* [PATCH V11 0/5] riscv: Optimize function trace
@ 2023-06-27 11:16 ` Song Shuai
0 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-06-27 11:16 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, suagrfillet, bjorn, jszhang, conor.dooley
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai
Changes in V11:
- append a patch that makes the DIRECT_CALL samples support RV32I in
this series fixing the rv32 build failure reported by Palmer
- validated with ftrace boottime selftest and manual sample modules test
in qemu-system for RV32I and RV64I
This series optimizes function trace. The first 3 independent
patches has been picked in the V7 version of this series, the
subsequent version continues the following 4 patches:
select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY [1] (patch 1)
==========================================================
In RISC-V, -fpatchable-function-entry option is used to support
dynamic ftrace in this commit afc76b8b8011 ("riscv: Using
PATCHABLE_FUNCTION_ENTRY instead of MCOUNT"). So recordmcount
don't have to be called to create the __mcount_loc section before
the vmlinux linking.
Here selects FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY to tell
Makefile not to run recordmcount.
Make function graph use ftrace directly [2] (patch 2)
========================================================
In RISC-V architecture, when we enable the ftrace_graph tracer on some
functions, the function tracings on other functions will suffer extra
graph tracing work. In essence, graph_ops isn't limited by its func_hash
due to the global ftrace_graph_[regs]_call label. That should be
corrected.
What inspires me is the commit 0c0593b45c9b ("x86/ftrace: Make function
graph use ftrace directly") that uses graph_ops::func function to
install return_hooker and makes the function called against its
func_hash.
Add WITH_DIRECT_CALLS support [3] (patch 3, 4)
==============================================
This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS support for RISC-V.
SAMPLE_FTRACE_DIRECT and SAMPLE_FTRACE_DIRECT_MULTI are also included
here as the samples for testing DIRECT_CALLS related interface.
First, select the DYNAMIC_FTRACE_WITH_DIRECT_CALLS to provide
register_ftrace_direct[_multi] interfaces allowing user to register
the customed trampoline (direct_caller) as the mcount for one or
more target functions. And modify_ftrace_direct[_multi] are also
provided for modify direct_caller.
At the same time, the samples in ./samples/ftrace/ can be built
as kerenl module for testing these interfaces with SAMPLE_FTRACE_DIRECT
and SAMPLE_FTRACE_DIRECT_MULTI selected.
Second, to make the direct_caller and the other ftrace hooks
(eg. function/fgraph tracer, k[ret]probes) co-exist, a temporary
register
are nominated to store the address of direct_caller in
ftrace_regs_caller.
After the setting of the address direct_caller by direct_ops->func and
the RESTORE_REGS in ftrace_regs_caller, direct_caller will be jumped to
by the `jr` inst.
The series's old changes related these patches
==========================================
Changes in v10:
https://lore.kernel.org/all/20230511093234.3123181-1-suagrfillet@gmail.com/
- add Acked-by from Björn Töpel in patch 2 and patch 4
- replace `move` with `mv` in patch3
- prettify patch 2/4 with proper tabs
Changes in v9:
https://lore.kernel.org/linux-riscv/20230510101857.2953955-1-suagrfillet@gmail.com/
1. add Acked-by from Björn Töpel in patch 1
2. rebase patch2/patch3 on Linux v6.4-rc1
- patch 2: to make the `SAVE_ABI_REGS` configurable, revert the
modification of mcount-dyn.S from commit (45b32b946a97 "riscv:
entry: Consolidate general regs saving/restoring")
- patch 3: to pass the trace_selftest, add the implement of
`ftrace_stub_direct_tramp` from commit (fee86a4ed536 "ftrace:
selftest: remove broken trace_direct_tramp") ; and fixup the context
conflict in Kconfig
Changes in v8:
https://lore.kernel.org/linux-riscv/20230324033342.3177979-1-suagrfillet@gmail.com/
- Fix incorrect address values in the 4nd patch
- Rebased on v6.3-rc2
Changes in v7:
https://lore.kernel.org/linux-riscv/20230112090603.1295340-1-guoren@kernel.org/
- Fixup RESTORE_ABI_REGS by remove PT_T0(sp) overwrite.
- Add FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY [1]
- Fixup kconfig with HAVE_SAMPLE_FTRACE_DIRECT &
HAVE_SAMPLE_FTRACE_DIRECT_MULTI
Changes in v6:
https://lore.kernel.org/linux-riscv/20230107133549.4192639-1-guoren@kernel.org/
- Replace 8 with MCOUNT_INSN_SIZE
- Replace "REG_L a1, PT_RA(sp)" with "mv a1, ra"
- Add Evgenii Shatokhin comment
Changes in v5:
https://lore.kernel.org/linux-riscv/20221208091244.203407-1-guoren@kernel.org/
- Sort Kconfig entries in alphabetical order.
Changes in v4:
https://lore.kernel.org/linux-riscv/20221129033230.255947-1-guoren@kernel.org/
- Include [3] for maintenance. [Song Shuai]
Changes in V3:
https://lore.kernel.org/linux-riscv/20221123153950.2911981-1-guoren@kernel.org/
- Include [2] for maintenance. [Song Shuai]
[1]: https://lore.kernel.org/linux-riscv/CAAYs2=j3Eak9vU6xbAw0zPuoh00rh8v5C2U3fePkokZFibWs2g@mail.gmail.com/T/#t
[2]: https://lore.kernel.org/lkml/20221120084230.910152-1-suagrfillet@gmail.com/
[3]: https://lore.kernel.org/linux-riscv/20221123142025.1504030-1-suagrfillet@gmail.com/
Song Shuai (5):
riscv: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
riscv: ftrace: Add ftrace_graph_func
riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support
samples: ftrace: Add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI]
samples: ftrace: Make the riscv samples support RV32I
arch/riscv/Kconfig | 4 +
arch/riscv/include/asm/ftrace.h | 19 +-
arch/riscv/kernel/ftrace.c | 30 ++-
arch/riscv/kernel/mcount-dyn.S | 200 ++++++++++++++++----
samples/ftrace/ftrace-direct-modify.c | 35 ++++
samples/ftrace/ftrace-direct-multi-modify.c | 41 ++++
samples/ftrace/ftrace-direct-multi.c | 25 +++
samples/ftrace/ftrace-direct-too.c | 28 +++
samples/ftrace/ftrace-direct.c | 24 +++
9 files changed, 350 insertions(+), 56 deletions(-)
--
2.20.1
^ permalink raw reply [flat|nested] 28+ messages in thread
* [PATCH V11 0/5] riscv: Optimize function trace
@ 2023-06-27 11:16 ` Song Shuai
0 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-06-27 11:16 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, suagrfillet, bjorn, jszhang, conor.dooley
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai
Changes in V11:
- append a patch that makes the DIRECT_CALL samples support RV32I in
this series fixing the rv32 build failure reported by Palmer
- validated with ftrace boottime selftest and manual sample modules test
in qemu-system for RV32I and RV64I
This series optimizes function trace. The first 3 independent
patches has been picked in the V7 version of this series, the
subsequent version continues the following 4 patches:
select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY [1] (patch 1)
==========================================================
In RISC-V, -fpatchable-function-entry option is used to support
dynamic ftrace in this commit afc76b8b8011 ("riscv: Using
PATCHABLE_FUNCTION_ENTRY instead of MCOUNT"). So recordmcount
don't have to be called to create the __mcount_loc section before
the vmlinux linking.
Here selects FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY to tell
Makefile not to run recordmcount.
Make function graph use ftrace directly [2] (patch 2)
========================================================
In RISC-V architecture, when we enable the ftrace_graph tracer on some
functions, the function tracings on other functions will suffer extra
graph tracing work. In essence, graph_ops isn't limited by its func_hash
due to the global ftrace_graph_[regs]_call label. That should be
corrected.
What inspires me is the commit 0c0593b45c9b ("x86/ftrace: Make function
graph use ftrace directly") that uses graph_ops::func function to
install return_hooker and makes the function called against its
func_hash.
Add WITH_DIRECT_CALLS support [3] (patch 3, 4)
==============================================
This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS support for RISC-V.
SAMPLE_FTRACE_DIRECT and SAMPLE_FTRACE_DIRECT_MULTI are also included
here as the samples for testing DIRECT_CALLS related interface.
First, select the DYNAMIC_FTRACE_WITH_DIRECT_CALLS to provide
register_ftrace_direct[_multi] interfaces allowing user to register
the customed trampoline (direct_caller) as the mcount for one or
more target functions. And modify_ftrace_direct[_multi] are also
provided for modify direct_caller.
At the same time, the samples in ./samples/ftrace/ can be built
as kerenl module for testing these interfaces with SAMPLE_FTRACE_DIRECT
and SAMPLE_FTRACE_DIRECT_MULTI selected.
Second, to make the direct_caller and the other ftrace hooks
(eg. function/fgraph tracer, k[ret]probes) co-exist, a temporary
register
are nominated to store the address of direct_caller in
ftrace_regs_caller.
After the setting of the address direct_caller by direct_ops->func and
the RESTORE_REGS in ftrace_regs_caller, direct_caller will be jumped to
by the `jr` inst.
The series's old changes related these patches
==========================================
Changes in v10:
https://lore.kernel.org/all/20230511093234.3123181-1-suagrfillet@gmail.com/
- add Acked-by from Björn Töpel in patch 2 and patch 4
- replace `move` with `mv` in patch3
- prettify patch 2/4 with proper tabs
Changes in v9:
https://lore.kernel.org/linux-riscv/20230510101857.2953955-1-suagrfillet@gmail.com/
1. add Acked-by from Björn Töpel in patch 1
2. rebase patch2/patch3 on Linux v6.4-rc1
- patch 2: to make the `SAVE_ABI_REGS` configurable, revert the
modification of mcount-dyn.S from commit (45b32b946a97 "riscv:
entry: Consolidate general regs saving/restoring")
- patch 3: to pass the trace_selftest, add the implement of
`ftrace_stub_direct_tramp` from commit (fee86a4ed536 "ftrace:
selftest: remove broken trace_direct_tramp") ; and fixup the context
conflict in Kconfig
Changes in v8:
https://lore.kernel.org/linux-riscv/20230324033342.3177979-1-suagrfillet@gmail.com/
- Fix incorrect address values in the 4nd patch
- Rebased on v6.3-rc2
Changes in v7:
https://lore.kernel.org/linux-riscv/20230112090603.1295340-1-guoren@kernel.org/
- Fixup RESTORE_ABI_REGS by remove PT_T0(sp) overwrite.
- Add FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY [1]
- Fixup kconfig with HAVE_SAMPLE_FTRACE_DIRECT &
HAVE_SAMPLE_FTRACE_DIRECT_MULTI
Changes in v6:
https://lore.kernel.org/linux-riscv/20230107133549.4192639-1-guoren@kernel.org/
- Replace 8 with MCOUNT_INSN_SIZE
- Replace "REG_L a1, PT_RA(sp)" with "mv a1, ra"
- Add Evgenii Shatokhin comment
Changes in v5:
https://lore.kernel.org/linux-riscv/20221208091244.203407-1-guoren@kernel.org/
- Sort Kconfig entries in alphabetical order.
Changes in v4:
https://lore.kernel.org/linux-riscv/20221129033230.255947-1-guoren@kernel.org/
- Include [3] for maintenance. [Song Shuai]
Changes in V3:
https://lore.kernel.org/linux-riscv/20221123153950.2911981-1-guoren@kernel.org/
- Include [2] for maintenance. [Song Shuai]
[1]: https://lore.kernel.org/linux-riscv/CAAYs2=j3Eak9vU6xbAw0zPuoh00rh8v5C2U3fePkokZFibWs2g@mail.gmail.com/T/#t
[2]: https://lore.kernel.org/lkml/20221120084230.910152-1-suagrfillet@gmail.com/
[3]: https://lore.kernel.org/linux-riscv/20221123142025.1504030-1-suagrfillet@gmail.com/
Song Shuai (5):
riscv: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
riscv: ftrace: Add ftrace_graph_func
riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support
samples: ftrace: Add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI]
samples: ftrace: Make the riscv samples support RV32I
arch/riscv/Kconfig | 4 +
arch/riscv/include/asm/ftrace.h | 19 +-
arch/riscv/kernel/ftrace.c | 30 ++-
arch/riscv/kernel/mcount-dyn.S | 200 ++++++++++++++++----
samples/ftrace/ftrace-direct-modify.c | 35 ++++
samples/ftrace/ftrace-direct-multi-modify.c | 41 ++++
samples/ftrace/ftrace-direct-multi.c | 25 +++
samples/ftrace/ftrace-direct-too.c | 28 +++
samples/ftrace/ftrace-direct.c | 24 +++
9 files changed, 350 insertions(+), 56 deletions(-)
--
2.20.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 28+ messages in thread
* [PATCH V11 1/5] riscv: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
2023-06-27 11:16 ` Song Shuai
@ 2023-06-27 11:16 ` Song Shuai
-1 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-06-27 11:16 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, suagrfillet, bjorn, jszhang, conor.dooley
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai
In RISC-V, -fpatchable-function-entry option is used to support
dynamic ftrace in this commit afc76b8b8011 ("riscv: Using
PATCHABLE_FUNCTION_ENTRY instead of MCOUNT"). So recordmcount
don't have to be called to create the __mcount_loc section before
the vmlinux linking.
Here selects FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY to tell
Makefile not to run recordmcount.
Link: https://lore.kernel.org/linux-riscv/CAAYs2=j3Eak9vU6xbAw0zPuoh00rh8v5C2U3fePkokZFibWs2g@mail.gmail.com/T/#t
Link: https://lore.kernel.org/linux-riscv/Y4jtfrJt+%2FQ5nMOz@spud/
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Tested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
---
arch/riscv/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 5966ad97c30c..756d854e6cdd 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -59,6 +59,7 @@ config RISCV
select COMMON_CLK
select CPU_PM if CPU_IDLE || HIBERNATION
select EDAC_SUPPORT
+ select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
select GENERIC_ARCH_TOPOLOGY
select GENERIC_ATOMIC64 if !64BIT
select GENERIC_CLOCKEVENTS_BROADCAST if SMP
--
2.20.1
^ permalink raw reply related [flat|nested] 28+ messages in thread
* [PATCH V11 1/5] riscv: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
@ 2023-06-27 11:16 ` Song Shuai
0 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-06-27 11:16 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, suagrfillet, bjorn, jszhang, conor.dooley
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai
In RISC-V, -fpatchable-function-entry option is used to support
dynamic ftrace in this commit afc76b8b8011 ("riscv: Using
PATCHABLE_FUNCTION_ENTRY instead of MCOUNT"). So recordmcount
don't have to be called to create the __mcount_loc section before
the vmlinux linking.
Here selects FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY to tell
Makefile not to run recordmcount.
Link: https://lore.kernel.org/linux-riscv/CAAYs2=j3Eak9vU6xbAw0zPuoh00rh8v5C2U3fePkokZFibWs2g@mail.gmail.com/T/#t
Link: https://lore.kernel.org/linux-riscv/Y4jtfrJt+%2FQ5nMOz@spud/
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Tested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
---
arch/riscv/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 5966ad97c30c..756d854e6cdd 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -59,6 +59,7 @@ config RISCV
select COMMON_CLK
select CPU_PM if CPU_IDLE || HIBERNATION
select EDAC_SUPPORT
+ select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE
select GENERIC_ARCH_TOPOLOGY
select GENERIC_ATOMIC64 if !64BIT
select GENERIC_CLOCKEVENTS_BROADCAST if SMP
--
2.20.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 28+ messages in thread
* [PATCH V11 2/5] riscv: ftrace: Add ftrace_graph_func
2023-06-27 11:16 ` Song Shuai
@ 2023-06-27 11:16 ` Song Shuai
-1 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-06-27 11:16 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, suagrfillet, bjorn, jszhang, conor.dooley
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai
Here implements ftrace_graph_func as the function graph tracing function
with FTRACE_WITH_REGS defined.
function_graph_func gets the point of the parent IP and the frame pointer
from fregs and call prepare_ftrace_return for function graph tracing.
If FTRACE_WITH_REGS isn't defined, the enable/disable helpers of
ftrace_graph_[regs]_call are revised for serving only ftrace_graph_call
in the !FTRACE_WITH_REGS version ftrace_caller.
