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authorLinus Torvalds <torvalds@linux-foundation.org>2023-06-30 10:33:17 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2023-06-30 10:33:17 -0700
commitcccf0c2ee52d3bd710be3a3f865df1b869a68f11 (patch)
tree561792a7a9bb45057f172b2d8fb07ee65dbc75ac /arch/riscv
parent533925cb760431cb496a8c965cfd765a1a21d37e (diff)
parentfc30ace06f250f79381a8e3f6ed92dd68e25a9f5 (diff)
Merge tag 'trace-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt: - Add new feature to have function graph tracer record the return value. Adds a new option: funcgraph-retval ; when set, will show the return value of a function in the function graph tracer. - Also add the option: funcgraph-retval-hex where if it is not set, and the return value is an error code, then it will return the decimal of the error code, otherwise it still reports the hex value. - Add the file /sys/kernel/tracing/osnoise/per_cpu/cpu<cpu>/timerlat_fd That when a application opens it, it becomes the task that the timer lat tracer traces. The application can also read this file to find out how it's being interrupted. - Add the file /sys/kernel/tracing/available_filter_functions_addrs that works just the same as available_filter_functions but also shows the addresses of the functions like kallsyms, except that it gives the address of where the fentry/mcount jump/nop is. This is used by BPF to make it easier to attach BPF programs to ftrace hooks. - Replace strlcpy with strscpy in the tracing boot code. * tag 'trace-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Fix warnings when building htmldocs for function graph retval riscv: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL tracing/boot: Replace strlcpy with strscpy tracing/timerlat: Add user-space interface tracing/osnoise: Skip running osnoise if all instances are off tracing/osnoise: Switch from PF_NO_SETAFFINITY to migrate_disable ftrace: Show all functions with addresses in available_filter_functions_addrs selftests/ftrace: Add funcgraph-retval test case LoongArch: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL x86/ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL arm64: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL tracing: Add documentation for funcgraph-retval and funcgraph-retval-hex function_graph: Support recording and printing the return value of function fgraph: Add declaration of "struct fgraph_ret_regs"
Diffstat (limited to 'arch/riscv')
-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 08f3a01fa1ea..b49793cf34eb 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -152,6 +152,7 @@ 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