From: Nicholas Piggin <npiggin@gmail.com>
To: Jessica Yu <jeyu@kernel.org>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
"Michael Ellerman" <mpe@ellerman.id.au>,
"Michal Suchánek" <msuchanek@suse.de>
Subject: Re: [PATCH v4 1/2] module: add elf_check_module_arch for module specific elf arch checks
Date: Tue, 15 Jun 2021 12:05:51 +1000 [thread overview]
Message-ID: <1623722110.amu32mwaqs.astroid@bobo.none> (raw)
In-Reply-To: <YMdGWjBOmcstBwOl@p200300cbcf109700df096d564fe976c3.dip0.t-ipconnect.de>
Excerpts from Jessica Yu's message of June 14, 2021 10:06 pm:
> +++ Nicholas Piggin [11/06/21 19:39 +1000]:
>>The elf_check_arch() function is used to test usermode binaries, but
>>kernel modules may have more specific requirements. powerpc would like
>>to test for ABI version compatibility.
>>
>>Add an arch-overridable function elf_check_module_arch() that defaults
>>to elf_check_arch() and use it in elf_validity_check().
>>
>>Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
>>[np: split patch, added changelog]
>>Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>>---
>> include/linux/moduleloader.h | 5 +++++
>> kernel/module.c | 2 +-
>> 2 files changed, 6 insertions(+), 1 deletion(-)
>>
>>diff --git a/include/linux/moduleloader.h b/include/linux/moduleloader.h
>>index 9e09d11ffe5b..fdc042a84562 100644
>>--- a/include/linux/moduleloader.h
>>+++ b/include/linux/moduleloader.h
>>@@ -13,6 +13,11 @@
>> * must be implemented by each architecture.
>> */
>>
>>+// Allow arch to optionally do additional checking of module ELF header
>>+#ifndef elf_check_module_arch
>>+#define elf_check_module_arch elf_check_arch
>>+#endif
>
> Hi Nicholas,
>
> Why not make elf_check_module_arch() consistent with the other
> arch-specific functions? Please see module_frob_arch_sections(),
> module_{init,exit}_section(), etc in moduleloader.h. That is, they are
> all __weak functions that are overridable by arches. We can maybe make
> elf_check_module_arch() a weak symbol, available for arches to
> override if they want to perform additional elf checks. Then we don't
> have to have this one-off #define.
Like this? I like it. Good idea.
Thanks,
Nick
diff --git a/include/linux/moduleloader.h b/include/linux/moduleloader.h
index 9e09d11ffe5b..7b4587a19189 100644
--- a/include/linux/moduleloader.h
+++ b/include/linux/moduleloader.h
@@ -13,6 +13,9 @@
* must be implemented by each architecture.
*/
+/* arch may override to do additional checking of ELF header architecture */
+bool module_elf_check_arch(Elf_Ehdr *hdr);
+
/* Adjust arch-specific sections. Return 0 on success. */
int module_frob_arch_sections(Elf_Ehdr *hdr,
Elf_Shdr *sechdrs,
diff --git a/kernel/module.c b/kernel/module.c
index 7e78dfabca97..8b31c0b7c2a0 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3459,6 +3459,11 @@ static void flush_module_icache(const struct module *mod)
(unsigned long)mod->core_layout.base + mod->core_layout.size);
}
+bool __weak module_elf_check_arch(Elf_Ehdr *hdr)
+{
+ return elf_check_arch(hdr);
+}
+
int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
Elf_Shdr *sechdrs,
char *secstrings,
next prev parent reply other threads:[~2021-06-15 2:33 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-11 9:39 [PATCH v4 0/2] powerpc/64: Option to use ELF V2 ABI for big-endian Nicholas Piggin
2021-06-11 9:39 ` [PATCH v4 1/2] module: add elf_check_module_arch for module specific elf arch checks Nicholas Piggin
2021-06-14 12:06 ` Jessica Yu
2021-06-15 2:05 ` Nicholas Piggin [this message]
2021-06-15 12:17 ` Jessica Yu
2021-06-15 12:50 ` Segher Boessenkool
2021-06-15 13:41 ` Jessica Yu
2021-06-15 14:30 ` Segher Boessenkool
2021-06-16 2:39 ` Michael Ellerman
2021-06-16 1:18 ` Nicholas Piggin
2021-06-16 12:54 ` Jessica Yu
2021-06-17 5:21 ` Nicholas Piggin
2021-06-16 2:37 ` Michael Ellerman
2021-06-16 13:49 ` Jessica Yu
2021-06-11 9:39 ` [PATCH v4 2/2] powerpc/64: Option to use ELF V2 ABI for big-endian kernels Nicholas Piggin
2021-06-11 9:58 ` Michal Suchánek
2021-06-11 10:20 ` Michal Suchánek
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=1623722110.amu32mwaqs.astroid@bobo.none \
--to=npiggin@gmail.com \
--cc=jeyu@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mpe@ellerman.id.au \
--cc=msuchanek@suse.de \
/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: 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 NNTP newsgroup(s).