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Tested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
---
arch/riscv/include/asm/ftrace.h | 11 +-
arch/riscv/kernel/ftrace.c | 30 +++--
arch/riscv/kernel/mcount-dyn.S | 190 +++++++++++++++++++++++++-------
3 files changed, 175 insertions(+), 56 deletions(-)
diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h
index d47d87c2d7e3..84f856a3286e 100644
--- a/arch/riscv/include/asm/ftrace.h
+++ b/arch/riscv/include/asm/ftrace.h
@@ -107,7 +107,16 @@ do { \
struct dyn_ftrace;
int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
#define ftrace_init_nop ftrace_init_nop
-#endif
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+struct ftrace_ops;
+struct ftrace_regs;
+void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct ftrace_regs *fregs);
+#define ftrace_graph_func ftrace_graph_func
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
+
+#endif /* __ASSEMBLY__ */
#endif /* CONFIG_DYNAMIC_FTRACE */
diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c
index 03a6434a8cdd..f5aa24d9e1c1 100644
--- a/arch/riscv/kernel/ftrace.c
+++ b/arch/riscv/kernel/ftrace.c
@@ -178,32 +178,28 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
}
#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
+{
+ struct pt_regs *regs = arch_ftrace_get_regs(fregs);
+ unsigned long *parent = (unsigned long *)®s->ra;
+
+ prepare_ftrace_return(parent, ip, frame_pointer(regs));
+}
+#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
extern void ftrace_graph_call(void);
-extern void ftrace_graph_regs_call(void);
int ftrace_enable_ftrace_graph_caller(void)
{
- int ret;
-
- ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call,
- (unsigned long)&prepare_ftrace_return, true, true);
- if (ret)
- return ret;
-
- return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call,
+ return __ftrace_modify_call((unsigned long)&ftrace_graph_call,
(unsigned long)&prepare_ftrace_return, true, true);
}
int ftrace_disable_ftrace_graph_caller(void)
{
- int ret;
-
- ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call,
- (unsigned long)&prepare_ftrace_return, false, true);
- if (ret)
- return ret;
-
- return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call,
+ return __ftrace_modify_call((unsigned long)&ftrace_graph_call,
(unsigned long)&prepare_ftrace_return, false, true);
}
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
#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 669b8697aa38..fb8286b80cfc 100644
--- a/arch/riscv/kernel/mcount-dyn.S
+++ b/arch/riscv/kernel/mcount-dyn.S
@@ -57,31 +57,150 @@
.endm
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
- .macro SAVE_ALL
+
+/**
+* SAVE_ABI_REGS - save regs against the pt_regs struct
+*
+* @all: tell if saving all the regs
+*
+* If all is set, all the regs will be saved, otherwise only ABI
+* related regs (a0-a7,epc,ra and optional s0) will be saved.
+*
+* After the stack is established,
+*
+* 0(sp) stores the PC of the traced function which can be accessed
+* by &(fregs)->regs->epc in tracing function. Note that the real
+* function entry address should be computed with -FENTRY_RA_OFFSET.
+*
+* 8(sp) stores the function return address (i.e. parent IP) that
+* can be accessed by &(fregs)->regs->ra in tracing function.
+*
+* The other regs are saved at the respective localtion and accessed
+* by the respective pt_regs member.
+*
+* Here is the layout of stack for your reference.
+*
+* PT_SIZE_ON_STACK -> +++++++++
+* + ..... +
+* + t3-t6 +
+* + s2-s11+
+* + a0-a7 + --++++-> ftrace_caller saved
+* + s1 + +
+* + s0 + --+
+* + t0-t2 + +
+* + tp + +
+* + gp + +
+* + sp + +
+* + ra + --+ // parent IP
+* sp -> + epc + --+ // PC
+* +++++++++
+**/
+ .macro SAVE_ABI_REGS, all=0
addi sp, sp, -PT_SIZE_ON_STACK
- REG_S t0, PT_EPC(sp)
- REG_S x1, PT_RA(sp)
- REG_S x2, PT_SP(sp)
- REG_S x3, PT_GP(sp)
- REG_S x4, PT_TP(sp)
- REG_S x5, PT_T0(sp)
- save_from_x6_to_x31
+ REG_S t0, PT_EPC(sp)
+ REG_S x1, PT_RA(sp)
+
+ // save the ABI regs
+
+ REG_S x10, PT_A0(sp)
+ REG_S x11, PT_A1(sp)
+ REG_S x12, PT_A2(sp)
+ REG_S x13, PT_A3(sp)
+ REG_S x14, PT_A4(sp)
+ REG_S x15, PT_A5(sp)
+ REG_S x16, PT_A6(sp)
+ REG_S x17, PT_A7(sp)
+
+ // save the leftover regs
+
+ .if \all == 1
+ REG_S x2, PT_SP(sp)
+ REG_S x3, PT_GP(sp)
+ REG_S x4, PT_TP(sp)
+ REG_S x5, PT_T0(sp)
+ REG_S x6, PT_T1(sp)
+ REG_S x7, PT_T2(sp)
+ REG_S x8, PT_S0(sp)
+ REG_S x9, PT_S1(sp)
+ REG_S x18, PT_S2(sp)
+ REG_S x19, PT_S3(sp)
+ REG_S x20, PT_S4(sp)
+ REG_S x21, PT_S5(sp)
+ REG_S x22, PT_S6(sp)
+ REG_S x23, PT_S7(sp)
+ REG_S x24, PT_S8(sp)
+ REG_S x25, PT_S9(sp)
+ REG_S x26, PT_S10(sp)
+ REG_S x27, PT_S11(sp)
+ REG_S x28, PT_T3(sp)
+ REG_S x29, PT_T4(sp)
+ REG_S x30, PT_T5(sp)
+ REG_S x31, PT_T6(sp)
+
+ // save s0 if FP_TEST defined
+
+ .else
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
+ REG_S x8, PT_S0(sp)
+#endif
+ .endif
.endm
- .macro RESTORE_ALL
- REG_L x1, PT_RA(sp)
- REG_L x2, PT_SP(sp)
- REG_L x3, PT_GP(sp)
- REG_L x4, PT_TP(sp)
- /* Restore t0 with PT_EPC */
- REG_L x5, PT_EPC(sp)
- restore_from_x6_to_x31
+ .macro RESTORE_ABI_REGS, all=0
+ REG_L t0, PT_EPC(sp)
+ REG_L x1, PT_RA(sp)
+ REG_L x10, PT_A0(sp)
+ REG_L x11, PT_A1(sp)
+ REG_L x12, PT_A2(sp)
+ REG_L x13, PT_A3(sp)
+ REG_L x14, PT_A4(sp)
+ REG_L x15, PT_A5(sp)
+ REG_L x16, PT_A6(sp)
+ REG_L x17, PT_A7(sp)
+ .if \all == 1
+ REG_L x2, PT_SP(sp)
+ REG_L x3, PT_GP(sp)
+ REG_L x4, PT_TP(sp)
+ REG_L x6, PT_T1(sp)
+ REG_L x7, PT_T2(sp)
+ REG_L x8, PT_S0(sp)
+ REG_L x9, PT_S1(sp)
+ REG_L x18, PT_S2(sp)
+ REG_L x19, PT_S3(sp)
+ REG_L x20, PT_S4(sp)
+ REG_L x21, PT_S5(sp)
+ REG_L x22, PT_S6(sp)
+ REG_L x23, PT_S7(sp)
+ REG_L x24, PT_S8(sp)
+ REG_L x25, PT_S9(sp)
+ REG_L x26, PT_S10(sp)
+ REG_L x27, PT_S11(sp)
+ REG_L x28, PT_T3(sp)
+ REG_L x29, PT_T4(sp)
+ REG_L x30, PT_T5(sp)
+ REG_L x31, PT_T6(sp)
+
+ .else
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
+ REG_L x8, PT_S0(sp)
+#endif
+ .endif
addi sp, sp, PT_SIZE_ON_STACK
.endm
+
+ .macro PREPARE_ARGS
+ addi a0, t0, -FENTRY_RA_OFFSET
+ la a1, function_trace_op
+ REG_L a2, 0(a1)
+ mv a1, ra
+ mv a3, sp
+ .endm
+
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
+#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
ENTRY(ftrace_caller)
SAVE_ABI
@@ -107,36 +226,31 @@ ftrace_graph_call:
call ftrace_stub
#endif
RESTORE_ABI
- jr t0
+ jr t0
ENDPROC(ftrace_caller)
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
ENTRY(ftrace_regs_caller)
- SAVE_ALL
-
- addi a0, t0, -FENTRY_RA_OFFSET
- la a1, function_trace_op
- REG_L a2, 0(a1)
- mv a1, ra
- mv a3, sp
+ SAVE_ABI_REGS 1
+ PREPARE_ARGS
ftrace_regs_call:
.global ftrace_regs_call
call ftrace_stub
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- addi a0, sp, PT_RA
- REG_L a1, PT_EPC(sp)
- addi a1, a1, -FENTRY_RA_OFFSET
-#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
- mv a2, s0
-#endif
-ftrace_graph_regs_call:
- .global ftrace_graph_regs_call
+ RESTORE_ABI_REGS 1
+ jr t0
+ENDPROC(ftrace_regs_caller)
+
+ENTRY(ftrace_caller)
+ SAVE_ABI_REGS 0
+ PREPARE_ARGS
+
+ftrace_call:
+ .global ftrace_call
call ftrace_stub
-#endif
- RESTORE_ALL
- jr t0
-ENDPROC(ftrace_regs_caller)
+ RESTORE_ABI_REGS 0
+ jr t0
+ENDPROC(ftrace_caller)
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
--
2.20.1
^ permalink raw reply related [flat|nested] 28+ messages in thread
* [PATCH V11 2/5] riscv: ftrace: Add ftrace_graph_func
@ 2023-06-27 11:16 ` Song Shuai
0 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-06-27 11:16 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, suagrfillet, bjorn, jszhang, conor.dooley
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai
Here implements ftrace_graph_func as the function graph tracing function
with FTRACE_WITH_REGS defined.
function_graph_func gets the point of the parent IP and the frame pointer
from fregs and call prepare_ftrace_return for function graph tracing.
If FTRACE_WITH_REGS isn't defined, the enable/disable helpers of
ftrace_graph_[regs]_call are revised for serving only ftrace_graph_call
in the !FTRACE_WITH_REGS version ftrace_caller.
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Tested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
---
arch/riscv/include/asm/ftrace.h | 11 +-
arch/riscv/kernel/ftrace.c | 30 +++--
arch/riscv/kernel/mcount-dyn.S | 190 +++++++++++++++++++++++++-------
3 files changed, 175 insertions(+), 56 deletions(-)
diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h
index d47d87c2d7e3..84f856a3286e 100644
--- a/arch/riscv/include/asm/ftrace.h
+++ b/arch/riscv/include/asm/ftrace.h
@@ -107,7 +107,16 @@ do { \
struct dyn_ftrace;
int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
#define ftrace_init_nop ftrace_init_nop
-#endif
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+struct ftrace_ops;
+struct ftrace_regs;
+void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct ftrace_regs *fregs);
+#define ftrace_graph_func ftrace_graph_func
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
+
+#endif /* __ASSEMBLY__ */
#endif /* CONFIG_DYNAMIC_FTRACE */
diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c
index 03a6434a8cdd..f5aa24d9e1c1 100644
--- a/arch/riscv/kernel/ftrace.c
+++ b/arch/riscv/kernel/ftrace.c
@@ -178,32 +178,28 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
}
#ifdef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *op, struct ftrace_regs *fregs)
+{
+ struct pt_regs *regs = arch_ftrace_get_regs(fregs);
+ unsigned long *parent = (unsigned long *)®s->ra;
+
+ prepare_ftrace_return(parent, ip, frame_pointer(regs));
+}
+#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
extern void ftrace_graph_call(void);
-extern void ftrace_graph_regs_call(void);
int ftrace_enable_ftrace_graph_caller(void)
{
- int ret;
-
- ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call,
- (unsigned long)&prepare_ftrace_return, true, true);
- if (ret)
- return ret;
-
- return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call,
+ return __ftrace_modify_call((unsigned long)&ftrace_graph_call,
(unsigned long)&prepare_ftrace_return, true, true);
}
int ftrace_disable_ftrace_graph_caller(void)
{
- int ret;
-
- ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call,
- (unsigned long)&prepare_ftrace_return, false, true);
- if (ret)
- return ret;
-
- return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call,
+ return __ftrace_modify_call((unsigned long)&ftrace_graph_call,
(unsigned long)&prepare_ftrace_return, false, true);
}
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
#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 669b8697aa38..fb8286b80cfc 100644
--- a/arch/riscv/kernel/mcount-dyn.S
+++ b/arch/riscv/kernel/mcount-dyn.S
@@ -57,31 +57,150 @@
.endm
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
- .macro SAVE_ALL
+
+/**
+* SAVE_ABI_REGS - save regs against the pt_regs struct
+*
+* @all: tell if saving all the regs
+*
+* If all is set, all the regs will be saved, otherwise only ABI
+* related regs (a0-a7,epc,ra and optional s0) will be saved.
+*
+* After the stack is established,
+*
+* 0(sp) stores the PC of the traced function which can be accessed
+* by &(fregs)->regs->epc in tracing function. Note that the real
+* function entry address should be computed with -FENTRY_RA_OFFSET.
+*
+* 8(sp) stores the function return address (i.e. parent IP) that
+* can be accessed by &(fregs)->regs->ra in tracing function.
+*
+* The other regs are saved at the respective localtion and accessed
+* by the respective pt_regs member.
+*
+* Here is the layout of stack for your reference.
+*
+* PT_SIZE_ON_STACK -> +++++++++
+* + ..... +
+* + t3-t6 +
+* + s2-s11+
+* + a0-a7 + --++++-> ftrace_caller saved
+* + s1 + +
+* + s0 + --+
+* + t0-t2 + +
+* + tp + +
+* + gp + +
+* + sp + +
+* + ra + --+ // parent IP
+* sp -> + epc + --+ // PC
+* +++++++++
+**/
+ .macro SAVE_ABI_REGS, all=0
addi sp, sp, -PT_SIZE_ON_STACK
- REG_S t0, PT_EPC(sp)
- REG_S x1, PT_RA(sp)
- REG_S x2, PT_SP(sp)
- REG_S x3, PT_GP(sp)
- REG_S x4, PT_TP(sp)
- REG_S x5, PT_T0(sp)
- save_from_x6_to_x31
+ REG_S t0, PT_EPC(sp)
+ REG_S x1, PT_RA(sp)
+
+ // save the ABI regs
+
+ REG_S x10, PT_A0(sp)
+ REG_S x11, PT_A1(sp)
+ REG_S x12, PT_A2(sp)
+ REG_S x13, PT_A3(sp)
+ REG_S x14, PT_A4(sp)
+ REG_S x15, PT_A5(sp)
+ REG_S x16, PT_A6(sp)
+ REG_S x17, PT_A7(sp)
+
+ // save the leftover regs
+
+ .if \all == 1
+ REG_S x2, PT_SP(sp)
+ REG_S x3, PT_GP(sp)
+ REG_S x4, PT_TP(sp)
+ REG_S x5, PT_T0(sp)
+ REG_S x6, PT_T1(sp)
+ REG_S x7, PT_T2(sp)
+ REG_S x8, PT_S0(sp)
+ REG_S x9, PT_S1(sp)
+ REG_S x18, PT_S2(sp)
+ REG_S x19, PT_S3(sp)
+ REG_S x20, PT_S4(sp)
+ REG_S x21, PT_S5(sp)
+ REG_S x22, PT_S6(sp)
+ REG_S x23, PT_S7(sp)
+ REG_S x24, PT_S8(sp)
+ REG_S x25, PT_S9(sp)
+ REG_S x26, PT_S10(sp)
+ REG_S x27, PT_S11(sp)
+ REG_S x28, PT_T3(sp)
+ REG_S x29, PT_T4(sp)
+ REG_S x30, PT_T5(sp)
+ REG_S x31, PT_T6(sp)
+
+ // save s0 if FP_TEST defined
+
+ .else
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
+ REG_S x8, PT_S0(sp)
+#endif
+ .endif
.endm
- .macro RESTORE_ALL
- REG_L x1, PT_RA(sp)
- REG_L x2, PT_SP(sp)
- REG_L x3, PT_GP(sp)
- REG_L x4, PT_TP(sp)
- /* Restore t0 with PT_EPC */
- REG_L x5, PT_EPC(sp)
- restore_from_x6_to_x31
+ .macro RESTORE_ABI_REGS, all=0
+ REG_L t0, PT_EPC(sp)
+ REG_L x1, PT_RA(sp)
+ REG_L x10, PT_A0(sp)
+ REG_L x11, PT_A1(sp)
+ REG_L x12, PT_A2(sp)
+ REG_L x13, PT_A3(sp)
+ REG_L x14, PT_A4(sp)
+ REG_L x15, PT_A5(sp)
+ REG_L x16, PT_A6(sp)
+ REG_L x17, PT_A7(sp)
+ .if \all == 1
+ REG_L x2, PT_SP(sp)
+ REG_L x3, PT_GP(sp)
+ REG_L x4, PT_TP(sp)
+ REG_L x6, PT_T1(sp)
+ REG_L x7, PT_T2(sp)
+ REG_L x8, PT_S0(sp)
+ REG_L x9, PT_S1(sp)
+ REG_L x18, PT_S2(sp)
+ REG_L x19, PT_S3(sp)
+ REG_L x20, PT_S4(sp)
+ REG_L x21, PT_S5(sp)
+ REG_L x22, PT_S6(sp)
+ REG_L x23, PT_S7(sp)
+ REG_L x24, PT_S8(sp)
+ REG_L x25, PT_S9(sp)
+ REG_L x26, PT_S10(sp)
+ REG_L x27, PT_S11(sp)
+ REG_L x28, PT_T3(sp)
+ REG_L x29, PT_T4(sp)
+ REG_L x30, PT_T5(sp)
+ REG_L x31, PT_T6(sp)
+
+ .else
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
+ REG_L x8, PT_S0(sp)
+#endif
+ .endif
addi sp, sp, PT_SIZE_ON_STACK
.endm
+
+ .macro PREPARE_ARGS
+ addi a0, t0, -FENTRY_RA_OFFSET
+ la a1, function_trace_op
+ REG_L a2, 0(a1)
+ mv a1, ra
+ mv a3, sp
+ .endm
+
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
+#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
ENTRY(ftrace_caller)
SAVE_ABI
@@ -107,36 +226,31 @@ ftrace_graph_call:
call ftrace_stub
#endif
RESTORE_ABI
- jr t0
+ jr t0
ENDPROC(ftrace_caller)
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
ENTRY(ftrace_regs_caller)
- SAVE_ALL
-
- addi a0, t0, -FENTRY_RA_OFFSET
- la a1, function_trace_op
- REG_L a2, 0(a1)
- mv a1, ra
- mv a3, sp
+ SAVE_ABI_REGS 1
+ PREPARE_ARGS
ftrace_regs_call:
.global ftrace_regs_call
call ftrace_stub
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- addi a0, sp, PT_RA
- REG_L a1, PT_EPC(sp)
- addi a1, a1, -FENTRY_RA_OFFSET
-#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
- mv a2, s0
-#endif
-ftrace_graph_regs_call:
- .global ftrace_graph_regs_call
+ RESTORE_ABI_REGS 1
+ jr t0
+ENDPROC(ftrace_regs_caller)
+
+ENTRY(ftrace_caller)
+ SAVE_ABI_REGS 0
+ PREPARE_ARGS
+
+ftrace_call:
+ .global ftrace_call
call ftrace_stub
-#endif
- RESTORE_ALL
- jr t0
-ENDPROC(ftrace_regs_caller)
+ RESTORE_ABI_REGS 0
+ jr t0
+ENDPROC(ftrace_caller)
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
--
2.20.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 28+ messages in thread
* [PATCH V11 3/5] riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support
2023-06-27 11:16 ` Song Shuai
@ 2023-06-27 11:16 ` Song Shuai
-1 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-06-27 11:16 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, suagrfillet, bjorn, jszhang, conor.dooley
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai
This patch adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS support for RISC-V.
