Can I get an Acked-by from the S390 maintainers for this patch? Thanks! -- Steve On Fri, 13 Sep 2024 00:08:51 +0900 "Masami Hiramatsu (Google)" <mhiramat@xxxxxxxxxx> wrote: > From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> > > Use ftrace_regs instead of fgraph_ret_regs for tracing return value > on function_graph tracer because of simplifying the callback interface. > > The CONFIG_HAVE_FUNCTION_GRAPH_RETVAL is also replaced by > CONFIG_HAVE_FUNCTION_GRAPH_FREGS. > > Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> > --- > Changes in v8: > - Newly added. > --- > arch/arm64/Kconfig | 1 + > arch/arm64/include/asm/ftrace.h | 23 ++++++----------------- > arch/arm64/kernel/asm-offsets.c | 12 ------------ > arch/arm64/kernel/entry-ftrace.S | 32 ++++++++++++++++++-------------- > arch/loongarch/Kconfig | 2 +- > arch/loongarch/include/asm/ftrace.h | 24 ++---------------------- > arch/loongarch/kernel/asm-offsets.c | 12 ------------ > arch/loongarch/kernel/mcount.S | 17 ++++++++++------- > arch/loongarch/kernel/mcount_dyn.S | 14 +++++++------- > arch/riscv/Kconfig | 2 +- > arch/riscv/include/asm/ftrace.h | 26 +++++--------------------- > arch/riscv/kernel/mcount.S | 24 +++++++++++++----------- > arch/s390/Kconfig | 2 +- > arch/s390/include/asm/ftrace.h | 26 +++++++++----------------- > arch/s390/kernel/asm-offsets.c | 6 ------ > arch/s390/kernel/mcount.S | 9 +++++---- > arch/x86/Kconfig | 2 +- > arch/x86/include/asm/ftrace.h | 22 ++-------------------- > arch/x86/kernel/ftrace_32.S | 15 +++++++++------ > arch/x86/kernel/ftrace_64.S | 17 +++++++++-------- > include/linux/ftrace.h | 14 +++++++++++--- > kernel/trace/Kconfig | 4 ++-- > kernel/trace/fgraph.c | 21 +++++++++------------ > 23 files changed, 122 insertions(+), 205 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index a2f8ff354ca6..17947f625b06 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -211,6 +211,7 @@ config ARM64 > select HAVE_FTRACE_MCOUNT_RECORD > select HAVE_FUNCTION_TRACER > select HAVE_FUNCTION_ERROR_INJECTION > + select HAVE_FUNCTION_GRAPH_FREGS > select HAVE_FUNCTION_GRAPH_TRACER > select HAVE_FUNCTION_GRAPH_RETVAL > select HAVE_GCC_PLUGINS > diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h > index dc9cf0bd2a4c..dffaab3dd1f1 100644 > --- a/arch/arm64/include/asm/ftrace.h > +++ b/arch/arm64/include/asm/ftrace.h > @@ -126,6 +126,12 @@ ftrace_override_function_with_return(struct ftrace_regs *fregs) > fregs->pc = fregs->lr; > } > > +static __always_inline unsigned long > +ftrace_regs_get_frame_pointer(const struct ftrace_regs *fregs) > +{ > + return fregs->fp; > +} > + > int ftrace_regs_query_register_offset(const char *name); > > int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); > @@ -183,23 +189,6 @@ static inline bool arch_syscall_match_sym_name(const char *sym, > > #ifndef __ASSEMBLY__ > #ifdef CONFIG_FUNCTION_GRAPH_TRACER > -struct fgraph_ret_regs { > - /* x0 - x7 */ > - unsigned long regs[8]; > - > - unsigned long fp; > - unsigned long __unused; > -}; > - > -static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs) > -{ > - return