mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 05:34:00 +08:00
aca9120977
Tony Jones reported that the ftrace self tests on s390 do not work: <6>Testing dynamic ftrace ops #1: (0 0 0 0 0) FAILED! <6>Testing tracer irqsoff: <3>failed to start irqsoff tracer <4>.. no entries found ..FAILED! <6>Testing tracer wakeup: <3>failed to start wakeup tracer <4>.. no entries found ..FAILED! <6>Testing tracer function_graph: <4>Failed to init function_graph tracer, init returned -19 <4>FAILED! This happens because we forgot to adjust the instruction pointer that gets passed to the ftrace trace function by MCOUNT_INSN_SIZE. In addition change MCOUNT_INSN_SIZE to the correct value on 31 bit. It only worked so far because the to be patched instruction was identical. Reported-by: Tony Jones <tonyj@suse.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
74 lines
1.3 KiB
ArmAsm
74 lines
1.3 KiB
ArmAsm
/*
|
|
* Copyright IBM Corp. 2008, 2009
|
|
*
|
|
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
|
|
*
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/asm-offsets.h>
|
|
#include <asm/ftrace.h>
|
|
|
|
.section .kprobes.text, "ax"
|
|
|
|
ENTRY(ftrace_stub)
|
|
br %r14
|
|
|
|
ENTRY(_mcount)
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
br %r14
|
|
|
|
ENTRY(ftrace_caller)
|
|
#endif
|
|
stm %r2,%r5,16(%r15)
|
|
bras %r1,2f
|
|
0: .long ftrace_trace_function
|
|
1: .long function_trace_stop
|
|
2: l %r2,1b-0b(%r1)
|
|
icm %r2,0xf,0(%r2)
|
|
jnz 3f
|
|
st %r14,56(%r15)
|
|
lr %r0,%r15
|
|
ahi %r15,-96
|
|
l %r3,100(%r15)
|
|
la %r2,0(%r14)
|
|
st %r0,__SF_BACKCHAIN(%r15)
|
|
la %r3,0(%r3)
|
|
ahi %r2,-MCOUNT_INSN_SIZE
|
|
l %r14,0b-0b(%r1)
|
|
l %r14,0(%r14)
|
|
basr %r14,%r14
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
l %r2,100(%r15)
|
|
l %r3,152(%r15)
|
|
ENTRY(ftrace_graph_caller)
|
|
# The bras instruction gets runtime patched to call prepare_ftrace_return.
|
|
# See ftrace_enable_ftrace_graph_caller. The patched instruction is:
|
|
# bras %r14,prepare_ftrace_return
|
|
bras %r14,0f
|
|
0: st %r2,100(%r15)
|
|
#endif
|
|
ahi %r15,96
|
|
l %r14,56(%r15)
|
|
3: lm %r2,%r5,16(%r15)
|
|
br %r14
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
|
|
ENTRY(return_to_handler)
|
|
stm %r2,%r5,16(%r15)
|
|
st %r14,56(%r15)
|
|
lr %r0,%r15
|
|
ahi %r15,-96
|
|
st %r0,__SF_BACKCHAIN(%r15)
|
|
bras %r1,0f
|
|
.long ftrace_return_to_handler
|
|
0: l %r2,0b-0b(%r1)
|
|
basr %r14,%r2
|
|
lr %r14,%r2
|
|
ahi %r15,96
|
|
lm %r2,%r5,16(%r15)
|
|
br %r14
|
|
|
|
#endif
|