select the DYNAMIC_FTRACE_WITH_DIRECT_CALLS to provide the
register_ftrace_direct[_multi] interfaces allowing users to register
the customed trampoline (direct_caller) as the mcount for one or
more target functions. And modify_ftrace_direct[_multi] are also
provided for modifying direct_caller.
To make the direct_caller and the other ftrace hooks (eg. function/fgraph
tracer, k[ret]probes) co-exist, a temporary register is nominated to
store the address of direct_caller in ftrace_regs_caller. After the
setting of the address direct_caller by direct_ops->func and the
RESTORE_REGS in ftrace_regs_caller, direct_caller will be jumped to
by the `jr` inst.
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Tested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
---
arch/riscv/Kconfig | 1 +
arch/riscv/include/asm/ftrace.h | 8 ++++++++
arch/riscv/kernel/mcount-dyn.S | 10 ++++++++++
3 files changed, 19 insertions(+)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 756d854e6cdd..c3e678450acf 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -145,6 +145,7 @@ config RISCV
select UACCESS_MEMCPY if !MMU
select ZONE_DMA32 if 64BIT
select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
+ select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
select HAVE_FUNCTION_GRAPH_TRACER
diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h
index 84f856a3286e..84904c1e4369 100644
--- a/arch/riscv/include/asm/ftrace.h
+++ b/arch/riscv/include/asm/ftrace.h
@@ -114,6 +114,14 @@ struct ftrace_regs;
void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs);
#define ftrace_graph_func ftrace_graph_func
+
+static inline void
+__arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr)
+{
+ regs->t1 = addr;
+}
+#define arch_ftrace_set_direct_caller(fregs, addr) \
+ __arch_ftrace_set_direct_caller(&(fregs)->regs, addr)
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
#endif /* __ASSEMBLY__ */
diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S
index fb8286b80cfc..b6f4e1847d61 100644
--- a/arch/riscv/kernel/mcount-dyn.S
+++ b/arch/riscv/kernel/mcount-dyn.S
@@ -231,6 +231,7 @@ ENDPROC(ftrace_caller)
#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
ENTRY(ftrace_regs_caller)
+ mv t1, zero
SAVE_ABI_REGS 1
PREPARE_ARGS
@@ -239,7 +240,10 @@ ftrace_regs_call:
call ftrace_stub
RESTORE_ABI_REGS 1
+ bnez t1,.Ldirect
jr t0
+.Ldirect:
+ jr t1
ENDPROC(ftrace_regs_caller)
ENTRY(ftrace_caller)
@@ -254,3 +258,9 @@ ftrace_call:
jr t0
ENDPROC(ftrace_caller)
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+SYM_CODE_START(ftrace_stub_direct_tramp)
+ jr t0
+SYM_CODE_END(ftrace_stub_direct_tramp)
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
--
2.20.1
^ permalink raw reply related [flat|nested] 28+ messages in thread
* [PATCH V11 3/5] riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support
@ 2023-06-27 11:16 ` Song Shuai
0 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-06-27 11:16 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, suagrfillet, bjorn, jszhang, conor.dooley
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai
This patch adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS support for RISC-V.
select the DYNAMIC_FTRACE_WITH_DIRECT_CALLS to provide the
register_ftrace_direct[_multi] interfaces allowing users to register
the customed trampoline (direct_caller) as the mcount for one or
more target functions. And modify_ftrace_direct[_multi] are also
provided for modifying direct_caller.
To make the direct_caller and the other ftrace hooks (eg. function/fgraph
tracer, k[ret]probes) co-exist, a temporary register is nominated to
store the address of direct_caller in ftrace_regs_caller. After the
setting of the address direct_caller by direct_ops->func and the
RESTORE_REGS in ftrace_regs_caller, direct_caller will be jumped to
by the `jr` inst.
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Tested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
---
arch/riscv/Kconfig | 1 +
arch/riscv/include/asm/ftrace.h | 8 ++++++++
arch/riscv/kernel/mcount-dyn.S | 10 ++++++++++
3 files changed, 19 insertions(+)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 756d854e6cdd..c3e678450acf 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -145,6 +145,7 @@ config RISCV
select UACCESS_MEMCPY if !MMU
select ZONE_DMA32 if 64BIT
select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE)
+ select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
select HAVE_FUNCTION_GRAPH_TRACER
diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h
index 84f856a3286e..84904c1e4369 100644
--- a/arch/riscv/include/asm/ftrace.h
+++ b/arch/riscv/include/asm/ftrace.h
@@ -114,6 +114,14 @@ struct ftrace_regs;
void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs);
#define ftrace_graph_func ftrace_graph_func
+
+static inline void
+__arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr)
+{
+ regs->t1 = addr;
+}
+#define arch_ftrace_set_direct_caller(fregs, addr) \
+ __arch_ftrace_set_direct_caller(&(fregs)->regs, addr)
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
#endif /* __ASSEMBLY__ */
diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S
index fb8286b80cfc..b6f4e1847d61 100644
--- a/arch/riscv/kernel/mcount-dyn.S
+++ b/arch/riscv/kernel/mcount-dyn.S
@@ -231,6 +231,7 @@ ENDPROC(ftrace_caller)
#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
ENTRY(ftrace_regs_caller)
+ mv t1, zero
SAVE_ABI_REGS 1
PREPARE_ARGS
@@ -239,7 +240,10 @@ ftrace_regs_call:
call ftrace_stub
RESTORE_ABI_REGS 1
+ bnez t1,.Ldirect
jr t0
+.Ldirect:
+ jr t1
ENDPROC(ftrace_regs_caller)
ENTRY(ftrace_caller)
@@ -254,3 +258,9 @@ ftrace_call:
jr t0
ENDPROC(ftrace_caller)
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+SYM_CODE_START(ftrace_stub_direct_tramp)
+ jr t0
+SYM_CODE_END(ftrace_stub_direct_tramp)
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
--
2.20.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 28+ messages in thread
* [PATCH V11 4/5] samples: ftrace: Add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI]
2023-06-27 11:16 ` Song Shuai
@ 2023-06-27 11:16 ` Song Shuai
-1 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-06-27 11:16 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, suagrfillet, bjorn, jszhang, conor.dooley
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai,
Evgenii Shatokhin
select HAVE_SAMPLE_FTRACE_DIRECT and HAVE_SAMPLE_FTRACE_DIRECT_MULTI
for ARCH_RV64I in arch/riscv/Kconfig. And add riscv asm code for
the ftrace-direct*.c files in samples/ftrace/.
Link: https://lore.kernel.org/linux-riscv/c68bac83-5c88-80b1-bac9-e1fd4ea8f07e@yadro.com/T/#ma13012560331c66b051b580b3ab4a04ba44455ec
Tested-by: Evgenii Shatokhin <e.shatokhin@yadro.com>
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Tested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
---
arch/riscv/Kconfig | 2 ++
samples/ftrace/ftrace-direct-modify.c | 34 ++++++++++++++++++
samples/ftrace/ftrace-direct-multi-modify.c | 40 +++++++++++++++++++++
samples/ftrace/ftrace-direct-multi.c | 24 +++++++++++++
samples/ftrace/ftrace-direct-too.c | 27 ++++++++++++++
samples/ftrace/ftrace-direct.c | 23 ++++++++++++
6 files changed, 150 insertions(+)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index c3e678450acf..35d8255a12c6 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -122,6 +122,8 @@ config RISCV
select HAVE_POSIX_CPU_TIMERS_TASK_WORK
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_RSEQ
+ select HAVE_SAMPLE_FTRACE_DIRECT
+ select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
select IRQ_DOMAIN
diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
index 06d889149012..e90ca7b68314 100644
--- a/samples/ftrace/ftrace-direct-modify.c
+++ b/samples/ftrace/ftrace-direct-modify.c
@@ -22,6 +22,40 @@ extern void my_tramp2(void *);
static unsigned long my_ip = (unsigned long)schedule;
+#ifdef CONFIG_RISCV
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:\n"
+" addi sp,sp,-16\n"
+" sd t0,0(sp)\n"
+" sd ra,8(sp)\n"
+" call my_direct_func1\n"
+" ld t0,0(sp)\n"
+" ld ra,8(sp)\n"
+" addi sp,sp,16\n"
+" jr t0\n"
+" .size my_tramp1, .-my_tramp1\n"
+
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:\n"
+" addi sp,sp,-16\n"
+" sd t0,0(sp)\n"
+" sd ra,8(sp)\n"
+" call my_direct_func2\n"
+" ld t0,0(sp)\n"
+" ld ra,8(sp)\n"
+" addi sp,sp,16\n"
+" jr t0\n"
+" .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_RISCV */
+
#ifdef CONFIG_X86_64
#include <asm/ibt.h>
diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c
index 62f6b681999e..5a81af7b3af3 100644
--- a/samples/ftrace/ftrace-direct-multi-modify.c
+++ b/samples/ftrace/ftrace-direct-multi-modify.c
@@ -20,6 +20,46 @@ void my_direct_func2(unsigned long ip)
extern void my_tramp1(void *);
extern void my_tramp2(void *);
+#ifdef CONFIG_RISCV
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:\n"
+" addi sp,sp,-24\n"
+" sd a0,0(sp)\n"
+" sd t0,8(sp)\n"
+" sd ra,16(sp)\n"
+" mv a0,t0\n"
+" call my_direct_func1\n"
+" ld a0,0(sp)\n"
+" ld t0,8(sp)\n"
+" ld ra,16(sp)\n"
+" addi sp,sp,24\n"
+" jr t0\n"
+" .size my_tramp1, .-my_tramp1\n"
+
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:\n"
+" addi sp,sp,-24\n"
+" sd a0,0(sp)\n"
+" sd t0,8(sp)\n"
+" sd ra,16(sp)\n"
+" mv a0,t0\n"
+" call my_direct_func2\n"
+" ld a0,0(sp)\n"
+" ld t0,8(sp)\n"
+" ld ra,16(sp)\n"
+" addi sp,sp,24\n"
+" jr t0\n"
+" .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_RISCV */
+
#ifdef CONFIG_X86_64
#include <asm/ibt.h>
diff --git a/samples/ftrace/ftrace-direct-multi.c b/samples/ftrace/ftrace-direct-multi.c
index 5482cf616b43..0e9bb94edade 100644
--- a/samples/ftrace/ftrace-direct-multi.c
+++ b/samples/ftrace/ftrace-direct-multi.c
@@ -15,6 +15,30 @@ void my_direct_func(unsigned long ip)
extern void my_tramp(void *);
+#ifdef CONFIG_RISCV
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:\n"
+" addi sp,sp,-24\n"
+" sd a0,0(sp)\n"
+" sd t0,8(sp)\n"
+" sd ra,16(sp)\n"
+" mv a0,t0\n"
+" call my_direct_func\n"
+" ld a0,0(sp)\n"
+" ld t0,8(sp)\n"
+" ld ra,16(sp)\n"
+" addi sp,sp,24\n"
+" jr t0\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_RISCV */
+
#ifdef CONFIG_X86_64
#include <asm/ibt.h>
diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
index a05bc2cc2261..5c319db48af2 100644
--- a/samples/ftrace/ftrace-direct-too.c
+++ b/samples/ftrace/ftrace-direct-too.c
@@ -17,6 +17,33 @@ void my_direct_func(struct vm_area_struct *vma,
extern void my_tramp(void *);
+#ifdef CONFIG_RISCV
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:\n"
+" addi sp,sp,-40\n"
+" sd a0,0(sp)\n"
+" sd a1,8(sp)\n"
+" sd a2,16(sp)\n"
+" sd t0,24(sp)\n"
+" sd ra,32(sp)\n"
+" call my_direct_func\n"
+" ld a0,0(sp)\n"
+" ld a1,8(sp)\n"
+" ld a2,16(sp)\n"
+" ld t0,24(sp)\n"
+" ld ra,32(sp)\n"
+" addi sp,sp,40\n"
+" jr t0\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_RISCV */
+
#ifdef CONFIG_X86_64
#include <asm/ibt.h>
diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
index 06879bbd3399..ca95506b0350 100644
--- a/samples/ftrace/ftrace-direct.c
+++ b/samples/ftrace/ftrace-direct.c
@@ -14,6 +14,29 @@ void my_direct_func(struct task_struct *p)
extern void my_tramp(void *);
+#ifdef CONFIG_RISCV
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:\n"
+" addi sp,sp,-24\n"
+" sd a0,0(sp)\n"
+" sd t0,8(sp)\n"
+" sd ra,16(sp)\n"
+" call my_direct_func\n"
+" ld a0,0(sp)\n"
+" ld t0,8(sp)\n"
+" ld ra,16(sp)\n"
+" addi sp,sp,24\n"
+" jr t0\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_RISCV */
+
#ifdef CONFIG_X86_64
#include <asm/ibt.h>
--
2.20.1
^ permalink raw reply related [flat|nested] 28+ messages in thread
* [PATCH V11 4/5] samples: ftrace: Add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI]
@ 2023-06-27 11:16 ` Song Shuai
0 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-06-27 11:16 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, suagrfillet, bjorn, jszhang, conor.dooley
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai,
Evgenii Shatokhin
select HAVE_SAMPLE_FTRACE_DIRECT and HAVE_SAMPLE_FTRACE_DIRECT_MULTI
for ARCH_RV64I in arch/riscv/Kconfig. And add riscv asm code for
the ftrace-direct*.c files in samples/ftrace/.