ret_regs->regs[0]; > -} > - > -static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs) > -{ > - return ret_regs->fp; > -} > > void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent, > unsigned long frame_pointer); > diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c > index 27de1dddb0ab..9e03c9a7e5c3 100644 > --- a/arch/arm64/kernel/asm-offsets.c > +++ b/arch/arm64/kernel/asm-offsets.c > @@ -201,18 +201,6 @@ int main(void) > DEFINE(FTRACE_OPS_FUNC, offsetof(struct ftrace_ops, func)); > #endif > BLANK(); > -#ifdef CONFIG_FUNCTION_GRAPH_TRACER > - DEFINE(FGRET_REGS_X0, offsetof(struct fgraph_ret_regs, regs[0])); > - DEFINE(FGRET_REGS_X1, offsetof(struct fgraph_ret_regs, regs[1])); > - DEFINE(FGRET_REGS_X2, offsetof(struct fgraph_ret_regs, regs[2])); > - DEFINE(FGRET_REGS_X3, offsetof(struct fgraph_ret_regs, regs[3])); > - DEFINE(FGRET_REGS_X4, offsetof(struct fgraph_ret_regs, regs[4])); > - DEFINE(FGRET_REGS_X5, offsetof(struct fgraph_ret_regs, regs[5])); > - DEFINE(FGRET_REGS_X6, offsetof(struct fgraph_ret_regs, regs[6])); > - DEFINE(FGRET_REGS_X7, offsetof(struct fgraph_ret_regs, regs[7])); > - DEFINE(FGRET_REGS_FP, offsetof(struct fgraph_ret_regs, fp)); > - DEFINE(FGRET_REGS_SIZE, sizeof(struct fgraph_ret_regs)); > -#endif > #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS > DEFINE(FTRACE_OPS_DIRECT_CALL, offsetof(struct ftrace_ops, direct_call)); > #endif > diff --git a/arch/arm64/kernel/entry-ftrace.S b/arch/arm64/kernel/entry-ftrace.S > index f0c16640ef21..169ccf600066 100644 > --- a/arch/arm64/kernel/entry-ftrace.S > +++ b/arch/arm64/kernel/entry-ftrace.S > @@ -329,24 +329,28 @@ SYM_FUNC_END(ftrace_stub_graph) > * @fp is checked against the value passed by ftrace_graph_caller(). > */ > SYM_CODE_START(return_to_handler) > - /* save return value regs */ > - sub sp, sp, #FGRET_REGS_SIZE > - stp x0, x1, [sp, #FGRET_REGS_X0] > - stp x2, x3, [sp, #FGRET_REGS_X2] > - stp x4, x5, [sp, #FGRET_REGS_X4] > - stp x6, x7, [sp, #FGRET_REGS_X6] > - str x29, [sp, #FGRET_REGS_FP] // parent's fp > + /* Make room for ftrace_regs */ > + sub sp, sp, #FREGS_SIZE > + > + /* Save return value regs */ > + stp x0, x1, [sp, #FREGS_X0] > + stp x2, x3, [sp, #FREGS_X2] > + stp x4, x5, [sp, #FREGS_X4] > + stp x6, x7, [sp, #FREGS_X6] > + > + /* Save the callsite's FP */ > + str x29, [sp, #FREGS_FP] > > mov x0, sp > - bl ftrace_return_to_handler // addr = ftrace_return_to_hander(regs); > + bl ftrace_return_to_handler // addr = ftrace_return_to_hander(fregs); > mov x30, x0 // restore the original return address > > - /* restore return value regs */ > - ldp x0, x1, [sp, #FGRET_REGS_X0] > - ldp x2, x3, [sp, #FGRET_REGS_X2] > - ldp x4, x5, [sp, #FGRET_REGS_X4] > - ldp x6, x7, [sp, #FGRET_REGS_X6] > - add sp, sp, #FGRET_REGS_SIZE > + /* Restore return value regs */ > + ldp x0, x1, [sp, #FREGS_X0] > + ldp x2, x3, [sp, #FREGS_X2] > + ldp x4, x5, [sp, #FREGS_X4] > + ldp x6, x7, [sp, #FREGS_X6] > + add sp, sp, #FREGS_SIZE > > ret > SYM_CODE_END(return_to_handler) > diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig > index 70f169210b52..974f08f65f63 100644 > --- a/arch/loongarch/Kconfig > +++ b/arch/loongarch/Kconfig > @@ -131,7 +131,7 @@ config LOONGARCH > select HAVE_FTRACE_MCOUNT_RECORD > select HAVE_FUNCTION_ARG_ACCESS_API > select HAVE_FUNCTION_ERROR_INJECTION > - select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER > + select HAVE_FUNCTION_GRAPH_FREGS > select HAVE_FUNCTION_GRAPH_TRACER > select HAVE_FUNCTION_TRACER > select HAVE_GCC_PLUGINS > diff --git a/arch/loongarch/include/asm/ftrace.h b/arch/loongarch/include/asm/ftrace.h > index 6f8517d59954..1a73f35ea9af 100644 > --- a/arch/loongarch/include/asm/ftrace.h > +++ b/arch/loongarch/include/asm/ftrace.h > @@ -77,6 +77,8 @@ ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs, unsigned long ip) > override_function_with_return(&(fregs)->regs) > #define ftrace_regs_query_register_offset(name) \ > regs_query_register_offset(name) > +#define ftrace_regs_get_frame_pointer(fregs) \ > + ((fregs)->regs.regs[22]) > > #define ftrace_graph_func ftrace_graph_func > void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, > @@ -99,26 +101,4 @@ __arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr) > > #endif /* CONFIG_FUNCTION_TRACER */ > > -#ifndef __ASSEMBLY__ > -#ifdef CONFIG_FUNCTION_GRAPH_TRACER > -struct fgraph_ret_regs { > - /* a0 - a1 */ > - unsigned long regs[2]; > - > - unsigned long fp; > - unsigned long __unused; > -}; > - > -static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs) > -{ > - return ret_regs->regs[0]; > -} > - > -static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs) > -{ > - return ret_regs->fp; > -} > -#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */ > -#endif > - > #endif /* _ASM_LOONGARCH_FTRACE_H */ > diff --git a/arch/loongarch/kernel/asm-offsets.c b/arch/loongarch/kernel/asm-offsets.c > index bee9f7a3108f..714f5b5f1956 100644 > --- a/arch/loongarch/kernel/asm-offsets.c > +++ b/arch/loongarch/kernel/asm-offsets.c > @@ -279,18 +279,6 @@ static void __used output_pbe_defines(void) > } > #endif > > -#ifdef CONFIG_FUNCTION_GRAPH_TRACER > -static void __used output_fgraph_ret_regs_defines(void) > -{ > - COMMENT("LoongArch fgraph_ret_regs offsets."); > - OFFSET(FGRET_REGS_A0, fgraph_ret_regs, regs[0]); > - OFFSET(FGRET_REGS_A1, fgraph_ret_regs, regs[1]); > - OFFSET(FGRET_REGS_FP, fgraph_ret_regs, fp); > - DEFINE(FGRET_REGS_SIZE, sizeof(struct fgraph_ret_regs)); > - BLANK(); > -} > -#endif > - > static void __used output_kvm_defines(void) > { > COMMENT("KVM/LoongArch Specific offsets."); > diff --git a/arch/loongarch/kernel/mcount.S b/arch/loongarch/kernel/mcount.S > index 3015896016a0..b6850503e061 100644 > --- a/arch/loongarch/kernel/mcount.S > +++ b/arch/loongarch/kernel/mcount.S > @@ -79,10 +79,11 @@ SYM_FUNC_START(ftrace_graph_caller) > SYM_FUNC_END(ftrace_graph_caller) > > SYM_FUNC_START(return_to_handler) > - PTR_ADDI sp, sp, -FGRET_REGS_SIZE > - PTR_S a0, sp, FGRET_REGS_A0 > - PTR_S a1, sp, FGRET_REGS_A1 > - PTR_S zero, sp, FGRET_REGS_FP > + /* Save return value regs */ > + PTR_ADDI sp, sp, -PT_SIZE > + PTR_S a0, sp, PT_R4 > + PTR_S a1, sp, PT_R5 > + PTR_S zero, sp, PT_R22 > > move a0, sp > bl ftrace_return_to_handler > @@ -90,9 +91,11 @@ SYM_FUNC_START(return_to_handler) > /* Restore the real