[PATCH 0/2] Update defconfig and fix kernel hang

[PATCH 0/2] Update defconfig and fix kernel hang

[Tiezhu Yang]

Tiezhu Yang (2):
  MIPS: Loongson64: Update loongson3_defconfig
  MIPS: Fix kernel hang under FUNCTION_GRAPH_TRACER and PREEMPT_TRACER

 arch/mips/configs/loongson3_defconfig | 12 +-----------
 arch/mips/lib/mips-atomic.c           | 12 ++++++------
 2 files changed, 7 insertions(+), 17 deletions(-)

-- 
2.1.0

[PATCH 1/2] MIPS: Loongson64: Update loongson3_defconfig

[Tiezhu Yang]

Some configs in loongson3_defconfig is invalid or needless,
use the following steps to update it:

make loongson3_defconfig
make savedefconfig
cp defconfig arch/mips/configs/loongson3_defconfig

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
 arch/mips/configs/loongson3_defconfig | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/arch/mips/configs/loongson3_defconfig b/arch/mips/configs/loongson3_defconfig
index a18609c..f02101f 100644
--- a/arch/mips/configs/loongson3_defconfig
+++ b/arch/mips/configs/loongson3_defconfig
@@ -13,7 +13,6 @@ CONFIG_TASK_DELAY_ACCT=y
 CONFIG_TASK_XACCT=y
 CONFIG_TASK_IO_ACCOUNTING=y
 CONFIG_MEMCG=y
-CONFIG_MEMCG_SWAP=y
 CONFIG_BLK_CGROUP=y
 CONFIG_CGROUP_PIDS=y
 CONFIG_CGROUP_FREEZER=y
@@ -31,9 +30,8 @@ CONFIG_EMBEDDED=y
 CONFIG_PERF_EVENTS=y
 CONFIG_MACH_LOONGSON64=y
 CONFIG_CPU_HAS_MSA=y
-CONFIG_NR_CPUS=16
 CONFIG_NUMA=y
-CONFIG_SMP=y
+CONFIG_NR_CPUS=16
 CONFIG_HZ_256=y
 CONFIG_KEXEC=y
 CONFIG_MIPS32_O32=y
@@ -206,7 +204,6 @@ CONFIG_VIRTIO_NET=m
 # CONFIG_NET_VENDOR_DEC is not set
 # CONFIG_NET_VENDOR_DLINK is not set
 # CONFIG_NET_VENDOR_EMULEX is not set
-# CONFIG_NET_VENDOR_HP is not set
 # CONFIG_NET_VENDOR_I825XX is not set
 CONFIG_E1000=y
 CONFIG_E1000E=y
@@ -248,7 +245,6 @@ CONFIG_PPP_ASYNC=m
 CONFIG_PPP_SYNC_TTY=m
 CONFIG_ATH9K=m
 CONFIG_HOSTAP=m
-CONFIG_INPUT_POLLDEV=m
 CONFIG_INPUT_SPARSEKMAP=y
 CONFIG_INPUT_MOUSEDEV=y
 CONFIG_INPUT_MOUSEDEV_PSAUX=y
@@ -280,7 +276,6 @@ CONFIG_SENSORS_LM75=m
 CONFIG_SENSORS_LM93=m
 CONFIG_SENSORS_W83627HF=m
 CONFIG_MEDIA_SUPPORT=m
-CONFIG_MEDIA_CAMERA_SUPPORT=y
 CONFIG_MEDIA_USB_SUPPORT=y
 CONFIG_USB_VIDEO_CLASS=m
 CONFIG_DRM=y
@@ -391,18 +386,13 @@ CONFIG_SECURITY_SELINUX=y
 CONFIG_SECURITY_SELINUX_BOOTPARAM=y
 CONFIG_SECURITY_SELINUX_DISABLE=y
 CONFIG_DEFAULT_SECURITY_DAC=y
-CONFIG_CRYPTO_AUTHENC=m
 CONFIG_CRYPTO_HMAC=y
 CONFIG_CRYPTO_MD5=y
-CONFIG_CRYPTO_TGR192=m
 CONFIG_CRYPTO_WP512=m
-CONFIG_CRYPTO_ANUBIS=m
 CONFIG_CRYPTO_BLOWFISH=m
 CONFIG_CRYPTO_CAST5=m
 CONFIG_CRYPTO_CAST6=m
-CONFIG_CRYPTO_KHAZAD=m
 CONFIG_CRYPTO_SERPENT=m
-CONFIG_CRYPTO_TEA=m
 CONFIG_CRYPTO_TWOFISH=m
 CONFIG_CRYPTO_DEFLATE=m
 CONFIG_PRINTK_TIME=y
-- 
2.1.0

[PATCH 2/2] MIPS: Fix kernel hang under FUNCTION_GRAPH_TRACER and PREEMPT_TRACER

[Tiezhu Yang]

When update the latest mainline kernel with the following three configs,
the kernel hangs during startup:

(1) CONFIG_FUNCTION_GRAPH_TRACER=y
(2) CONFIG_PREEMPT_TRACER=y
(3) CONFIG_FTRACE_STARTUP_TEST=y

When update the latest mainline kernel with the above two configs (1)
and (2), the kernel starts normally, but it still hangs when execute
the following command:

echo "function_graph" > /sys/kernel/debug/tracing/current_tracer

Without CONFIG_PREEMPT_TRACER=y, the above two kinds of kernel hangs
disappeared, so it seems that CONFIG_PREEMPT_TRACER has some influences
with function_graph tracer at the first glance.

