+ x86-ftrace-enable-dynamic-ftrace-without-config_modules.patch added to mm-unstable branch

+ x86-ftrace-enable-dynamic-ftrace-without-config_modules.patch added to mm-unstable branch

[Andrew Morton]

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The patch titled
     Subject: x86/ftrace: enable dynamic ftrace without CONFIG_MODULES
has been added to the -mm mm-unstable branch.  Its filename is
     x86-ftrace-enable-dynamic-ftrace-without-config_modules.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/x86-ftrace-enable-dynamic-ftrace-without-config_modules.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: "Mike Rapoport (IBM)" <rppt@kernel.org>
Subject: x86/ftrace: enable dynamic ftrace without CONFIG_MODULES
Date: Mon, 18 Sep 2023 10:29:53 +0300

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.

Link: https://lkml.kernel.org/r/20230918072955.2507221-12-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Björn Töpel <bjorn@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Puranjay Mohan <puranjay12@gmail.com>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Russell King (Oracle) <linux@armlinux.org.uk>
Cc: Song Liu <song@kernel.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/x86/Kconfig         |    1 +
 arch/x86/kernel/ftrace.c |   10 ----------
 2 files changed, 1 insertion(+), 10 deletions(-)

--- a/arch/x86/Kconfig~x86-ftrace-enable-dynamic-ftrace-without-config_modules
+++ a/arch/x86/Kconfig
@@ -35,6 +35,7 @@ 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
--- a/arch/x86/kernel/ftrace.c~x86-ftrace-enable-dynamic-ftrace-without-config_modules
+++ a/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_text_alloc(EXECMEM_FTRACE, size);
@@ -271,14 +269,6 @@ static inline void tramp_free(void *tram
 {
 	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);
_

Patches currently in -mm which might be from rppt@kernel.org are

nios2-define-virtual-address-space-for-modules.patch
mm-introduce-execmem_text_alloc-and-execmem_free.patch
mm-execmem-arch-convert-simple-overrides-of-module_alloc-to-execmem.patch
mm-execmem-arch-convert-remaining-overrides-of-module_alloc-to-execmem.patch
modules-execmem-drop-module_alloc.patch
mm-execmem-introduce-execmem_data_alloc.patch
arm64-execmem-extend-execmem_params-for-generated-code-allocations.patch
riscv-extend-execmem_params-for-generated-code-allocations.patch
powerpc-extend-execmem_params-for-kprobes-allocations.patch
arch-make-execmem-setup-available-regardless-of-config_modules.patch
x86-ftrace-enable-dynamic-ftrace-without-config_modules.patch
kprobes-remove-dependency-on-config_modules.patch
bpf-remove-config_bpf_jit-dependency-on-config_modules-of.patch