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From: Daniel Axtens <dja@axtens•net>
To: "Christopher M. Riedl" <cmr@codefail•de>, linuxppc-dev@lists•ozlabs.org
Subject: Re: [PATCH v5 02/10] powerpc/signal: Add unsafe_copy_{vsx, fpr}_from_user()
Date: Fri, 05 Feb 2021 16:17:01 +1100	[thread overview]
Message-ID: <87h7mrdrg2.fsf@dja-thinkpad.axtens.net> (raw)
In-Reply-To: <20210203184323.20792-3-cmr@codefail.de>

Hi Christopher,

I have checked that each implementation matches the corresponding
*_to_user implementation. We've had some debate about whether the
overarching implementation in the to/from pairs (especially where things
go via a bounce buffer) can be simplified - but that's probably not
really something that this patch set should do.

On that basis:
Reviewed-by: Daniel Axtens <dja@axtens•net>

Kind regards,
Daniel

> Reuse the "safe" implementation from signal.c except for calling
> unsafe_copy_from_user() to copy into a local buffer.
>
> Signed-off-by: Christopher M. Riedl <cmr@codefail•de>
> ---
>  arch/powerpc/kernel/signal.h | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
>
> diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
> index 2559a681536e..7dfc536c78ef 100644
> --- a/arch/powerpc/kernel/signal.h
> +++ b/arch/powerpc/kernel/signal.h
> @@ -53,6 +53,30 @@ unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user *from);
>  				&buf[i], label);\
>  } while (0)
>  
> +#define unsafe_copy_fpr_from_user(task, from, label)	do {		\
> +	struct task_struct *__t = task;					\
> +	u64 __user *__f = (u64 __user *)from;				\
> +	u64 buf[ELF_NFPREG];						\
> +	int i;								\
> +									\
> +	unsafe_copy_from_user(buf, __f, sizeof(buf), label);		\
> +	for (i = 0; i < ELF_NFPREG - 1; i++)				\
> +		__t->thread.TS_FPR(i) = buf[i];				\
> +	__t->thread.fp_state.fpscr = buf[i];				\
> +} while (0)
> +
> +#define unsafe_copy_vsx_from_user(task, from, label)	do {		\
> +	struct task_struct *__t = task;					\
> +	u64 __user *__f = (u64 __user *)from;				\
> +	u64 buf[ELF_NVSRHALFREG];					\
> +	int i;								\
> +									\
> +	unsafe_copy_from_user(buf, __f, sizeof(buf), label);		\
> +	for (i = 0; i < ELF_NVSRHALFREG ; i++)				\
> +		__t->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i];	\
> +} while (0)
> +
> +
>  #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
>  #define unsafe_copy_ckfpr_to_user(to, task, label)	do {		\
>  	struct task_struct *__t = task;					\
> @@ -80,6 +104,10 @@ unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user *from);
>  	unsafe_copy_to_user(to, (task)->thread.fp_state.fpr,	\
>  			    ELF_NFPREG * sizeof(double), label)
>  
> +#define unsafe_copy_fpr_from_user(task, from, label)			\
> +	unsafe_copy_from_user((task)->thread.fp_state.fpr, from,	\
> +			    ELF_NFPREG * sizeof(double), label)
> +
>  static inline unsigned long
>  copy_fpr_to_user(void __user *to, struct task_struct *task)
>  {
> @@ -115,6 +143,8 @@ copy_ckfpr_from_user(struct task_struct *task, void __user *from)
>  #else
>  #define unsafe_copy_fpr_to_user(to, task, label) do { } while (0)
>  
> +#define unsafe_copy_fpr_from_user(task, from, label) do { } while (0)
> +
>  static inline unsigned long
>  copy_fpr_to_user(void __user *to, struct task_struct *task)
>  {
> -- 
> 2.26.1

  reply	other threads:[~2021-02-05  5:18 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-03 18:43 [PATCH v5 00/10] Improve signal performance on PPC64 with KUAP Christopher M. Riedl
2021-02-03 18:43 ` [PATCH v5 01/10] powerpc/uaccess: Add unsafe_copy_from_user Christopher M. Riedl
2021-02-05  4:47   ` Daniel Axtens
2021-02-03 18:43 ` [PATCH v5 02/10] powerpc/signal: Add unsafe_copy_{vsx, fpr}_from_user() Christopher M. Riedl
2021-02-05  5:17   ` Daniel Axtens [this message]
2021-02-03 18:43 ` [PATCH v5 03/10] powerpc/signal64: Move non-inline functions out of setup_sigcontext() Christopher M. Riedl
2021-02-08  4:44   ` Daniel Axtens
2021-02-10  4:37     ` Christopher M. Riedl
2021-02-10 21:06       ` Daniel Axtens
2021-02-10 23:51         ` Christopher M. Riedl
2021-02-03 18:43 ` [PATCH v5 04/10] powerpc: Reference param in MSR_TM_ACTIVE() macro Christopher M. Riedl
2021-02-12  4:52   ` Daniel Axtens
2021-02-03 18:43 ` [PATCH v5 05/10] powerpc/signal64: Remove TM ifdefery in middle of if/else block Christopher M. Riedl
2021-02-12  5:21   ` Daniel Axtens
2021-02-17 19:27     ` Christopher M. Riedl
2021-02-18 10:47       ` Michael Ellerman
2021-02-03 18:43 ` [PATCH v5 06/10] powerpc/signal64: Replace setup_sigcontext() w/ unsafe_setup_sigcontext() Christopher M. Riedl
2021-02-12  5:41   ` Daniel Axtens
2021-02-17 19:31     ` Christopher M. Riedl
2021-02-03 18:43 ` [PATCH v5 07/10] powerpc/signal64: Replace restore_sigcontext() w/ unsafe_restore_sigcontext() Christopher M. Riedl
2021-02-12 21:17   ` Daniel Axtens
2021-02-17 19:32     ` Christopher M. Riedl
2021-02-03 18:43 ` [PATCH v5 08/10] powerpc/signal64: Rewrite handle_rt_signal64() to minimise uaccess switches Christopher M. Riedl
2021-02-03 18:43 ` [PATCH v5 09/10] powerpc/signal64: Rewrite rt_sigreturn() " Christopher M. Riedl
2021-02-03 18:43 ` [PATCH v5 10/10] powerpc/signal64: Use __get_user() to copy sigset_t Christopher M. Riedl
2021-02-05  4:40   ` Christopher M. Riedl
2021-02-09 21:45   ` Christophe Leroy
2021-02-10  4:16     ` Christopher M. Riedl
2021-02-12 21:21   ` Daniel Axtens
2021-02-17 19:53     ` Christopher M. Riedl

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