da <masahi...@kernel.org>, Jarkko Sakkinen <jar...@profian.com>, Sami Tolvanen <samitolva...@google.com>, "Naveen N. Rao" <naveen.n....@linux.ibm.com>, Marco Elver <el...@google.com>, Kees Cook <keesc...@chromium.org>, Steven Rostedt <rost...@goodmis.org>, Nathan Chancellor <nat...@kernel.org>, "Russell King \(Oracle\)" <rmk+ker...@armlinux.org.uk>, Mark Brown <broo...@kernel.org>, Borislav Petkov <b...@alien8.de>, Alexander Egorenkov <egore...@linux.ibm.com>, Thomas Bogendoerfer <tsbog...@alpha.franken.de>, Parisc List <linux-par...@vger.kernel.org>, Nathaniel McCallum <nathan...@profian.com>, Dmitry Torokhov <dmitry.torok...@gmail.com>, "David S. Miller" <da...@davemloft.net>, "Kirill A. Shutemov" <kirill.shute...@linux.intel.com>, Tobias Huschle <husc...@linux.ibm.com>, "Peter Zijlstra \(Intel\)" <pet...@infradead.org>, "H. Peter Anvin" <h...@zytor.com>, sparclinux <sparcli...@vger.kernel.org>, Tiezhu Yang <yangtie...@loongson.cn>, Miroslav Benes <mbe...@suse.cz>, Chen Zhongjin <chen zhong...@huawei.com>, Ard Biesheuvel <a...@kernel.org>, the arch/x86 maintainers <x...@kernel.org>, Russell King <li...@armlinux.org.uk>, linux-riscv <linux-ri...@lists.infradead.org>, Ingo Molnar <mi...@redhat.com>, Aaron Tomlin <atom...@redhat.com>, Albert Ou <a...@eecs.berkeley.edu>, Heiko Carstens <h...@linux.ibm.com>, Liao Chang <liaocha...@huawei.com>, Paul Walmsley <paul.walms...@sifive.com>, Josh Poimboeuf <jpoim...@kernel.org>, Thomas Richter <tmri...@linux.ibm.com>, "open list:BROADCOM NVRAM DRIVER" <linux-m...@vger.kernel.org>, Changbin Du <changbin...@intel.com>, Palmer Dabbelt <pal...@dabbelt.com>, linuxppc-dev <linuxppc-dev@lists.ozlabs.org>, linux-modu...@vger.kernel.org Errors-To: linuxppc-dev-bounces+archive=mail-archive....@lists.ozlabs.org Sender: "Linuxppc-dev" <linuxppc-dev-bounces+archive=mail-archive....@lists.ozlabs.org>
On Wed, Jun 08, 2022 at 10:35:42AM +0800, Guo Ren wrote: > . > > On Wed, Jun 8, 2022 at 8:02 AM Jarkko Sakkinen <jar...@profian.com> wrote: > > > > Tracing with kprobes while running a monolithic kernel is currently > > impossible because CONFIG_KPROBES is dependent of CONFIG_MODULES. This > > dependency is a result of kprobes code using the module allocator for the > > trampoline code. > > > > Detaching kprobes from modules helps to squeeze down the user space, > > e.g. when developing new core kernel features, while still having all > > the nice tracing capabilities. > > > > For kernel/ and arch/*, move module_alloc() and module_memfree() to > > module_alloc.c, and compile as part of vmlinux when either CONFIG_MODULES > > or CONFIG_KPROBES is enabled. In addition, flag kernel module specific > > code with CONFIG_MODULES. > > > > As the result, kprobes can be used with a monolithic kernel. > It's strange when MODULES is n, but vmlinux still obtains module_alloc. > > Maybe we need a kprobe_alloc, right? Perhaps not the best name but at least it documents the fact that they use the same allocator. Few years ago I carved up something "half-way there" for kprobes, and I used the name text_alloc() [*]. [*] https://lore.kernel.org/all/20200724050553.1724168-1-jarkko.sakki...@linux.intel.com/ BR, Jarkko