parent address: a0 -> ra */ > move ra, a0 > > - PTR_L a0, sp, FGRET_REGS_A0 > - PTR_L a1, sp, FGRET_REGS_A1 > - PTR_ADDI sp, sp, FGRET_REGS_SIZE > + /* Restore return value regs */ > + PTR_L a0, sp, PT_R4 > + PTR_L a1, sp, PT_R5 > + PTR_ADDI sp, sp, PT_SIZE > + > jr ra > SYM_FUNC_END(return_to_handler) > #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ > diff --git a/arch/loongarch/kernel/mcount_dyn.S b/arch/loongarch/kernel/mcount_dyn.S > index 0c65cf09110c..d6b474ad1d5e 100644 > --- a/arch/loongarch/kernel/mcount_dyn.S > +++ b/arch/loongarch/kernel/mcount_dyn.S > @@ -140,19 +140,19 @@ SYM_CODE_END(ftrace_graph_caller) > SYM_CODE_START(return_to_handler) > UNWIND_HINT_UNDEFINED > /* Save return value regs */ > - PTR_ADDI sp, sp, -FGRET_REGS_SIZE > - PTR_S a0, sp, FGRET_REGS_A0 > - PTR_S a1, sp, FGRET_REGS_A1 > - PTR_S zero, sp, FGRET_REGS_FP > + PTR_ADDI sp, sp, -PT_SIZE > + PTR_S a0, sp, PT_R4 > + PTR_S a1, sp, PT_R5 > + PTR_S zero, sp, PT_R22 > > move a0, sp > bl ftrace_return_to_handler > move ra, a0 > > /* Restore return value regs */ > - PTR_L a0, sp, FGRET_REGS_A0 > - PTR_L a1, sp, FGRET_REGS_A1 > - PTR_ADDI sp, sp, FGRET_REGS_SIZE > + PTR_L a0, sp, PT_R4 > + PTR_L a1, sp, PT_R5 > + PTR_ADDI sp, sp, PT_SIZE > > jr ra > SYM_CODE_END(return_to_handler) > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 0f3cd7c3a436..6e8422269ba4 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -140,7 +140,7 @@ config RISCV > select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE > select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL > select HAVE_FUNCTION_GRAPH_TRACER > - select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER > + select HAVE_FUNCTION_GRAPH_FREGS > select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION > select HAVE_EBPF_JIT if MMU > select HAVE_GUP_FAST if MMU > diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h > index 2cddd79ff21b..e9f364ce9fe8 100644 > --- a/arch/riscv/include/asm/ftrace.h > +++ b/arch/riscv/include/asm/ftrace.h > @@ -164,6 +164,11 @@ static __always_inline unsigned long ftrace_regs_get_stack_pointer(const struct > return fregs->sp; > } > > +static __always_inline unsigned long ftrace_regs_get_frame_pointer(const struct ftrace_regs *fregs) > +{ > + return fregs->s0; > +} > + > static __always_inline unsigned long ftrace_regs_get_argument(struct ftrace_regs *fregs, > unsigned int n) > { > @@ -204,25 +209,4 @@ static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, unsi > > #endif /* CONFIG_DYNAMIC_FTRACE */ > > -#ifndef __ASSEMBLY__ > -#ifdef CONFIG_FUNCTION_GRAPH_TRACER > -struct fgraph_ret_regs { > - unsigned long a1; > - unsigned long a0; > - unsigned long s0; > - unsigned long ra; > -}; > - > -static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs) > -{ > - return ret_regs->a0; > -} > - > -static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs) > -{ > - return ret_regs->s0; > -} > -#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */ > -#endif > - > #endif /* _ASM_RISCV_FTRACE_H */ > diff --git a/arch/riscv/kernel/mcount.S b/arch/riscv/kernel/mcount.S > index 3a42f6287909..068168046e0e 