This patch implements the arch_fgraph_record_params() function for x86_64
platform and deliver the return value of function to ftrace core part.
Signed-off-by: Changbin Du <changbin...@gmail.com>
---
arch/x86/Kconfig | 1 +
arch/x86/kernel/ftrace.c | 84 +++++++++++++++++++++++++++++++++++--
arch/x86/kernel/ftrace_64.S | 4 +-
3 files changed, 85 insertions(+), 4 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 222855cc0158..34e583bfdab8 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -31,6 +31,7 @@ config X86_64
select NEED_DMA_MAP_STATE
select SWIOTLB
select ARCH_HAS_SYSCALL_WRAPPER
+ select HAVE_FTRACE_FUNC_PROTOTYPE
config FORCE_DYNAMIC_FTRACE
def_bool y
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index a044734167af..fc0a062ce762 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -31,6 +31,7 @@
#include <asm/ftrace.h>
#include <asm/nops.h>
#include <asm/text-patching.h>
+#include <asm-generic/dwarf.h>
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -918,7 +919,8 @@ static void *addr_from_call(void *ptr)
}
void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
- unsigned long frame_pointer);
+ unsigned long frame_pointer,
+ struct pt_regs *pt_regs);
/*
* If the ops->trampoline was not allocated, then it probably
@@ -973,6 +975,82 @@ void arch_ftrace_trampoline_free(struct ftrace_ops *ops)
ops->trampoline = 0;
}
+#ifdef CONFIG_FTRACE_FUNC_PROTOTYPE
+void arch_fgraph_record_params(struct ftrace_graph_ent *trace,
+ struct func_prototype *proto,
+ struct pt_regs *pt_regs)
+{
+ int i;
+
+ trace->nr_param = min(proto->nr_param, (uint8_t)FTRACE_MAX_FUNC_PARAMS);
+
+ for (i = 0; i < trace->nr_param; i++) {
+ struct func_param *param = &proto->params[i];
+ unsigned int sz = FTRACE_PROTOTYPE_SIZE(param->type);
+ long off = (char)param->loc[1];
+ unsigned long value = 0;
+ bool good = true;
+
+ if (sz > sizeof(value)) {
+ /* Don't record value of complex type. */
+ trace->param_types[i] = param->type;
+ trace->param_values[i] = 0;
+ continue;
+ }
+
+ switch (param->loc[0]) {
+ case DW_OP_reg1:
+ value = pt_regs->dx;
+ break;
+ case DW_OP_reg2:
+ value = pt_regs->cx;
+ break;
+ case DW_OP_reg3:
+ value = pt_regs->bx;
+ break;
+ case DW_OP_reg4:
+ value = pt_regs->si;
+ break;
+ case DW_OP_reg5:
+ value = pt_regs->di;
+ break;
+ case DW_OP_reg6:
+ value = pt_regs->bp;
+ break;
+ case DW_OP_reg8:
+ value = pt_regs->r8;
+ break;
+ case DW_OP_reg9:
+ value = pt_regs->r9;
+ break;
+ case DW_OP_fbreg:
+ if (probe_kernel_read(&value,
+ (void *)pt_regs->bp + off,
+ sz))
+ good = false;
+ break;
+ case DW_OP_breg7:
+ if (probe_kernel_read(&value,
+ (void *)pt_regs->sp + off,
+ sz))
+ good = false;
+ break;
+ default:
+ /* unexpected loc expression */
+ good = false;
+ }
+
+ trace->param_names[i] = param->name;
+ if (good) {
+ trace->param_types[i] = param->type;
+ trace->param_values[i] = value;
+ } else {
+ /* set the type to 0 so we skip it when printing. */
+ trace->param_types[i] = 0;
+ }
+ }
+}
+#endif /* CONFIG_FTRACE_FUNC_PROTOTYPE */
#endif /* CONFIG_X86_64 */
#endif /* CONFIG_DYNAMIC_FTRACE */
@@ -1017,7 +1095,7 @@ int ftrace_disable_ftrace_graph_caller(void)
* in current thread info.
*/
void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
- unsigned long frame_pointer)
+ unsigned long frame_pointer, struct pt_regs *pt_regs)
{
unsigned long old;
int faulted;
@@ -1072,7 +1150,7 @@ void prepare_ftrace_return(unsigned long self_addr,
unsigned long *parent,
return;
}
- if (function_graph_enter(old, self_addr, frame_pointer, parent, NULL))
+ if (function_graph_enter(old, self_addr, frame_pointer, parent,
pt_regs))
*parent = old;
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index 809d54397dba..e01d6358e859 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -289,7 +289,8 @@ ENTRY(ftrace_graph_caller)
leaq MCOUNT_REG_SIZE+8(%rsp), %rsi
movq $0, %rdx /* No framepointers needed */
- call prepare_ftrace_return
+ movq %rsp, %rcx /* the fourth parameter */
+ call prepare_ftrace_return
restore_mcount_regs
@@ -304,6 +305,7 @@ ENTRY(return_to_handler)
movq %rax, (%rsp)
movq %rdx, 8(%rsp)
movq %rbp, %rdi
+ movq %rax, %rsi
call ftrace_return_to_handler
--
2.20.1
