| Message ID | 20221208091244.203407-4-guoren@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Palmer Dabbelt |
| Headers | show |
| Series | riscv: Optimize function trace | expand |
Hi, On 08.12.2022 12:12, guoren@kernel.org wrote: > From: Guo Ren <guoren@linux.alibaba.com> > > Use a temporary register to reduce the size of detour code from > 16 bytes to 8 bytes. The previous implementation is from > afc76b8b8011 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of > MCOUNT"). > > Before the patch: > <func_prolog>: > 0: REG_S ra, -SZREG(sp) > 4: auipc ra, ? > 8: jalr ?(ra) > 12: REG_L ra, -SZREG(sp) > (func_boddy) > > After the patch: > <func_prolog>: > 0: auipc t0, ? > 4: jalr t0, ?(t0) > (func_boddy) > This patch not just reduces the size of detour code, but also fixes an important issue. An Ftrace callback registered with FTRACE_OPS_FL_IPMODIFY flag can actually change the instruction pointer, e.g. to "replace" the given kernel function with a new one, which is needed for livepatching, etc. In this case, the trampoline (ftrace_regs_caller) would not return to <func_prolog+12> but would rather jump to the new function. So, "REG_L ra, -SZREG(sp)" would not run and the original return address would not be restored. The kernel is likely to hang or crash as a result. This can be easily demonstrated if one tries to "replace", say, cmdline_proc_show() with a new function with the same signature using instruction_pointer_set(&fregs->regs, new_func_addr) in the Ftrace callback. Your patch fixes the issue, and such "function replacement" starts working, which is great. > Link: https://lore.kernel.org/linux-riscv/20221122075440.1165172-1-suagrfillet@gmail.com/ > Co-developed-by: Song Shuai <suagrfillet@gmail.com> > Signed-off-by: Song Shuai <suagrfillet@gmail.com> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com> > Signed-off-by: Guo Ren <guoren@kernel.org> > --- > Changes in v4: > - Add Sob of Song Shuai > > Changes in v3: > - Fixup ftrace_modify_call without "caller = rec->ip + 4". [Song Shuai] > - Optimize .macro make_call_ra & make_call_t0 > --- > arch/riscv/Makefile | 4 +- > arch/riscv/include/asm/ftrace.h | 50 +++++++++++++++++++------ > arch/riscv/kernel/ftrace.c | 65 ++++++++++----------------------- > arch/riscv/kernel/mcount-dyn.S | 43 +++++++++------------- > 4 files changed, 76 insertions(+), 86 deletions(-) > > diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile > index 36cc609c5d03..d60939e2c596 100644 > --- a/arch/riscv/Makefile > +++ b/arch/riscv/Makefile > @@ -12,9 +12,9 @@ ifeq ($(CONFIG_DYNAMIC_FTRACE),y) > LDFLAGS_vmlinux := --no-relax > KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY > ifeq ($(CONFIG_RISCV_ISA_C),y) > - CC_FLAGS_FTRACE := -fpatchable-function-entry=8 > -else > CC_FLAGS_FTRACE := -fpatchable-function-entry=4 > +else > + CC_FLAGS_FTRACE := -fpatchable-function-entry=2 > endif > endif > > diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h > index 04dad3380041..9e73922e1e2e 100644 > --- a/arch/riscv/include/asm/ftrace.h > +++ b/arch/riscv/include/asm/ftrace.h > @@ -42,6 +42,14 @@ struct dyn_arch_ftrace { > * 2) jalr: setting low-12 offset to ra, jump to ra, and set ra to > * return address (original pc + 4) > * > + *<ftrace enable>: > + * 0: auipc t0/ra, 0x? > + * 4: jalr t0/ra, ?(t0/ra) > + * > + *<ftrace disable>: > + * 0: nop > + * 4: nop > + * > * Dynamic ftrace generates probes to call sites, so we must deal with > * both auipc and jalr at the same time. > */ > @@ -52,25 +60,43 @@ struct dyn_arch_ftrace { > #define AUIPC_OFFSET_MASK (0xfffff000) > #define AUIPC_PAD (0x00001000) > #define JALR_SHIFT 20 > -#define JALR_BASIC (0x000080e7) > -#define AUIPC_BASIC (0x00000097) > +#define JALR_RA (0x000080e7) > +#define AUIPC_RA (0x00000097) > +#define JALR_T0 (0x000282e7) > +#define AUIPC_T0 (0x00000297) > #define NOP4 (0x00000013) > > -#define make_call(caller, callee, call) \ > +#define to_jalr_t0(offset) \ > + (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_T0) > + > +#define to_auipc_t0(offset) \ > + ((offset & JALR_SIGN_MASK) ? \ > + (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_T0) : \ > + ((offset & AUIPC_OFFSET_MASK) | AUIPC_T0)) > + > +#define make_call_t0(caller, callee, call) \ > do { \ > - call[0] = to_auipc_insn((unsigned int)((unsigned long)callee - \ > - (unsigned long)caller)); \ > - call[1] = to_jalr_insn((unsigned int)((unsigned long)callee - \ > - (unsigned long)caller)); \ > + unsigned int offset = \ > + (unsigned long) callee - (unsigned long) caller; \ > + call[0] = to_auipc_t0(offset); \ > + call[1] = to_jalr_t0(offset); \ > } while (0) > > -#define to_jalr_insn(offset) \ > - (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_BASIC) > +#define to_jalr_ra(offset) \ > + (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_RA) > > -#define to_auipc_insn(offset) \ > +#define to_auipc_ra(offset) \ > ((offset & JALR_SIGN_MASK) ? \ > - (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_BASIC) : \ > - ((offset & AUIPC_OFFSET_MASK) | AUIPC_BASIC)) > + (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_RA) : \ > + ((offset & AUIPC_OFFSET_MASK) | AUIPC_RA)) > + > +#define make_call_ra(caller, callee, call) \ > +do { \ > + unsigned int offset = \ > + (unsigned long) callee - (unsigned long) caller; \ > + call[0] = to_auipc_ra(offset); \ > + call[1] = to_jalr_ra(offset); \ > +} while (0) > > /* > * Let auipc+jalr be the basic *mcount unit*, so we make it 8 bytes here. > diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c > index 2086f6585773..61b24d767e2e 100644 > --- a/arch/riscv/kernel/ftrace.c > +++ b/arch/riscv/kernel/ftrace.c > @@ -55,12 +55,15 @@ static int ftrace_check_current_call(unsigned long hook_pos, > } > > static int __ftrace_modify_call(unsigned long hook_pos, unsigned long target, > - bool enable) > + bool enable, bool ra) > { > unsigned int call[2]; > unsigned int nops[2] = {NOP4, NOP4}; > > - make_call(hook_pos, target, call); > + if (ra) > + make_call_ra(hook_pos, target, call); > + else > + make_call_t0(hook_pos, target, call); > > /* Replace the auipc-jalr pair at once. Return -EPERM on write error. */ > if (patch_text_nosync > @@ -70,42 +73,13 @@ static int __ftrace_modify_call(unsigned long hook_pos, unsigned long target, > return 0; > } > > -/* > - * Put 5 instructions with 16 bytes at the front of function within > - * patchable function entry nops' area. > - * > - * 0: REG_S ra, -SZREG(sp) > - * 1: auipc ra, 0x? > - * 2: jalr -?(ra) > - * 3: REG_L ra, -SZREG(sp) > - * > - * So the opcodes is: > - * 0: 0xfe113c23 (sd)/0xfe112e23 (sw) > - * 1: 0x???????? -> auipc > - * 2: 0x???????? -> jalr > - * 3: 0xff813083 (ld)/0xffc12083 (lw) > - */ > -#if __riscv_xlen == 64 > -#define INSN0 0xfe113c23 > -#define INSN3 0xff813083 > -#elif __riscv_xlen == 32 > -#define INSN0 0xfe112e23 > -#define INSN3 0xffc12083 > -#endif > - > -#define FUNC_ENTRY_SIZE 16 > -#define FUNC_ENTRY_JMP 4 > - > int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > { > - unsigned int call[4] = {INSN0, 0, 0, INSN3}; > - unsigned long target = addr; > - unsigned long caller = rec->ip + FUNC_ENTRY_JMP; > + unsigned int call[2]; > > - call[1] = to_auipc_insn((unsigned int)(target - caller)); > - call[2] = to_jalr_insn((unsigned int)(target - caller)); > + make_call_t0(rec->ip, addr, call); > > - if (patch_text_nosync((void *)rec->ip, call, FUNC_ENTRY_SIZE)) > + if (patch_text_nosync((void *)rec->ip, call, 8)) A small nit: how about using sizeof(call) or MCOUNT_INSN_SIZE here rather than 8? Besides, adding BUILD_BUG_ON(sizeof(call) != MCOUNT_INSN_SIZE) would help catch the errors if someone changes the sizes in the future. > return -EPERM; > > return 0; > @@ -114,15 +88,14 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, > unsigned long addr) > { > - unsigned int nops[4] = {NOP4, NOP4, NOP4, NOP4}; > + unsigned int nops[2] = {NOP4, NOP4}; > > - if (patch_text_nosync((void *)rec->ip, nops, FUNC_ENTRY_SIZE)) > + if (patch_text_nosync((void *)rec->ip, nops, MCOUNT_INSN_SIZE)) > return -EPERM; > > return 0; > } > > - > /* > * This is called early on, and isn't wrapped by > * ftrace_arch_code_modify_{prepare,post_process}() and therefor doesn't hold > @@ -144,10 +117,10 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) > int ftrace_update_ftrace_func(ftrace_func_t func) > { > int ret = __ftrace_modify_call((unsigned long)&ftrace_call, > - (unsigned long)func, true); > + (unsigned long)func, true, true); > if (!ret) { > ret = __ftrace_modify_call((unsigned long)&ftrace_regs_call, > - (unsigned long)func, true); > + (unsigned long)func, true, true); > } > > return ret; > @@ -159,16 +132,16 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, > unsigned long addr) > { > unsigned int call[2]; > - unsigned long caller = rec->ip + FUNC_ENTRY_JMP; > + unsigned long caller = rec->ip; > int ret; > > - make_call(caller, old_addr, call); > + make_call_t0(caller, old_addr, call); > ret = ftrace_check_current_call(caller, call); > > if (ret) > return ret; > > - return __ftrace_modify_call(caller, addr, true); > + return __ftrace_modify_call(caller, addr, true, false); > } > #endif > > @@ -203,12 +176,12 @@ int ftrace_enable_ftrace_graph_caller(void) > int ret; > > ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call, > - (unsigned long)&prepare_ftrace_return, true); > + (unsigned long)&prepare_ftrace_return, true, true); > if (ret) > return ret; > > return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call, > - (unsigned