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x86/ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL

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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 x86 platform.

We introduce a new structure called fgraph_ret_regs for the x86
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://lkml.kernel.org/r/53a506f0f18ff4b7aeb0feb762f1c9a5e9b83ee9.1680954589.git.pengdonglin@sangfor.com.cn

Signed-off-by: Donglin Peng <pengdonglin@sangfor.com.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Donglin Peng 2023-04-08 05:42:20 -07:00 committed by Steven Rostedt (Google)
parent 3646970322
commit d938ba1768
4 changed files with 30 additions and 6 deletions
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1
arch/x86/Kconfig
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@ -216,6 +216,7 @@ config X86
select HAVE_FAST_GUP
select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE)
select HAVE_FUNCTION_TRACER
select HAVE_GCC_PLUGINS

20
arch/x86/include/asm/ftrace.h
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@ -147,4 +147,24 @@ static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
#endif /* !COMPILE_OFFSETS */
#endif /* !__ASSEMBLY__ */
#ifndef __ASSEMBLY__
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
struct fgraph_ret_regs {
unsigned long ax;
unsigned long dx;
unsigned long bp;
};
static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->ax;
}
static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->bp;
}
#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */
#endif
#endif /* _ASM_X86_FTRACE_H */

8
arch/x86/kernel/ftrace_32.S
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@ -187,12 +187,14 @@ SYM_CODE_END(ftrace_graph_caller)
.globl return_to_handler
return_to_handler:
pushl %eax
pushl $0
pushl %edx
movl $0, %eax
pushl %eax
movl %esp, %eax
call ftrace_return_to_handler
movl %eax, %ecx
popl %edx
popl %eax
popl %edx
addl $4, %esp # skip ebp
JMP_NOSPEC ecx
#endif

7
arch/x86/kernel/ftrace_64.S
View File

@ -348,12 +348,13 @@ STACK_FRAME_NON_STANDARD_FP(__fentry__)
SYM_CODE_START(return_to_handler)
UNWIND_HINT_UNDEFINED
ANNOTATE_NOENDBR
subq $16, %rsp
subq $24, %rsp
/* Save the return values */
movq %rax, (%rsp)
movq %rdx, 8(%rsp)
movq %rbp, %rdi
movq %rbp, 16(%rsp)
movq %rsp, %rdi
call ftrace_return_to_handler
@ -361,7 +362,7 @@ SYM_CODE_START(return_to_handler)
movq 8(%rsp), %rdx
movq (%rsp), %rax
addq $16, %rsp
addq $24, %rsp
/*
* Jump back to the old return address. This cannot be JMP_NOSPEC rdi
* since IBT would demand that contain ENDBR, which simply isn't so for