100644 > --- a/arch/riscv/kernel/mcount.S > +++ b/arch/riscv/kernel/mcount.S > @@ -12,6 +12,8 @@ > #include <asm/asm-offsets.h> > #include <asm/ftrace.h> > > +#define ABI_SIZE_ON_STACK 80 > + > .text > > .macro SAVE_ABI_STATE > @@ -26,12 +28,12 @@ > * register if a0 was not saved. > */ > .macro SAVE_RET_ABI_STATE > - addi sp, sp, -4*SZREG > - REG_S s0, 2*SZREG(sp) > - REG_S ra, 3*SZREG(sp) > - REG_S a0, 1*SZREG(sp) > - REG_S a1, 0*SZREG(sp) > - addi s0, sp, 4*SZREG > + addi sp, sp, -ABI_SIZE_ON_STACK > + REG_S ra, 1*SZREG(sp) > + REG_S s0, 8*SZREG(sp) > + REG_S a0, 10*SZREG(sp) > + REG_S a1, 11*SZREG(sp) > + addi s0, sp, ABI_SIZE_ON_STACK > .endm > > .macro RESTORE_ABI_STATE > @@ -41,11 +43,11 @@ > .endm > > .macro RESTORE_RET_ABI_STATE > - REG_L ra, 3*SZREG(sp) > - REG_L s0, 2*SZREG(sp) > - REG_L a0, 1*SZREG(sp) > - REG_L a1, 0*SZREG(sp) > - addi sp, sp, 4*SZREG > + REG_L ra, 1*SZREG(sp) > + REG_L s0, 8*SZREG(sp) > + REG_L a0, 10*SZREG(sp) > + REG_L a1, 11*SZREG(sp) > + addi sp, sp, ABI_SIZE_ON_STACK > .endm > > SYM_TYPED_FUNC_START(ftrace_stub) > diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig > index a822f952f64a..12e942cfbcde 100644 > --- a/arch/s390/Kconfig > +++ b/arch/s390/Kconfig > @@ -184,7 +184,7 @@ config S390 > select HAVE_FTRACE_MCOUNT_RECORD > select HAVE_FUNCTION_ARG_ACCESS_API > select HAVE_FUNCTION_ERROR_INJECTION > - select HAVE_FUNCTION_GRAPH_RETVAL > + select HAVE_FUNCTION_GRAPH_FREGS > select HAVE_FUNCTION_GRAPH_TRACER > select HAVE_FUNCTION_TRACER > select HAVE_GCC_PLUGINS > diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h > index de76c21eb4a3..9cdd48a46bf7 100644 > --- a/arch/s390/include/asm/ftrace.h > +++ b/arch/s390/include/asm/ftrace.h > @@ -49,23 +49,6 @@ static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs * > return NULL; > } > > -#ifdef CONFIG_FUNCTION_GRAPH_TRACER > -struct fgraph_ret_regs { > - unsigned long gpr2; > - unsigned long fp; > -}; > - > -static __always_inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs) > -{ > - return ret_regs->gpr2; > -} > - > -static __always_inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs) > -{ > - return ret_regs->fp; > -} > -#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ > - > static __always_inline unsigned long > ftrace_regs_get_instruction_pointer(const struct ftrace_regs *fregs) > { > @@ -92,6 +75,15 @@ ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs, > #define ftrace_regs_query_register_offset(name) \ > regs_query_register_offset(name) > > +static __always_inline unsigned long > +ftrace_regs_get_frame_pointer(struct ftrace_regs *fregs) > +{ > + unsigned long *sp; > + > + sp = (void *)ftrace_regs_get_stack_pointer(fregs); > + return sp[0]; /* return backchain */ > +} > + > #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS > /* > * When an ftrace registered caller is tracing a function that is > diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c > index ffa0dd2dbaac..d38ed80615d5 100644 > --- a/arch/s390/kernel/asm-offsets.c > +++ b/arch/s390/kernel/asm-offsets.c > @@ -179,12 +179,6 @@ int main(void) > DEFINE(OLDMEM_SIZE, PARMAREA + offsetof(struct