long)&prepare_ftrace_return, true); > + (unsigned long)&prepare_ftrace_return, true, true); > } > > int ftrace_disable_ftrace_graph_caller(void) > @@ -216,12 +189,12 @@ int ftrace_disable_ftrace_graph_caller(void) > int ret; > > ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call, > - (unsigned long)&prepare_ftrace_return, false); > + (unsigned long)&prepare_ftrace_return, false, true); > if (ret) > return ret; > > return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call, > - (unsigned long)&prepare_ftrace_return, false); > + (unsigned long)&prepare_ftrace_return, false, true); > } > #endif /* CONFIG_DYNAMIC_FTRACE */ > #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ > diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S > index d171eca623b6..64bc79816f5e 100644 > --- a/arch/riscv/kernel/mcount-dyn.S > +++ b/arch/riscv/kernel/mcount-dyn.S > @@ -13,8 +13,8 @@ > > .text > > -#define FENTRY_RA_OFFSET 12 > -#define ABI_SIZE_ON_STACK 72 > +#define FENTRY_RA_OFFSET 8 > +#define ABI_SIZE_ON_STACK 80 > #define ABI_A0 0 > #define ABI_A1 8 > #define ABI_A2 16 > @@ -23,10 +23,10 @@ > #define ABI_A5 40 > #define ABI_A6 48 > #define ABI_A7 56 > -#define ABI_RA 64 > +#define ABI_T0 64 > +#define ABI_RA 72 > > .macro SAVE_ABI > - addi sp, sp, -SZREG > addi sp, sp, -ABI_SIZE_ON_STACK > > REG_S a0, ABI_A0(sp) > @@ -37,6 +37,7 @@ > REG_S a5, ABI_A5(sp) > REG_S a6, ABI_A6(sp) > REG_S a7, ABI_A7(sp) > + REG_S t0, ABI_T0(sp) > REG_S ra, ABI_RA(sp) > .endm > > @@ -49,24 +50,18 @@ > REG_L a5, ABI_A5(sp) > REG_L a6, ABI_A6(sp) > REG_L a7, ABI_A7(sp) > + REG_L t0, ABI_T0(sp) > REG_L ra, ABI_RA(sp) > > addi sp, sp, ABI_SIZE_ON_STACK > - addi sp, sp, SZREG > .endm > > #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS > .macro SAVE_ALL > - addi sp, sp, -SZREG > addi sp, sp, -PT_SIZE_ON_STACK > > - REG_S x1, PT_EPC(sp) > - addi sp, sp, PT_SIZE_ON_STACK > - REG_L x1, (sp) > - addi sp, sp, -PT_SIZE_ON_STACK > + REG_S t0, PT_EPC(sp) > REG_S x1, PT_RA(sp) > - REG_L x1, PT_EPC(sp) > - > REG_S x2, PT_SP(sp) > REG_S x3, PT_GP(sp) > REG_S x4, PT_TP(sp) > @@ -100,11 +95,8 @@ > .endm > > .macro RESTORE_ALL > + REG_L t0, PT_EPC(sp) > REG_L x1, PT_RA(sp) > - addi sp, sp, PT_SIZE_ON_STACK > - REG_S x1, (sp) > - addi sp, sp, -PT_SIZE_ON_STACK > - REG_L x1, PT_EPC(sp) > REG_L x2, PT_SP(sp) > REG_L x3, PT_GP(sp) > REG_L x4, PT_TP(sp) > @@ -137,17 +129,16 @@ > REG_L x31, PT_T6(sp) > > addi sp, sp, PT_SIZE_ON_STACK > - addi sp, sp, SZREG > .endm > #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ > > ENTRY(ftrace_caller) > SAVE_ABI > > - addi a0, ra, -FENTRY_RA_OFFSET > + addi a0, t0, -FENTRY_RA_OFFSET > la a1, function_trace_op > REG_L a2, 0(a1) > - REG_L a1, ABI_SIZE_ON_STACK(sp) > + mv a1, ra > mv a3, sp > > ftrace_call: > @@ -155,8 +146,8 @@ ftrace_call: > call ftrace_stub > > #ifdef CONFIG_FUNCTION_GRAPH_TRACER > - addi a0, sp, ABI_SIZE_ON_STACK > - REG_L a1, ABI_RA(sp) > + addi a0, sp, ABI_RA > + REG_L a1, ABI_T0(sp) > addi a1, a1, -FENTRY_RA_OFFSET > #ifdef HAVE_FUNCTION_GRAPH_FP_TEST > mv a2, s0 > @@ -166,17 +157,17 @@ ftrace_graph_call: > call ftrace_stub > #endif > RESTORE_ABI > - ret > + jr t0 > ENDPROC(ftrace_caller) > > #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS > ENTRY(ftrace_regs_caller) > SAVE_ALL > > - addi a0, ra, -FENTRY_RA_OFFSET > + addi a0, t0, -FENTRY_RA_OFFSET > la a1, function_trace_op > REG_L a2, 0(a1) > - REG_L a1, PT_SIZE_ON_STACK(sp) > + REG_L a1, PT_RA(sp) ra contains the original return address at this point, so, I think, you can load it into a1 directly, like you do in ftrace_caller: mv a1, ra > mv a3, sp > > ftrace_regs_call: > @@ -185,7 +176,7 @@ ftrace_regs_call: > > #ifdef CONFIG_FUNCTION_GRAPH_TRACER > addi a0, sp, PT_RA > - REG_L a1, PT_EPC(sp) > + REG_L a1, PT_T0(sp) > addi a1, a1, -FENTRY_RA_OFFSET > #ifdef HAVE_FUNCTION_GRAPH_FP_TEST > mv a2, s0 > @@ -196,6 +187,6 @@ ftrace_graph_regs_call: > #endif > > RESTORE_ALL > - ret > + jr t0 > ENDPROC(ftrace_regs_caller) > #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ > -- > 2.36.1 Regards, Evgenii
On Tue, Dec 27, 2022 at 4:50 PM Evgenii Shatokhin <e.shatokhin@yadro.com> wrote: > > Hi, > > On 08.12.2022 12:12, guoren@kernel.org wrote: > > From: Guo Ren <guoren@linux.alibaba.com> > > > > Use a temporary register to reduce the size of detour code from > > 16 bytes to 8 bytes. The previous implementation is from > > afc76b8b8011 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of > > MCOUNT"). > > > > Before the patch: > > <func_prolog>: > > 0: REG_S ra, -SZREG(sp) > > 4: auipc ra, ? > > 8: jalr ?(ra) > > 12: REG_L ra, -SZREG(sp) > > (func_boddy) > > > > After the patch: > > <func_prolog>: > > 0: auipc t0, ? > > 4: jalr t0, ?