The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 84ade0a6655bee803d176525ef457175cbf4df22 Mon Sep 17 00:00:00 2001 From: "Naveen N. Rao" naveen.n.rao@linux.vnet.ibm.com Date: Mon, 16 May 2022 12:44:22 +0530 Subject: [PATCH] powerpc/ftrace: Remove ftrace init tramp once kernel init is complete
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 Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20220516071422.463738-1-naveen.n.rao@linux.vnet.ib...
diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h index b56166b7ea68..3cee7115441b 100644 --- a/arch/powerpc/include/asm/ftrace.h +++ b/arch/powerpc/include/asm/ftrace.h @@ -86,7 +86,7 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name #endif /* CONFIG_PPC64_ELF_ABI_V1 */ #endif /* CONFIG_FTRACE_SYSCALLS */
-#ifdef CONFIG_PPC64 +#if defined(CONFIG_PPC64) && defined(CONFIG_FUNCTION_TRACER) #include <asm/paca.h>
static inline void this_cpu_disable_ftrace(void) @@ -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 2807136a1c19..2a893e06e4f1 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -257,9 +257,7 @@ 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;
/* New trampoline -- read where this goes */ @@ -710,6 +708,17 @@ 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 177fae5ea0d1..09b7b5e7bb9a 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 <asm/code-patching.h>
#include <mm/mmu_decl.h> @@ -314,6 +315,7 @@ void free_initmem(void) mark_initmem_nx(); static_branch_enable(&init_mem_is_free); free_initmem_default(POISON_FREE_INITMEM); + ftrace_free_init_tramp(); }
/*