Fix assertion failure in libsanitizer when using glibc 2.31 and later.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92154
https://reviews.llvm.org/D69104

Adapted from these upstream revision:

https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=277981
https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=279653

diff --git a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
index 97eae3fc7bc..4089d4695e2 100644
--- a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
@@ -1145,8 +1145,9 @@ CHECK_SIZE_AND_OFFSET(ipc_perm, uid);
 CHECK_SIZE_AND_OFFSET(ipc_perm, gid);
 CHECK_SIZE_AND_OFFSET(ipc_perm, cuid);
 CHECK_SIZE_AND_OFFSET(ipc_perm, cgid);
-#if !defined(__aarch64__) || !SANITIZER_LINUX || __GLIBC_PREREQ (2, 21)
-/* On aarch64 glibc 2.20 and earlier provided incorrect mode field.  */
+#if !SANITIZER_LINUX || __GLIBC_PREREQ (2, 31)
+/* glibc 2.30 and earlier provided 16-bit mode field instead of 32-bit
+   on many architectures.  */
 CHECK_SIZE_AND_OFFSET(ipc_perm, mode);
 #endif
 
diff --git a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
index c139322839a..7c3c2d866e5 100644
--- a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
+++ b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
@@ -211,20 +211,13 @@ namespace __sanitizer {
     unsigned long __unused1;
     unsigned long __unused2;
 #elif defined(__sparc__)
-# if defined(__arch64__)
     unsigned mode;
-    unsigned short __pad1;
-# else
-    unsigned short __pad1;
-    unsigned short mode;
     unsigned short __pad2;
-# endif
     unsigned short __seq;
     unsigned long long __unused1;
     unsigned long long __unused2;
 #else
-    unsigned short mode;
-    unsigned short __pad1;
+    unsigned int mode;
     unsigned short __seq;
     unsigned short __pad2;
 #if defined(__x86_64__) && !defined(_LP64)

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<div class='path'>path: <a href='/guix/log/?id=d7942ac12ad51615cd43d3debb8b561a503e8fc0'>root</a>/<a href='/guix/log/gnu?id=d7942ac12ad51615cd43d3debb8b561a503e8fc0'>gnu</a>/<a href='/guix/log/gnu/packages?id=d7942ac12ad51615cd43d3debb8b561a503e8fc0'>packages</a>/<a href='/guix/log/gnu/packages/patches?id=d7942ac12ad51615cd43d3debb8b561a503e8fc0'>patches</a>/<a href='/guix/log/gnu/packages/patches/emacs-ignore-empty-xim-styles.patch?id=d7942ac12ad51615cd43d3debb8b561a503e8fc0'>emacs-ignore-empty-xim-styles.patch</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/packages/patches/emacs-ignore-empty-xim-styles.patch?id=d7942ac12ad51615cd43d3debb8b561a503e8fc0&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-08-28 00:13:51 -0400'>2020-08-28</span></td><td><a href='/guix/commit/gnu/packages/patches/emacs-ignore-empty-xim-styles.patch?id=36a09d185343375a5cba370431870f9c4435d623'>gnu: emacs: Update to 27.1.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/emacs.scm (emacs): Update to 27.1.
[source]: In snippet, use 'find-files' to find 'eshell/esh-groups.el'
if it exists, but gracefully handle its absence.
[arguments]: Add "--with-cairo" to configure-flags.  Add 'restore-emacs-pdmp'
and 'make-compressed-files-writable' phases.  Explicitly return #t from
'install-site-start' phase.
[inputs]: Add cairo, pango, harfbuzz, jansson, and gmp.  Remove imagemagick.
(emacs-next): Remove variable.
(emacs-minimal, emacs-xwidgets): Use 'package/inherit'.
[arguments]: Remove 'restore-emacs-pdmp' phase.
(emacs-no-x): Use 'package/inherit'.
[arguments]: Remove "--with-cairo" from configure-flags.  Remove
'restore-emacs-pdmp' phase.
[inputs]: Remove cairo, pango, and harfbuzz.
(emacs-no-x-toolkit): Use 'package/inherit'.
[arguments]: Remove 'restore-emacs-pdmp' phase.  Remove superfluous
quasiquote+unquote-splicing pair.
(emacs-wide-int): Use 'package/inherit'.
(guile-emacs): Use 'package/inherit'.
[arguments]: Remove "--with-cairo" from configure-flags.  Remove
'restore-emacs-pdmp' phase.
* gnu/packages/patches/emacs-ignore-empty-xim-styles.patch,
gnu/packages/patches/emacs-source-date-epoch.patch: Adapt to
apply cleanly to emacs-27.1.
* gnu/packages/patches/emacs-exec-path.patch: Replace with the previous
contents of 'emacs27-exec-path.patch', but remove the superfluous comment
about it being "like emacs-exec-path.patch, but for Emacs 27".
* gnu/packages/patches/emacs27-exec-path.patch: Delete file.
* gnu/local.mk (dist_patch_DATA): Remove 'emacs27-exec-path.patch'.
</span></span></td><td>Mark H Weaver</td></tr>
<tr><td><span title='2020-08-03 12:26:02 +0200'>2020-08-03</span></td><td><a href='/guix/commit/gnu/packages/patches/emacs-ignore-empty-xim-styles.patch?id=f574f859ee7343d894ecf7318fa53b7a73426775'>gnu: emacs: Ignore empty XIM styles.</a><span class='msg-avail'>...<span class='msg-tooltip'>As of libx11 version 1.6.10, xim may be NULL, which causes a segmentation
fault in the execution of ARRAYELTS.  As a cautionary measure, we
short-circuit this logic.

* gnu/packages/patches/emacs-ignore-empty-xim-styles.patch: New file.
* gnu/packages/emacs.scm (emacs emacs-next)[patches]: Use it.
* gnu/local.mk: Register it.

Signed-off-by: Mathieu Othacehe &lt;othacehe@gnu.org&gt;
</span></span></td><td>Leo Prikler</td></tr>