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x86/ftrace: enable dynamic ftrace without CONFIG_MODULES

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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>
This commit is contained in:
Mike Rapoport (IBM) 2024-05-05 19:06:25 +03:00 committed by Luis Chamberlain
parent 0cc2dc4902
commit 14e56fb2ed
2 changed files with 1 additions and 10 deletions
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1
arch/x86/Kconfig
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@ -34,6 +34,7 @@ config X86_64
select SWIOTLB select SWIOTLB
select ARCH_HAS_ELFCORE_COMPAT select ARCH_HAS_ELFCORE_COMPAT
select ZONE_DMA32 select ZONE_DMA32
select EXECMEM if DYNAMIC_FTRACE
config FORCE_DYNAMIC_FTRACE config FORCE_DYNAMIC_FTRACE
def_bool y def_bool y

10
arch/x86/kernel/ftrace.c
View File

@ -261,8 +261,6 @@ void arch_ftrace_update_code(int command)
/* Currently only x86_64 supports dynamic trampolines */ /* Currently only x86_64 supports dynamic trampolines */
#ifdef CONFIG_X86_64 #ifdef CONFIG_X86_64
#ifdef CONFIG_MODULES
/* Module allocation simplifies allocating memory for code */
static inline void *alloc_tramp(unsigned long size) static inline void *alloc_tramp(unsigned long size)
{ {
return execmem_alloc(EXECMEM_FTRACE, size); return execmem_alloc(EXECMEM_FTRACE, size);
@ -271,14 +269,6 @@ static inline void tramp_free(void *tramp)
{ {
execmem_free(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 */ /* Defined as markers to the end of the ftrace default trampolines */
extern void ftrace_regs_caller_end(void); extern void ftrace_regs_caller_end(void);