(t0) > > (func_boddy) > > > > This patch not just reduces the size of detour code, but also fixes an > important issue. > > An Ftrace callback registered with FTRACE_OPS_FL_IPMODIFY flag can > actually change the instruction pointer, e.g. to "replace" the given > kernel function with a new one, which is needed for livepatching, etc. > > In this case, the trampoline (ftrace_regs_caller) would not return to > <func_prolog+12> but would rather jump to the new function. So, "REG_L > ra, -SZREG(sp)" would not run and the original return address would not > be restored. The kernel is likely to hang or crash as a result. > > This can be easily demonstrated if one tries to "replace", say, > cmdline_proc_show() with a new function with the same signature using > instruction_pointer_set(&fregs->regs, new_func_addr) in the Ftrace callback. > > Your patch fixes the issue, and such "function replacement" starts > working, which is great. Thx for the comment and test. > > > Link: https://lore.kernel.org/linux-riscv/20221122075440.1165172-1-suagrfillet@gmail.com/ > > Co-developed-by: Song Shuai <suagrfillet@gmail.com> > > Signed-off-by: Song Shuai <suagrfillet@gmail.com> > > Signed-off-by: Guo Ren <guoren@linux.alibaba.com> > > Signed-off-by: Guo Ren <guoren@kernel.org> > > --- > > Changes in v4: > > - Add Sob of Song Shuai > > > > Changes in v3: > > - Fixup ftrace_modify_call without "caller = rec->ip + 4". [Song Shuai] > > - Optimize .macro make_call_ra & make_call_t0 > > --- > > arch/riscv/Makefile | 4 +- > > arch/riscv/include/asm/ftrace.h | 50 +++++++++++++++++++------ > > arch/riscv/kernel/ftrace.c | 65 ++++++++++----------------------- > > arch/riscv/kernel/mcount-dyn.S | 43 +++++++++------------- > > 4 files changed, 76 insertions(+), 86 deletions(-) > > > > diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile > > index 36cc609c5d03..d60939e2c596 100644 > > --- a/arch/riscv/Makefile > > +++ b/arch/riscv/Makefile > > @@ -12,9 +12,9 @@ ifeq ($(CONFIG_DYNAMIC_FTRACE),y) > > LDFLAGS_vmlinux := --no-relax > > KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY > > ifeq ($(CONFIG_RISCV_ISA_C),y) > > - CC_FLAGS_FTRACE := -fpatchable-function-entry=8 > > -else > > CC_FLAGS_FTRACE := -fpatchable-function-entry=4 > > +else > > + CC_FLAGS_FTRACE := -fpatchable-function-entry=2 > > endif > > endif > > > > diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h > > index 04dad3380041..9e73922e1e2e 100644 > > --- a/arch/riscv/include/asm/ftrace.h > > +++ b/arch/riscv/include/asm/ftrace.h > > @@ -42,6 +42,14 @@ struct dyn_arch_ftrace { > > * 2) jalr: setting low-12 offset to ra, jump to ra, and set ra to > > * return address (original pc + 4) > > * > > + *<ftrace enable>: > > + * 0: auipc t0/ra, 0x? > > + * 4: jalr t0/ra, ?(t0/ra) > > + * > > + *<ftrace disable>: > > + * 0: nop > > + * 4: nop > > + * > > * Dynamic ftrace generates probes to call sites, so we must deal with > > * both auipc and jalr at the same time. > > */ > > @@ -52,25 +60,43 @@ struct dyn_arch_ftrace { > > #define AUIPC_OFFSET_MASK (0xfffff000) > > #define AUIPC_PAD (0x00001000) > > #define JALR_SHIFT 20 > > -#define JALR_BASIC (0x000080e7) > > -#define AUIPC_BASIC (0x00000097) > > +#define JALR_RA (0x000080e7) > > +#define AUIPC_RA (0x00000097) > > +#define JALR_T0 (0x000282e7) > > +#define AUIPC_T0 (0x00000297) > > #define NOP4 (0x00000013) > > > > -#define make_call(caller, callee, call) \ > > +#define to_jalr_t0(offset) \ > > + (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_T0) > > + > > +#define to_auipc_t0(offset) \ > > + ((offset & JALR_SIGN_MASK) ? \ > > + (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_T0) : \ > > + ((offset & AUIPC_OFFSET_MASK) | AUIPC_T0)) > > + > > +#define make_call_t0(caller, callee, call) \ > > do { \ > > - call[0] = to_auipc_insn((unsigned int)((unsigned long)callee - \ > > - (unsigned long)caller)); \ > > - call[1] = to_jalr_insn((unsigned int)((unsigned long)callee - \ > > - (unsigned long)caller)); \ > > + unsigned int offset = \ > > + (unsigned long) callee - (unsigned long) caller; \ > > + call[0] = to_auipc_t0(offset); \ > > + call[1] = to_jalr_t0(offset); \ > > } while (0) > > > > -#define to_jalr_insn(offset) \ > > - (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_BASIC) > > +#define to_jalr_ra(offset) \ > > + (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_RA) > > > > -#define to_auipc_insn(offset) \ > > +#define to_auipc_ra(offset) \ > > ((offset & JALR_SIGN_MASK) ? \ > > - (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_BASIC) : \ > > - ((offset & AUIPC_OFFSET_MASK) | AUIPC_BASIC)) > > + (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_RA) : \ > > + ((offset & AUIPC_OFFSET_MASK) | AUIPC_RA)) > > + > > +#define make_call_ra(caller, callee, call) \ > > +do { \ > > + unsigned int offset = \ > > + (unsigned long) callee - (unsigned long) caller; \ > > + call[0] = to_auipc_ra(offset); \ > > + call[1] = to_jalr_ra(offset); \ > > +} while (0) > > > > /* > > * Let auipc+jalr be the basic *mcount unit*, so we make it 8 bytes here. > > diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c > > index 2086f6585773..61b24d767e2e 100644 > > --- a/arch/riscv/kernel/ftrace.c > > +++ b/arch/riscv/kernel/ftrace.c > > @@ -55,12 +55,15 @@ static int ftrace_check_current_call(unsigned long hook_pos, > > } > > > > static int __ftrace_modify_call(unsigned long hook_pos, unsigned long target, > > - bool enable) > > + bool enable, bool ra) > > { > > unsigned int call[2]; > > unsigned int nops[2] = {NOP4, NOP4}; > > > > - make_call(hook_pos, target, call); > > + if (ra) > > + make_call_ra(hook_pos, target, call); > > + else > > + make_call_t0(hook_pos, target, call); > > > > /* Replace the auipc-jalr pair at once. Return -EPERM on write error. */ > > if (patch_text_nosync > > @@ -70,42 +73,13 @@ static int __ftrace_modify_call(unsigned long hook_pos, unsigned long target, > > return 0; > > } > > > > -/* > > - * Put 5 instructions with 16 bytes at the front of function within > > - * patchable function entry nops' area. > > - * > > - * 0: REG_S ra, -SZREG(sp) > > - * 1: auipc ra, 0x? > > - * 2: jalr -?(ra) > > - * 3: REG_L ra, -SZREG(sp) > > - * > > - * So the opcodes is: > > - * 0: 0xfe113c23 (sd)/0xfe112e23 (sw) > > - * 1: 0x???????? -> auipc > > - * 2: 0x???????? -> jalr > > - * 3: 0xff813083 (ld)/0xffc12083 (lw) > > - */ > > -#if __riscv_xlen == 64 > > -#define INSN0 0xfe113c23 > > -#define INSN3 0xff813083 > > -#elif __riscv_xlen == 32 > > -#define INSN0 0xfe112e23 > > -#define INSN3 0xffc12083 > > -#endif > > - > > -#define FUNC_ENTRY_SIZE 16 > > -#define FUNC_ENTRY_JMP 4 > > - > > int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > > { > > - unsigned int call[4] = {INSN0, 0, 0, INSN3}; > > - unsigned long target = addr; > > - unsigned long caller = rec->ip + FUNC_ENTRY_JMP; > > + unsigned int call[2]; > > > > - call[1] = to_auipc_insn((unsigned int)(target - caller)); > > - call[2] = to_jalr_insn((unsigned int)(target - caller)); > > + make_call_t0(rec->ip, addr, call); > > > > - if (patch_text_nosync((void *)rec->ip, call, FUNC_ENTRY_SIZE)) > > + if (patch_text_nosync((void *)rec->ip, call, 8)) > > A small nit: how about using sizeof(call) or MCOUNT_INSN_SIZE here > rather than 8? Yes, I shouldn't use 8 here. > > Besides, adding BUILD_BUG_ON(sizeof(call) != MCOUNT_INSN_SIZE) would > help catch the errors if someone changes the sizes in the future. The call[2], nop[2], and replace[2] all need it, and it could be another enhancement patchset for the future. > > > return -EPERM; > > > > return 0; > > @@ -114,15 +88,14 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > > int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, > > unsigned long addr) > > { > > - unsigned int nops[4] = {NOP4, NOP4, NOP4, NOP4}; > > + unsigned int nops[2] = {NOP4, NOP4}; > > > > - if (patch_text_nosync((void *)rec->ip, nops, FUNC_ENTRY_SIZE)) > > + if (patch_text_nosync((void *)rec->ip, nops, MCOUNT_INSN_SIZE)) > > return -EPERM; > > > > return 0; > > } > > > > - > > /* > > * This is called early on, and isn't wrapped by > > * ftrace_arch_code_modify_{prepare,post_process}() and therefor doesn't hold > > @@ -144,10 +117,10 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) > > int ftrace_update_ftrace_func(ftrace_func_t func) > > { > > int ret = __ftrace_modify_call((unsigned long)&ftrace_call, > > - (unsigned long)func, true); > > + (unsigned long)func, true, true); > > if (!ret) { > > ret = __ftrace_modify_call((unsigned long)&ftrace_regs_call, > > - (unsigned long)func, true); > > + (unsigned long)func, true, true); > > } > > > > return ret; > > @@ -159,16 +132,16 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, > > unsigned long addr) > > { > > unsigned int call[2]; > > - unsigned long caller = rec->ip + FUNC_ENTRY_JMP; > > + unsigned long caller = rec->ip; > > int ret; > > > > - make_call(caller, old_addr, call); > > + make_call_t0(caller, old_addr, call); > > ret = ftrace_check_current_call(caller, call); > > > > if (ret) > > return ret; > > > > - return __ftrace_modify_call(caller, addr, true); > > + return __ftrace_modify_call(caller, addr, true, false); > > } > > #endif > > > > @@ -203,12 +176,12 @@ int ftrace_enable_ftrace_graph_caller(void) > > int ret; > > > > ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call, > > - (unsigned long)&prepare_ftrace_return, true); > > + (unsigned long)&prepare_ftrace_return, true, true); > > if (ret) > > return ret; > > > > return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call, > > - (unsigned long)&prepare_ftrace_return, true); > > + (unsigned