Link: https://lore.kernel.org/linux-riscv/c68bac83-5c88-80b1-bac9-e1fd4ea8f07e@yadro.com/T/#ma13012560331c66b051b580b3ab4a04ba44455ec
Tested-by: Evgenii Shatokhin <e.shatokhin@yadro.com>
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Tested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
---
arch/riscv/Kconfig | 2 ++
samples/ftrace/ftrace-direct-modify.c | 34 ++++++++++++++++++
samples/ftrace/ftrace-direct-multi-modify.c | 40 +++++++++++++++++++++
samples/ftrace/ftrace-direct-multi.c | 24 +++++++++++++
samples/ftrace/ftrace-direct-too.c | 27 ++++++++++++++
samples/ftrace/ftrace-direct.c | 23 ++++++++++++
6 files changed, 150 insertions(+)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index c3e678450acf..35d8255a12c6 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -122,6 +122,8 @@ config RISCV
select HAVE_POSIX_CPU_TIMERS_TASK_WORK
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_RSEQ
+ select HAVE_SAMPLE_FTRACE_DIRECT
+ select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
select IRQ_DOMAIN
diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
index 06d889149012..e90ca7b68314 100644
--- a/samples/ftrace/ftrace-direct-modify.c
+++ b/samples/ftrace/ftrace-direct-modify.c
@@ -22,6 +22,40 @@ extern void my_tramp2(void *);
static unsigned long my_ip = (unsigned long)schedule;
+#ifdef CONFIG_RISCV
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:\n"
+" addi sp,sp,-16\n"
+" sd t0,0(sp)\n"
+" sd ra,8(sp)\n"
+" call my_direct_func1\n"
+" ld t0,0(sp)\n"
+" ld ra,8(sp)\n"
+" addi sp,sp,16\n"
+" jr t0\n"
+" .size my_tramp1, .-my_tramp1\n"
+
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:\n"
+" addi sp,sp,-16\n"
+" sd t0,0(sp)\n"
+" sd ra,8(sp)\n"
+" call my_direct_func2\n"
+" ld t0,0(sp)\n"
+" ld ra,8(sp)\n"
+" addi sp,sp,16\n"
+" jr t0\n"
+" .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_RISCV */
+
#ifdef CONFIG_X86_64
#include <asm/ibt.h>
diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c
index 62f6b681999e..5a81af7b3af3 100644
--- a/samples/ftrace/ftrace-direct-multi-modify.c
+++ b/samples/ftrace/ftrace-direct-multi-modify.c
@@ -20,6 +20,46 @@ void my_direct_func2(unsigned long ip)
extern void my_tramp1(void *);
extern void my_tramp2(void *);
+#ifdef CONFIG_RISCV
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:\n"
+" addi sp,sp,-24\n"
+" sd a0,0(sp)\n"
+" sd t0,8(sp)\n"
+" sd ra,16(sp)\n"
+" mv a0,t0\n"
+" call my_direct_func1\n"
+" ld a0,0(sp)\n"
+" ld t0,8(sp)\n"
+" ld ra,16(sp)\n"
+" addi sp,sp,24\n"
+" jr t0\n"
+" .size my_tramp1, .-my_tramp1\n"
+
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:\n"
+" addi sp,sp,-24\n"
+" sd a0,0(sp)\n"
+" sd t0,8(sp)\n"
+" sd ra,16(sp)\n"
+" mv a0,t0\n"
+" call my_direct_func2\n"
+" ld a0,0(sp)\n"
+" ld t0,8(sp)\n"
+" ld ra,16(sp)\n"
+" addi sp,sp,24\n"
+" jr t0\n"
+" .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_RISCV */
+
#ifdef CONFIG_X86_64
#include <asm/ibt.h>
diff --git a/samples/ftrace/ftrace-direct-multi.c b/samples/ftrace/ftrace-direct-multi.c
index 5482cf616b43..0e9bb94edade 100644
--- a/samples/ftrace/ftrace-direct-multi.c
+++ b/samples/ftrace/ftrace-direct-multi.c
@@ -15,6 +15,30 @@ void my_direct_func(unsigned long ip)
extern void my_tramp(void *);
+#ifdef CONFIG_RISCV
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:\n"
+" addi sp,sp,-24\n"
+" sd a0,0(sp)\n"
+" sd t0,8(sp)\n"
+" sd ra,16(sp)\n"
+" mv a0,t0\n"
+" call my_direct_func\n"
+" ld a0,0(sp)\n"
+" ld t0,8(sp)\n"
+" ld ra,16(sp)\n"
+" addi sp,sp,24\n"
+" jr t0\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_RISCV */
+
#ifdef CONFIG_X86_64
#include <asm/ibt.h>
diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
index a05bc2cc2261..5c319db48af2 100644
--- a/samples/ftrace/ftrace-direct-too.c
+++ b/samples/ftrace/ftrace-direct-too.c
@@ -17,6 +17,33 @@ void my_direct_func(struct vm_area_struct *vma,
extern void my_tramp(void *);
+#ifdef CONFIG_RISCV
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:\n"
+" addi sp,sp,-40\n"
+" sd a0,0(sp)\n"
+" sd a1,8(sp)\n"
+" sd a2,16(sp)\n"
+" sd t0,24(sp)\n"
+" sd ra,32(sp)\n"
+" call my_direct_func\n"
+" ld a0,0(sp)\n"
+" ld a1,8(sp)\n"
+" ld a2,16(sp)\n"
+" ld t0,24(sp)\n"
+" ld ra,32(sp)\n"
+" addi sp,sp,40\n"
+" jr t0\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_RISCV */
+
#ifdef CONFIG_X86_64
#include <asm/ibt.h>
diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
index 06879bbd3399..ca95506b0350 100644
--- a/samples/ftrace/ftrace-direct.c
+++ b/samples/ftrace/ftrace-direct.c
@@ -14,6 +14,29 @@ void my_direct_func(struct task_struct *p)
extern void my_tramp(void *);
+#ifdef CONFIG_RISCV
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp, @function\n"
+" .globl my_tramp\n"
+" my_tramp:\n"
+" addi sp,sp,-24\n"
+" sd a0,0(sp)\n"
+" sd t0,8(sp)\n"
+" sd ra,16(sp)\n"
+" call my_direct_func\n"
+" ld a0,0(sp)\n"
+" ld t0,8(sp)\n"
+" ld ra,16(sp)\n"
+" addi sp,sp,24\n"
+" jr t0\n"
+" .size my_tramp, .-my_tramp\n"
+" .popsection\n"
+);
+
+#endif /* CONFIG_RISCV */
+
#ifdef CONFIG_X86_64
#include <asm/ibt.h>
--
2.20.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 28+ messages in thread
* [PATCH V11 5/5] samples: ftrace: Make the riscv samples support RV32I
2023-06-27 11:16 ` Song Shuai
@ 2023-06-27 11:16 ` Song Shuai
-1 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-06-27 11:16 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, suagrfillet, bjorn, jszhang, conor.dooley
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai
Since the commit f32b4b467ebd ("RISC-V: enable dynamic ftrace for
RV32I") enables dynamic ftrace for RV32I, make these riscv samples
also support RV32I.
Link: https://lore.kernel.org/all/mhng-29a592bf-1b25-4c6c-8f37-0d05d39bc093@palmer-ri-x1c9a/
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
---
samples/ftrace/ftrace-direct-modify.c | 27 +++++++++--------
samples/ftrace/ftrace-direct-multi-modify.c | 33 +++++++++++----------
samples/ftrace/ftrace-direct-multi.c | 17 ++++++-----
samples/ftrace/ftrace-direct-too.c | 25 ++++++++--------
samples/ftrace/ftrace-direct.c | 17 ++++++-----
5 files changed, 62 insertions(+), 57 deletions(-)
diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
index e90ca7b68314..071cf4093a24 100644
--- a/samples/ftrace/ftrace-direct-modify.c
+++ b/samples/ftrace/ftrace-direct-modify.c
@@ -23,32 +23,33 @@ extern void my_tramp2(void *);
static unsigned long my_ip = (unsigned long)schedule;
#ifdef CONFIG_RISCV
+#include <asm/asm.h>
asm (
" .pushsection .text, \"ax\", @progbits\n"
" .type my_tramp1, @function\n"
" .globl my_tramp1\n"
" my_tramp1:\n"
-" addi sp,sp,-16\n"
-" sd t0,0(sp)\n"
-" sd ra,8(sp)\n"
+" addi sp,sp,-2*"SZREG"\n"
+" "REG_S" t0,0*"SZREG"(sp)\n"
+" "REG_S" ra,1*"SZREG"(sp)\n"
" call my_direct_func1\n"
-" ld t0,0(sp)\n"
-" ld ra,8(sp)\n"
-" addi sp,sp,16\n"
+" "REG_L" t0,0*"SZREG"(sp)\n"
+" "REG_L" ra,1*"SZREG"(sp)\n"
+" addi sp,sp,2*"SZREG"\n"
" jr t0\n"
" .size my_tramp1, .-my_tramp1\n"
-
" .type my_tramp2, @function\n"
" .globl my_tramp2\n"
+
" my_tramp2:\n"
-" addi sp,sp,-16\n"
-" sd t0,0(sp)\n"
-" sd ra,8(sp)\n"
+" addi sp,sp,-2*"SZREG"\n"
+" "REG_S" t0,0*"SZREG"(sp)\n"
+" "REG_S" ra,1*"SZREG"(sp)\n"
" call my_direct_func2\n"
-" ld t0,0(sp)\n"
-" ld ra,8(sp)\n"
-" addi sp,sp,16\n"
+" "REG_L" t0,0*"SZREG"(sp)\n"
+" "REG_L" ra,1*"SZREG"(sp)\n"
+" addi sp,sp,2*"SZREG"\n"
" jr t0\n"
" .size my_tramp2, .-my_tramp2\n"
" .popsection\n"
diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c
index 5a81af7b3af3..b754803d0a50 100644
--- a/samples/ftrace/ftrace-direct-multi-modify.c
+++ b/samples/ftrace/ftrace-direct-multi-modify.c
@@ -21,38 +21,39 @@ extern void my_tramp1(void *);
extern void my_tramp2(void *);
#ifdef CONFIG_RISCV
+#include <asm/asm.h>
asm (
" .pushsection .text, \"ax\", @progbits\n"
" .type my_tramp1, @function\n"
" .globl my_tramp1\n"
" my_tramp1:\n"
-" addi sp,sp,-24\n"
-" sd a0,0(sp)\n"
-" sd t0,8(sp)\n"
-" sd ra,16(sp)\n"
+" addi sp,sp,-3*"SZREG"\n"
+" "REG_S" a0,0*"SZREG"(sp)\n"
+" "REG_S" t0,1*"SZREG"(sp)\n"
+" "REG_S" ra,2*"SZREG"(sp)\n"
" mv a0,t0\n"
" call my_direct_func1\n"
-" ld a0,0(sp)\n"
-" ld t0,8(sp)\n"
-" ld ra,16(sp)\n"
-" addi sp,sp,24\n"
+" "REG_L" a0,0*"SZREG"(sp)\n"
+" "REG_L" t0,1*"SZREG"(sp)\n"
+" "REG_L" ra,2*"SZREG"(sp)\n"
+" addi sp,sp,3*"SZREG"\n"
" jr t0\n"
" .size my_tramp1, .-my_tramp1\n"
" .type my_tramp2, @function\n"
" .globl my_tramp2\n"
" my_tramp2:\n"
-" addi sp,sp,-24\n"
-" sd a0,0(sp)\n"
-" sd t0,8(sp)\n"
-" sd ra,16(sp)\n"
+" addi sp,sp,-3*"SZREG"\n"
+" "REG_S" a0,0*"SZREG"(sp)\n"
+" "REG_S" t0,1*"SZREG"(sp)\n"
+" "REG_S" ra,2*"SZREG"(sp)\n"
" mv a0,t0\n"
" call my_direct_func2\n"
-" ld a0,0(sp)\n"
-" ld t0,8(sp)\n"
-" ld ra,16(sp)\n"
-" addi sp,sp,24\n"
+" "REG_L" a0,0*"SZREG"(sp)\n"
+" "REG_L" t0,1*"SZREG"(sp)\n"
+" "REG_L" ra,2*"SZREG"(sp)\n"
+" addi sp,sp,3*"SZREG"\n"
" jr t0\n"
" .size my_tramp2, .-my_tramp2\n"
" .popsection\n"
diff --git a/samples/ftrace/ftrace-direct-multi.c b/samples/ftrace/ftrace-direct-multi.c
index 0e9bb94edade..a31f43ace85c 100644
--- a/samples/ftrace/ftrace-direct-multi.c
+++ b/samples/ftrace/ftrace-direct-multi.c
@@ -16,22 +16,23 @@ void my_direct_func(unsigned long ip)
extern void my_tramp(void *);
#ifdef CONFIG_RISCV
+#include <asm/asm.h>
asm (
" .pushsection .text, \"ax\", @progbits\n"
" .type my_tramp, @function\n"
" .globl my_tramp\n"
" my_tramp:\n"
-" addi sp,sp,-24\n"
-" sd a0,0(sp)\n"
-" sd t0,8(sp)\n"
-" sd ra,16(sp)\n"
+" addi sp,sp,-3*"SZREG"\n"
+" "REG_S" a0,0*"SZREG"(sp)\n"
+" "REG_S" t0,1*"SZREG"(sp)\n"
+" "REG_S" ra,2*"SZREG"(sp)\n"
" mv a0,t0\n"
" call my_direct_func\n"
-" ld a0,0(sp)\n"
-" ld t0,8(sp)\n"
-" ld ra,16(sp)\n"
-" addi sp,sp,24\n"
+" "REG_L" a0,0*"SZREG"(sp)\n"
+" "REG_L" t0,1*"SZREG"(sp)\n"
+" "REG_L" ra,2*"SZREG"(sp)\n"
+" addi sp,sp,3*"SZREG"\n"
" jr t0\n"
" .size my_tramp, .-my_tramp\n"
" .popsection\n"
diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
index 5c319db48af2..a1f86dd48847 100644
--- a/samples/ftrace/ftrace-direct-too.c
+++ b/samples/ftrace/ftrace-direct-too.c
@@ -18,25 +18,26 @@ void my_direct_func(struct vm_area_struct *vma,
extern void my_tramp(void *);
#ifdef CONFIG_RISCV
+#include <asm/asm.h>
asm (
" .pushsection .text, \"ax\", @progbits\n"
" .type my_tramp, @function\n"
" .globl my_tramp\n"
" my_tramp:\n"
-" addi sp,sp,-40\n"
-" sd a0,0(sp)\n"
-" sd a1,8(sp)\n"
-" sd a2,16(sp)\n"
-" sd t0,24(sp)\n"
-" sd ra,32(sp)\n"
+" addi sp,sp,-5*"SZREG"\n"
+" "REG_S" a0,0*"SZREG"(sp)\n"
+" "REG_S" a1,1*"SZREG"(sp)\n"
+" "REG_S" a2,2*"SZREG"(sp)\n"
+" "REG_S" t0,3*"SZREG"(sp)\n"
+" "REG_S" ra,4*"SZREG"(sp)\n"
" call my_direct_func\n"
-" ld a0,0(sp)\n"
-" ld a1,8(sp)\n"
-" ld a2,16(sp)\n"
-" ld t0,24(sp)\n"
-" ld ra,32(sp)\n"
-" addi sp,sp,40\n"
+" "REG_L" a0,0*"SZREG"(sp)\n"
+" "REG_L" a1,1*"SZREG"(sp)\n"
+" "REG_L" a2,2*"SZREG"(sp)\n"
+" "REG_L" t0,3*"SZREG"(sp)\n"
+" "REG_L" ra,4*"SZREG"(sp)\n"
+" addi sp,sp,5*"SZREG"\n"
" jr t0\n"
" .size my_tramp, .-my_tramp\n"
" .popsection\n"
diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
index ca95506b0350..fe6b7ef0a2d5 100644
--- a/samples/ftrace/ftrace-direct.c
+++ b/samples/ftrace/ftrace-direct.c
@@ -15,21 +15,22 @@ void my_direct_func(struct task_struct *p)
extern void my_tramp(void *);
#ifdef CONFIG_RISCV
+#include <asm/asm.h>
asm (
" .pushsection .text, \"ax\", @progbits\n"
" .type my_tramp, @function\n"
" .globl my_tramp\n"
" my_tramp:\n"
-" addi sp,sp,-24\n"
-" sd a0,0(sp)\n"
-" sd t0,8(sp)\n"
-" sd ra,16(sp)\n"
+" addi sp,sp,-3*"SZREG"\n"
+" "REG_S" a0,0*"SZREG"(sp)\n"
+" "REG_S" t0,1*"SZREG"(sp)\n"
+" "REG_S" ra,2*"SZREG"(sp)\n"
" call my_direct_func\n"
-" ld a0,0(sp)\n"
-" ld t0,8(sp)\n"
-" ld ra,16(sp)\n"
-" addi sp,sp,24\n"
+" "REG_L" a0,0*"SZREG"(sp)\n"
+" "REG_L" t0,1*"SZREG"(sp)\n"
+" "REG_L" ra,2*"SZREG"(sp)\n"
+" addi sp,sp,3*"SZREG"\n"
" jr t0\n"
" .size my_tramp, .-my_tramp\n"
" .popsection\n"
--
2.20.1
^ permalink raw reply related [flat|nested] 28+ messages in thread
* [PATCH V11 5/5] samples: ftrace: Make the riscv samples support RV32I
@ 2023-06-27 11:16 ` Song Shuai
0 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-06-27 11:16 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, suagrfillet, bjorn, jszhang, conor.dooley
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai
Since the commit f32b4b467ebd ("RISC-V: enable dynamic ftrace for
RV32I") enables dynamic ftrace for RV32I, make these riscv samples
also support RV32I.
Link: https://lore.kernel.org/all/mhng-29a592bf-1b25-4c6c-8f37-0d05d39bc093@palmer-ri-x1c9a/
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
---
samples/ftrace/ftrace-direct-modify.c | 27 +++++++++--------
samples/ftrace/ftrace-direct-multi-modify.c | 33 +++++++++++----------
samples/ftrace/ftrace-direct-multi.c | 17 ++++++-----
samples/ftrace/ftrace-direct-too.c | 25 ++++++++--------
samples/ftrace/ftrace-direct.c | 17 ++++++-----
5 files changed, 62 insertions(+), 57 deletions(-)
diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
index e90ca7b68314..071cf4093a24 100644
--- a/samples/ftrace/ftrace-direct-modify.c
+++ b/samples/ftrace/ftrace-direct-modify.c
@@ -23,32 +23,33 @@ extern void my_tramp2(void *);
static unsigned long my_ip = (unsigned long)schedule;
#ifdef CONFIG_RISCV
+#include <asm/asm.h>
asm (
" .pushsection .text, \"ax\", @progbits\n"
" .type my_tramp1, @function\n"
" .globl my_tramp1\n"
" my_tramp1:\n"
-" addi sp,sp,-16\n"
-" sd t0,0(sp)\n"
-" sd ra,8(sp)\n"
+" addi sp,sp,-2*"SZREG"\n"
+" "REG_S" t0,0*"SZREG"(sp)\n"
+" "REG_S" ra,1*"SZREG"(sp)\n"
" call my_direct_func1\n"
-" ld t0,0(sp)\n"
-" ld ra,8(sp)\n"
-" addi sp,sp,16\n"
+" "REG_L" t0,0*"SZREG"(sp)\n"
+" "REG_L" ra,1*"SZREG"(sp)\n"
+" addi sp,sp,2*"SZREG"\n"
" jr t0\n"
" .size my_tramp1, .-my_tramp1\n"
-
" .type my_tramp2, @function\n"
" .globl my_tramp2\n"
+
" my_tramp2:\n"
-" addi sp,sp,-16\n"
-" sd t0,0(sp)\n"
-" sd ra,8(sp)\n"
+" addi sp,sp,-2*"SZREG"\n"
+" "REG_S" t0,0*"SZREG"(sp)\n"
+" "REG_S" ra,1*"SZREG"(sp)\n"
" call my_direct_func2\n"
-" ld t0,0(sp)\n"
-" ld ra,8(sp)\n"
-" addi sp,sp,16\n"
+" "REG_L" t0,0*"SZREG"(sp)\n"
+" "REG_L" ra,1*"SZREG"(sp)\n"
+" addi sp,sp,2*"SZREG"\n"
" jr t0\n"
" .size my_tramp2, .-my_tramp2\n"
" .popsection\n"
diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c
index 5a81af7b3af3..b754803d0a50 100644
--- a/samples/ftrace/ftrace-direct-multi-modify.c
+++ b/samples/ftrace/ftrace-direct-multi-modify.c
@@ -21,38 +21,39 @@ extern void my_tramp1(void *);
extern void my_tramp2(void *);
#ifdef CONFIG_RISCV
+#include <asm/asm.h>
asm (
" .pushsection .text, \"ax\", @progbits\n"
" .type my_tramp1, @function\n"
" .globl my_tramp1\n"
" my_tramp1:\n"
-" addi sp,sp,-24\n"
-" sd a0,0(sp)\n"
-" sd t0,8(sp)\n"
-" sd ra,16(sp)\n"
+" addi sp,sp,-3*"SZREG"\n"
+" "REG_S" a0,0*"SZREG"(sp)\n"
+" "REG_S" t0,1*"SZREG"(sp)\n"
+" "REG_S" ra,2*"SZREG"(sp)\n"
" mv a0,t0\n"
" call my_direct_func1\n"
-" ld a0,0(sp)\n"
-" ld t0,8(sp)\n"
-" ld ra,16(sp)\n"
-" addi sp,sp,24\n"
+" "REG_L" a0,0*"SZREG"(sp)\n"
+" "REG_L" t0,1*"SZREG"(sp)\n"
+" "REG_L" ra,2*"SZREG"(sp)\n"
+" addi sp,sp,3*"SZREG"\n"
" jr t0\n"
" .size my_tramp1, .-my_tramp1\n"
" .type my_tramp2, @function\n"
" .globl my_tramp2\n"
" my_tramp2:\n"
-" addi sp,sp,-24\n"
-" sd a0,0(sp)\n"
-" sd t0,8(sp)\n"
-" sd ra,16(sp)\n"
+" addi sp,sp,-3*"SZREG"\n"
+" "REG_S" a0,0*"SZREG"(sp)\n"
+" "REG_S" t0,1*"SZREG"(sp)\n"
+" "REG_S" ra,2*"SZREG"(sp)\n"
" mv a0,t0\n"
" call my_direct_func2\n"
-" ld a0,0(sp)\n"
-" ld t0,8(sp)\n"
-" ld ra,16(sp)\n"
-" addi sp,sp,24\n"
+" "REG_L" a0,0*"SZREG"(sp)\n"
+" "REG_L" t0,1*"SZREG"(sp)\n"
+" "REG_L" ra,2*"SZREG"(sp)\n"
+" addi sp,sp,3*"SZREG"\n"
" jr t0\n"
" .size my_tramp2, .-my_tramp2\n"
" .popsection\n"
diff --git a/samples/ftrace/ftrace-direct-multi.c b/samples/ftrace/ftrace-direct-multi.c
index 0e9bb94edade..a31f43ace85c 100644
--- a/samples/ftrace/ftrace-direct-multi.c
+++ b/samples/ftrace/ftrace-direct-multi.c
@@ -16,22 +16,23 @@ void my_direct_func(unsigned long ip)
extern void my_tramp(void *);
#ifdef CONFIG_RISCV
+#include <asm/asm.h>
asm (
" .pushsection .text, \"ax\", @progbits\n"
" .type my_tramp, @function\n"
" .globl my_tramp\n"
" my_tramp:\n"
-" addi sp,sp,-24\n"
-" sd a0,0(sp)\n"
-" sd t0,8(sp)\n"
-" sd ra,16(sp)\n"
+" addi sp,sp,-3*"SZREG"\n"
+" "REG_S" a0,0*"SZREG"(sp)\n"
+" "REG_S" t0,1*"SZREG"(sp)\n"
+" "REG_S" ra,2*"SZREG"(sp)\n"
" mv a0,t0\n"
" call my_direct_func\n"
-" ld a0,0(sp)\n"
-" ld t0,8(sp)\n"
-" ld ra,16(sp)\n"
-" addi sp,sp,24\n"
+" "REG_L" a0,0*"SZREG"(sp)\n"
+" "REG_L" t0,1*"SZREG"(sp)\n"
+" "REG_L" ra,2*"SZREG"(sp)\n"
+" addi sp,sp,3*"SZREG"\n"
" jr t0\n"
" .size my_tramp, .-my_tramp\n"
" .popsection\n"
diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
index 5c319db48af2..a1f86dd48847 100644
--- a/samples/ftrace/ftrace-direct-too.c
+++ b/samples/ftrace/ftrace-direct-too.c
@@ -18,25 +18,26 @@ void my_direct_func(struct vm_area_struct *vma,
extern void my_tramp(void *);
#ifdef CONFIG_RISCV
+#include <asm/asm.h>
asm (
" .pushsection .text, \"ax\", @progbits\n"
" .type my_tramp, @function\n"
" .globl my_tramp\n"
" my_tramp:\n"
-" addi sp,sp,-40\n"
-" sd a0,0(sp)\n"
-" sd a1,8(sp)\n"
-" sd a2,16(sp)\n"
-" sd t0,24(sp)\n"
-" sd ra,32(sp)\n"
+" addi sp,sp,-5*"SZREG"\n"
+" "REG_S" a0,0*"SZREG"(sp)\n"
+" "REG_S" a1,1*"SZREG"(sp)\n"
+" "REG_S" a2,2*"SZREG"(sp)\n"
+" "REG_S" t0,3*"SZREG"(sp)\n"
+" "REG_S" ra,4*"SZREG"(sp)\n"
" call my_direct_func\n"
-" ld a0,0(sp)\n"
-" ld a1,8(sp)\n"
-" ld a2,16(sp)\n"
-" ld t0,24(sp)\n"
-" ld ra,32(sp)\n"
-" addi sp,sp,40\n"
+" "REG_L" a0,0*"SZREG"(sp)\n"
+" "REG_L" a1,1*"SZREG"(sp)\n"
+" "REG_L" a2,2*"SZREG"(sp)\n"
+" "REG_L" t0,3*"SZREG"(sp)\n"
+" "REG_L" ra,4*"SZREG"(sp)\n"
+" addi sp,sp,5*"SZREG"\n"
" jr t0\n"
" .size my_tramp, .-my_tramp\n"
" .popsection\n"
diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
index ca95506b0350..fe6b7ef0a2d5 100644
--- a/samples/ftrace/ftrace-direct.c
+++ b/samples/ftrace/ftrace-direct.c
@@ -15,21 +15,22 @@ void my_direct_func(struct task_struct *p)
extern void my_tramp(void *);
#ifdef CONFIG_RISCV
+#include <asm/asm.h>
asm (
" .pushsection .text, \"ax\", @progbits\n"
" .type my_tramp, @function\n"
" .globl my_tramp\n"
" my_tramp:\n"
-" addi sp,sp,-24\n"
-" sd a0,0(sp)\n"
-" sd t0,8(sp)\n"
-" sd ra,16(sp)\n"
+" addi sp,sp,-3*"SZREG"\n"
+" "REG_S" a0,0*"SZREG"(sp)\n"
+" "REG_S" t0,1*"SZREG"(sp)\n"
+" "REG_S" ra,2*"SZREG"(sp)\n"
" call my_direct_func\n"
-" ld a0,0(sp)\n"
-" ld t0,8(sp)\n"
-" ld ra,16(sp)\n"
-" addi sp,sp,24\n"
+" "REG_L" a0,0*"SZREG"(sp)\n"
+" "REG_L" t0,1*"SZREG"(sp)\n"
+" "REG_L" ra,2*"SZREG"(sp)\n"
+" addi sp,sp,3*"SZREG"\n"
" jr t0\n"
" .size my_tramp, .-my_tramp\n"
" .popsection\n"
--
2.20.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
2023-06-27 11:16 ` Song Shuai
@ 2023-07-06 9:35 ` Song Shuai
-1 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-07-06 9:35 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, bjorn, jszhang, conor.dooley
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai
Ping...
在 2023/6/27 19:16, Song Shuai 写道:
> Changes in V11:
>
> - append a patch that makes the DIRECT_CALL samples support RV32I in
> this series fixing the rv32 build failure reported by Palmer
>
> - validated with ftrace boottime selftest and manual sample modules test
> in qemu-system for RV32I and RV64I
>
> This series optimizes function trace. The first 3 independent
> patches has been picked in the V7 version of this series, the
> subsequent version continues the following 4 patches:
>
> select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY [1] (patch 1)
> ==========================================================
>
> In RISC-V, -fpatchable-function-entry option is used to support
> dynamic ftrace in this commit afc76b8b8011 ("riscv: Using
> PATCHABLE_FUNCTION_ENTRY instead of MCOUNT"). So recordmcount
> don't have to be called to create the __mcount_loc section before
> the vmlinux linking.
>
> Here selects FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY to tell
> Makefile not to run recordmcount.
>
> Make function graph use ftrace directly [2] (patch 2)
> ========================================================
>
> In RISC-V architecture, when we enable the ftrace_graph tracer on some
> functions, the function tracings on other functions will suffer extra
> graph tracing work. In essence, graph_ops isn't limited by its func_hash
> due to the global ftrace_graph_[regs]_call label. That should be
> corrected.
>
> What inspires me is the commit 0c0593b45c9b ("x86/ftrace: Make function
> graph use ftrace directly") that uses graph_ops::func function to
> install return_hooker and makes the function called against its
> func_hash.
>
> Add WITH_DIRECT_CALLS support [3] (patch 3, 4)
> ==============================================
>
> This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS support for RISC-V.
> SAMPLE_FTRACE_DIRECT and SAMPLE_FTRACE_DIRECT_MULTI are also included
> here as the samples for testing DIRECT_CALLS related interface.
>
> First, select the DYNAMIC_FTRACE_WITH_DIRECT_CALLS to provide
> register_ftrace_direct[_multi] interfaces allowing user to register
> the customed trampoline (direct_caller) as the mcount for one or
> more target functions. And modify_ftrace_direct[_multi] are also
> provided for modify direct_caller.
>
> At the same time, the samples in ./samples/ftrace/ can be built
> as kerenl module for testing these interfaces with SAMPLE_FTRACE_DIRECT
> and SAMPLE_FTRACE_DIRECT_MULTI selected.
>
> Second, to make the direct_caller and the other ftrace hooks
> (eg. function/fgraph tracer, k[ret]probes) co-exist, a temporary
> register
> are nominated to store the address of direct_caller in
> ftrace_regs_caller.
> After the setting of the address direct_caller by direct_ops->func and
> the RESTORE_REGS in ftrace_regs_caller, direct_caller will be jumped to
> by the `jr` inst.
>
> The series's old changes related these patches
> ==========================================
>
> Changes in v10:
> https://lore.kernel.org/all/20230511093234.3123181-1-suagrfillet@gmail.com/
>
> - add Acked-by from Björn Töpel in patch 2 and patch 4
> - replace `move` with `mv` in patch3
> - prettify patch 2/4 with proper tabs
>
> Changes in v9:
> https://lore.kernel.org/linux-riscv/20230510101857.2953955-1-suagrfillet@gmail.com/
>
> 1. add Acked-by from Björn Töpel in patch 1
>
> 2. rebase patch2/patch3 on Linux v6.4-rc1
>
> - patch 2: to make the `SAVE_ABI_REGS` configurable, revert the
> modification of mcount-dyn.S from commit (45b32b946a97 "riscv:
> entry: Consolidate general regs saving/restoring")
>
> - patch 3: to pass the trace_selftest, add the implement of
> `ftrace_stub_direct_tramp` from commit (fee86a4ed536 "ftrace:
> selftest: remove broken trace_direct_tramp") ; and fixup the context
> conflict in Kconfig
>
> Changes in v8:
> https://lore.kernel.org/linux-riscv/20230324033342.3177979-1-suagrfillet@gmail.com/
> - Fix incorrect address values in the 4nd patch
> - Rebased on v6.3-rc2
>
> Changes in v7:
> https://lore.kernel.org/linux-riscv/20230112090603.1295340-1-guoren@kernel.org/
> - Fixup RESTORE_ABI_REGS by remove PT_T0(sp) overwrite.
> - Add FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY [1]
> - Fixup kconfig with HAVE_SAMPLE_FTRACE_DIRECT &
> HAVE_SAMPLE_FTRACE_DIRECT_MULTI
>
> Changes in v6:
> https://lore.kernel.org/linux-riscv/20230107133549.4192639-1-guoren@kernel.org/
> - Replace 8 with MCOUNT_INSN_SIZE
> - Replace "REG_L a1, PT_RA(sp)" with "mv a1, ra"
> - Add Evgenii Shatokhin comment
>
> Changes in v5:
> https://lore.kernel.org/linux-riscv/20221208091244.203407-1-guoren@kernel.org/
> - Sort Kconfig entries in alphabetical order.
>
> Changes in v4:
> https://lore.kernel.org/linux-riscv/20221129033230.255947-1-guoren@kernel.org/
> - Include [3] for maintenance. [Song Shuai]
>
> Changes in V3:
> https://lore.kernel.org/linux-riscv/20221123153950.2911981-1-guoren@kernel.org/
> - Include [2] for maintenance. [Song Shuai]
>
> [1]: https://lore.kernel.org/linux-riscv/CAAYs2=j3Eak9vU6xbAw0zPuoh00rh8v5C2U3fePkokZFibWs2g@mail.gmail.com/T/#t
> [2]: https://lore.kernel.org/lkml/20221120084230.910152-1-suagrfillet@gmail.com/
> [3]: https://lore.kernel.org/linux-riscv/20221123142025.1504030-1-suagrfillet@gmail.com/
>
> Song Shuai (5):
> riscv: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
> riscv: ftrace: Add ftrace_graph_func
> riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support
> samples: ftrace: Add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI]
> samples: ftrace: Make the riscv samples support RV32I
>
> arch/riscv/Kconfig | 4 +
> arch/riscv/include/asm/ftrace.h | 19 +-
> arch/riscv/kernel/ftrace.c | 30 ++-
> arch/riscv/kernel/mcount-dyn.S | 200 ++++++++++++++++----
> samples/ftrace/ftrace-direct-modify.c | 35 ++++
> samples/ftrace/ftrace-direct-multi-modify.c | 41 ++++
> samples/ftrace/ftrace-direct-multi.c | 25 +++
> samples/ftrace/ftrace-direct-too.c | 28 +++
> samples/ftrace/ftrace-direct.c | 24 +++
> 9 files changed, 350 insertions(+), 56 deletions(-)
>
--
Thanks
Song Shuai
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
@ 2023-07-06 9:35 ` Song Shuai
0 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-07-06 9:35 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, bjorn, jszhang, conor.dooley
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai
Ping...
在 2023/6/27 19:16, Song Shuai 写道:
> Changes in V11:
>
> - append a patch that makes the DIRECT_CALL samples support RV32I in
> this series fixing the rv32 build failure reported by Palmer
>
> - validated with ftrace boottime selftest and manual sample modules test
> in qemu-system for RV32I and RV64I
>
> This series optimizes function trace. The first 3 independent
> patches has been picked in the V7 version of this series, the
> subsequent version continues the following 4 patches:
>
> select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY [1] (patch 1)
> ==========================================================
>
> In RISC-V, -fpatchable-function-entry option is used to support
> dynamic ftrace in this commit afc76b8b8011 ("riscv: Using
> PATCHABLE_FUNCTION_ENTRY instead of MCOUNT"). So recordmcount
> don't have to be called to create the __mcount_loc section before
> the vmlinux linking.
>
> Here selects FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY to tell
> Makefile not to run recordmcount.
>
> Make function graph use ftrace directly [2] (patch 2)
> ========================================================
>
> In RISC-V architecture, when we enable the ftrace_graph tracer on some
> functions, the function tracings on other functions will suffer extra
> graph tracing work. In essence, graph_ops isn't limited by its func_hash
> due to the global ftrace_graph_[regs]_call label. That should be
> corrected.
>
> What inspires me is the commit 0c0593b45c9b ("x86/ftrace: Make function
> graph use ftrace directly") that uses graph_ops::func function to
> install return_hooker and makes the function called against its
> func_hash.
>
> Add WITH_DIRECT_CALLS support [3] (patch 3, 4)
> ==============================================
>
> This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS support for RISC-V.
> SAMPLE_FTRACE_DIRECT and SAMPLE_FTRACE_DIRECT_MULTI are also included
> here as the samples for testing DIRECT_CALLS related interface.
>
> First, select the DYNAMIC_FTRACE_WITH_DIRECT_CALLS to provide
> register_ftrace_direct[_multi] interfaces allowing user to register
> the customed trampoline (direct_caller) as the mcount for one or
> more target functions. And modify_ftrace_direct[_multi] are also
> provided for modify direct_caller.
>
> At the same time, the samples in ./samples/ftrace/ can be built
> as kerenl module for testing these interfaces with SAMPLE_FTRACE_DIRECT
> and SAMPLE_FTRACE_DIRECT_MULTI selected.
>
> Second, to make the direct_caller and the other ftrace hooks
> (eg. function/fgraph tracer, k[ret]probes) co-exist, a temporary
> register
> are nominated to store the address of direct_caller in
> ftrace_regs_caller.
> After the setting of the address direct_caller by direct_ops->func and
> the RESTORE_REGS in ftrace_regs_caller, direct_caller will be jumped to
> by the `jr` inst.
>
> The series's old changes related these patches
> ==========================================
>
> Changes in v10:
> https://lore.kernel.org/all/20230511093234.3123181-1-suagrfillet@gmail.com/
>
> - add Acked-by from Björn Töpel in patch 2 and patch 4
> - replace `move` with `mv` in patch3
> - prettify patch 2/4 with proper tabs
>
> Changes in v9:
> https://lore.kernel.org/linux-riscv/20230510101857.2953955-1-suagrfillet@gmail.com/
>
> 1. add Acked-by from Björn Töpel in patch 1
>
> 2. rebase patch2/patch3 on Linux v6.4-rc1
>
> - patch 2: to make the `SAVE_ABI_REGS` configurable, revert the
> modification of mcount-dyn.S from commit (45b32b946a97 "riscv:
> entry: Consolidate general regs saving/restoring")
>
> - patch 3: to pass the trace_selftest, add the implement of
> `ftrace_stub_direct_tramp` from commit (fee86a4ed536 "ftrace:
> selftest: remove broken trace_direct_tramp") ; and fixup the context
> conflict in Kconfig
>
> Changes in v8:
> https://lore.kernel.org/linux-riscv/20230324033342.3177979-1-suagrfillet@gmail.com/
> - Fix incorrect address values in the 4nd patch
> - Rebased on v6.3-rc2
>
> Changes in v7:
> https://lore.kernel.org/linux-riscv/20230112090603.1295340-1-guoren@kernel.org/
> - Fixup RESTORE_ABI_REGS by remove PT_T0(sp) overwrite.
> - Add FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY [1]
> - Fixup kconfig with HAVE_SAMPLE_FTRACE_DIRECT &
> HAVE_SAMPLE_FTRACE_DIRECT_MULTI
>
> Changes in v6:
> https://lore.kernel.org/linux-riscv/20230107133549.4192639-1-guoren@kernel.org/
> - Replace 8 with MCOUNT_INSN_SIZE
> - Replace "REG_L a1, PT_RA(sp)" with "mv a1, ra"
> - Add Evgenii Shatokhin comment
>
> Changes in v5:
> https://lore.kernel.org/linux-riscv/20221208091244.203407-1-guoren@kernel.org/
> - Sort Kconfig entries in alphabetical order.
>
> Changes in v4:
> https://lore.kernel.org/linux-riscv/20221129033230.255947-1-guoren@kernel.org/
> - Include [3] for maintenance. [Song Shuai]
>
> Changes in V3:
> https://lore.kernel.org/linux-riscv/20221123153950.2911981-1-guoren@kernel.org/
> - Include [2] for maintenance. [Song Shuai]
>
> [1]: https://lore.kernel.org/linux-riscv/CAAYs2=j3Eak9vU6xbAw0zPuoh00rh8v5C2U3fePkokZFibWs2g@mail.gmail.com/T/#t
> [2]: https://lore.kernel.org/lkml/20221120084230.910152-1-suagrfillet@gmail.com/
> [3]: https://lore.kernel.org/linux-riscv/20221123142025.1504030-1-suagrfillet@gmail.com/
>
> Song Shuai (5):
> riscv: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY
> riscv: ftrace: Add ftrace_graph_func
> riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support
> samples: ftrace: Add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI]
> samples: ftrace: Make the riscv samples support RV32I
>
> arch/riscv/Kconfig | 4 +
> arch/riscv/include/asm/ftrace.h | 19 +-
> arch/riscv/kernel/ftrace.c | 30 ++-
> arch/riscv/kernel/mcount-dyn.S | 200 ++++++++++++++++----
> samples/ftrace/ftrace-direct-modify.c | 35 ++++
> samples/ftrace/ftrace-direct-multi-modify.c | 41 ++++
> samples/ftrace/ftrace-direct-multi.c | 25 +++
> samples/ftrace/ftrace-direct-too.c | 28 +++
> samples/ftrace/ftrace-direct.c | 24 +++
> 9 files changed, 350 insertions(+), 56 deletions(-)
>
--
Thanks
Song Shuai
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
2023-07-06 9:35 ` Song Shuai
@ 2023-07-06 9:53 ` Conor Dooley
-1 siblings, 0 replies; 28+ messages in thread
From: Conor Dooley @ 2023-07-06 9:53 UTC (permalink / raw)
To: Song Shuai
Cc: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, bjorn, jszhang, linux-riscv, linux-kernel,
linux-trace-kernel, songshuaishuai
[-- Attachment #1: Type: text/plain, Size: 499 bytes --]
On Thu, Jul 06, 2023 at 05:35:49PM +0800, Song Shuai wrote:
> Ping...
A context-less ping is not very helpful - what are you looking for here?
More reviews? For example, someone to look at 5/5?
> 在 2023/6/27 19:16, Song Shuai 写道:
If it's application you want, you sent the patch only last week - which
was during the merge window, making it unlikely to be applied.
Either way, please try to explain what it is that you are looking for
when you do a ping!
Cheers,
Conor.
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
@ 2023-07-06 9:53 ` Conor Dooley
0 siblings, 0 replies; 28+ messages in thread
From: Conor Dooley @ 2023-07-06 9:53 UTC (permalink / raw)
To: Song Shuai
Cc: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, bjorn, jszhang, linux-riscv, linux-kernel,
linux-trace-kernel, songshuaishuai
[-- Attachment #1.1: Type: text/plain, Size: 499 bytes --]
On Thu, Jul 06, 2023 at 05:35:49PM +0800, Song Shuai wrote:
> Ping...
A context-less ping is not very helpful - what are you looking for here?
More reviews? For example, someone to look at 5/5?
> 在 2023/6/27 19:16, Song Shuai 写道:
If it's application you want, you sent the patch only last week - which
was during the merge window, making it unlikely to be applied.
Either way, please try to explain what it is that you are looking for
when you do a ping!
Cheers,
Conor.
[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]
[-- Attachment #2: Type: text/plain, Size: 161 bytes --]
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
2023-07-06 9:53 ` Conor Dooley
@ 2023-07-06 10:10 ` Song Shuai
-1 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-07-06 10:10 UTC (permalink / raw)
To: Conor Dooley, Song Shuai
Cc: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, bjorn, jszhang, linux-riscv, linux-kernel,
linux-trace-kernel
在 2023/7/6 17:53, Conor Dooley 写道:
> On Thu, Jul 06, 2023 at 05:35:49PM +0800, Song Shuai wrote:
>> Ping...
>
> A context-less ping is not very helpful - what are you looking for here?
> More reviews? For example, someone to look at 5/5? >
Sorry for the context-less ping. I hoped someone could look at the 5th
patch.
>> 在 2023/6/27 19:16, Song Shuai 写道:
>
> If it's application you want, you sent the patch only last week - which
> was during the merge window, making it unlikely to be applied.
> > Either way, please try to explain what it is that you are looking for
> when you do a ping!
Thanks for your correction, I'll follow this thread after the merge
window closes.
>
> Cheers,
> Conor.
>
--
Thanks
Song Shuai
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
@ 2023-07-06 10:10 ` Song Shuai
0 siblings, 0 replies; 28+ messages in thread
From: Song Shuai @ 2023-07-06 10:10 UTC (permalink / raw)
To: Conor Dooley, Song Shuai
Cc: paul.walmsley, palmer, aou, rostedt, mhiramat, mark.rutland,
guoren, bjorn, jszhang, linux-riscv, linux-kernel,
linux-trace-kernel
在 2023/7/6 17:53, Conor Dooley 写道:
> On Thu, Jul 06, 2023 at 05:35:49PM +0800, Song Shuai wrote:
>> Ping...
>
> A context-less ping is not very helpful - what are you looking for here?
> More reviews? For example, someone to look at 5/5? >
Sorry for the context-less ping. I hoped someone could look at the 5th
patch.
>> 在 2023/6/27 19:16, Song Shuai 写道:
>
> If it's application you want, you sent the patch only last week - which
> was during the merge window, making it unlikely to be applied.
> > Either way, please try to explain what it is that you are looking for
> when you do a ping!
Thanks for your correction, I'll follow this thread after the merge
window closes.
>
> Cheers,
> Conor.
>
--
Thanks
Song Shuai
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
2023-06-27 11:16 ` Song Shuai
@ 2023-07-12 18:11 ` Björn Töpel
-1 siblings, 0 replies; 28+ messages in thread
From: Björn Töpel @ 2023-07-12 18:11 UTC (permalink / raw)
To: Song Shuai, paul.walmsley, palmer, aou, rostedt, mhiramat,
mark.rutland, guoren, suagrfillet, bjorn, jszhang, conor.dooley,
Pu Lehui, palmer
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai, bpf
Song Shuai <suagrfillet@gmail.com> writes:
[...]
> Add WITH_DIRECT_CALLS support [3] (patch 3, 4)
> ==============================================
We've had some offlist discussions, so here's some input for a wider
audience! Most importantly, this is for Palmer, so that this series is
not merged until a proper BPF trampoline fix is in place.
Note that what's currently usable from BPF trampoline *works*. It's
when this series is added that it breaks.
TL;DR This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS, which enables
fentry/fexit BPF trampoline support. Unfortunately the
fexit/BPF_TRAMP_F_SKIP_FRAME parts of the RV BPF trampoline breaks
with this addition, and need to be addressed *prior* merging this
series. An easy way to reproduce, is just calling any of the kselftest
tests that uses fexit patching.
The issue is around the nop seld, and how a call is done; The nop sled
(patchable-function-entry) size changed from 16B to 8B in commit
6724a76cff85 ("riscv: ftrace: Reduce the detour code size to half"), but
BPF code still uses the old 16B. So it'll work for BPF programs, but not
for regular kernel functions.
An example:
| ffffffff80fa4150 <bpf_fentry_test1>:
| ffffffff80fa4150: 0001 nop
| ffffffff80fa4152: 0001 nop
| ffffffff80fa4154: 0001 nop
| ffffffff80fa4156: 0001 nop
| ffffffff80fa4158: 1141 add sp,sp,-16
| ffffffff80fa415a: e422 sd s0,8(sp)
| ffffffff80fa415c: 0800 add s0,sp,16
| ffffffff80fa415e: 6422 ld s0,8(sp)
| ffffffff80fa4160: 2505 addw a0,a0,1
| ffffffff80fa4162: 0141 add sp,sp,16
| ffffffff80fa4164: 8082 ret
is patched to:
| ffffffff80fa4150: f70c0297 auipc t0,-150208512
| ffffffff80fa4154: eb0282e7 jalr t0,t0,-336
The return address to bpf_fentry_test1 is stored in t0 at BPF
trampoline entry. Return to the *parent* is in ra. The trampline has
to deal with this.
For BPF_TRAMP_F_SKIP_FRAME/CALL_ORIG, the BPF trampoline will skip too
many bytes, and not correctly handle parent calls.
Further; The BPF trampoline currently has a different way of patching
the nops for BPF programs, than what ftrace does. That should be changed
to match what ftrace does (auipc/jalr t0).
To summarize:
* Align BPF nop sled with patchable-function-entry: 8B.
* Adapt BPF trampoline for 8B nop sleds.
* Adapt BPF trampoline t0 return, ra parent scheme.
Cheers,
Björn
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
@ 2023-07-12 18:11 ` Björn Töpel
0 siblings, 0 replies; 28+ messages in thread
From: Björn Töpel @ 2023-07-12 18:11 UTC (permalink / raw)
To: Song Shuai, paul.walmsley, palmer, aou, rostedt, mhiramat,
mark.rutland, guoren, suagrfillet, bjorn, jszhang, conor.dooley,
Pu Lehui, palmer
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai, bpf
Song Shuai <suagrfillet@gmail.com> writes:
[...]
> Add WITH_DIRECT_CALLS support [3] (patch 3, 4)
> ==============================================
We've had some offlist discussions, so here's some input for a wider
audience! Most importantly, this is for Palmer, so that this series is
not merged until a proper BPF trampoline fix is in place.
Note that what's currently usable from BPF trampoline *works*. It's
when this series is added that it breaks.
TL;DR This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS, which enables
fentry/fexit BPF trampoline support. Unfortunately the
fexit/BPF_TRAMP_F_SKIP_FRAME parts of the RV BPF trampoline breaks
with this addition, and need to be addressed *prior* merging this
series. An easy way to reproduce, is just calling any of the kselftest
tests that uses fexit patching.
The issue is around the nop seld, and how a call is done; The nop sled
(patchable-function-entry) size changed from 16B to 8B in commit
6724a76cff85 ("riscv: ftrace: Reduce the detour code size to half"), but
BPF code still uses the old 16B. So it'll work for BPF programs, but not
for regular kernel functions.
An example:
| ffffffff80fa4150 <bpf_fentry_test1>:
| ffffffff80fa4150: 0001 nop
| ffffffff80fa4152: 0001 nop
| ffffffff80fa4154: 0001 nop
| ffffffff80fa4156: 0001 nop
| ffffffff80fa4158: 1141 add sp,sp,-16
| ffffffff80fa415a: e422 sd s0,8(sp)
| ffffffff80fa415c: 0800 add s0,sp,16
| ffffffff80fa415e: 6422 ld s0,8(sp)
| ffffffff80fa4160: 2505 addw a0,a0,1
| ffffffff80fa4162: 0141 add sp,sp,16
| ffffffff80fa4164: 8082 ret
is patched to:
| ffffffff80fa4150: f70c0297 auipc t0,-150208512
| ffffffff80fa4154: eb0282e7 jalr t0,t0,-336
The return address to bpf_fentry_test1 is stored in t0 at BPF
trampoline entry. Return to the *parent* is in ra. The trampline has
to deal with this.
