On Wed, Apr 28, 2010 at 8:29 AM, Christoffer Dall
<christofferdall@xxxxxxxxxxxxxxxxxx> wrote:
> Hi Matt.
>
> Thanks for the feedback. I have changed the path according to your comments
> and am attaching it below.
>
> - Let me know if I need to adjust my patch before inclusion with respect to
> the s/clone_with_pids// later.
>
> - Much better with the 'local SYS_NR_DEF_REGEX' in get_unistd_regex().
> Thanks.
>
> - I pondered about inserting arch-specific code when printing the header
> content, and thought about a file function like add_arch_syscall_base()
> but it seems rhather synthetic as I think ARM is the only possible
> architecture, which would use it. Instead, I added whitespace around the
> line as you suggest.
>
> - I agree regarding the make variables - it was simply a glitch. I
> adjusted the assignment in both Makefile and test/Makefile.
sorry, I forgot to include the changes to test/Makefile in the patch below.
>
>
> Thanks,
> Christoffer
>
> diff --git a/Makefile b/Makefile
> index 6c9ff93..37ed40a 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -18,6 +18,13 @@ CR_OBJS = checkpoint.o checkpoint-main.o restart.o restart-main.o
> # detect architecture (for eclone)
> SUBARCH ?= $(patsubst i%86,x86_32,$(shell uname -m))
>
> +# handle cross-compilation
> +AR := ${CROSS_COMPILE}ar
> +AS := ${CROSS_COMPILE}as
> +CC := ${CROSS_COMPILE}gcc
> +CPP := ${CROSS_COMPILE}cpp
> +LD := ${CROSS_COMPILE}ld
> +
> # compile with debug ?
> DEBUG = -DCHECKPOINT_DEBUG
>
> @@ -77,6 +84,11 @@ ASFLAGS += -m64
> $(LIB_ECLONE): clone_$(SUBARCH)_.o
> endif
>
> +# also on ARM, need also assembly file
> +ifeq ($(SUBARCH),arm)
> +$(LIB_ECLONE): eclone_$(SUBARCH)_.o
> +endif
> +
> # ckptinfo dependencies
> ckptinfo: ckptinfo_types.o
>
> diff --git a/clone.h b/clone.h
> index 3569a45..b6b18ce 100644
> --- a/clone.h
> +++ b/clone.h
> @@ -25,6 +25,14 @@
> # define __NR_unshare 303
> #elif __powerpc__
> # define __NR_unshare 282
> +#elif __arm__
> +# define __NR_OABI_SYSCALL_BASE 0x900000
> +# if defined(__thumb__) || defined(__ARM_EABI__)
> +# define __NR_SYSCALL_BASE 0
> +# else
> +# define __NR_SYSCALL_BASE __NR_OABI_SYSCALL_BASE
> +# endif
> +# define __NR_unshare (__NR_SYSCALL_BASE+337)
> #else
> # error "Architecture not supported"
> #endif
> diff --git a/clone_arm.c b/clone_arm.c
> new file mode 100644
> index 0000000..b62b4ad
> --- /dev/null
> +++ b/clone_arm.c
> @@ -0,0 +1,79 @@
> +/*
> + * clone_arm.c: support for eclone() on ARM
> + *
> + * Author: Christoffer Dall <christofferdall@xxxxxxxxxxxxxxxxxx>
> + *
> + * This file is subject to the terms and conditions of the GNU General Public
> + * License. See the file COPYING in the main directory of the Linux
> + * distribution for more details.
> + */
> +
> +#define _GNU_SOURCE
> +
> +#include <unistd.h>
> +#include <errno.h>
> +#include <stdio.h>
> +#include <sys/types.h>
> +#include <sys/syscall.h>
> +#include <asm/unistd.h>
> +
> +/*
> + * libc doesn't support eclone() yet...
> + * below is arch-dependent code to use the syscall
> + */
> +#include <linux/checkpoint.h>
> +
> +#include "eclone.h"
> +
> +extern int __eclone(int clone_flags_low,
> + struct clone_args *clone_args,
> + unsigned int args_size,
> + pid_t *pids);
> +
> +static unsigned long get_stack_pointer(unsigned long base, unsigned long size)
> +{
> + size_t page_size = sysconf(_SC_PAGESIZE);
> + return (base + size - page_size) - 1;
> +}
> +
> +int eclone(int (*fn)(void *), void *fn_arg, int clone_flags_low,
> + struct clone_args *clone_args, pid_t *pids)
> +{
> + struct clone_args my_args;
> + long newpid;
> + void **sp = NULL;
> +
> + if (!fn) {
> + fprintf(stderr, "Please provide a valid function pointer "
> + "for the child process.\n");
> + return -1;
> + }
> +
> + if (clone_args->child_stack) {
> + sp = (void **)get_stack_pointer(clone_args->child_stack,
> + clone_args->child_stack_size);
> + *--sp = fn_arg;
> + *--sp = fn;
> + } else {
> + fprintf(stderr, "The ARM architecture requires a valid child "
> + "stack. clon_args->child_stack was 0.\n");
> + return -1;
> + }
> +
> +
> + my_args = *clone_args;
> + my_args.child_stack = (unsigned long long)sp;
> + my_args.child_stack_size = 0;
> +
> + newpid = __eclone(clone_flags_low,
> + &my_args,
> + sizeof(my_args),
> + pids);
> +
> + if (newpid < 0) {
> + errno = -newpid;
> + newpid = -1;
> + }
> +
> + return newpid;
> +}
> diff --git a/eclone_arm_.S b/eclone_arm_.S
> new file mode 100644
> index 0000000..0f71d0f
> --- /dev/null
> +++ b/eclone_arm_.S
> @@ -0,0 +1,86 @@
> +/*
> + * eclone_arm_.S: ARM support for eclone()
> + *
> + * Author: Christoffer Dall <christofferdall@xxxxxxxxxxxxxxxxxx>
> + *
> + * This file is subject to the terms and conditions of the GNU General Public
> + * License. See the file COPYING in the main directory of the Linux
> + * distribution for more details.
> + */
> +
> +#define _ERRNO_H 1
> +#include <bits/errno.h>
> +#include <asm/unistd.h>
> +
> +
> +#define CLONE_VM 0x00000100
> +#define CLONE_THREAD 0x00010000
> +
> +#ifndef __NR_eclone
> +#define __NR_eclone 366
> +#endif
> +
> +/*
> + * Implements the following system call wrapper:
> + *
> + * extern int __eclone(int clone_flags_low,
> + * struct clone_args *clone_args,
> + * pid_t *pids);
> + *
> + * The system call wrapper and the system call themselves have slightly
> + * different layouts and the following transformation takes place in
> + * the code below:
> + *
> + */
> +
> + .text
> + .align 4
> + .globl __eclone
> + .type __eclone,%function
> +__eclone:
> + @ save flags
> + mov ip, r0
> +
> + @ do the system call
> +#ifdef __ARM_EABI__
> + str r7, [sp, #-4]!
> + ldr r7, =__NR_eclone
> + swi 0x0
> +#else
> + swi __NR_eclone
> +#endif
> + cmp r0, #0
> + beq 1f
> +#ifdef __ARM_EABI__
> + ldr r7, [sp], #4
> +#endif
> + @ return to caller
> + bx lr
> +
> +1:
> + tst ip, #CLONE_THREAD
> + bne 3f
> + mov r0, #0xffff0fff
> + mov lr, pc
> + sub pc, r0, #31
> + mov r1, r0
> + tst ip, #CLONE_VM
> + movne r0, #-1
> +#ifdef __ARM_EABI__
> + ldr r7, =__NR_getpid
> + swieq 0x0
> +#else
> + swieq __NR_getpid
> +#endif
> + str r0, [r1, #-1108]
> + str r0, [r1, #-1112]
> +3:
> + @ pick the function arg and call address off the stack and execute
> + ldr r0, [sp, #4]
> + mov lr, pc
> + ldr pc, [sp], #8
> +
> + @ and we are done, passing the return value through r0
> + @b PLTJMP(HIDDEN_JUMPTARGET(_exit))
> + b _exit
> +
> diff --git a/include/asm-arm/checkpoint_hdr.h b/include/asm-arm/checkpoint_hdr.h
> new file mode 100644
> index 0000000..9295f85
> --- /dev/null
> +++ b/include/asm-arm/checkpoint_hdr.h
> @@ -0,0 +1,55 @@
> +/*
> + * Generated by extract-headers.sh.