long)&prepare_ftrace_return, true, true); > > } > > > > int ftrace_disable_ftrace_graph_caller(void) > > @@ -216,12 +189,12 @@ int ftrace_disable_ftrace_graph_caller(void) > > int ret; > > > > ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call, > > - (unsigned long)&prepare_ftrace_return, false); > > + (unsigned long)&prepare_ftrace_return, false, true); > > if (ret) > > return ret; > > > > return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call, > > - (unsigned long)&prepare_ftrace_return, false); > > + (unsigned long)&prepare_ftrace_return, false, true); > > } > > #endif /* CONFIG_DYNAMIC_FTRACE */ > > #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ > > diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S > > index d171eca623b6..64bc79816f5e 100644 > > --- a/arch/riscv/kernel/mcount-dyn.S > > +++ b/arch/riscv/kernel/mcount-dyn.S > > @@ -13,8 +13,8 @@ > > > > .text > > > > -#define FENTRY_RA_OFFSET 12 > > -#define ABI_SIZE_ON_STACK 72 > > +#define FENTRY_RA_OFFSET 8 > > +#define ABI_SIZE_ON_STACK 80 > > #define ABI_A0 0 > > #define ABI_A1 8 > > #define ABI_A2 16 > > @@ -23,10 +23,10 @@ > > #define ABI_A5 40 > > #define ABI_A6 48 > > #define ABI_A7 56 > > -#define ABI_RA 64 > > +#define ABI_T0 64 > > +#define ABI_RA 72 > > > > .macro SAVE_ABI > > - addi sp, sp, -SZREG > > addi sp, sp, -ABI_SIZE_ON_STACK > > > > REG_S a0, ABI_A0(sp) > > @@ -37,6 +37,7 @@ > > REG_S a5, ABI_A5(sp) > > REG_S a6, ABI_A6(sp) > > REG_S a7, ABI_A7(sp) > > + REG_S t0, ABI_T0(sp) > > REG_S ra, ABI_RA(sp) > > .endm > > > > @@ -49,24 +50,18 @@ > > REG_L a5, ABI_A5(sp) > > REG_L a6, ABI_A6(sp) > > REG_L a7, ABI_A7(sp) > > + REG_L t0, ABI_T0(sp) > > REG_L ra, ABI_RA(sp) > > > > addi sp, sp, ABI_SIZE_ON_STACK > > - addi sp, sp, SZREG > > .endm > > > > #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS > > .macro SAVE_ALL > > - addi sp, sp, -SZREG > > addi sp, sp, -PT_SIZE_ON_STACK > > > > - REG_S x1, PT_EPC(sp) > > - addi sp, sp, PT_SIZE_ON_STACK > > - REG_L x1, (sp) > > - addi sp, sp, -PT_SIZE_ON_STACK > > + REG_S t0, PT_EPC(sp) > > REG_S x1, PT_RA(sp) > > - REG_L x1, PT_EPC(sp) > > - > > REG_S x2, PT_SP(sp) > > REG_S x3, PT_GP(sp) > > REG_S x4, PT_TP(sp) > > @@ -100,11 +95,8 @@ > > .endm > > > > .macro RESTORE_ALL > > + REG_L t0, PT_EPC(sp) > > REG_L x1, PT_RA(sp) > > - addi sp, sp, PT_SIZE_ON_STACK > > - REG_S x1, (sp) > > - addi sp, sp, -PT_SIZE_ON_STACK > > - REG_L x1, PT_EPC(sp) > > REG_L x2, PT_SP(sp) > > REG_L x3, PT_GP(sp) > > REG_L x4, PT_TP(sp) > > @@ -137,17 +129,16 @@ > > REG_L x31, PT_T6(sp) > > > > addi sp, sp, PT_SIZE_ON_STACK > > - addi sp, sp, SZREG > > .endm > > #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ > > > > ENTRY(ftrace_caller) > > SAVE_ABI > > > > - addi a0, ra, -FENTRY_RA_OFFSET > > + addi a0, t0, -FENTRY_RA_OFFSET > > la a1, function_trace_op > > REG_L a2, 0(a1) > > - REG_L a1, ABI_SIZE_ON_STACK(sp) > > + mv a1, ra > > mv a3, sp > > > > ftrace_call: > > @@ -155,8 +146,8 @@ ftrace_call: > > call ftrace_stub > > > > #ifdef CONFIG_FUNCTION_GRAPH_TRACER > > - addi a0, sp, ABI_SIZE_ON_STACK > > - REG_L a1, ABI_RA(sp) > > + addi a0, sp, ABI_RA > > + REG_L a1, ABI_T0(sp) > > addi a1, a1, -FENTRY_RA_OFFSET > > #ifdef HAVE_FUNCTION_GRAPH_FP_TEST > > mv a2, s0 > > @@ -166,17 +157,17 @@ ftrace_graph_call: > > call ftrace_stub > > #endif > > RESTORE_ABI > > - ret > > + jr t0 > > ENDPROC(ftrace_caller) > > > > #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS > > ENTRY(ftrace_regs_caller) > > SAVE_ALL > > > > - addi a0, ra, -FENTRY_RA_OFFSET > > + addi a0, t0, -FENTRY_RA_OFFSET > > la a1, function_trace_op > > REG_L a2, 0(a1) > > - REG_L a1, PT_SIZE_ON_STACK(sp) > > + REG_L a1, PT_RA(sp) > > ra contains the original return address at this point, so, I think, you > can load it into a1 directly, like you do in ftrace_caller: > > mv a1, ra > > > mv a3, sp > > > > ftrace_regs_call: > > @@ -185,7 +176,7 @@ ftrace_regs_call: > > > > #ifdef CONFIG_FUNCTION_GRAPH_TRACER > > addi a0, sp, PT_RA > > - REG_L a1, PT_EPC(sp) > > + REG_L a1, PT_T0(sp) > > addi a1, a1, -FENTRY_RA_OFFSET > > #ifdef HAVE_FUNCTION_GRAPH_FP_TEST > > mv a2, s0 > > @@ -196,6 +187,6 @@ ftrace_graph_regs_call: > > #endif > > > > RESTORE_ALL > > - ret > > + jr t0 > > ENDPROC(ftrace_regs_caller) > > #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ > > -- > > 2.36.1 > > Regards, > Evgenii > > >