parmarea, oldmem_size)); > DEFINE(COMMAND_LINE, PARMAREA + offsetof(struct parmarea, command_line)); > DEFINE(MAX_COMMAND_LINE_SIZE, PARMAREA + offsetof(struct parmarea, max_command_line_size)); > -#ifdef CONFIG_FUNCTION_GRAPH_TRACER > - /* function graph return value tracing */ > - OFFSET(__FGRAPH_RET_GPR2, fgraph_ret_regs, gpr2); > - OFFSET(__FGRAPH_RET_FP, fgraph_ret_regs, fp); > - DEFINE(__FGRAPH_RET_SIZE, sizeof(struct fgraph_ret_regs)); > -#endif > OFFSET(__FTRACE_REGS_PT_REGS, ftrace_regs, regs); > DEFINE(__FTRACE_REGS_SIZE, sizeof(struct ftrace_regs)); > > diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S > index ae4d4fd9afcd..cda798b976de 100644 > --- a/arch/s390/kernel/mcount.S > +++ b/arch/s390/kernel/mcount.S > @@ -133,14 +133,15 @@ SYM_CODE_END(ftrace_common) > SYM_FUNC_START(return_to_handler) > stmg %r2,%r5,32(%r15) > lgr %r1,%r15 > - aghi %r15,-(STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE) > +# Allocate ftrace_regs + backchain on the stack > + aghi %r15,-STACK_FRAME_SIZE_FREGS > stg %r1,__SF_BACKCHAIN(%r15) > la %r3,STACK_FRAME_OVERHEAD(%r15) > - stg %r1,__FGRAPH_RET_FP(%r3) > - stg %r2,__FGRAPH_RET_GPR2(%r3) > + stg %r2,(__SF_GPRS+2*8)(%r15) > + stg %r15,(__SF_GPRS+15*8)(%r15) > lgr %r2,%r3 > brasl %r14,ftrace_return_to_handler > - aghi %r15,STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE > + aghi %r15,STACK_FRAME_SIZE_FREGS > lgr %r14,%r2 > lmg %r2,%r5,32(%r15) > BR_EX %r14 > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 007bab9f2a0e..047384e4d93a 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -228,7 +228,7 @@ config X86 > select HAVE_GUP_FAST > select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE > select HAVE_FTRACE_MCOUNT_RECORD > - select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER > + select HAVE_FUNCTION_GRAPH_FREGS if HAVE_FUNCTION_GRAPH_TRACER > select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE) > select HAVE_FUNCTION_TRACER > select HAVE_GCC_PLUGINS > diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h > index 78f6a200e15b..669771ef3b5b 100644 > --- a/arch/x86/include/asm/ftrace.h > +++ b/arch/x86/include/asm/ftrace.h > @@ -64,6 +64,8 @@ arch_ftrace_get_regs(struct ftrace_regs *fregs) > override_function_with_return(&(fregs)->regs) > #define ftrace_regs_query_register_offset(name) \ > regs_query_register_offset(name) > +#define ftrace_regs_get_frame_pointer(fregs) \ > + frame_pointer(&(fregs)->regs) > > struct ftrace_ops; > #define ftrace_graph_func ftrace_graph_func > @@ -148,24 +150,4 @@ static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) > #endif /* !COMPILE_OFFSETS */ > #endif /* !__ASSEMBLY__ */ > > -#ifndef __ASSEMBLY__ > -#ifdef CONFIG_FUNCTION_GRAPH_TRACER > -struct fgraph_ret_regs { > - unsigned long ax; > - unsigned long dx; > - unsigned long bp; > -}; > - > -static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs) > -{ > - return ret_regs->ax; > -} > - > -static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs) > -{ > - return ret_regs->bp; > -} > -#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */ > -#endif > - > #endif /* _ASM_X86_FTRACE_H */ > diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S > index 58d9ed50fe61..4b265884d06c 100644 > --- a/arch/x86/kernel/ftrace_32.S > +++ b/arch/x86/kernel/ftrace_32.S > @@ -23,6 +23,8 @@ SYM_FUNC_START(__fentry__) > SYM_FUNC_END(__fentry__) > EXPORT_SYMBOL(__fentry__) > > +#define FRAME_SIZE PT_OLDSS+4 > + > SYM_CODE_START(ftrace_caller) > > #ifdef CONFIG_FRAME_POINTER > @@ -187,14 +189,15 @@ SYM_CODE_END(ftrace_graph_caller) > > .globl return_to_handler > return_to_handler: > - pushl $0 > - pushl %edx > - pushl %eax > + subl $(FRAME_SIZE), %esp > + movl $0, PT_EBP(%esp) > + movl %edx, PT_EDX(%esp) > + movl %eax, PT_EAX(%esp) > movl %esp, %eax > call ftrace_return_to_handler > movl %eax, %ecx > - popl %eax > - popl %edx > - addl $4, %esp # skip ebp > + movl %eax, PT_EAX(%esp) > + movl %edx, PT_EDX(%esp) > + addl $(FRAME_SIZE), %esp > JMP_NOSPEC ecx > #endif > diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S > index 214f30e9f0c0..d51647228596 100644 > --- a/arch/x86/kernel/ftrace_64.S > +++ b/arch/x86/kernel/ftrace_64.S > @@ -348,21 +348,22 @@ STACK_FRAME_NON_STANDARD_FP(__fentry__) > SYM_CODE_START(return_to_handler) > UNWIND_HINT_UNDEFINED > ANNOTATE_NOENDBR > - subq $24, %rsp > > - /* Save the return values */ > - movq %rax, (%rsp) > - movq %rdx, 8(%rsp) > - movq %rbp, 16(%rsp) > + /* Save ftrace_regs for function exit context */ > + subq $(FRAME_SIZE), %rsp > + > + movq %rax, RAX(%rsp) > + movq %rdx, RDX(%rsp) > + movq %rbp, RBP(%rsp) > movq %rsp, %rdi > > call ftrace_return_to_handler > > movq %rax, %rdi > - movq 8(%rsp), %rdx > - movq (%rsp), %rax > + movq RDX(%rsp), %rdx > + movq RAX(%rsp), %rax > > - addq $24, %rsp > + addq $(FRAME_SIZE), %rsp > /* > * Jump back to the old return address. This cannot be JMP_NOSPEC rdi > * since IBT would demand that contain ENDBR, which simply isn't so for > diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h > index 1fe49a28de2d..13987cd63553 100644 > --- a/include/linux/ftrace.h > +++ b/include/linux/ftrace.h > @@ -43,9 +43,8 @@ struct dyn_ftrace; > > char *arch_ftrace_match_adjust(char *str, const char *search); > > -#ifdef CONFIG_HAVE_FUNCTION_GRAPH_RETVAL > -struct fgraph_ret_regs; > -unsigned long ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs); > +#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FREGS > +unsigned long ftrace_return_to_handler(struct ftrace_regs *fregs); > #else > unsigned long ftrace_return_to_handler(unsigned long frame_pointer); > #endif > @@ -134,6 +133,13 @@ extern int ftrace_enabled; > * Also, architecture dependent fields can be used for internal process. > * (e.g. orig_ax on x86_64) > * > + * Basically, ftrace_regs stores the registers related to the context. > + * On function entry, registers for function parameters and hooking the > + * function call are stored, and on function exit, registers for function > + * return value and frame pointers are stored. > + * > + * And also, it dpends on the context that which registers are restored > + * from the ftrace_regs. > * On the function entry, those registers will be restored except for > * the stack pointer, so that user can change