For BPF_TRAMP_F_SKIP_FRAME/CALL_ORIG, the BPF trampoline will skip too
many bytes, and not correctly handle parent calls.
Further; The BPF trampoline currently has a different way of patching
the nops for BPF programs, than what ftrace does. That should be changed
to match what ftrace does (auipc/jalr t0).
To summarize:
* Align BPF nop sled with patchable-function-entry: 8B.
* Adapt BPF trampoline for 8B nop sleds.
* Adapt BPF trampoline t0 return, ra parent scheme.
Cheers,
Björn
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
2023-07-12 18:11 ` Björn Töpel
@ 2023-07-12 18:26 ` Palmer Dabbelt
-1 siblings, 0 replies; 28+ messages in thread
From: Palmer Dabbelt @ 2023-07-12 18:26 UTC (permalink / raw)
To: bjorn
Cc: suagrfillet, Paul Walmsley, aou, rostedt, mhiramat, Mark Rutland,
guoren, suagrfillet, Bjorn Topel, jszhang, Conor Dooley, pulehui,
linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai,
bpf
On Wed, 12 Jul 2023 11:11:08 PDT (-0700), bjorn@kernel.org wrote:
> Song Shuai <suagrfillet@gmail.com> writes:
>
> [...]
>
>> Add WITH_DIRECT_CALLS support [3] (patch 3, 4)
>> ==============================================
>
> We've had some offlist discussions, so here's some input for a wider
> audience! Most importantly, this is for Palmer, so that this series is
> not merged until a proper BPF trampoline fix is in place.
>
> Note that what's currently usable from BPF trampoline *works*. It's
> when this series is added that it breaks.
>
> TL;DR This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS, which enables
> fentry/fexit BPF trampoline support. Unfortunately the
> fexit/BPF_TRAMP_F_SKIP_FRAME parts of the RV BPF trampoline breaks
> with this addition, and need to be addressed *prior* merging this
> series. An easy way to reproduce, is just calling any of the kselftest
> tests that uses fexit patching.
>
> The issue is around the nop seld, and how a call is done; The nop sled
> (patchable-function-entry) size changed from 16B to 8B in commit
> 6724a76cff85 ("riscv: ftrace: Reduce the detour code size to half"), but
> BPF code still uses the old 16B. So it'll work for BPF programs, but not
> for regular kernel functions.
>
> An example:
>
> | ffffffff80fa4150 <bpf_fentry_test1>:
> | ffffffff80fa4150: 0001 nop
> | ffffffff80fa4152: 0001 nop
> | ffffffff80fa4154: 0001 nop
> | ffffffff80fa4156: 0001 nop
> | ffffffff80fa4158: 1141 add sp,sp,-16
> | ffffffff80fa415a: e422 sd s0,8(sp)
> | ffffffff80fa415c: 0800 add s0,sp,16
> | ffffffff80fa415e: 6422 ld s0,8(sp)
> | ffffffff80fa4160: 2505 addw a0,a0,1
> | ffffffff80fa4162: 0141 add sp,sp,16
> | ffffffff80fa4164: 8082 ret
>
> is patched to:
>
> | ffffffff80fa4150: f70c0297 auipc t0,-150208512
> | ffffffff80fa4154: eb0282e7 jalr t0,t0,-336
>
> The return address to bpf_fentry_test1 is stored in t0 at BPF
> trampoline entry. Return to the *parent* is in ra. The trampline has
> to deal with this.
>
> For BPF_TRAMP_F_SKIP_FRAME/CALL_ORIG, the BPF trampoline will skip too
> many bytes, and not correctly handle parent calls.
>
> Further; The BPF trampoline currently has a different way of patching
> the nops for BPF programs, than what ftrace does. That should be changed
> to match what ftrace does (auipc/jalr t0).
>
> To summarize:
> * Align BPF nop sled with patchable-function-entry: 8B.
> * Adapt BPF trampoline for 8B nop sleds.
> * Adapt BPF trampoline t0 return, ra parent scheme.
Thanks for digging into this one, I agree we need to sort out the BPF
breakages before we merge this. Sounds like there's a rabbit hole here,
but hopefully we can get it sorted out.
I've dropped this from patchwork and such, as we'll need at least
another spin.
> Cheers,
> Björn
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
@ 2023-07-12 18:26 ` Palmer Dabbelt
0 siblings, 0 replies; 28+ messages in thread
From: Palmer Dabbelt @ 2023-07-12 18:26 UTC (permalink / raw)
To: bjorn
Cc: suagrfillet, Paul Walmsley, aou, rostedt, mhiramat, Mark Rutland,
guoren, suagrfillet, Bjorn Topel, jszhang, Conor Dooley, pulehui,
linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai,
bpf
On Wed, 12 Jul 2023 11:11:08 PDT (-0700), bjorn@kernel.org wrote:
> Song Shuai <suagrfillet@gmail.com> writes:
>
> [...]
>
>> Add WITH_DIRECT_CALLS support [3] (patch 3, 4)
>> ==============================================
>
> We've had some offlist discussions, so here's some input for a wider
> audience! Most importantly, this is for Palmer, so that this series is
> not merged until a proper BPF trampoline fix is in place.
>
> Note that what's currently usable from BPF trampoline *works*. It's
> when this series is added that it breaks.
>
> TL;DR This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS, which enables
> fentry/fexit BPF trampoline support. Unfortunately the
> fexit/BPF_TRAMP_F_SKIP_FRAME parts of the RV BPF trampoline breaks
> with this addition, and need to be addressed *prior* merging this
> series. An easy way to reproduce, is just calling any of the kselftest
> tests that uses fexit patching.
>
> The issue is around the nop seld, and how a call is done; The nop sled
> (patchable-function-entry) size changed from 16B to 8B in commit
> 6724a76cff85 ("riscv: ftrace: Reduce the detour code size to half"), but
> BPF code still uses the old 16B. So it'll work for BPF programs, but not
> for regular kernel functions.
>
> An example:
>
> | ffffffff80fa4150 <bpf_fentry_test1>:
> | ffffffff80fa4150: 0001 nop
> | ffffffff80fa4152: 0001 nop
> | ffffffff80fa4154: 0001 nop
> | ffffffff80fa4156: 0001 nop
> | ffffffff80fa4158: 1141 add sp,sp,-16
> | ffffffff80fa415a: e422 sd s0,8(sp)
> | ffffffff80fa415c: 0800 add s0,sp,16
> | ffffffff80fa415e: 6422 ld s0,8(sp)
> | ffffffff80fa4160: 2505 addw a0,a0,1
> | ffffffff80fa4162: 0141 add sp,sp,16
> | ffffffff80fa4164: 8082 ret
>
> is patched to:
>
> | ffffffff80fa4150: f70c0297 auipc t0,-150208512
> | ffffffff80fa4154: eb0282e7 jalr t0,t0,-336
>
> The return address to bpf_fentry_test1 is stored in t0 at BPF
> trampoline entry. Return to the *parent* is in ra. The trampline has
> to deal with this.
>
> For BPF_TRAMP_F_SKIP_FRAME/CALL_ORIG, the BPF trampoline will skip too
> many bytes, and not correctly handle parent calls.
>
> Further; The BPF trampoline currently has a different way of patching
> the nops for BPF programs, than what ftrace does. That should be changed
> to match what ftrace does (auipc/jalr t0).
>
> To summarize:
> * Align BPF nop sled with patchable-function-entry: 8B.
> * Adapt BPF trampoline for 8B nop sleds.
> * Adapt BPF trampoline t0 return, ra parent scheme.
Thanks for digging into this one, I agree we need to sort out the BPF
breakages before we merge this. Sounds like there's a rabbit hole here,
but hopefully we can get it sorted out.
I've dropped this from patchwork and such, as we'll need at least
another spin.
> Cheers,
> Björn
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
2023-07-12 18:11 ` Björn Töpel
@ 2023-07-15 9:10 ` Pu Lehui
-1 siblings, 0 replies; 28+ messages in thread
From: Pu Lehui @ 2023-07-15 9:10 UTC (permalink / raw)
To: Björn Töpel, Song Shuai, paul.walmsley, palmer, aou,
rostedt, mhiramat, mark.rutland, guoren, bjorn, jszhang,
conor.dooley, palmer
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai, bpf
On 2023/7/13 2:11, Björn Töpel wrote:
> Song Shuai <suagrfillet@gmail.com> writes:
>
> [...]
>
>> Add WITH_DIRECT_CALLS support [3] (patch 3, 4)
>> ==============================================
>
> We've had some offlist discussions, so here's some input for a wider
> audience! Most importantly, this is for Palmer, so that this series is
> not merged until a proper BPF trampoline fix is in place.
>
> Note that what's currently usable from BPF trampoline *works*. It's
> when this series is added that it breaks.
>
> TL;DR This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS, which enables
> fentry/fexit BPF trampoline support. Unfortunately the
> fexit/BPF_TRAMP_F_SKIP_FRAME parts of the RV BPF trampoline breaks
> with this addition, and need to be addressed *prior* merging this
> series. An easy way to reproduce, is just calling any of the kselftest
> tests that uses fexit patching.
>
> The issue is around the nop seld, and how a call is done; The nop sled
> (patchable-function-entry) size changed from 16B to 8B in commit
> 6724a76cff85 ("riscv: ftrace: Reduce the detour code size to half"), but
> BPF code still uses the old 16B. So it'll work for BPF programs, but not
> for regular kernel functions.
>
> An example:
>
> | ffffffff80fa4150 <bpf_fentry_test1>:
> | ffffffff80fa4150: 0001 nop
> | ffffffff80fa4152: 0001 nop
> | ffffffff80fa4154: 0001 nop
> | ffffffff80fa4156: 0001 nop
> | ffffffff80fa4158: 1141 add sp,sp,-16
> | ffffffff80fa415a: e422 sd s0,8(sp)
> | ffffffff80fa415c: 0800 add s0,sp,16
> | ffffffff80fa415e: 6422 ld s0,8(sp)
> | ffffffff80fa4160: 2505 addw a0,a0,1
> | ffffffff80fa4162: 0141 add sp,sp,16
> | ffffffff80fa4164: 8082 ret
>
> is patched to:
>
> | ffffffff80fa4150: f70c0297 auipc t0,-150208512
> | ffffffff80fa4154: eb0282e7 jalr t0,t0,-336
>
> The return address to bpf_fentry_test1 is stored in t0 at BPF
> trampoline entry. Return to the *parent* is in ra. The trampline has
> to deal with this.
>
> For BPF_TRAMP_F_SKIP_FRAME/CALL_ORIG, the BPF trampoline will skip too
> many bytes, and not correctly handle parent calls.
>
> Further; The BPF trampoline currently has a different way of patching
> the nops for BPF programs, than what ftrace does. That should be changed
> to match what ftrace does (auipc/jalr t0).
>
> To summarize:
> * Align BPF nop sled with patchable-function-entry: 8B.
> * Adapt BPF trampoline for 8B nop sleds.
> * Adapt BPF trampoline t0 return, ra parent scheme.
>
Thanks Björn, I make a adaptation as follows, looking forward to your
review.
https://lore.kernel.org/bpf/20230715090137.2141358-1-pulehui@huaweicloud.com/
>
> Cheers,
> Björn
>
>
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
@ 2023-07-15 9:10 ` Pu Lehui
0 siblings, 0 replies; 28+ messages in thread
From: Pu Lehui @ 2023-07-15 9:10 UTC (permalink / raw)
To: Björn Töpel, Song Shuai, paul.walmsley, palmer, aou,
rostedt, mhiramat, mark.rutland, guoren, bjorn, jszhang,
conor.dooley, palmer
Cc: linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai, bpf
On 2023/7/13 2:11, Björn Töpel wrote:
> Song Shuai <suagrfillet@gmail.com> writes:
>
> [...]
>
>> Add WITH_DIRECT_CALLS support [3] (patch 3, 4)
>> ==============================================
>
> We've had some offlist discussions, so here's some input for a wider
> audience! Most importantly, this is for Palmer, so that this series is
> not merged until a proper BPF trampoline fix is in place.
>
> Note that what's currently usable from BPF trampoline *works*. It's
> when this series is added that it breaks.
>
> TL;DR This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS, which enables
> fentry/fexit BPF trampoline support. Unfortunately the
> fexit/BPF_TRAMP_F_SKIP_FRAME parts of the RV BPF trampoline breaks
> with this addition, and need to be addressed *prior* merging this
> series. An easy way to reproduce, is just calling any of the kselftest
> tests that uses fexit patching.
>
> The issue is around the nop seld, and how a call is done; The nop sled
> (patchable-function-entry) size changed from 16B to 8B in commit
> 6724a76cff85 ("riscv: ftrace: Reduce the detour code size to half"), but
> BPF code still uses the old 16B. So it'll work for BPF programs, but not
> for regular kernel functions.
>
> An example:
>
> | ffffffff80fa4150 <bpf_fentry_test1>:
> | ffffffff80fa4150: 0001 nop
> | ffffffff80fa4152: 0001 nop
> | ffffffff80fa4154: 0001 nop
> | ffffffff80fa4156: 0001 nop
> | ffffffff80fa4158: 1141 add sp,sp,-16
> | ffffffff80fa415a: e422 sd s0,8(sp)
> | ffffffff80fa415c: 0800 add s0,sp,16
> | ffffffff80fa415e: 6422 ld s0,8(sp)
> | ffffffff80fa4160: 2505 addw a0,a0,1
> | ffffffff80fa4162: 0141 add sp,sp,16
> | ffffffff80fa4164: 8082 ret
>
> is patched to:
>
> | ffffffff80fa4150: f70c0297 auipc t0,-150208512
> | ffffffff80fa4154: eb0282e7 jalr t0,t0,-336
>
> The return address to bpf_fentry_test1 is stored in t0 at BPF
> trampoline entry. Return to the *parent* is in ra. The trampline has
> to deal with this.
>
> For BPF_TRAMP_F_SKIP_FRAME/CALL_ORIG, the BPF trampoline will skip too
> many bytes, and not correctly handle parent calls.
>
> Further; The BPF trampoline currently has a different way of patching
> the nops for BPF programs, than what ftrace does. That should be changed
> to match what ftrace does (auipc/jalr t0).
>
> To summarize:
> * Align BPF nop sled with patchable-function-entry: 8B.
> * Adapt BPF trampoline for 8B nop sleds.
> * Adapt BPF trampoline t0 return, ra parent scheme.
>
Thanks Björn, I make a adaptation as follows, looking forward to your
review.
https://lore.kernel.org/bpf/20230715090137.2141358-1-pulehui@huaweicloud.com/
>
> Cheers,
> Björn
>
>
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
2023-07-12 18:26 ` Palmer Dabbelt
@ 2023-08-23 20:20 ` Björn Töpel
-1 siblings, 0 replies; 28+ messages in thread
From: Björn Töpel @ 2023-08-23 20:20 UTC (permalink / raw)
To: Palmer Dabbelt
Cc: suagrfillet, Paul Walmsley, aou, rostedt, mhiramat, Mark Rutland,
guoren, suagrfillet, Bjorn Topel, jszhang, Conor Dooley, pulehui,
linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai,
bpf
Palmer Dabbelt <palmer@rivosinc.com> writes:
> On Wed, 12 Jul 2023 11:11:08 PDT (-0700), bjorn@kernel.org wrote:
>> Song Shuai <suagrfillet@gmail.com> writes:
>>
>> [...]
>>
>>> Add WITH_DIRECT_CALLS support [3] (patch 3, 4)
>>> ==============================================
>>
>> We've had some offlist discussions, so here's some input for a wider
>> audience! Most importantly, this is for Palmer, so that this series is
>> not merged until a proper BPF trampoline fix is in place.
>>
>> Note that what's currently usable from BPF trampoline *works*. It's
>> when this series is added that it breaks.
>>
>> TL;DR This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS, which enables
>> fentry/fexit BPF trampoline support. Unfortunately the
>> fexit/BPF_TRAMP_F_SKIP_FRAME parts of the RV BPF trampoline breaks
>> with this addition, and need to be addressed *prior* merging this
>> series. An easy way to reproduce, is just calling any of the kselftest
>> tests that uses fexit patching.
>>
>> The issue is around the nop seld, and how a call is done; The nop sled
>> (patchable-function-entry) size changed from 16B to 8B in commit
>> 6724a76cff85 ("riscv: ftrace: Reduce the detour code size to half"), but
>> BPF code still uses the old 16B. So it'll work for BPF programs, but not
>> for regular kernel functions.