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 36cc609c5d03..d60939e2c596 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -12,9 +12,9 @@ ifeq ($(CONFIG_DYNAMIC_FTRACE),y) LDFLAGS_vmlinux := --no-relax KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY ifeq ($(CONFIG_RISCV_ISA_C),y) - CC_FLAGS_FTRACE := -fpatchable-function-entry=8 -else CC_FLAGS_FTRACE := -fpatchable-function-entry=4 +else + CC_FLAGS_FTRACE := -fpatchable-function-entry=2 endif endif diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h index 04dad3380041..9e73922e1e2e 100644 --- a/arch/riscv/include/asm/ftrace.h +++ b/arch/riscv/include/asm/ftrace.h @@ -42,6 +42,14 @@ struct dyn_arch_ftrace { * 2) jalr: setting low-12 offset to ra, jump to ra, and set ra to * return address (original pc + 4) * + *<ftrace enable>: + * 0: auipc t0/ra, 0x? + * 4: jalr t0/ra, ?(t0/ra) + * + *<ftrace disable>: + * 0: nop + * 4: nop + * * Dynamic ftrace generates probes to call sites, so we must deal with * both auipc and jalr at the same time. */ @@ -52,25 +60,43 @@ struct dyn_arch_ftrace { #define AUIPC_OFFSET_MASK (0xfffff000) #define AUIPC_PAD (0x00001000) #define JALR_SHIFT 20 -#define JALR_BASIC (0x000080e7) -#define AUIPC_BASIC (0x00000097) +#define JALR_RA (0x000080e7) +#define AUIPC_RA (0x00000097) +#define JALR_T0 (0x000282e7) +#define AUIPC_T0 (0x00000297) #define NOP4 (0x00000013) -#define make_call(caller, callee, call) \ +#define to_jalr_t0(offset) \ + (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_T0) + +#define to_auipc_t0(offset) \ + ((offset & JALR_SIGN_MASK) ? \ + (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_T0) : \ + ((offset & AUIPC_OFFSET_MASK) | AUIPC_T0)) + +#define make_call_t0(caller, callee, call) \ do { \ - call[0] = to_auipc_insn((unsigned int)((unsigned long)callee - \ - (unsigned long)caller)); \ - call[1] = to_jalr_insn((unsigned int)((unsigned long)callee - \ - (unsigned long)caller)); \ + unsigned int offset = \ + (unsigned long) callee - (unsigned long) caller; \ + call[0] = to_auipc_t0(offset); \ + call[1] = to_jalr_t0(offset); \ } while (0) -#define to_jalr_insn(offset) \ - (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_BASIC) +#define to_jalr_ra(offset) \ + (((offset & JALR_OFFSET_MASK) << JALR_SHIFT) | JALR_RA) -#define to_auipc_insn(offset) \ +#define to_auipc_ra(offset) \ ((offset & JALR_SIGN_MASK) ? \ - (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_BASIC) : \ - ((offset & AUIPC_OFFSET_MASK) | AUIPC_BASIC)) + (((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) | AUIPC_RA) : \ + ((offset & AUIPC_OFFSET_MASK) | AUIPC_RA)) + +#define make_call_ra(caller, callee, call) \ +do { \ + unsigned int offset = \ + (unsigned long) callee - (unsigned long) caller; \ + call[0] = to_auipc_ra(offset); \ + call[1] = to_jalr_ra(offset); \ +} while (0) /* * Let auipc+jalr be the basic *mcount unit*, so we make it 8 bytes here. diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c index 2086f6585773..61b24d767e2e 100644 --- a/arch/riscv/kernel/ftrace.c +++ b/arch/riscv/kernel/ftrace.c @@ -55,12 +55,15 @@ static int ftrace_check_current_call(unsigned long hook_pos, } static int __ftrace_modify_call(unsigned long hook_pos, unsigned long target, - bool enable) + bool enable, bool ra) { unsigned int call[2]; unsigned int nops[2] = {NOP4, NOP4}; - make_call(hook_pos, target, call); + if (ra) + make_call_ra(hook_pos, target, call); + else + make_call_t0(hook_pos, target, call); /* Replace the auipc-jalr pair at once. Return -EPERM on write error. */ if (patch_text_nosync @@ -70,42 +73,13 @@ static int __ftrace_modify_call(unsigned long hook_pos, unsigned long target, return 0; } -/* - * Put 5 instructions with 16 bytes at the front of function within - * patchable function entry nops' area. - * - * 0: REG_S ra, -SZREG(sp) - * 1: auipc ra, 0x? - * 2: jalr -?(ra) - * 3: REG_L ra, -SZREG(sp) - * - * So the opcodes is: - * 0: 0xfe113c23 (sd)/0xfe112e23 (sw) - * 1: 0x???????? -> auipc - * 2: 0x???????? -> jalr - * 3: 0xff813083 (ld)/0xffc12083 (lw) - */ -#if __riscv_xlen == 64 -#define INSN0 0xfe113c23 -#define INSN3 0xff813083 -#elif __riscv_xlen == 32 -#define INSN0 0xfe112e23 -#define INSN3 0xffc12083 -#endif - -#define FUNC_ENTRY_SIZE 16 -#define FUNC_ENTRY_JMP 4 - int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { - unsigned int call[4] = {INSN0, 0, 0, INSN3}; - unsigned long target = addr; - unsigned long caller = rec->ip + FUNC_ENTRY_JMP; + unsigned int call[2]; - call[1] = to_auipc_insn((unsigned int)(target - caller)); - call[2] = to_jalr_insn((unsigned int)(target - caller)); + make_call_t0(rec->ip, addr, call); - if (patch_text_nosync((void *)rec->ip, call, FUNC_ENTRY_SIZE)) + if (patch_text_nosync((void *)rec->ip, call, 8)) return -EPERM; return 0; @@ -114,15 +88,14 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) { - unsigned int nops[4] = {NOP4, NOP4, NOP4, NOP4}; + unsigned int nops[2] = {NOP4, NOP4}; - if (patch_text_nosync((void *)rec->ip, nops, FUNC_ENTRY_SIZE)) + if (patch_text_nosync((void *)rec->ip, nops, MCOUNT_INSN_SIZE)) return -EPERM; return 0; } - /* * This is called early on, and isn't wrapped by * ftrace_arch_code_modify_{prepare,post_process}() and therefor doesn't hold @@ -144,10 +117,10 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) int ftrace_update_ftrace_func(ftrace_func_t func) { int ret = __ftrace_modify_call((unsigned long)&ftrace_call, - (unsigned long)func, true); + (unsigned long)func, true, true); if (!ret) { ret = __ftrace_modify_call((unsigned long)&ftrace_regs_call, - (unsigned long)func, true); + (unsigned long)func, true, true); } return ret; @@ -159,16 +132,16 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, unsigned long addr) { unsigned int call[2]; - unsigned long caller = rec->ip + FUNC_ENTRY_JMP; + unsigned long caller = rec->ip; int ret; - make_call(caller, old_addr, call); + make_call_t0(caller, old_addr, call); ret = ftrace_check_current_call(caller, call); if (ret) return ret; - return __ftrace_modify_call(caller, addr, true); + return __ftrace_modify_call(caller, addr, true, false); } #endif @@ -203,12 +176,12 @@ int ftrace_enable_ftrace_graph_caller(void) int ret; ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call, - (unsigned long)&prepare_ftrace_return, true); + (unsigned long)&prepare_ftrace_return, true, true); if (ret) return ret; return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call, - (unsigned long)&prepare_ftrace_return, true); + (unsigned long)&prepare_ftrace_return, true, true); } int ftrace_disable_ftrace_graph_caller(void) @@ -216,12 +189,12 @@ int ftrace_disable_ftrace_graph_caller(void) int ret; ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call, - (unsigned long)&prepare_ftrace_return, false); + (unsigned long)&prepare_ftrace_return, false, true); if (ret) return ret; return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call, - (unsigned long)&prepare_ftrace_return, false); + (unsigned long)&prepare_ftrace_return, false, true); } #endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S index d171eca623b6..64bc79816f5e 100644 --- a/arch/riscv/kernel/mcount-dyn.S +++ b/arch/riscv/kernel/mcount-dyn.S @@ -13,8 +13,8 @@ .text -#define FENTRY_RA_OFFSET 12 -#define ABI_SIZE_ON_STACK 72 +#define FENTRY_RA_OFFSET 8 +#define ABI_SIZE_ON_STACK 80 #define ABI_A0 0 #define ABI_A1 8 #define ABI_A2 16 @@ -23,10 +23,10 @@ #define ABI_A5 40 #define ABI_A6 48 #define ABI_A7 56 -#define ABI_RA 64 +#define ABI_T0 64 +#define ABI_RA 72 .macro SAVE_ABI - addi sp, sp, -SZREG addi sp, sp, -ABI_SIZE_ON_STACK REG_S a0, ABI_A0(sp) @@ -37,6 +37,7 @@ REG_S a5, ABI_A5(sp) REG_S a6, ABI_A6(sp) REG_S a7, ABI_A7(sp) + REG_S t0, ABI_T0(sp) REG_S ra, ABI_RA(sp) .endm @@ -49,24 +50,18 @@ REG_L a5, ABI_A5(sp) REG_L a6, ABI_A6(sp) REG_L a7, ABI_A7(sp) + REG_L t0, ABI_T0(sp) REG_L ra, ABI_RA(sp) addi sp, sp, ABI_SIZE_ON_STACK - addi sp, sp, SZREG .endm #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS .macro SAVE_ALL - addi sp, sp, -SZREG addi sp, sp, -PT_SIZE_ON_STACK - REG_S x1, PT_EPC(sp) - addi sp, sp, PT_SIZE_ON_STACK - REG_L x1, (sp) - addi sp, sp, -PT_SIZE_ON_STACK + REG_S t0, PT_EPC(sp) REG_S x1, PT_RA(sp) - REG_L x1, PT_EPC(sp) - REG_S x2, PT_SP(sp) REG_S x3, PT_GP(sp) REG_S x4, PT_TP(sp) @@ -100,11 +95,8 @@ .endm .macro RESTORE_ALL + REG_L t0, PT_EPC(sp) REG_L x1, PT_RA(sp) - addi sp, sp, PT_SIZE_ON_STACK - REG_S x1, (sp) - addi sp, sp, -PT_SIZE_ON_STACK - REG_L x1, PT_EPC(sp) REG_L x2, PT_SP(sp) REG_L x3, PT_GP(sp) REG_L x4, PT_TP(sp) @@ -137,17 +129,16 @@ REG_L x31, PT_T6(sp) addi sp, sp, PT_SIZE_ON_STACK - addi sp, sp, SZREG .endm #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ ENTRY(ftrace_caller) SAVE_ABI - addi a0, ra, -FENTRY_RA_OFFSET + addi a0, t0, -FENTRY_RA_OFFSET la a1, function_trace_op REG_L a2, 0(a1) - REG_L a1, ABI_SIZE_ON_STACK(sp) + mv a1, ra mv a3, sp ftrace_call: @@ -155,8 +146,8 @@ ftrace_call: call ftrace_stub #ifdef CONFIG_FUNCTION_GRAPH_TRACER - addi a0, sp, ABI_SIZE_ON_STACK - REG_L a1, ABI_RA(sp) + addi a0, sp, ABI_RA + REG_L a1, ABI_T0(sp) addi a1, a1, -FENTRY_RA_OFFSET #ifdef HAVE_FUNCTION_GRAPH_FP_TEST mv a2, s0 @@ -166,17 +157,17 @@ ftrace_graph_call: call ftrace_stub #endif RESTORE_ABI - ret + jr t0 ENDPROC(ftrace_caller) #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS ENTRY(ftrace_regs_caller) SAVE_ALL - addi a0, ra, -FENTRY_RA_OFFSET + addi a0, t0, -FENTRY_RA_OFFSET la a1, function_trace_op REG_L a2, 0(a1) - REG_L a1, PT_SIZE_ON_STACK(sp) + REG_L a1, PT_RA(sp) mv a3, sp ftrace_regs_call: @@ -185,7 +176,7 @@ ftrace_regs_call: #ifdef CONFIG_FUNCTION_GRAPH_TRACER addi a0, sp, PT_RA - REG_L a1, PT_EPC(sp) + REG_L a1, PT_T0(sp) addi a1, a1, -FENTRY_RA_OFFSET #ifdef HAVE_FUNCTION_GRAPH_FP_TEST mv a2, s0 @@ -196,6 +187,6 @@ ftrace_graph_regs_call: #endif RESTORE_ALL - ret + jr t0 ENDPROC(ftrace_regs_caller) #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */