[CRIU] [PATCH] parasite-syscall: get rid of code_syscall{, size} globals

Dmitry Safonov dsafonov at virtuozzo.com
Wed Mar 16 07:46:25 PDT 2016 

On 03/16/2016 05:32 PM, Dmitry Safonov wrote:
> I think, we may safetly remove this exports, as:
> - code_syscall is used only in one function, which now will have
>    it as a parameter;
> - code_syscall_size is equall to BUILTIN_SYSCALL_SIZE under
>    BUILD_BUG_ON, so BUILTIN_SYSCALL_SIZE may be used instead.
Oh, drop it: code_syscall_size is word-aligned because of
PTRACE_PEEKUSER wants it to be so.
And BUILTIN_SYSCALL_SIZE isn't word-aligned.
Will rework this.
>
> This will reduce arch-depended code coupling a little.
>
> (and I also interested in this because of I need __parasite_execute_syscall
> to execute 32-bit syscall code on x86_64, which I prefer to leave without
> some CONFIG_X86_64 as it's generic code)
>
> Signed-off-by: Dmitry Safonov <dsafonov at virtuozzo.com>
> ---
>   criu/arch/aarch64/crtools.c                      | 2 +-
>   criu/arch/aarch64/include/asm/parasite-syscall.h | 3 ---
>   criu/arch/arm/crtools.c                          | 2 +-
>   criu/arch/arm/include/asm/parasite-syscall.h     | 4 ----
>   criu/arch/ppc64/crtools.c                        | 2 +-
>   criu/arch/ppc64/include/asm/parasite-syscall.h   | 3 ---
>   criu/arch/x86/crtools.c                          | 2 +-
>   criu/arch/x86/include/asm/parasite-syscall.h     | 3 ---
>   criu/include/parasite-syscall.h                  | 2 +-
>   criu/parasite-syscall.c                          | 5 +++--
>   10 files changed, 8 insertions(+), 20 deletions(-)
>
> diff --git a/criu/arch/aarch64/crtools.c b/criu/arch/aarch64/crtools.c
> index 7a25106..f56b864 100644
> --- a/criu/arch/aarch64/crtools.c
> +++ b/criu/arch/aarch64/crtools.c
> @@ -71,7 +71,7 @@ int syscall_seized(struct parasite_ctl *ctl, int nr, unsigned long *ret,
>   	regs.regs[6] = 0;
>   	regs.regs[7] = 0;
>   
> -	err = __parasite_execute_syscall(ctl, &regs);
> +	err = __parasite_execute_syscall(ctl, &regs, code_syscall);
>   
>   	*ret = regs.regs[0];
>   	return err;
> diff --git a/criu/arch/aarch64/include/asm/parasite-syscall.h b/criu/arch/aarch64/include/asm/parasite-syscall.h
> index 0c07121..f992bca 100644
> --- a/criu/arch/aarch64/include/asm/parasite-syscall.h
> +++ b/criu/arch/aarch64/include/asm/parasite-syscall.h
> @@ -6,9 +6,6 @@ struct parasite_ctl;
>   #define ARCH_SI_TRAP TRAP_BRKPT
>   
>   
> -extern const char code_syscall[];
> -extern const int code_syscall_size;
> -
>   void parasite_setup_regs(unsigned long new_ip, void *stack, user_regs_struct_t *regs);
>   
>   void *mmap_seized(struct parasite_ctl *ctl,
> diff --git a/criu/arch/arm/crtools.c b/criu/arch/arm/crtools.c
> index 9588990..a82e9ef 100644
> --- a/criu/arch/arm/crtools.c
> +++ b/criu/arch/arm/crtools.c
> @@ -73,7 +73,7 @@ int syscall_seized(struct parasite_ctl *ctl, int nr, unsigned long *ret,
>   	regs.ARM_r4 = arg5;
>   	regs.ARM_r5 = arg6;
>   
> -	err = __parasite_execute_syscall(ctl, &regs);
> +	err = __parasite_execute_syscall(ctl, &regs, code_syscall);
>   
>   	*ret = regs.ARM_r0;
>   	return err;
> diff --git a/criu/arch/arm/include/asm/parasite-syscall.h b/criu/arch/arm/include/asm/parasite-syscall.h
> index 0c66bf9..2d6b85f 100644
> --- a/criu/arch/arm/include/asm/parasite-syscall.h
> +++ b/criu/arch/arm/include/asm/parasite-syscall.h
> @@ -5,10 +5,6 @@
>   #define ARCH_SI_TRAP TRAP_BRKPT
>   
>   
> -extern const char code_syscall[];
> -extern const int code_syscall_size;
> -
> -
>   void parasite_setup_regs(unsigned long new_ip, void *stack, user_regs_struct_t *regs);
>   
>   void *mmap_seized(struct parasite_ctl *ctl,
> diff --git a/criu/arch/ppc64/crtools.c b/criu/arch/ppc64/crtools.c
> index 14b1e7c..9ed377e 100644
> --- a/criu/arch/ppc64/crtools.c
> +++ b/criu/arch/ppc64/crtools.c
> @@ -80,7 +80,7 @@ int syscall_seized(struct parasite_ctl *ctl, int nr, unsigned long *ret,
>   	regs.gpr[7] = arg5;
>   	regs.gpr[8] = arg6;
>   
> -	err = __parasite_execute_syscall(ctl, &regs);
> +	err = __parasite_execute_syscall(ctl, &regs, code_syscall);
>   
>   	*ret = regs.gpr[3];
>   	return err;
> diff --git a/criu/arch/ppc64/include/asm/parasite-syscall.h b/criu/arch/ppc64/include/asm/parasite-syscall.h
> index 7665e20..1ac6b3b 100644
> --- a/criu/arch/ppc64/include/asm/parasite-syscall.h
> +++ b/criu/arch/ppc64/include/asm/parasite-syscall.h
> @@ -5,9 +5,6 @@ struct parasite_ctl;
>   
>   #define ARCH_SI_TRAP TRAP_BRKPT
>   
> -extern const char code_syscall[];
> -extern const int code_syscall_size;
> -
>   void parasite_setup_regs(unsigned long new_ip, void *stack, user_regs_struct_t *regs);
>   
>   void *mmap_seized(struct parasite_ctl *ctl,
> diff --git a/criu/arch/x86/crtools.c b/criu/arch/x86/crtools.c
> index 1c43ab1..83d3c8e 100644
> --- a/criu/arch/x86/crtools.c
> +++ b/criu/arch/x86/crtools.c
> @@ -103,7 +103,7 @@ int syscall_seized(struct parasite_ctl *ctl, int nr, unsigned long *ret,
>   	regs.r8  = arg5;
>   	regs.r9  = arg6;
>   
> -	err = __parasite_execute_syscall(ctl, &regs);
> +	err = __parasite_execute_syscall(ctl, &regs, code_syscall);
>   
>   	*ret = regs.ax;
>   	return err;
> diff --git a/criu/arch/x86/include/asm/parasite-syscall.h b/criu/arch/x86/include/asm/parasite-syscall.h
> index 4d56cb0..e2c7a5a 100644
> --- a/criu/arch/x86/include/asm/parasite-syscall.h
> +++ b/criu/arch/x86/include/asm/parasite-syscall.h
> @@ -8,9 +8,6 @@ struct parasite_ctl;
>   #define ARCH_SI_TRAP SI_KERNEL
>   
>   
> -extern const char code_syscall[];
> -extern const int code_syscall_size;
> -
>   void parasite_setup_regs(unsigned long new_ip, void *stack, user_regs_struct_t *regs);
>   
>   void *mmap_seized(struct parasite_ctl *ctl,
> diff --git a/criu/include/parasite-syscall.h b/criu/include/parasite-syscall.h
> index 5ed8e35..04d2602 100644
> --- a/criu/include/parasite-syscall.h
> +++ b/criu/include/parasite-syscall.h
> @@ -119,7 +119,7 @@ extern int syscall_seized(struct parasite_ctl *ctl, int nr, unsigned long *ret,
>   			  unsigned long arg5, unsigned long arg6);
>   
>   extern int __parasite_execute_syscall(struct parasite_ctl *ctl,
> -				user_regs_struct_t *regs);
> +		user_regs_struct_t *regs, const char *code_syscall);
>   extern bool arch_can_dump_task(pid_t pid);
>   
>   /*
> diff --git a/criu/parasite-syscall.c b/criu/parasite-syscall.c
> index bcdadcb..0a1bdc6 100644
> --- a/criu/parasite-syscall.c
> +++ b/criu/parasite-syscall.c
> @@ -44,7 +44,7 @@
>   static int can_run_syscall(unsigned long ip, unsigned long start,
>   			   unsigned long end, unsigned long pad)
>   {
> -	return ip >= start && ip < (end - code_syscall_size - pad);
> +	return ip >= start && ip < (end - BUILTIN_SYSCALL_SIZE - pad);
>   }
>   
>   static int syscall_fits_vma_area(struct vma_area *vma_area, unsigned long pad)
> @@ -210,7 +210,8 @@ err:
>   	return ret;
>   }
>   
> -int __parasite_execute_syscall(struct parasite_ctl *ctl, user_regs_struct_t *regs)
> +int __parasite_execute_syscall(struct parasite_ctl *ctl,
> +		user_regs_struct_t *regs, const char *code_syscall)
>   {
>   	pid_t pid = ctl->pid.real;
>   	int err;


-- 
Regards,
Dmitry Safonov

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