> + */
> +#ifndef __ASM_ARM_CHECKPOINT_HDR_H_
> +#define __ASM_ARM_CHECKPOINT_HDR_H_
> +
> +/*
> + * Checkpoint/restart - architecture specific headers ARM
> + *
> + * Copyright (C) 2008-2010 Oren Laadan
> + * Copyright (C) 2010 Christoffer Dall
> + *
> + * This file is subject to the terms and conditions of the GNU General Public
> + * License. See the file COPYING in the main directory of the Linux
> + * distribution for more details.
> + */
> +
> +#include <linux/types.h>
> +
> +/* ARM structure seen from kernel/userspace */
> +
> +#define CKPT_ARCH_ID CKPT_ARCH_ARM
> +
> +/* arch dependent constants */
> +#define CKPT_ARCH_NSIG 64
> +#define CKPT_TTY_NCC 8
> +
> +struct ckpt_hdr_header_arch {
> + struct ckpt_hdr h;
> + __u32 cpu_architecture;
> + __u8 mmu; /* Checkpointed on mmu system */
> + __u8 aeabi; /* Checkpointed on AEABI kernel */
> + __u8 oabi_compat; /* Checkpointed on OABI compat. system */
> +} __attribute__((aligned(8)));
> +
> +struct ckpt_hdr_thread {
> + struct ckpt_hdr h;
> + __u32 syscall;
> + __u32 tp_value;
> + __u32 thumbee_state;
> +} __attribute__((aligned(8)));
> +
> +struct ckpt_hdr_cpu {
> + struct ckpt_hdr h;
> + __u32 uregs[18];
> +} __attribute__((aligned(8)));
> +
> +struct ckpt_hdr_mm_context {
> + struct ckpt_hdr h;
> + __u32 end_brk;
> +} __attribute__((aligned(8)));
> +
> +
> +
> +#endif /* __ASM_ARM_CHECKPOINT_HDR_H_ */
> diff --git a/include/asm/checkpoint_hdr.h b/include/asm/checkpoint_hdr.h
> index 859f58e..7f18e0e 100644
> --- a/include/asm/checkpoint_hdr.h
> +++ b/include/asm/checkpoint_hdr.h
> @@ -3,7 +3,9 @@
> */
> #ifndef __ASM_CHECKPOINT_HDR_H_
> #define __ASM_CHECKPOINT_HDR_H_
> -#if __powerpc__
> +#if __arm__
> +#include <asm-arm/checkpoint_hdr.h>
> +#elif __powerpc__
> #include <asm-powerpc/checkpoint_hdr.h>
> #elif __s390x__
> #include <asm-s390/checkpoint_hdr.h>
> diff --git a/include/linux/checkpoint.h b/include/linux/checkpoint.h
> index f6a6448..359023f 100644
> --- a/include/linux/checkpoint.h
> +++ b/include/linux/checkpoint.h
> @@ -31,7 +31,25 @@
> #define CHECKPOINT_FD_NONE -1
>
>
> -#if __powerpc__
> +#if __arm__
> +
> +# define __NR_OABI_SYSCALL_BASE 0x900000
> +# if defined(__thumb__) || defined(__ARM_EABI__)
> +# define __NR_SYSCALL_BASE 0
> +# else
> +# define __NR_SYSCALL_BASE __NR_OABI_SYSCALL_BASE
> +# endif
> +
> +
> +# ifndef __NR_checkpoint
> +# define __NR_checkpoint (__NR_SYSCALL_BASE+367)
> +# endif
> +
> +# ifndef __NR_restart
> +# define __NR_restart (__NR_SYSCALL_BASE+368)
> +# endif
> +
> +#elif __powerpc__
>
> # ifndef __NR_checkpoint
> # define __NR_checkpoint 324
> diff --git a/include/linux/checkpoint_hdr.h b/include/linux/checkpoint_hdr.h
> index 65d5256..214cd11 100644
> --- a/include/linux/checkpoint_hdr.h
> +++ b/include/linux/checkpoint_hdr.h
> @@ -202,6 +202,8 @@ enum {
> #define CKPT_ARCH_PPC32 CKPT_ARCH_PPC32
> CKPT_ARCH_PPC64,
> #define CKPT_ARCH_PPC64 CKPT_ARCH_PPC64
> + CKPT_ARCH_ARM,
> +#define CKPT_ARCH_ARM CKPT_ARCH_ARM
> };
>
> /* shared objrects (objref) */
> diff --git a/scripts/extract-headers.sh b/scripts/extract-headers.sh
> index 8c8ae69..19f63b4 100755
> --- a/scripts/extract-headers.sh
> +++ b/scripts/extract-headers.sh
> @@ -144,7 +144,27 @@ echo '#endif /* _CHECKPOINT_CKPT_HDR_H_ */' >> "${OUTPUT_INCLUDES}/linux/checkpo
> # We use ARCH_COND to break up architecture-specific sections of the header.
