lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <ZiOea81saMutayxt@kernel.org>
Date: Sat, 20 Apr 2024 13:52:27 +0300
From: Mike Rapoport <rppt@...nel.org>
To: Masami Hiramatsu <mhiramat@...nel.org>
Cc: Christophe Leroy <christophe.leroy@...roup.eu>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Alexandre Ghiti <alexghiti@...osinc.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Björn Töpel <bjorn@...nel.org>,
	Catalin Marinas <catalin.marinas@....com>,
	"David S. Miller" <davem@...emloft.net>,
	Dinh Nguyen <dinguyen@...nel.org>,
	Donald Dutile <ddutile@...hat.com>,
	Eric Chanudet <echanude@...hat.com>,
	Heiko Carstens <hca@...ux.ibm.com>, Helge Deller <deller@....de>,
	Huacai Chen <chenhuacai@...nel.org>,
	Kent Overstreet <kent.overstreet@...ux.dev>,
	Luis Chamberlain <mcgrof@...nel.org>,
	Mark Rutland <mark.rutland@....com>,
	Michael Ellerman <mpe@...erman.id.au>,
	Nadav Amit <nadav.amit@...il.com>,
	Palmer Dabbelt <palmer@...belt.com>,
	Puranjay Mohan <puranjay12@...il.com>,
	Rick Edgecombe <rick.p.edgecombe@...el.com>,
	Russell King <linux@...linux.org.uk>, Song Liu <song@...nel.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
	Thomas Gleixner <tglx@...utronix.de>, Will Deacon <will@...nel.org>,
	"bpf@...r.kernel.org" <bpf@...r.kernel.org>,
	"linux-arch@...r.kernel.org" <linux-arch@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" <linux-arm-kernel@...ts.infradead.org>,
	"linux-mips@...r.kernel.org" <linux-mips@...r.kernel.org>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	"linux-modules@...r.kernel.org" <linux-modules@...r.kernel.org>,
	"linux-parisc@...r.kernel.org" <linux-parisc@...r.kernel.org>,
	"linux-riscv@...ts.infradead.org" <linux-riscv@...ts.infradead.org>,
	"linux-s390@...r.kernel.org" <linux-s390@...r.kernel.org>,
	"linux-trace-kernel@...r.kernel.org" <linux-trace-kernel@...r.kernel.org>,
	"linuxppc-dev@...ts.ozlabs.org" <linuxppc-dev@...ts.ozlabs.org>,
	"loongarch@...ts.linux.dev" <loongarch@...ts.linux.dev>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"sparclinux@...r.kernel.org" <sparclinux@...r.kernel.org>,
	"x86@...nel.org" <x86@...nel.org>
Subject: Re: [PATCH v4 14/15] kprobes: remove dependency on CONFIG_MODULES

On Sat, Apr 20, 2024 at 06:15:00PM +0900, Masami Hiramatsu wrote:
> On Sat, 20 Apr 2024 10:33:38 +0300
> Mike Rapoport <rppt@...nel.org> wrote:
> 
> > On Fri, Apr 19, 2024 at 03:59:40PM +0000, Christophe Leroy wrote:
> > > 
> > > 
> > > Le 19/04/2024 à 17:49, Mike Rapoport a écrit :
> > > > Hi Masami,
> > > > 
> > > > On Thu, Apr 18, 2024 at 06:16:15AM +0900, Masami Hiramatsu wrote:
> > > >> Hi Mike,
> > > >>
> > > >> On Thu, 11 Apr 2024 19:00:50 +0300
> > > >> Mike Rapoport <rppt@...nel.org> wrote:
> > > >>
> > > >>> From: "Mike Rapoport (IBM)" <rppt@...nel.org>
> > > >>>
> > > >>> kprobes depended on CONFIG_MODULES because it has to allocate memory for
> > > >>> code.
> > > >>>
> > > >>> Since code allocations are now implemented with execmem, kprobes can be
> > > >>> enabled in non-modular kernels.
> > > >>>
> > > >>> Add #ifdef CONFIG_MODULE guards for the code dealing with kprobes inside
> > > >>> modules, make CONFIG_KPROBES select CONFIG_EXECMEM and drop the
> > > >>> dependency of CONFIG_KPROBES on CONFIG_MODULES.
> > > >>
> > > >> Thanks for this work, but this conflicts with the latest fix in v6.9-rc4.
> > > >> Also, can you use IS_ENABLED(CONFIG_MODULES) instead of #ifdefs in
> > > >> function body? We have enough dummy functions for that, so it should
> > > >> not make a problem.
> > > > 
> > > > The code in check_kprobe_address_safe() that gets the module and checks for
> > > > __init functions does not compile with IS_ENABLED(CONFIG_MODULES).
> > > > I can pull it out to a helper or leave #ifdef in the function body,
> > > > whichever you prefer.
> > > 
> > > As far as I can see, the only problem is MODULE_STATE_COMING.
> > > Can we move 'enum module_state' out of #ifdef CONFIG_MODULES in module.h  ?
> > 
> > There's dereference of 'struct module' there:
> >  
> > 		(*probed_mod)->state != MODULE_STATE_COMING) {
> > 			...
> > 		}
> > 
> > so moving out 'enum module_state' won't be enough.
> 
> Hmm, this part should be inline functions like;
> 
> #ifdef CONFIG_MODULES
> static inline bool module_is_coming(struct module *mod)
> {
> 	return mod->state == MODULE_STATE_COMING;
> }
> #else
> #define module_is_coming(mod) (false)

I'd prefer

static inline module_is_coming(struct module *mod)
{
	return false;
}

> #endif
>
> Then we don't need the enum.
> Thank you,
> 
> -- 
> Masami Hiramatsu (Google) <mhiramat@...nel.org>

-- 
Sincerely yours,
Mike.

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