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authorDonglin Peng <pengdonglin@sangfor.com.cn>2023-04-08 14:42:19 +0200
committerSteven Rostedt (Google) <rostedt@goodmis.org>2023-06-22 16:39:56 +0200
commitb97aec082b51a0728adc9f69494826d32e0d1f8f (patch)
tree9c6f0e1c384e0ed29ae6b76aba825cdde0aa18e6
parenttracing/boot: Replace strlcpy with strscpy (diff)
downloadlinux-b97aec082b51a0728adc9f69494826d32e0d1f8f.tar.xz
linux-b97aec082b51a0728adc9f69494826d32e0d1f8f.zip
riscv: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL
The previous patch ("function_graph: Support recording and printing the return value of function") has laid the groundwork for the for the funcgraph-retval, and this modification makes it available on the RISC-V platform. We introduce a new structure called fgraph_ret_regs for the RISC-V platform to hold return registers and the frame pointer. We then fill its content in the return_to_handler and pass its address to the function ftrace_return_to_handler to record the return value. Link: https://lore.kernel.org/linux-trace-kernel/a8d71b12259f90e7e63d0ea654fcac95b0232bbc.1680954589.git.pengdonglin@sangfor.com.cn Signed-off-by: Donglin Peng <pengdonglin@sangfor.com.cn> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-rw-r--r--arch/riscv/Kconfig1
-rw-r--r--arch/riscv/include/asm/ftrace.h21
-rw-r--r--arch/riscv/kernel/mcount.S7
3 files changed, 23 insertions, 6 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 2bb0c38419ff..62c1e375183c 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -146,6 +146,7 @@ config RISCV
select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
select HAVE_FUNCTION_GRAPH_TRACER
+ select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
config CLANG_SUPPORTS_DYNAMIC_FTRACE
diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h
index d47d87c2d7e3..740a979171e5 100644
--- a/arch/riscv/include/asm/ftrace.h
+++ b/arch/riscv/include/asm/ftrace.h
@@ -111,4 +111,25 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
#endif /* CONFIG_DYNAMIC_FTRACE */
+#ifndef __ASSEMBLY__
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+struct fgraph_ret_regs {
+ unsigned long a1;
+ unsigned long a0;
+ unsigned long s0;
+ unsigned long ra;
+};
+
+static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
+{
+ return ret_regs->a0;
+}
+
+static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
+{
+ return ret_regs->s0;
+}
+#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */
+#endif
+
#endif /* _ASM_RISCV_FTRACE_H */
diff --git a/arch/riscv/kernel/mcount.S b/arch/riscv/kernel/mcount.S
index 30102aadc4d7..8a6e5a9e842a 100644
--- a/arch/riscv/kernel/mcount.S
+++ b/arch/riscv/kernel/mcount.S
@@ -65,13 +65,8 @@ ENTRY(return_to_handler)
* So alternatively we check the *old* frame pointer position, that is, the
* value stored in -16(s0) on entry, and the s0 on return.
*/
-#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
- mv t6, s0
-#endif
SAVE_RET_ABI_STATE
-#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
- mv a0, t6
-#endif
+ mv a0, sp
call ftrace_return_to_handler
mv a2, a0
RESTORE_RET_ABI_STATE