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Date:   Mon, 13 Jul 2020 08:55:03 +0300
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     Steven Rostedt <rostedt@goodmis.org>
Cc:     Masami Hiramatsu <mhiramat@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        linux-kernel@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>,
        "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
        Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
        "David S. Miller" <davem@davemloft.net>,
        Andrew Morton <akpm@linux-foundation.org>,
        "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
        Will Deacon <will@kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Arnd Bergmann <arnd@arndb.de>, Alexandre Ghiti <alex@ghiti.fr>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Sami Tolvanen <samitolvanen@google.com>,
        Peter Collingbourne <pcc@google.com>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        Frederic Weisbecker <frederic@kernel.org>,
        Stephen Boyd <sboyd@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Mike Rapoport <rppt@linux.ibm.com>,
        Sean Christopherson <sean.j.christopherson@intel.com>,
        Jiri Olsa <jolsa@redhat.com>, hch@lst.de
Subject: Re: [PATCH RFC] kprobes: Remove MODULES dependency
Message-ID: <20200713055503.GE956284@linux.intel.com>
References: <20200709234521.194005-1-jarkko.sakkinen@linux.intel.com>
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On Fri, Jul 10, 2020 at 09:22:43AM -0400, Steven Rostedt wrote:
> On Fri, 10 Jul 2020 22:18:02 +0900
> Masami Hiramatsu <mhiramat@kernel.org> wrote:
> 
> > 
> > Agreed. As far as I know, ftrace and bpf also depends on module_alloc(),
> > so text_alloc() will help them too.
> > 
> 
> Yes please.
> 
> arch/x86/kernel/ftrace.c:
> 
> #ifdef CONFIG_MODULES
> #include <linux/moduleloader.h>
> /* Module allocation simplifies allocating memory for code */
> static inline void *alloc_tramp(unsigned long size)
> {
> 	return module_alloc(size);
> }
> static inline void tramp_free(void *tramp)
> {
> 	module_memfree(tramp);
> }
> #else
> /* Trampolines can only be created if modules are supported */
> static inline void *alloc_tramp(unsigned long size)
> {
> 	return NULL;
> }
> static inline void tramp_free(void *tramp) { }
> #endif
> 
> -- Steve

Thanks, note taken. I'll take this into account in the next version.

/Jarkko