I use ejtag to find out the epc address is related with preempt_enable()
in the file arch/mips/lib/mips-atomic.c, because function tracing can
trace the preempt_{enable,disable} calls that are traced, replace them
with preempt_{enable,disable}_notrace to prevent function tracing from
going into an infinite loop, and then it can fix the kernel hang issue.

By the way, it seems that this commit is a complement and improvement of
commit f93a1a00f2bd ("MIPS: Fix crash that occurs when function tracing
is enabled").

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Steven Rostedt <rostedt@goodmis.org>
---
 arch/mips/lib/mips-atomic.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/mips/lib/mips-atomic.c b/arch/mips/lib/mips-atomic.c
index de03838..a9b72ea 100644
--- a/arch/mips/lib/mips-atomic.c
+++ b/arch/mips/lib/mips-atomic.c
@@ -37,7 +37,7 @@
  */
 notrace void arch_local_irq_disable(void)
 {
-	preempt_disable();
+	preempt_disable_notrace();
 
 	__asm__ __volatile__(
 	"	.set	push						\n"
@@ -53,7 +53,7 @@ notrace void arch_local_irq_disable(void)
 	: /* no inputs */
 	: "memory");
 
-	preempt_enable();
+	preempt_enable_notrace();
 }
 EXPORT_SYMBOL(arch_local_irq_disable);
 
@@ -61,7 +61,7 @@ notrace unsigned long arch_local_irq_save(void)
 {
 	unsigned long flags;
 
-	preempt_disable();
+	preempt_disable_notrace();
 
 	__asm__ __volatile__(
 	"	.set	push						\n"
@@ -78,7 +78,7 @@ notrace unsigned long arch_local_irq_save(void)
 	: /* no inputs */
 	: "memory");
 
-	preempt_enable();
+	preempt_enable_notrace();
 
 	return flags;
 }
@@ -88,7 +88,7 @@ notrace void arch_local_irq_restore(unsigned long flags)
 {
 	unsigned long __tmp1;
 
-	preempt_disable();
+	preempt_disable_notrace();
 
 	__asm__ __volatile__(
 	"	.set	push						\n"
@@ -106,7 +106,7 @@ notrace void arch_local_irq_restore(unsigned long flags)
 	: "0" (flags)
 	: "memory");
 
-	preempt_enable();
+	preempt_enable_notrace();
 }
 EXPORT_SYMBOL(arch_local_irq_restore);
 
-- 
2.1.0

Re: [PATCH 2/2] MIPS: Fix kernel hang under FUNCTION_GRAPH_TRACER and PREEMPT_TRACER

[Thomas Bogendoerfer]

On Sat, May 15, 2021 at 07:02:01PM +0800, Tiezhu Yang wrote:
> When update the latest mainline kernel with the following three configs,
> the kernel hangs during startup:
> 
> (1) CONFIG_FUNCTION_GRAPH_TRACER=y
> (2) CONFIG_PREEMPT_TRACER=y
> (3) CONFIG_FTRACE_STARTUP_TEST=y
> 
> When update the latest mainline kernel with the above two configs (1)
> and (2), the kernel starts normally, but it still hangs when execute
> the following command:
> 
> echo "function_graph" > /sys/kernel/debug/tracing/current_tracer
> 
> Without CONFIG_PREEMPT_TRACER=y, the above two kinds of kernel hangs
> disappeared, so it seems that CONFIG_PREEMPT_TRACER has some influences
> with function_graph tracer at the first glance.
> 
> I use ejtag to find out the epc address is related with preempt_enable()
> in the file arch/mips/lib/mips-atomic.c, because function tracing can
> trace the preempt_{enable,disable} calls that are traced, replace them
> with preempt_{enable,disable}_notrace to prevent function tracing from
> going into an infinite loop, and then it can fix the kernel hang issue.
> 
> By the way, it seems that this commit is a complement and improvement of
> commit f93a1a00f2bd ("MIPS: Fix crash that occurs when function tracing
> is enabled").
> 
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> ---
>  arch/mips/lib/mips-atomic.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)

applied to mips-fixes.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH 1/2] MIPS: Loongson64: Update loongson3_defconfig

[Thomas Bogendoerfer]

On Sat, May 15, 2021 at 07:02:00PM +0800, Tiezhu Yang wrote:
> Some configs in loongson3_defconfig is invalid or needless,
> use the following steps to update it:
> 
> make loongson3_defconfig
> make savedefconfig
> cp defconfig arch/mips/configs/loongson3_defconfig
> 
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> ---
>  arch/mips/configs/loongson3_defconfig | 12 +-----------
>  1 file changed, 1 insertion(+), 11 deletions(-)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]