s390/ftrace: enable HAVE_FUNCTION_GRAPH_RETVAL

Add support for tracing return values in the function graph tracer.
This requires return_to_handler() to record gpr2 and the frame pointer

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Sven Schnelle 2023-06-29 12:02:19 +02:00 committed by Heiko Carstens
parent 3325b4d857
commit 1256e70a08
4 changed files with 31 additions and 2 deletions

View File

@ -174,6 +174,7 @@ config S390
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_ARG_ACCESS_API
select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_FUNCTION_GRAPH_RETVAL
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER
select HAVE_GCC_PLUGINS

View File

@ -54,6 +54,23 @@ static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *
return NULL;
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
struct fgraph_ret_regs {
unsigned long gpr2;
unsigned long fp;
};
static __always_inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->gpr2;
}
static __always_inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->fp;
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
static __always_inline unsigned long
ftrace_regs_get_instruction_pointer(const struct ftrace_regs *fregs)
{

View File

@ -12,6 +12,7 @@
#include <linux/sched.h>
#include <linux/purgatory.h>
#include <linux/pgtable.h>
#include <linux/ftrace.h>
#include <asm/idle.h>
#include <asm/gmap.h>
#include <asm/stacktrace.h>
@ -177,5 +178,11 @@ int main(void)
DEFINE(OLDMEM_SIZE, PARMAREA + offsetof(struct parmarea, oldmem_size));
DEFINE(COMMAND_LINE, PARMAREA + offsetof(struct parmarea, command_line));
DEFINE(MAX_COMMAND_LINE_SIZE, PARMAREA + offsetof(struct parmarea, max_command_line_size));
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
/* function graph return value tracing */
OFFSET(__FGRAPH_RET_GPR2, fgraph_ret_regs, gpr2);
OFFSET(__FGRAPH_RET_FP, fgraph_ret_regs, fp);
DEFINE(__FGRAPH_RET_SIZE, sizeof(struct fgraph_ret_regs));
#endif
return 0;
}

View File

@ -128,10 +128,14 @@ SYM_CODE_END(ftrace_common)
SYM_FUNC_START(return_to_handler)
stmg %r2,%r5,32(%r15)
lgr %r1,%r15
aghi %r15,-STACK_FRAME_OVERHEAD
aghi %r15,-(STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE)
stg %r1,__SF_BACKCHAIN(%r15)
aghik %r3,%r15,STACK_FRAME_OVERHEAD
stg %r1,__FGRAPH_RET_FP(%r3)
stg %r2,__FGRAPH_RET_GPR2(%r3)
lgr %r2,%r3
brasl %r14,ftrace_return_to_handler
aghi %r15,STACK_FRAME_OVERHEAD
aghi %r15,STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE
lgr %r14,%r2
lmg %r2,%r5,32(%r15)
BR_EX %r14