Received-SPF: pass (google.com: domain of linux-kernel+bounces-153026-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1;
From: Mike Rapoport <rppt@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	=?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= <bjorn@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Christophe Leroy <christophe.leroy@csgroup.eu>,
	"David S. Miller" <davem@davemloft.net>,
	Dinh Nguyen <dinguyen@kernel.org>,
	Donald Dutile <ddutile@redhat.com>,
	Eric Chanudet <echanude@redhat.com>,
	Heiko Carstens <hca@linux.ibm.com>,
	Helge Deller <deller@gmx.de>,
	Huacai Chen <chenhuacai@kernel.org>,
	Kent Overstreet <kent.overstreet@linux.dev>,
	Luis Chamberlain <mcgrof@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Mike Rapoport <rppt@kernel.org>,
	Nadav Amit <nadav.amit@gmail.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Rick Edgecombe <rick.p.edgecombe@intel.com>,
	Russell King <linux@armlinux.org.uk>,
	Sam Ravnborg <sam@ravnborg.org>,
	Song Liu <song@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Will Deacon <will@kernel.org>,
	bpf@vger.kernel.org,
	linux-arch@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-mips@vger.kernel.org,
	linux-mm@kvack.org,
	linux-modules@vger.kernel.org,
	linux-parisc@vger.kernel.org,
	linux-riscv@lists.infradead.org,
	linux-s390@vger.kernel.org,
	linux-trace-kernel@vger.kernel.org,
	linuxppc-dev@lists.ozlabs.org,
	loongarch@lists.linux.dev,
	netdev@vger.kernel.org,
	sparclinux@vger.kernel.org,
	x86@kernel.org
Subject: [PATCH v5 12/15] x86/ftrace: enable dynamic ftrace without CONFIG_MODULES
Date: Mon, 22 Apr 2024 11:50:25 +0300
Message-ID: <20240422085028.3602777-3-rppt@kernel.org>
In-Reply-To: <20240422085028.3602777-1-rppt@kernel.org>
References: <20240422085028.3602777-1-rppt@kernel.org>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

From: "Mike Rapoport (IBM)" <rppt@kernel.org>

Dynamic ftrace must allocate memory for code and this was impossible
without CONFIG_MODULES.

With execmem separated from the modules code, execmem_text_alloc() is
available regardless of CONFIG_MODULES.

Remove dependency of dynamic ftrace on CONFIG_MODULES and make
CONFIG_DYNAMIC_FTRACE select CONFIG_EXECMEM in Kconfig.

Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
---
 arch/x86/Kconfig         |  1 +
 arch/x86/kernel/ftrace.c | 10 ----------
 2 files changed, 1 insertion(+), 10 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 3f5ba72c9480..cd8addb96a0b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -34,6 +34,7 @@ config X86_64
 	select SWIOTLB
 	select ARCH_HAS_ELFCORE_COMPAT
 	select ZONE_DMA32
+	select EXECMEM if DYNAMIC_FTRACE
 
 config FORCE_DYNAMIC_FTRACE
 	def_bool y
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index c8ddb7abda7c..8da0e66ca22d 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -261,8 +261,6 @@ void arch_ftrace_update_code(int command)
 /* Currently only x86_64 supports dynamic trampolines */
 #ifdef CONFIG_X86_64
 
-#ifdef CONFIG_MODULES
-/* Module allocation simplifies allocating memory for code */
 static inline void *alloc_tramp(unsigned long size)
 {
 	return execmem_alloc(EXECMEM_FTRACE, size);
@@ -271,14 +269,6 @@ static inline void tramp_free(void *tramp)
 {
 	execmem_free(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
 
 /* Defined as markers to the end of the ftrace default trampolines */
 extern void ftrace_regs_caller_end(void);
-- 
2.43.0