From: guoren@kernel.org
To: anup@brainfault.org, paul.walmsley@sifive.com,
palmer@dabbelt.com, conor.dooley@microchip.com, heiko@sntech.de,
rostedt@goodmis.org, mhiramat@kernel.org, jolsa@redhat.com,
bp@suse.de, jpoimboe@kernel.org, suagrfillet@gmail.com,
andy.chiu@sifive.com, mark.rutland@arm.com
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
Guo Ren <guoren@linux.alibaba.com>, Guo Ren <guoren@kernel.org>
Subject: [PATCH V4 3/7] riscv: ftrace: Reduce the detour code size to half
Date: Mon, 28 Nov 2022 22:32:26 -0500 [thread overview]
Message-ID: <20221129033230.255947-4-guoren@kernel.org> (raw)
In-Reply-To: <20221129033230.255947-1-guoren@kernel.org>
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)
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))
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 */
--
2.36.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
WARNING: multiple messages have this Message-ID (diff)
From: guoren@kernel.org
To: anup@brainfault.org, paul.walmsley@sifive.com,
palmer@dabbelt.com, conor.dooley@microchip.com, heiko@sntech.de,
rostedt@goodmis.org, mhiramat@kernel.org, jolsa@redhat.com,
bp@suse.de, jpoimboe@kernel.org, suagrfillet@gmail.com,
andy.chiu@sifive.com, mark.rutland@arm.com
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
Guo Ren <guoren@linux.alibaba.com>, Guo Ren <guoren@kernel.org>
Subject: [PATCH V4 3/7] riscv: ftrace: Reduce the detour code size to half
Date: Mon, 28 Nov 2022 22:32:26 -0500 [thread overview]
Message-ID: <20221129033230.255947-4-guoren@kernel.org> (raw)
In-Reply-To: <20221129033230.255947-1-guoren@kernel.org>
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)
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))
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 */
--
2.36.1
next prev parent reply other threads:[~2022-11-29 3:33 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-29 3:32 [PATCH V4 0/7] riscv: ftrace: Fixup ftrace detour code & Optimization guoren
2022-11-29 3:32 ` guoren
2022-11-29 3:32 ` [PATCH V4 1/7] riscv: ftrace: Fixup panic by disabling preemption guoren
2022-11-29 3:32 ` guoren
2022-11-29 3:32 ` [PATCH V4 2/7] riscv: ftrace: Remove wasted nops for !RISCV_ISA_C guoren
2022-11-29 3:32 ` guoren
2022-11-29 3:32 ` guoren [this message]
2022-11-29 3:32 ` [PATCH V4 3/7] riscv: ftrace: Reduce the detour code size to half guoren
2022-11-29 3:32 ` [PATCH V4 4/7] riscv: ftrace: Add ftrace_graph_func guoren
2022-11-29 3:32 ` guoren
2022-11-29 3:32 ` [PATCH V4 5/7] riscv: ftrace: Make ftrace_caller call ftrace_graph_func guoren
2022-11-29 3:32 ` guoren
2022-11-29 3:32 ` [PATCH V4 6/7] riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support guoren
2022-11-29 3:32 ` guoren
2022-11-29 12:03 ` Song Shuai
2022-11-29 12:03 ` Song Shuai
2022-11-30 7:29 ` Guo Ren
2022-11-30 7:29 ` Guo Ren
2022-12-01 20:02 ` Conor Dooley
2022-12-01 20:02 ` Conor Dooley
2022-12-01 20:06 ` Palmer Dabbelt
2022-12-01 20:06 ` Palmer Dabbelt
2022-12-01 20:15 ` Conor Dooley
2022-12-01 20:15 ` Conor Dooley
2022-11-29 3:32 ` [PATCH V4 7/7] samples: ftrace: Add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI] guoren
2022-11-29 3:32 ` guoren
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20221129033230.255947-4-guoren@kernel.org \
--to=guoren@kernel.org \
--cc=andy.chiu@sifive.com \
--cc=anup@brainfault.org \
--cc=bp@suse.de \
--cc=conor.dooley@microchip.com \
--cc=guoren@linux.alibaba.com \
--cc=heiko@sntech.de \
--cc=jolsa@redhat.com \
--cc=jpoimboe@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=mark.rutland@arm.com \
--cc=mhiramat@kernel.org \
--cc=palmer@dabbelt.com \
--cc=paul.walmsley@sifive.com \
--cc=rostedt@goodmis.org \
--cc=suagrfillet@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.