> #
> ARCH_COND='#if'
> -REGEX='[[:space:]]*#[[:space:]]*define[[:space:]]*__NR_(checkpoint|restart|clone_with_pids)[[:space:]]+[0-9]+'
> +ARM_SYSCALL_BASE="# define __NR_OABI_SYSCALL_BASE 0x900000\n\
> +# if defined(__thumb__) || defined(__ARM_EABI__)\n\
> +# define __NR_SYSCALL_BASE 0\n\
> +# else\n\
> +# define __NR_SYSCALL_BASE __NR_OABI_SYSCALL_BASE\n\
> +# endif\n"
> +
> +# Get the regular expression for the current architecture
> +function get_unistd_regex()
> +{
> + local SYS_NR_DEF_REGEX='[[:space:]]*#[[:space:]]*define[[:space:]]*__NR_(checkpoint|restart|clone_with_pids)[[:space:]]+'
> +
> + case "$1" in
> + arm) echo -n "${SYS_NR_DEF_REGEX}"
> + echo -n '\(__NR_SYSCALL_BASE\+[[:space:]]*[0-9]*\)'
> + ;;
> + *) echo -n "${SYS_NR_DEF_REGEX}"'[0-9]+'
> + ;;
> + esac
> + return 0
> +}
>
> cat - <<-EOFOE
> /*
> @@ -160,11 +180,15 @@ do_cpp "${KERNELSRC}/include/linux/checkpoint.h" "_LINUX_CHECKPOINT_H_"
> find "${KERNELSRC}/arch" -name 'unistd*.h' -print | sort | \
> while read UNISTDH ; do
> [ -n "${UNISTDH}" ] || continue
> - grep -q -E "${REGEX}" "${UNISTDH}" || continue
> KARCH=$(echo "${UNISTDH}" | sed -e 's|.*/arch/\([^/]\+\)/.*|\1|')
> + REGEX="$(get_unistd_regex "${KARCH}")"
> + grep -q -E "${REGEX}" "${UNISTDH}" || continue
> WORDBITS=$(basename "${UNISTDH}" | sed -e 's/unistd_*\([[:digit:]]\+\)\.h/\1/')
> CPPARCH="$(karch_to_cpparch "${KARCH}" "${WORDBITS}")"
> echo -e "${ARCH_COND} __${CPPARCH}__\\n"
> +
> + [ "${KARCH}" == "arm" ] && echo -e "${ARM_SYSCALL_BASE}\n"
> +
> grep -E "${REGEX}" "${UNISTDH}" | \
> sed -e 's/^[ \t]*#[ \t]*define[ \t]*__NR_\([^ \t]\+\)[ \t]\+\([^ \t]\+\).*$/#\tifndef __NR_\1\n#\t\tdefine __NR_\1 \2\n#\tendif\n/'
> ARCH_COND='#elif'
> diff --git a/test/Makefile b/test/Makefile
> index cad40e0..516eee8 100644
> --- a/test/Makefile
> +++ b/test/Makefile
> @@ -1,3 +1,9 @@
> +# handle cross-compilation
> +AR = ${CROSS_COMPILE}ar
> +AS = ${CROSS_COMPILE}as
> +CC = ${CROSS_COMPILE}gcc
> +CPP = ${CROSS_COMPILE}cpp
> +LD = ${CROSS_COMPILE}ld
>
> # extra warnings and fun
> WARNS := -Wall -Wstrict-prototypes -Wno-trigraphs
> --
> 1.5.6.5
>
>
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