ef6d5d..16139e3bfa3 100755
--- a/configure
+++ b/configure
@@ -790,6 +790,7 @@ enable_gold
 enable_ld
 enable_gprofng
 enable_compressed_debug_sections
+enable_year2038
 enable_libquadmath
 enable_libquadmath_support
 enable_libada
@@ -1520,6 +1521,7 @@ Optional Features:
   --enable-compressed-debug-sections={all,gas,gold,ld,none}
                           Enable compressed debug sections for gas, gold or ld
                           by default
+  --enable-year2038       enable support for timestamps past the year 2038
   --disable-libquadmath   do not build libquadmath directory
   --disable-libquadmath-support
                           disable libquadmath support for Fortran
@@ -3127,6 +3129,20 @@ case "${host}" in
     ;;
 esac
 
+# Default to --disable-year2038 until we can handle differences between
+# projects that use gnulib (which understands year 2038) and projects that
+# do not (like BFD).
+# Check whether --enable-year2038 was given.
+if test "${enable_year2038+set}" = set; then :
+  enableval=$enable_year2038; ENABLE_YEAR2038=$enableval
+else
+  ENABLE_YEAR2038=no
+fi
+
+enable_year2038=
+if test "${ENABLE_YEAR2038}" = "no" ; then
+  enable_year2038=no
+fi
 
 # Check whether --enable-libquadmath was given.
 if test "${enable_libquadmath+set}" = set; then :
@@ -7836,9 +7852,15 @@ if test "$silent" = yes; then
   baseargs="$baseargs --silent"
   tbaseargs="$tbaseargs --silent"
 fi
+
 baseargs="$baseargs --disable-option-checking"
 tbaseargs="$tbaseargs --disable-option-checking"
 
+if test "$enable_year2038" = no; then
+  baseargs="$baseargs --disable-year2038"
+  tbaseargs="$tbaseargs --disable-year2038"
+fi
+
 # Record and document user additions to sub configure arguments.
 
 
diff --git a/configure.ac b/configure.ac
index 1651cbf3b02..a5555a9c91b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -440,6 +440,18 @@ case "${host}" in
     ;;
 esac
 
+# Default to --disable-year2038 until we can handle differences between
+# projects that use gnulib (which understands year 2038) and projects that
+# do not (like BFD).
+AC_ARG_ENABLE(year2038,
+AS_HELP_STRING([--enable-year2038],
+  [enable support for timestamps past the year 2038]),
+ENABLE_YEAR2038=$enableval,
+ENABLE_YEAR2038=no)
+enable_year2038=
+if test "${ENABLE_YEAR2038}" = "no" ; then
+  enable_year2038=no
+fi
 
 AC_ARG_ENABLE(libquadmath,
 AS_HELP_STRING([--disable-libquadmath],
@@ -3139,9 +3151,15 @@ if test "$silent" = yes; then
   baseargs="$baseargs --silent"
   tbaseargs="$tbaseargs --silent"
 fi
+
 baseargs="$baseargs --disable-option-checking"
 tbaseargs="$tbaseargs --disable-option-checking"
 
+if test "$enable_year2038" = no; then
+  baseargs="$baseargs --disable-year2038"
+  tbaseargs="$tbaseargs --disable-year2038"
+fi
+
 # Record and document user additions to sub configure arguments.
 AC_ARG_VAR([build_configargs],
 	   [additional configure arguments for build directories])