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authorVasily Gorbik <gor@linux.ibm.com>2018-08-06 15:17:47 +0200
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2018-08-15 22:39:53 -0400
commitd983c89cc96a87db0c00821e81aa3d8296c12225 (patch)
tree76e22e4f68f712b61d4ad485f89c9a2f877cd093 /arch/s390
parent2f4df0017baedd535254d987c6b10f855f1fb11f (diff)
downloadblackbird-op-linux-d983c89cc96a87db0c00821e81aa3d8296c12225.tar.gz
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s390/ftrace: Add -mfentry and -mnop-mcount support
Utilize -mfentry and -mnop-mcount gcc options together with -mrecord-mcount to get compiler generated calls to the profiling functions as nops which are compatible with current -mhotpatch=0,3 approach. At the same time -mrecord-mcount enables __mcount_loc section generation by the compiler which allows to avoid using scripts/recordmcount.pl script. Link: http://lkml.kernel.org/r/patch-4.thread-aa7b8d.git-aa7b8dbf236f.your-ad-here.call-01533557518-ext-9465@work.hours Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/Kconfig2
-rw-r--r--arch/s390/Makefile16
-rw-r--r--arch/s390/include/asm/ftrace.h6
-rw-r--r--arch/s390/kernel/ftrace.c2
-rw-r--r--arch/s390/kernel/mcount.S2
5 files changed, 16 insertions, 12 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index e44bb2b2873e..4e914445553e 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -136,6 +136,7 @@ config S390
select HAVE_DYNAMIC_FTRACE
select HAVE_DYNAMIC_FTRACE_WITH_REGS
select HAVE_EFFICIENT_UNALIGNED_ACCESS
+ select HAVE_FENTRY
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER
@@ -157,6 +158,7 @@ config S390
select HAVE_MEMBLOCK_NODE_MAP
select HAVE_MEMBLOCK_PHYS_MAP
select HAVE_MOD_ARCH_SPECIFIC
+ select HAVE_NOP_MCOUNT
select HAVE_OPROFILE
select HAVE_PERF_EVENTS
select HAVE_REGS_AND_STACK_ACCESS_API
diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index 68a690442be0..8498babb5dad 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -86,13 +86,15 @@ ifdef CONFIG_EXPOLINE
endif
ifdef CONFIG_FUNCTION_TRACER
-# make use of hotpatch feature if the compiler supports it
-cc_hotpatch := -mhotpatch=0,3
-ifeq ($(call cc-option-yn,$(cc_hotpatch)),y)
-CC_FLAGS_FTRACE := $(cc_hotpatch)
-KBUILD_AFLAGS += -DCC_USING_HOTPATCH
-KBUILD_CFLAGS += -DCC_USING_HOTPATCH
-endif
+ ifeq ($(call cc-option-yn,-mfentry -mnop-mcount),n)
+ # make use of hotpatch feature if the compiler supports it
+ cc_hotpatch := -mhotpatch=0,3
+ ifeq ($(call cc-option-yn,$(cc_hotpatch)),y)
+ CC_FLAGS_FTRACE := $(cc_hotpatch)
+ KBUILD_AFLAGS += -DCC_USING_HOTPATCH
+ KBUILD_CFLAGS += -DCC_USING_HOTPATCH
+ endif
+ endif
endif
# Test CFI features of binutils
diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h
index cfccc0edd00d..8ea270fdc7fb 100644
--- a/arch/s390/include/asm/ftrace.h
+++ b/arch/s390/include/asm/ftrace.h
@@ -4,7 +4,7 @@
#define ARCH_SUPPORTS_FTRACE_OPS 1
-#ifdef CC_USING_HOTPATCH
+#if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)
#define MCOUNT_INSN_SIZE 6
#else
#define MCOUNT_INSN_SIZE 24
@@ -42,7 +42,7 @@ struct ftrace_insn {
static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn)
{
#ifdef CONFIG_FUNCTION_TRACER
-#ifdef CC_USING_HOTPATCH
+#if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)
/* brcl 0,0 */
insn->opc = 0xc004;
insn->disp = 0;
@@ -57,7 +57,7 @@ static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn)
static inline int is_ftrace_nop(struct ftrace_insn *insn)
{
#ifdef CONFIG_FUNCTION_TRACER
-#ifdef CC_USING_HOTPATCH
+#if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)
if (insn->disp == 0)
return 1;
#else
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index dc76d813e420..84be7f02d0c2 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -61,7 +61,7 @@ unsigned long ftrace_plt;
static inline void ftrace_generate_orig_insn(struct ftrace_insn *insn)
{
-#ifdef CC_USING_HOTPATCH
+#if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)
/* brcl 0,0 */
insn->opc = 0xc004;
insn->disp = 0;
diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S
index 27110f3294ed..e93fbf02490c 100644
--- a/arch/s390/kernel/mcount.S
+++ b/arch/s390/kernel/mcount.S
@@ -35,7 +35,7 @@ ENTRY(ftrace_caller)
.globl ftrace_regs_caller
.set ftrace_regs_caller,ftrace_caller
lgr %r1,%r15
-#ifndef CC_USING_HOTPATCH
+#if !(defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT))
aghi %r0,MCOUNT_RETURN_FIXUP
#endif
aghi %r15,-STACK_FRAME_SIZE
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