the function parameters > * and instruction pointer (e.g. live patching.) > @@ -191,6 +197,8 @@ static __always_inline bool ftrace_regs_has_args(struct ftrace_regs *fregs) > override_function_with_return(ftrace_get_regs(fregs)) > #define ftrace_regs_query_register_offset(name) \ > regs_query_register_offset(name) > +#define ftrace_regs_get_frame_pointer(fregs) \ > + frame_pointer(&(fregs)->regs) > #endif > > typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, > diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig > index 721c3b221048..ab277eff80dc 100644 > --- a/kernel/trace/Kconfig > +++ b/kernel/trace/Kconfig > @@ -31,7 +31,7 @@ config HAVE_FUNCTION_GRAPH_TRACER > help > See Documentation/trace/ftrace-design.rst > > -config HAVE_FUNCTION_GRAPH_RETVAL > +config HAVE_FUNCTION_GRAPH_FREGS > bool > > config HAVE_DYNAMIC_FTRACE > @@ -232,7 +232,7 @@ config FUNCTION_GRAPH_TRACER > > config FUNCTION_GRAPH_RETVAL > bool "Kernel Function Graph Return Value" > - depends on HAVE_FUNCTION_GRAPH_RETVAL > + depends on HAVE_FUNCTION_GRAPH_FREGS > depends on FUNCTION_GRAPH_TRACER > default n > help > diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c > index 0322c5723748..30bebe43607d 100644 > --- a/kernel/trace/fgraph.c > +++ b/kernel/trace/fgraph.c > @@ -763,15 +763,12 @@ static struct notifier_block ftrace_suspend_notifier = { > .notifier_call = ftrace_suspend_notifier_call, > }; > > -/* fgraph_ret_regs is not defined without CONFIG_FUNCTION_GRAPH_RETVAL */ > -struct fgraph_ret_regs; > - > /* > * Send the trace to the ring-buffer. > * @return the original return address. > */ > -static unsigned long __ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs, > - unsigned long frame_pointer) > +static inline unsigned long > +__ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointer) > { > struct ftrace_ret_stack *ret_stack; > struct ftrace_graph_ret trace; > @@ -791,7 +788,7 @@ static unsigned long __ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs > > trace.rettime = trace_clock_local(); > #ifdef CONFIG_FUNCTION_GRAPH_RETVAL > - trace.retval = fgraph_ret_regs_return_value(ret_regs); > + trace.retval = ftrace_regs_get_return_value(fregs); > #endif > > bitmap = get_bitmap_bits(current, offset); > @@ -826,14 +823,14 @@ static unsigned long __ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs > } > > /* > - * After all architecures have selected HAVE_FUNCTION_GRAPH_RETVAL, we can > - * leave only ftrace_return_to_handler(ret_regs). > + * After all architecures have selected HAVE_FUNCTION_GRAPH_FREGS, we can > + * leave only ftrace_return_to_handler(fregs). > */ > -#ifdef CONFIG_HAVE_FUNCTION_GRAPH_RETVAL > -unsigned long ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs) > +#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FREGS > +unsigned long ftrace_return_to_handler(struct ftrace_regs *fregs) > { > - return __ftrace_return_to_handler(ret_regs, > - fgraph_ret_regs_frame_pointer(ret_regs)); > + return __ftrace_return_to_handler(fregs, > + ftrace_regs_get_frame_pointer(fregs)); > } > #else > unsigned long ftrace_return_to_handler(unsigned long frame_pointer)