[PATCH v5.4] powerpc/ftrace: Remove ftrace init tramp once kernel init is complete
From: Naveen N. Rao <hidden>
Date: 2022-06-27 17:40:10
Also in:
stable
Subsystem:
function hooks (ftrace), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Steven Rostedt, Masami Hiramatsu, Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
commit 84ade0a6655bee803d176525ef457175cbf4df22 upstream.
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 <redacted>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220516071422.463738-1-naveen.n.rao@linux.vnet.ibm.com (local)
---
arch/powerpc/include/asm/ftrace.h | 5 ++++-
arch/powerpc/kernel/trace/ftrace.c | 15 ++++++++++++---
arch/powerpc/mm/mem.c | 2 ++
3 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h
index f54a08a2cd7092..017336f2b0864a 100644
--- a/arch/powerpc/include/asm/ftrace.h
+++ b/arch/powerpc/include/asm/ftrace.h@@ -96,7 +96,7 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name #endif /* 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)
@@ -108,9 +108,12 @@ static inline void this_cpu_enable_ftrace(void) { get_paca()->ftrace_enabled = 1; } + +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 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 7ea0ca044b6500..d816e714f2f489 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c@@ -328,9 +328,7 @@ 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? */
@@ -868,6 +866,17 @@ 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 c48705c726ac6d..d427f70556eab5 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c@@ -48,6 +48,7 @@ #include <asm/fixmap.h> #include <asm/swiotlb.h> #include <asm/rtas.h> +#include <asm/ftrace.h> #include <mm/mmu_decl.h>
@@ -346,6 +347,7 @@ void free_initmem(void) mark_initmem_nx(); init_mem_is_free = true; free_initmem_default(POISON_FREE_INITMEM); + ftrace_free_init_tramp(); } /**
base-commit: 23db944f754e99abf814a79a2273b0191d35e4ff -- 2.36.1