Message ID | 20220323171834.42637-1-naveen.n.rao@linux.vnet.ibm.com (mailing list archive) |
---|---|
State | Changes Requested |
Headers | show |
Series | powerpc/ftrace: Remove ftrace init tramp once kernel init is complete | expand |
"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> writes: > Stop using the ftrace trampoline for init section once kernel init is > complete. > > Fixes: 67361cf8071286 ("powerpc/ftrace: Handle large kernel configs") > Cc: stable@vger.kernel.org # v4.20+ > Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> > --- > arch/powerpc/include/asm/ftrace.h | 2 ++ > arch/powerpc/kernel/trace/ftrace.c | 15 ++++++++++++--- > arch/powerpc/mm/mem.c | 2 ++ > 3 files changed, 16 insertions(+), 3 deletions(-) This breaks the corenet64_smp_defconfig build: ld: arch/powerpc/mm/mem.o: in function `.free_initmem': (.text+0x130): undefined reference to `.ftrace_free_init_tramp' make[1]: *** [/home/michael/linux/Makefile:1158: vmlinux] Error 1 make: *** [Makefile:219: __sub-make] Error 2 > diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h > index d83758acd1c7c3..d329f4ad18944d 100644 > --- a/arch/powerpc/include/asm/ftrace.h > +++ b/arch/powerpc/include/asm/ftrace.h > @@ -110,11 +110,13 @@ static inline u8 this_cpu_get_ftrace_enabled(void) > return get_paca()->ftrace_enabled; > } > > +void ftrace_free_init_tramp(void); > #else /* CONFIG_PPC64 */ > static inline void this_cpu_disable_ftrace(void) { } > static inline void this_cpu_enable_ftrace(void) { } > static inline void this_cpu_set_ftrace_enabled(u8 ftrace_enabled) { } > static inline u8 this_cpu_get_ftrace_enabled(void) { return 1; } > +static inline void ftrace_free_init_tramp(void) { } > #endif /* CONFIG_PPC64 */ I think because we need that stub to be defined. But this config does have PPC64=y but *doesn't* have DYNAMIC_FTRACE or FTRACE_SYSCALLS or FUNCTION_GRAPH_TRACER enabled. cheers
diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h index d83758acd1c7c3..d329f4ad18944d 100644 --- a/arch/powerpc/include/asm/ftrace.h +++ b/arch/powerpc/include/asm/ftrace.h @@ -110,11 +110,13 @@ static inline u8 this_cpu_get_ftrace_enabled(void) return get_paca()->ftrace_enabled; } +void ftrace_free_init_tramp(void); #else /* CONFIG_PPC64 */ static inline void this_cpu_disable_ftrace(void) { } static inline void this_cpu_enable_ftrace(void) { } static inline void this_cpu_set_ftrace_enabled(u8 ftrace_enabled) { } static inline u8 this_cpu_get_ftrace_enabled(void) { return 1; } +static inline void ftrace_free_init_tramp(void) { } #endif /* CONFIG_PPC64 */ #endif /* !__ASSEMBLY__ */ diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index 4ee04aacf9f13c..a778f2ae1f3f50 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -306,9 +306,7 @@ static int setup_mcount_compiler_tramp(unsigned long tramp) /* Is this a known long jump tramp? */ for (i = 0; i < NUM_FTRACE_TRAMPS; i++) - if (!ftrace_tramps[i]) - break; - else if (ftrace_tramps[i] == tramp) + if (ftrace_tramps[i] == tramp) return 0; /* Is this a known plt tramp? */ @@ -863,6 +861,17 @@ void arch_ftrace_update_code(int command) extern unsigned int ftrace_tramp_text[], ftrace_tramp_init[]; +void ftrace_free_init_tramp(void) +{ + int i; + + for (i = 0; i < NUM_FTRACE_TRAMPS && ftrace_tramps[i]; i++) + if (ftrace_tramps[i] == (unsigned long)ftrace_tramp_init) { + ftrace_tramps[i] = 0; + return; + } +} + int __init ftrace_dyn_arch_init(void) { int i; diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 8e301cd8925b2b..78aafd644b777c 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -22,6 +22,7 @@ #include <asm/kasan.h> #include <asm/svm.h> #include <asm/mmzone.h> +#include <asm/ftrace.h> #include <mm/mmu_decl.h> @@ -312,6 +313,7 @@ void free_initmem(void) ppc_md.progress = ppc_printk_progress; mark_initmem_nx(); free_initmem_default(POISON_FREE_INITMEM); + ftrace_free_init_tramp(); } /*
Stop using the ftrace trampoline for init section once kernel init is complete. Fixes: 67361cf8071286 ("powerpc/ftrace: Handle large kernel configs") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> --- arch/powerpc/include/asm/ftrace.h | 2 ++ arch/powerpc/kernel/trace/ftrace.c | 15 ++++++++++++--- arch/powerpc/mm/mem.c | 2 ++ 3 files changed, 16 insertions(+), 3 deletions(-) base-commit: e8833c5edc5903f8c8c4fa3dd4f34d6b813c87c8