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arm64: 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 ARM64 platform.

We introduce a new structure called fgraph_ret_regs for the ARM64
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/c78366416ce93f704ae7000c4ee60eb4258c38f7.1680954589.git.pengdonglin@sangfor.com.cn

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
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 05:42:18 -07:00 committed by Steven Rostedt (Google)
parent 21c094d3f8
commit 3646970322
4 changed files with 50 additions and 13 deletions
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1
arch/arm64/Kconfig
View File

@ -201,6 +201,7 @@ config ARM64
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_GCC_PLUGINS
select HAVE_HW_BREAKPOINT if PERF_EVENTS

22
arch/arm64/include/asm/ftrace.h
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@ -192,4 +192,26 @@ static inline bool arch_syscall_match_sym_name(const char *sym,
}
#endif /* ifndef __ASSEMBLY__ */
#ifndef __ASSEMBLY__
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
struct fgraph_ret_regs {
/* x0 - x7 */
unsigned long regs[8];
unsigned long fp;
unsigned long __unused;
};
static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->regs[0];
}
static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->fp;
}
#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */
#endif
#endif /* __ASM_FTRACE_H */

13
arch/arm64/kernel/asm-offsets.c
View File

@ -200,6 +200,19 @@ int main(void)
#endif
#ifdef CONFIG_FUNCTION_TRACER
DEFINE(FTRACE_OPS_FUNC, offsetof(struct ftrace_ops, func));
#endif
BLANK();
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
DEFINE(FGRET_REGS_X0, offsetof(struct fgraph_ret_regs, regs[0]));
DEFINE(FGRET_REGS_X1, offsetof(struct fgraph_ret_regs, regs[1]));
DEFINE(FGRET_REGS_X2, offsetof(struct fgraph_ret_regs, regs[2]));
DEFINE(FGRET_REGS_X3, offsetof(struct fgraph_ret_regs, regs[3]));
DEFINE(FGRET_REGS_X4, offsetof(struct fgraph_ret_regs, regs[4]));
DEFINE(FGRET_REGS_X5, offsetof(struct fgraph_ret_regs, regs[5]));
DEFINE(FGRET_REGS_X6, offsetof(struct fgraph_ret_regs, regs[6]));
DEFINE(FGRET_REGS_X7, offsetof(struct fgraph_ret_regs, regs[7]));
DEFINE(FGRET_REGS_FP, offsetof(struct fgraph_ret_regs, fp));
DEFINE(FGRET_REGS_SIZE, sizeof(struct fgraph_ret_regs));
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
DEFINE(FTRACE_OPS_DIRECT_CALL, offsetof(struct ftrace_ops, direct_call));
#endif

27
arch/arm64/kernel/entry-ftrace.S
View File

@ -330,22 +330,23 @@ SYM_FUNC_END(ftrace_stub_graph)
*/
SYM_CODE_START(return_to_handler)
/* save return value regs */
sub sp, sp, #64
stp x0, x1, [sp]
stp x2, x3, [sp, #16]
stp x4, x5, [sp, #32]
stp x6, x7, [sp, #48]
sub sp, sp, #FGRET_REGS_SIZE
stp x0, x1, [sp, #FGRET_REGS_X0]
stp x2, x3, [sp, #FGRET_REGS_X2]
stp x4, x5, [sp, #FGRET_REGS_X4]
stp x6, x7, [sp, #FGRET_REGS_X6]
str x29, [sp, #FGRET_REGS_FP] // parent's fp
mov x0, x29 // parent's fp
bl ftrace_return_to_handler// addr = ftrace_return_to_hander(fp);
mov x30, x0 // restore the original return address
mov x0, sp
bl ftrace_return_to_handler // addr = ftrace_return_to_hander(regs);
mov x30, x0 // restore the original return address
/* restore return value regs */
ldp x0, x1, [sp]
ldp x2, x3, [sp, #16]
ldp x4, x5, [sp, #32]
ldp x6, x7, [sp, #48]
add sp, sp, #64
ldp x0, x1, [sp, #FGRET_REGS_X0]
ldp x2, x3, [sp, #FGRET_REGS_X2]
ldp x4, x5, [sp, #FGRET_REGS_X4]
ldp x6, x7, [sp, #FGRET_REGS_X6]
add sp, sp, #FGRET_REGS_SIZE
ret
SYM_CODE_END(return_to_handler)