Re: [PATCH 1/1] powerpc/debug: implement HAVE_USER_RETURN_NOTIFIER

2023-12-11 Thread Michael Ellerman 
Luming Yu  writes:

> The support for user return notifier infrastructure
> is hooked into powerpc architecture.
> ---
>  arch/powerpc/Kconfig|  1 +
>  arch/powerpc/include/asm/entry-common.h | 16 
>  arch/powerpc/include/asm/thread_info.h  |  2 ++
>  arch/powerpc/kernel/process.c   |  2 ++
>  4 files changed, 21 insertions(+)
>  create mode 100644 arch/powerpc/include/asm/entry-common.h
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index c10229c0243c..b968068cc04a 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -277,6 +277,7 @@ config PPC
>   select HAVE_STACKPROTECTOR  if PPC64 && 
> $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r13)
>   select HAVE_STATIC_CALL if PPC32
>   select HAVE_SYSCALL_TRACEPOINTS
> + select HAVE_USER_RETURN_NOTIFIER
>   select HAVE_VIRT_CPU_ACCOUNTING
>   select HAVE_VIRT_CPU_ACCOUNTING_GEN
>   select HOTPLUG_SMT  if HOTPLUG_CPU
> diff --git a/arch/powerpc/include/asm/entry-common.h 
> b/arch/powerpc/include/asm/entry-common.h
> new file mode 100644
> index ..51f1eb767696
> --- /dev/null
> +++ b/arch/powerpc/include/asm/entry-common.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef ARCH_POWERPC_ENTRY_COMMON_H
> +#define ARCH_POWERPC_ENTRY_COMMON_H
> +
> +#include 
> +
> +static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
> +   unsigned long ti_work)
> +{
> + if (ti_work & _TIF_USER_RETURN_NOTIFY)
> + fire_user_return_notifiers();
> +}
> +
> +#define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare

AFAICS this is never called because we don't use CONFIG_GENERIC_ENTRY ?

cheers

Re: [PATCH 1/1] powerpc/debug: implement HAVE_USER_RETURN_NOTIFIER

2023-12-10 Thread Christophe Leroy 


Le 11/12/2023 à 03:50, Luming Yu a écrit :
> [Vous ne recevez pas souvent de courriers de luming...@shingroup.cn. 
> Découvrez pourquoi ceci est important à 
> https://aka.ms/LearnAboutSenderIdentification ]
> 
> The support for user return notifier infrastructure
> is hooked into powerpc architecture.

"The support ... is hooked". So what ? It's like saying "The sky is 
blue". Ok, and then ? What's the link between that statement and the patch ?

I don't understand what you mean. Please provide more details, tell what 
this patch does and how.

Christophe


> ---
>   arch/powerpc/Kconfig|  1 +
>   arch/powerpc/include/asm/entry-common.h | 16 
>   arch/powerpc/include/asm/thread_info.h  |  2 ++
>   arch/powerpc/kernel/process.c   |  2 ++
>   4 files changed, 21 insertions(+)
>   create mode 100644 arch/powerpc/include/asm/entry-common.h
> 
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index c10229c0243c..b968068cc04a 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -277,6 +277,7 @@ config PPC
>  select HAVE_STACKPROTECTOR  if PPC64 && 
> $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r13)
>  select HAVE_STATIC_CALL if PPC32
>  select HAVE_SYSCALL_TRACEPOINTS
> +   select HAVE_USER_RETURN_NOTIFIER
>  select HAVE_VIRT_CPU_ACCOUNTING
>  select HAVE_VIRT_CPU_ACCOUNTING_GEN
>  select HOTPLUG_SMT  if HOTPLUG_CPU
> diff --git a/arch/powerpc/include/asm/entry-common.h 
> b/arch/powerpc/include/asm/entry-common.h
> new file mode 100644
> index ..51f1eb767696
> --- /dev/null
> +++ b/arch/powerpc/include/asm/entry-common.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef ARCH_POWERPC_ENTRY_COMMON_H
> +#define ARCH_POWERPC_ENTRY_COMMON_H
> +
> +#include 
> +
> +static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
> + unsigned long ti_work)
> +{
> +   if (ti_work & _TIF_USER_RETURN_NOTIFY)
> +   fire_user_return_notifiers();
> +}
> +
> +#define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare
> +
> +#endif
> diff --git a/arch/powerpc/include/asm/thread_info.h 
> b/arch/powerpc/include/asm/thread_info.h
> index bf5dde1a4114..47e226032f9c 100644
> --- a/arch/powerpc/include/asm/thread_info.h
> +++ b/arch/powerpc/include/asm/thread_info.h
> @@ -117,6 +117,7 @@ void arch_setup_new_exec(void);
>   #endif
>   #define TIF_POLLING_NRFLAG 19  /* true if poll_idle() is polling 
> TIF_NEED_RESCHED */
>   #define TIF_32BIT  20  /* 32 bit binary */
> +#define TIF_USER_RETURN_NOTIFY 21  /* notify kernel of userspace return 
> */
> 
>   /* as above, but as bit values */
>   #define _TIF_SYSCALL_TRACE (1< @@ -125,6 +126,7 @@ void arch_setup_new_exec(void);
>   #define _TIF_NOTIFY_SIGNAL (1<   #define _TIF_POLLING_NRFLAG(1<   #define _TIF_32BIT (1< +#define _TIF_USER_RETURN_NOTIFY(1<   #define _TIF_RESTORE_TM(1<   #define _TIF_PATCH_PENDING (1<   #define _TIF_SYSCALL_AUDIT (1< diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
> index 392404688cec..70a9ea949798 100644
> --- a/arch/powerpc/kernel/process.c
> +++ b/arch/powerpc/kernel/process.c
> @@ -38,6 +38,7 @@
>   #include 
>   #include 
>   #include 
> +#include 
> 
>   #include 
>   #include 
> @@ -1386,6 +1387,7 @@ struct task_struct *__switch_to(struct task_struct 
> *prev,
>  if (current->thread.regs)
>  restore_math(current->thread.regs);
>   #endif /* CONFIG_PPC_BOOK3S_64 */
> +   propagate_user_return_notify(prev, new);
> 
>  return last;
>   }
> --
> 2.42.0.windows.2
>

