public inbox for
help / color / mirror / Atom feed
From: Szabolcs Nagy <>
Subject: [glibc/arm/morello/main] cheri: rseq: remove const to avoid readonly permission
Date: Wed, 26 Oct 2022 15:17:55 +0000 (GMT)	[thread overview]
Message-ID: <> (raw);h=f7805973566d87ac2224ba8c0b8a3b385e9ad0f5

commit f7805973566d87ac2224ba8c0b8a3b385e9ad0f5
Author: Szabolcs Nagy <>
Date:   Tue Mar 1 09:44:14 2022 +0000

    cheri: rseq: remove const to avoid readonly permission
    Using const on the definition does not work for a pure capability ABI:
    the capability permissions when accessing the object will be read only.
    Use a hack to hide the public declaration in the TU where the const
    objects are initialized. (This should work on non-capability targets
    too, but to err on the safe side only enable the hack on capability

 sysdeps/nptl/dl-tls_init_tp.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/sysdeps/nptl/dl-tls_init_tp.c b/sysdeps/nptl/dl-tls_init_tp.c
index 53fba774a5..e4d7bb71ad 100644
--- a/sysdeps/nptl/dl-tls_init_tp.c
+++ b/sysdeps/nptl/dl-tls_init_tp.c
@@ -16,6 +16,15 @@
    License along with the GNU C Library; if not, see
    <>.  */
+/* This hack ensures that the later indirectly included public const
+   declaration does not conflict with the non-const definition here.  */
+# define __rseq_size __rseq_size_public_const
+# define __rseq_offset __rseq_offset_public_const
+# include <sys/rseq.h>
+# undef __rseq_size
+# undef __rseq_offset
 #include <kernel-features.h>
 #include <ldsodefs.h>
 #include <list.h>
@@ -45,8 +54,13 @@ rtld_mutex_dummy (pthread_mutex_t *lock)
 const unsigned int __rseq_flags;
+unsigned int __rseq_size attribute_relro;
+ptrdiff_t __rseq_offset attribute_relro;
 const unsigned int __rseq_size attribute_relro;
 const ptrdiff_t __rseq_offset attribute_relro;
 __tls_pre_init_tp (void)

             reply	other threads:[~2022-10-26 15:17 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-26 15:17 Szabolcs Nagy [this message]
  -- strict thread matches above, loose matches on Subject: below --
2022-11-23 14:46 Szabolcs Nagy
2022-10-27 13:56 Szabolcs Nagy
2022-08-05 19:35 Szabolcs Nagy

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).