From: Mike Rapoport <rppt@kernel.org>
To: Nadav Amit <nadav.amit@gmail.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Catalin Marinas <catalin.marinas@arm.com>,
Christoph Hellwig <hch@infradead.org>,
Helge Deller <deller@gmx.de>,
Lorenzo Stoakes <lstoakes@gmail.com>,
Luis Chamberlain <mcgrof@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Palmer Dabbelt <palmer@dabbelt.com>,
Peter Zijlstra <peterz@infradead.org>,
Russell King <linux@armlinux.org.uk>, Song Liu <song@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>,
Uladzislau Rezki <urezki@gmail.com>,
Will Deacon <will@kernel.org>,
bpf@vger.kernel.org, linux-arch@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
"open list:MEMORY MANAGEMENT" <linux-mm@kvack.org>,
linux-modules@vger.kernel.org, linux-parisc@vger.kernel.org,
linux-riscv@lists.infradead.org,
linux-trace-kernel@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org,
the arch/x86 maintainers <x86@kernel.org>
Subject: Re: [RFC PATCH 3/7] module: prepare to handle ROX allocations for text
Date: Thu, 18 Apr 2024 13:20:17 +0300 [thread overview]
Message-ID: <ZiDz4YbIHEOAnpwF@kernel.org> (raw)
In-Reply-To: <0C4B9C1A-97DE-4798-8256-158369AF42A4@gmail.com>
On Tue, Apr 16, 2024 at 12:36:08PM +0300, Nadav Amit wrote:
>
>
> > On 11 Apr 2024, at 19:05, Mike Rapoport <rppt@kernel.org> wrote:
> >
> > @@ -2440,7 +2479,24 @@ static int post_relocation(struct module *mod, const struct load_info *info)
> > add_kallsyms(mod, info);
> >
> > /* Arch-specific module finalizing. */
> > - return module_finalize(info->hdr, info->sechdrs, mod);
> > + ret = module_finalize(info->hdr, info->sechdrs, mod);
> > + if (ret)
> > + return ret;
> > +
> > + for_each_mod_mem_type(type) {
> > + struct module_memory *mem = &mod->mem[type];
> > +
> > + if (mem->is_rox) {
> > + if (!execmem_update_copy(mem->base, mem->rw_copy,
> > + mem->size))
> > + return -ENOMEM;
> > +
> > + vfree(mem->rw_copy);
> > + mem->rw_copy = NULL;
> > + }
> > + }
> > +
> > + return 0;
> > }
>
> I might be missing something, but it seems a bit racy.
>
> IIUC, module_finalize() calls alternatives_smp_module_add(). At this
> point, since you don’t hold the text_mutex, some might do text_poke(),
> e.g., by enabling/disabling static-key, and the update would be
> overwritten. No?
Right :(
Even worse, for UP case alternatives_smp_unlock() will "patch" still empty
area.
So I'm thinking about calling alternatives_smp_module_add() from an
additional callback after the execmem_update_copy().
Does it make sense to you?
--
Sincerely yours,
Mike.
next prev parent reply other threads:[~2024-04-18 10:21 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-11 16:05 [RFC PATCH 0/7] x86/module: use large ROX pages for text allocations Mike Rapoport
2024-04-11 16:05 ` [RFC PATCH 1/7] asm-generic: introduce text-patching.h Mike Rapoport
2024-04-11 16:05 ` [RFC PATCH 2/7] mm: vmalloc: don't account for number of nodes for HUGE_VMAP allocations Mike Rapoport
2024-04-12 6:07 ` Christophe Leroy
2024-04-14 7:34 ` Mike Rapoport
2024-04-11 16:05 ` [RFC PATCH 3/7] module: prepare to handle ROX allocations for text Mike Rapoport
2024-04-16 9:36 ` Nadav Amit
2024-04-18 10:20 ` Mike Rapoport [this message]
2024-04-18 19:31 ` [RFC PATCH 3/7] module: [ Nadav Amit
2024-04-18 19:44 ` Mike Rapoport
2024-04-11 16:05 ` [RFC PATCH 4/7] ftrace: Add swap_func to ftrace_process_locs() Mike Rapoport
2024-04-11 16:05 ` [RFC PATCH 5/7] x86/module: perpare module loading for ROX allocations of text Mike Rapoport
2024-04-12 9:08 ` Ingo Molnar
2024-04-14 7:35 ` Mike Rapoport
2024-04-15 10:43 ` Peter Zijlstra
2024-04-15 17:04 ` Mike Rapoport
2024-04-11 16:05 ` [RFC PATCH 6/7] execmem: add support for cache of large ROX pages Mike Rapoport
2024-04-15 10:47 ` Peter Zijlstra
2024-04-15 17:00 ` Mike Rapoport
2024-04-16 7:52 ` Peter Zijlstra
2024-04-18 10:23 ` Mike Rapoport
2024-04-11 16:05 ` [RFC PATCH 7/7] x86/module: enable ROX caches for module text Mike Rapoport
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=ZiDz4YbIHEOAnpwF@kernel.org \
--to=rppt@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=arnd@arndb.de \
--cc=bpf@vger.kernel.org \
--cc=catalin.marinas@arm.com \
--cc=deller@gmx.de \
--cc=hch@infradead.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-modules@vger.kernel.org \
--cc=linux-parisc@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=lstoakes@gmail.com \
--cc=luto@kernel.org \
--cc=mark.rutland@arm.com \
--cc=mathieu.desnoyers@efficios.com \
--cc=mcgrof@kernel.org \
--cc=mhiramat@kernel.org \
--cc=mpe@ellerman.id.au \
--cc=nadav.amit@gmail.com \
--cc=palmer@dabbelt.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=song@kernel.org \
--cc=tglx@linutronix.de \
--cc=urezki@gmail.com \
--cc=will@kernel.org \
--cc=x86@kernel.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: 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).