[PATCH 1/1] powerpc/debug: implement HAVE_USER_RETURN_NOTIFIER

2023-12-10 Thread Luming Yu 
The support for user return notifier infrastructure
is hooked into powerpc architecture.
---
 arch/powerpc/Kconfig|  1 +
 arch/powerpc/include/asm/entry-common.h | 16 
 arch/powerpc/include/asm/thread_info.h  |  2 ++
 arch/powerpc/kernel/process.c   |  2 ++
 4 files changed, 21 insertions(+)
 create mode 100644 arch/powerpc/include/asm/entry-common.h

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c10229c0243c..b968068cc04a 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -277,6 +277,7 @@ config PPC
select HAVE_STACKPROTECTOR  if PPC64 && 
$(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=r13)
select HAVE_STATIC_CALL if PPC32
select HAVE_SYSCALL_TRACEPOINTS
+   select HAVE_USER_RETURN_NOTIFIER
select HAVE_VIRT_CPU_ACCOUNTING
select HAVE_VIRT_CPU_ACCOUNTING_GEN
select HOTPLUG_SMT  if HOTPLUG_CPU
diff --git a/arch/powerpc/include/asm/entry-common.h 
b/arch/powerpc/include/asm/entry-common.h
new file mode 100644
index ..51f1eb767696
--- /dev/null
+++ b/arch/powerpc/include/asm/entry-common.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ARCH_POWERPC_ENTRY_COMMON_H
+#define ARCH_POWERPC_ENTRY_COMMON_H
+
+#include 
+
+static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
+ unsigned long ti_work)
+{
+   if (ti_work & _TIF_USER_RETURN_NOTIFY)
+   fire_user_return_notifiers();
+}
+
+#define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare
+
+#endif
diff --git a/arch/powerpc/include/asm/thread_info.h 
b/arch/powerpc/include/asm/thread_info.h
index bf5dde1a4114..47e226032f9c 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -117,6 +117,7 @@ void arch_setup_new_exec(void);
 #endif
 #define TIF_POLLING_NRFLAG 19  /* true if poll_idle() is polling 
TIF_NEED_RESCHED */
 #define TIF_32BIT  20  /* 32 bit binary */
+#define TIF_USER_RETURN_NOTIFY 21  /* notify kernel of userspace return */
 
 /* as above, but as bit values */
 #define _TIF_SYSCALL_TRACE (1<
 #include 
 #include 
+#include 
 
 #include 
 #include 
@@ -1386,6 +1387,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
if (current->thread.regs)
restore_math(current->thread.regs);
 #endif /* CONFIG_PPC_BOOK3S_64 */
+   propagate_user_return_notify(prev, new);
 
return last;
 }
-- 
2.42.0.windows.2