From 14e56fb2ed1dbc3c3171d12ab435b0f691f6f215 Mon Sep 17 00:00:00 2001
From: "Mike Rapoport (IBM)" <rppt@kernel.org>
Date: Sun, 5 May 2024 19:06:25 +0300
Subject: [PATCH] x86/ftrace: enable dynamic ftrace without CONFIG_MODULES
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>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Luis Chamberlain <mcgrof@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 fe196f49d2782..965d65edbae04 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 c8ddb7abda7cf..8da0e66ca22de 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);
--
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