public inbox for glibc-cvs@sourceware.org help / color / mirror / Atom feed
From: Szabolcs Nagy <nsz@sourceware.org> To: glibc-cvs@sourceware.org Subject: [glibc/arm/morello/main] cheri: elf: Use RW permissions for l_ld when needed Date: Thu, 27 Oct 2022 13:58:38 +0000 (GMT) [thread overview] Message-ID: <20221027135838.66D2F3851520@sourceware.org> (raw) https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=c3e46aa5d253c23ca3828538127aee15efbabfc0 commit c3e46aa5d253c23ca3828538127aee15efbabfc0 Author: Szabolcs Nagy <szabolcs.nagy@arm.com> Date: Fri Sep 2 14:07:06 2022 +0100 cheri: elf: Use RW permissions for l_ld when needed The dynamic section of an executable needs to be written to set the DT_DEBUG entry for debuggers (unless the target has some other place to store r_debug). For this reason we make l_ld writable whenever the dynamic section is writable. The ld.so l_ld is kept RX, since it does not have DT_DEBUG. (Note: relocating the dynamic section is not allowed on cheri and that's the only other reason glibc would write to it.) Diff: --- elf/dl-load.c | 4 +++- elf/rtld.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/elf/dl-load.c b/elf/dl-load.c index 7d74214626..b25ddaec05 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -1276,7 +1276,9 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, } if (l->l_ld != 0) - l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr); + l->l_ld = (ElfW(Dyn) *) (l->l_ld_readonly + ? dl_rx_ptr (l, (elfptr_t) l->l_ld) + : dl_rw_ptr (l, (elfptr_t) l->l_ld)); elf_get_dynamic_info (l, false, false); diff --git a/elf/rtld.c b/elf/rtld.c index 1dac96c94b..41ffb297e5 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -1175,8 +1175,10 @@ rtld_setup_main_map (struct link_map *main_map) case PT_DYNAMIC: /* This tells us where to find the dynamic section, which tells us everything we need to do. */ - main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr; main_map->l_ld_readonly = (ph->p_flags & PF_W) == 0; + main_map->l_ld = (void *) (main_map->l_ld_readonly + ? dl_rx_ptr (main_map, ph->p_vaddr) + : dl_rw_ptr (main_map, ph->p_vaddr)); break; case PT_INTERP: /* This "interpreter segment" was used by the program loader to
next reply other threads:[~2022-10-27 13:58 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-10-27 13:58 Szabolcs Nagy [this message] -- strict thread matches above, loose matches on Subject: below -- 2022-11-23 14:48 Szabolcs Nagy 2022-10-26 15:20 Szabolcs Nagy 2022-10-12 14:17 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: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20221027135838.66D2F3851520@sourceware.org \ --to=nsz@sourceware.org \ --cc=glibc-cvs@sourceware.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe 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).