tile: ftrace: fix function_graph tracer issues

- Add support for ARCH_SUPPORTS_FTRACE_OPS
- Replace the instruction in ftrace_call with the bundle {move r10, lr;
jal ftrace_stub}, so that the lr contains the right value after returning
from ftrace_stub.  An alternative fix might be to leave the instruction
in ftrace_call alone when it is being updated with ftrace_stub.

Signed-off-by: Tony Lu <zlu@ezchip.com>
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
This commit is contained in:
Tony Lu 2015-03-27 14:46:38 -04:00 committed by Chris Metcalf
parent a84f24230c
commit 437d3e124d
3 changed files with 13 additions and 2 deletions

View File

@ -23,6 +23,8 @@
#ifndef __ASSEMBLY__
extern void __mcount(void);
#define ARCH_SUPPORTS_FTRACE_OPS 1
#ifdef CONFIG_DYNAMIC_FTRACE
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{

View File

@ -74,7 +74,11 @@ static unsigned long ftrace_gen_branch(unsigned long pc, unsigned long addr,
create_JumpOff_X1(pcrel_by_instr);
}
if (addr == FTRACE_ADDR) {
/*
* Also put { move r10, lr; jal ftrace_stub } in a bundle, which
* is used to replace the instruction in address ftrace_call.
*/
if (addr == FTRACE_ADDR || addr == (unsigned long)ftrace_stub) {
/* opcode: or r10, lr, zero */
opcode_x0 =
create_Dest_X0(10) |

View File

@ -81,7 +81,12 @@ STD_ENTRY(ftrace_caller)
/* arg1: self return address */
/* arg2: parent's return address */
{ move r0, lr; move r1, r10 }
/* arg3: ftrace_ops */
/* arg4: regs (but make it NULL) */
{ move r0, lr; moveli r2, hw2_last(function_trace_op) }
{ move r1, r10; shl16insli r2, r2, hw1(function_trace_op) }
{ movei r3, 0; shl16insli r2, r2, hw0(function_trace_op) }
ld r2,r2
.global ftrace_call
ftrace_call: