[PATCH v4 12/15] x86/ftrace: enable dynamic ftrace without CONFIG_MODULES

From: Mike Rapoport <rppt@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: "Alexandre Ghiti" <alexghiti@rivosinc.com>,
	"Andrew Morton" <akpm@linux-foundation.org>,
	"Björn Töpel" <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>,
	"Michael Ellerman" <mpe@ellerman.id.au>,
	"Mike Rapoport" <rppt@kernel.org>,
	"Nadav Amit" <nadav.amit@gmail.com>,
	"Palmer Dabbelt" <palmer@dabbelt.com>,
	"Puranjay Mohan" <puranjay12@gmail.com>,
	"Rick Edgecombe" <rick.p.edgecombe@intel.com>,
	"Russell King" <linux@armlinux.org.uk>,
	"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 v4 12/15] x86/ftrace: enable dynamic ftrace without CONFIG_MODULES
Date: Thu, 11 Apr 2024 19:00:48 +0300	[thread overview]
Message-ID: <20240411160051.2093261-13-rppt@kernel.org> (raw)
In-Reply-To: <20240411160051.2093261-1-rppt@kernel.org>

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 e87ddbdaaeb2..5100a769ffda 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


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
