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[1/1] powerpc/debug: implement HAVE_USER_RETURN_NOTIFIER

Message ID 475A60AEEAA99F6C+20231211025054.885-1-luming.yu@shingroup.cn (mailing list archive)
State Changes Requested
Headers show
Series [1/1] powerpc/debug: implement HAVE_USER_RETURN_NOTIFIER | expand

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Commit Message

Luming Yu Dec. 11, 2023, 2:50 a.m. UTC 
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

Comments

Christophe Leroy Dec. 11, 2023, 6:34 a.m. UTC | #1 
Le 11/12/2023 à 03:50, Luming Yu a écrit :
> [Vous ne recevez pas souvent de courriers de luming.yu@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 000000000000..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 <linux/user-return-notifier.h>
> +
> +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<<TIF_SYSCALL_TRACE)
> @@ -125,6 +126,7 @@ void arch_setup_new_exec(void);
>   #define _TIF_NOTIFY_SIGNAL     (1<<TIF_NOTIFY_SIGNAL)
>   #define _TIF_POLLING_NRFLAG    (1<<TIF_POLLING_NRFLAG)
>   #define _TIF_32BIT             (1<<TIF_32BIT)
> +#define _TIF_USER_RETURN_NOTIFY        (1<<TIF_USER_RETURN_NOTIFY)
>   #define _TIF_RESTORE_TM                (1<<TIF_RESTORE_TM)
>   #define _TIF_PATCH_PENDING     (1<<TIF_PATCH_PENDING)
>   #define _TIF_SYSCALL_AUDIT     (1<<TIF_SYSCALL_AUDIT)
> 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 <linux/uaccess.h>
>   #include <linux/pkeys.h>
>   #include <linux/seq_buf.h>
> +#include <linux/user-return-notifier.h>
> 
>   #include <asm/interrupt.h>
>   #include <asm/io.h>
> @@ -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
>
Michael Ellerman Dec. 11, 2023, 10:05 a.m. UTC | #2 
Luming Yu <luming.yu@shingroup.cn> 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 000000000000..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 <linux/user-return-notifier.h>
> +
> +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
diff mbox series

Patch

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 000000000000..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 <linux/user-return-notifier.h>
+
+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<<TIF_SYSCALL_TRACE)
@@ -125,6 +126,7 @@  void arch_setup_new_exec(void);
 #define _TIF_NOTIFY_SIGNAL	(1<<TIF_NOTIFY_SIGNAL)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 #define _TIF_32BIT		(1<<TIF_32BIT)
+#define _TIF_USER_RETURN_NOTIFY	(1<<TIF_USER_RETURN_NOTIFY)
 #define _TIF_RESTORE_TM		(1<<TIF_RESTORE_TM)
 #define _TIF_PATCH_PENDING	(1<<TIF_PATCH_PENDING)
 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
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 <linux/uaccess.h>
 #include <linux/pkeys.h>
 #include <linux/seq_buf.h>
+#include <linux/user-return-notifier.h>
 
 #include <asm/interrupt.h>
 #include <asm/io.h>
@@ -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;
 }