Re: [PATCH v2 11/12] x86/ftrace: enable dynamic ftrace without CONFIG_MODULES
From: Song Liu <song@kernel.org>
Date: 2023-06-16 20:19:08
Also in:
bpf, linux-arm-kernel, linux-mips, linux-mm, linux-modules, linux-riscv, linux-s390, linuxppc-dev, lkml, loongarch, netdev, sparclinux
On Fri, Jun 16, 2023 at 1:52 AM Mike Rapoport [off-list ref] wrote:
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>
Acked-by: Song Liu <song@kernel.org>
quoted hunk ↗ jump to hunk
--- 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 53bab123a8ee..ab64bbef9e50 100644 --- a/arch/x86/Kconfig +++ b/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 ydiff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index f77c63bb3203..a824a5d3b129 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_text_alloc(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); --2.35.1