>>
>> An example:
>>
>> | ffffffff80fa4150 <bpf_fentry_test1>:
>> | ffffffff80fa4150: 0001 nop
>> | ffffffff80fa4152: 0001 nop
>> | ffffffff80fa4154: 0001 nop
>> | ffffffff80fa4156: 0001 nop
>> | ffffffff80fa4158: 1141 add sp,sp,-16
>> | ffffffff80fa415a: e422 sd s0,8(sp)
>> | ffffffff80fa415c: 0800 add s0,sp,16
>> | ffffffff80fa415e: 6422 ld s0,8(sp)
>> | ffffffff80fa4160: 2505 addw a0,a0,1
>> | ffffffff80fa4162: 0141 add sp,sp,16
>> | ffffffff80fa4164: 8082 ret
>>
>> is patched to:
>>
>> | ffffffff80fa4150: f70c0297 auipc t0,-150208512
>> | ffffffff80fa4154: eb0282e7 jalr t0,t0,-336
>>
>> The return address to bpf_fentry_test1 is stored in t0 at BPF
>> trampoline entry. Return to the *parent* is in ra. The trampline has
>> to deal with this.
>>
>> For BPF_TRAMP_F_SKIP_FRAME/CALL_ORIG, the BPF trampoline will skip too
>> many bytes, and not correctly handle parent calls.
>>
>> Further; The BPF trampoline currently has a different way of patching
>> the nops for BPF programs, than what ftrace does. That should be changed
>> to match what ftrace does (auipc/jalr t0).
>>
>> To summarize:
>> * Align BPF nop sled with patchable-function-entry: 8B.
>> * Adapt BPF trampoline for 8B nop sleds.
>> * Adapt BPF trampoline t0 return, ra parent scheme.
>
> Thanks for digging into this one, I agree we need to sort out the BPF
> breakages before we merge this. Sounds like there's a rabbit hole here,
> but hopefully we can get it sorted out.
>
> I've dropped this from patchwork and such, as we'll need at least
> another spin.
Palmer,
The needed BPF patch is upstream in the bpf-next tree, and has been for
a couple of weeks.
I think this series is a candidate for RISC-V -next! It would help
RISC-V BPF a lot in terms of completeness.
Björn
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
@ 2023-08-23 20:20 ` Björn Töpel
0 siblings, 0 replies; 28+ messages in thread
From: Björn Töpel @ 2023-08-23 20:20 UTC (permalink / raw)
To: Palmer Dabbelt
Cc: suagrfillet, Paul Walmsley, aou, rostedt, mhiramat, Mark Rutland,
guoren, suagrfillet, Bjorn Topel, jszhang, Conor Dooley, pulehui,
linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai,
bpf
Palmer Dabbelt <palmer@rivosinc.com> writes:
> On Wed, 12 Jul 2023 11:11:08 PDT (-0700), bjorn@kernel.org wrote:
>> Song Shuai <suagrfillet@gmail.com> writes:
>>
>> [...]
>>
>>> Add WITH_DIRECT_CALLS support [3] (patch 3, 4)
>>> ==============================================
>>
>> We've had some offlist discussions, so here's some input for a wider
>> audience! Most importantly, this is for Palmer, so that this series is
>> not merged until a proper BPF trampoline fix is in place.
>>
>> Note that what's currently usable from BPF trampoline *works*. It's
>> when this series is added that it breaks.
>>
>> TL;DR This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS, which enables
>> fentry/fexit BPF trampoline support. Unfortunately the
>> fexit/BPF_TRAMP_F_SKIP_FRAME parts of the RV BPF trampoline breaks
>> with this addition, and need to be addressed *prior* merging this
>> series. An easy way to reproduce, is just calling any of the kselftest
>> tests that uses fexit patching.
>>
>> The issue is around the nop seld, and how a call is done; The nop sled
>> (patchable-function-entry) size changed from 16B to 8B in commit
>> 6724a76cff85 ("riscv: ftrace: Reduce the detour code size to half"), but
>> BPF code still uses the old 16B. So it'll work for BPF programs, but not
>> for regular kernel functions.
>>
>> An example:
>>
>> | ffffffff80fa4150 <bpf_fentry_test1>:
>> | ffffffff80fa4150: 0001 nop
>> | ffffffff80fa4152: 0001 nop
>> | ffffffff80fa4154: 0001 nop
>> | ffffffff80fa4156: 0001 nop
>> | ffffffff80fa4158: 1141 add sp,sp,-16
>> | ffffffff80fa415a: e422 sd s0,8(sp)
>> | ffffffff80fa415c: 0800 add s0,sp,16
>> | ffffffff80fa415e: 6422 ld s0,8(sp)
>> | ffffffff80fa4160: 2505 addw a0,a0,1
>> | ffffffff80fa4162: 0141 add sp,sp,16
>> | ffffffff80fa4164: 8082 ret
>>
>> is patched to:
>>
>> | ffffffff80fa4150: f70c0297 auipc t0,-150208512
>> | ffffffff80fa4154: eb0282e7 jalr t0,t0,-336
>>
>> The return address to bpf_fentry_test1 is stored in t0 at BPF
>> trampoline entry. Return to the *parent* is in ra. The trampline has
>> to deal with this.
>>
>> For BPF_TRAMP_F_SKIP_FRAME/CALL_ORIG, the BPF trampoline will skip too
>> many bytes, and not correctly handle parent calls.
>>
>> Further; The BPF trampoline currently has a different way of patching
>> the nops for BPF programs, than what ftrace does. That should be changed
>> to match what ftrace does (auipc/jalr t0).
>>
>> To summarize:
>> * Align BPF nop sled with patchable-function-entry: 8B.
>> * Adapt BPF trampoline for 8B nop sleds.
>> * Adapt BPF trampoline t0 return, ra parent scheme.
>
> Thanks for digging into this one, I agree we need to sort out the BPF
> breakages before we merge this. Sounds like there's a rabbit hole here,
> but hopefully we can get it sorted out.
>
> I've dropped this from patchwork and such, as we'll need at least
> another spin.
Palmer,
The needed BPF patch is upstream in the bpf-next tree, and has been for
a couple of weeks.
I think this series is a candidate for RISC-V -next! It would help
RISC-V BPF a lot in terms of completeness.
Björn
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
2023-08-23 20:20 ` Björn Töpel
@ 2023-08-30 15:28 ` Björn Töpel
-1 siblings, 0 replies; 28+ messages in thread
From: Björn Töpel @ 2023-08-30 15:28 UTC (permalink / raw)
To: Palmer Dabbelt
Cc: suagrfillet, Paul Walmsley, aou, rostedt, mhiramat, Mark Rutland,
guoren, suagrfillet, Bjorn Topel, jszhang, Conor Dooley, pulehui,
linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai,
bpf
Björn Töpel <bjorn@kernel.org> writes:
> Palmer Dabbelt <palmer@rivosinc.com> writes:
>
>> On Wed, 12 Jul 2023 11:11:08 PDT (-0700), bjorn@kernel.org wrote:
>>> Song Shuai <suagrfillet@gmail.com> writes:
>>>
>>> [...]
>>>
>>>> Add WITH_DIRECT_CALLS support [3] (patch 3, 4)
>>>> ==============================================
>>>
>>> We've had some offlist discussions, so here's some input for a wider
>>> audience! Most importantly, this is for Palmer, so that this series is
>>> not merged until a proper BPF trampoline fix is in place.
>>>
>>> Note that what's currently usable from BPF trampoline *works*. It's
>>> when this series is added that it breaks.
>>>
>>> TL;DR This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS, which enables
>>> fentry/fexit BPF trampoline support. Unfortunately the
>>> fexit/BPF_TRAMP_F_SKIP_FRAME parts of the RV BPF trampoline breaks
>>> with this addition, and need to be addressed *prior* merging this
>>> series. An easy way to reproduce, is just calling any of the kselftest
>>> tests that uses fexit patching.
>>>
>>> The issue is around the nop seld, and how a call is done; The nop sled
>>> (patchable-function-entry) size changed from 16B to 8B in commit
>>> 6724a76cff85 ("riscv: ftrace: Reduce the detour code size to half"), but
>>> BPF code still uses the old 16B. So it'll work for BPF programs, but not
>>> for regular kernel functions.
>>>
>>> An example:
>>>
>>> | ffffffff80fa4150 <bpf_fentry_test1>:
>>> | ffffffff80fa4150: 0001 nop
>>> | ffffffff80fa4152: 0001 nop
>>> | ffffffff80fa4154: 0001 nop
>>> | ffffffff80fa4156: 0001 nop
>>> | ffffffff80fa4158: 1141 add sp,sp,-16
>>> | ffffffff80fa415a: e422 sd s0,8(sp)
>>> | ffffffff80fa415c: 0800 add s0,sp,16
>>> | ffffffff80fa415e: 6422 ld s0,8(sp)
>>> | ffffffff80fa4160: 2505 addw a0,a0,1
>>> | ffffffff80fa4162: 0141 add sp,sp,16
>>> | ffffffff80fa4164: 8082 ret
>>>
>>> is patched to:
>>>
>>> | ffffffff80fa4150: f70c0297 auipc t0,-150208512
>>> | ffffffff80fa4154: eb0282e7 jalr t0,t0,-336
>>>
>>> The return address to bpf_fentry_test1 is stored in t0 at BPF
>>> trampoline entry. Return to the *parent* is in ra. The trampline has
>>> to deal with this.
>>>
>>> For BPF_TRAMP_F_SKIP_FRAME/CALL_ORIG, the BPF trampoline will skip too
>>> many bytes, and not correctly handle parent calls.
>>>
>>> Further; The BPF trampoline currently has a different way of patching
>>> the nops for BPF programs, than what ftrace does. That should be changed
>>> to match what ftrace does (auipc/jalr t0).
>>>
>>> To summarize:
>>> * Align BPF nop sled with patchable-function-entry: 8B.
>>> * Adapt BPF trampoline for 8B nop sleds.
>>> * Adapt BPF trampoline t0 return, ra parent scheme.
>>
>> Thanks for digging into this one, I agree we need to sort out the BPF
>> breakages before we merge this. Sounds like there's a rabbit hole here,
>> but hopefully we can get it sorted out.
>>
>> I've dropped this from patchwork and such, as we'll need at least
>> another spin.
>
> Palmer,
>
> The needed BPF patch is upstream in the bpf-next tree, and has been for
> a couple of weeks.
>
> I think this series is a candidate for RISC-V -next! It would help
> RISC-V BPF a lot in terms of completeness.
Palmer,
The needed fix for BPF is now in Linus' tree, commit 25ad10658dc1
("riscv, bpf: Adapt bpf trampoline to optimized riscv ftrace
framework"). IOW, this ftrace series can be merged now.
Björn
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH V11 0/5] riscv: Optimize function trace
@ 2023-08-30 15:28 ` Björn Töpel
0 siblings, 0 replies; 28+ messages in thread
From: Björn Töpel @ 2023-08-30 15:28 UTC (permalink / raw)
To: Palmer Dabbelt
Cc: suagrfillet, Paul Walmsley, aou, rostedt, mhiramat, Mark Rutland,
guoren, suagrfillet, Bjorn Topel, jszhang, Conor Dooley, pulehui,
linux-riscv, linux-kernel, linux-trace-kernel, songshuaishuai,
bpf
Björn Töpel <bjorn@kernel.org> writes:
> Palmer Dabbelt <palmer@rivosinc.com> writes:
>
>> On Wed, 12 Jul 2023 11:11:08 PDT (-0700), bjorn@kernel.org wrote:
>>> Song Shuai <suagrfillet@gmail.com> writes:
>>>
>>> [...]
>>>
>>>> Add WITH_DIRECT_CALLS support [3] (patch 3, 4)
>>>> ==============================================
>>>
>>> We've had some offlist discussions, so here's some input for a wider
>>> audience! Most importantly, this is for Palmer, so that this series is
>>> not merged until a proper BPF trampoline fix is in place.
>>>
>>> Note that what's currently usable from BPF trampoline *works*. It's
>>> when this series is added that it breaks.
>>>
>>> TL;DR This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS, which enables
>>> fentry/fexit BPF trampoline support. Unfortunately the
>>> fexit/BPF_TRAMP_F_SKIP_FRAME parts of the RV BPF trampoline breaks
>>> with this addition, and need to be addressed *prior* merging this
>>> series. An easy way to reproduce, is just calling any of the kselftest
>>> tests that uses fexit patching.
>>>
>>> The issue is around the nop seld, and how a call is done; The nop sled
>>> (patchable-function-entry) size changed from 16B to 8B in commit
>>> 6724a76cff85 ("riscv: ftrace: Reduce the detour code size to half"), but
>>> BPF code still uses the old 16B. So it'll work for BPF programs, but not
>>> for regular kernel functions.
>>>
>>> An example:
>>>
>>> | ffffffff80fa4150 <bpf_fentry_test1>:
>>> | ffffffff80fa4150: 0001 nop
>>> | ffffffff80fa4152: 0001 nop
>>> | ffffffff80fa4154: 0001 nop
>>> | ffffffff80fa4156: 0001 nop
>>> | ffffffff80fa4158: 1141 add sp,sp,-16
>>> | ffffffff80fa415a: e422 sd s0,8(sp)
>>> | ffffffff80fa415c: 0800 add s0,sp,16
>>> | ffffffff80fa415e: 6422 ld s0,8(sp)
>>> | ffffffff80fa4160: 2505 addw a0,a0,1
>>> | ffffffff80fa4162: 0141 add sp,sp,16
>>> | ffffffff80fa4164: 8082 ret
>>>
>>> is patched to:
>>>
>>> | ffffffff80fa4150: f70c0297 auipc t0,-150208512
>>> | ffffffff80fa4154: eb0282e7 jalr t0,t0,-336
>>>
>>> The return address to bpf_fentry_test1 is stored in t0 at BPF
>>> trampoline entry. Return to the *parent* is in ra. The trampline has
>>> to deal with this.
>>>
>>> For BPF_TRAMP_F_SKIP_FRAME/CALL_ORIG, the BPF trampoline will skip too
>>> many bytes, and not correctly handle parent calls.
>>>
>>> Further; The BPF trampoline currently has a different way of patching
>>> the nops for BPF programs, than what ftrace does. That should be changed
>>> to match what ftrace does (auipc/jalr t0).
>>>
>>> To summarize:
>>> * Align BPF nop sled with patchable-function-entry: 8B.
>>> * Adapt BPF trampoline for 8B nop sleds.
>>> * Adapt BPF trampoline t0 return, ra parent scheme.
>>
>> Thanks for digging into this one, I agree we need to sort out the BPF
>> breakages before we merge this. Sounds like there's a rabbit hole here,
>> but hopefully we can get it sorted out.
>>
>> I've dropped this from patchwork and such, as we'll need at least
>> another spin.
>
> Palmer,
>
> The needed BPF patch is upstream in the bpf-next tree, and has been for
> a couple of weeks.
>
> I think this series is a candidate for RISC-V -next! It would help
> RISC-V BPF a lot in terms of completeness.
Palmer,
The needed fix for BPF is now in Linus' tree, commit 25ad10658dc1
("riscv, bpf: Adapt bpf trampoline to optimized riscv ftrace
framework"). IOW, this ftrace series can be merged now.
Björn
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 28+ messages in thread
end of thread, other threads:[~2023-08-30 18:47 UTC | newest]
Thread overview: 28+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-06-27 11:16 [PATCH V11 0/5] riscv: Optimize function trace Song Shuai
2023-06-27 11:16 ` Song Shuai
2023-06-27 11:16 ` [PATCH V11 1/5] riscv: select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY Song Shuai
2023-06-27 11:16 ` Song Shuai
2023-06-27 11:16 ` [PATCH V11 2/5] riscv: ftrace: Add ftrace_graph_func Song Shuai
2023-06-27 11:16 ` Song Shuai
2023-06-27 11:16 ` [PATCH V11 3/5] riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support Song Shuai
2023-06-27 11:16 ` Song Shuai
2023-06-27 11:16 ` [PATCH V11 4/5] samples: ftrace: Add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI] Song Shuai
2023-06-27 11:16 ` Song Shuai
2023-06-27 11:16 ` [PATCH V11 5/5] samples: ftrace: Make the riscv samples support RV32I Song Shuai
2023-06-27 11:16 ` Song Shuai
2023-07-06 9:35 ` [PATCH V11 0/5] riscv: Optimize function trace Song Shuai
2023-07-06 9:35 ` Song Shuai
2023-07-06 9:53 ` Conor Dooley
2023-07-06 9:53 ` Conor Dooley
2023-07-06 10:10 ` Song Shuai
2023-07-06 10:10 ` Song Shuai
2023-07-12 18:11 ` Björn Töpel
2023-07-12 18:11 ` Björn Töpel
2023-07-12 18:26 ` Palmer Dabbelt
2023-07-12 18:26 ` Palmer Dabbelt
2023-08-23 20:20 ` Björn Töpel
2023-08-23 20:20 ` Björn Töpel
2023-08-30 15:28 ` Björn Töpel
2023-08-30 15:28 ` Björn Töpel
2023-07-15 9:10 ` Pu Lehui
2023-07-15 9:10 ` Pu Lehui
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