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@xxxxxxxxxx>
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@xxxxxxxxxx
Signed-off-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Cc: Björn Töpel <bjorn@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Dinh Nguyen <dinguyen@xxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: Huacai Chen <chenhuacai@xxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Nadav Amit <nadav.amit@xxxxxxxxx>
Cc: "Naveen N. Rao" <naveen.n.rao@xxxxxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Puranjay Mohan <puranjay12@xxxxxxxxx>
Cc: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
Cc: Russell King (Oracle) <linux@xxxxxxxxxxxxxxx>
Cc: Song Liu <song@xxxxxxxxxx>
Cc: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxx 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
