Quoting Sukadev Bhattiprolu (sukadev@xxxxxxxxxxxxxxxxxx):
>
> From: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
> Date: Sat, 30 Jan 2010 12:49:30 -0800
> Subject: [PATCH 1/6] eclone-1: Test basic functionality
>
> Verify that a child process gets the expected pid and arguments on stack
> when it is created with eclone() system call.
>
> NOTE: The myclone() function in eclone-lib.c supports just x86 for now.
> Needs to be ported to other architectures.
Thanks, but
I'd prefer to see a libeclone patch for user-cr, and cr_tests programs
compiled against that. user-cr already has done the ugliness required
to do eclone per-arch right now.
Would it be a lot of work to do so? (I shouldn't think so)
thanks,
-serge
> Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
> ---
> Makefile | 2 +-
> eclone/Makefile | 16 +++++++
> eclone/clone_args.h | 37 ++++++++++++++++
> eclone/eclone-1.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++++++
> eclone/eclone-lib.c | 85 ++++++++++++++++++++++++++++++++++++
> 5 files changed, 260 insertions(+), 1 deletions(-)
> create mode 100644 eclone/Makefile
> create mode 100644 eclone/clone_args.h
> create mode 100644 eclone/eclone-1.c
> create mode 100644 eclone/eclone-lib.c
>
> diff --git a/Makefile b/Makefile
> index 95f8b6e..1d412b9 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1,5 +1,5 @@
> SUBDIRS = libcrtest counterloop fileio simple userns ipc sleep \
> - process-tree futex epoll taskfs
> + process-tree futex epoll taskfs eclone
>
> targets = ns_exec mysu
>
> diff --git a/eclone/Makefile b/eclone/Makefile
> new file mode 100644
> index 0000000..43cef65
> --- /dev/null
> +++ b/eclone/Makefile
> @@ -0,0 +1,16 @@
> +
> +CFLAGS = -Wall
> +
> +LDFLAGS =
> +
> +PROGS = eclone-1
> +
> +all: $(PROGS)
> +
> +eclone-lib.o: eclone-lib.c clone_args.h
> +
> +$(PROGS): %: %.c eclone-lib.o
> + $(CC) $(CFLAGS) -o $@ $< eclone-lib.o $(LDFLAGS)
> +
> +clean:
> + rm -f $(PROGS) eclone-lib.o
> diff --git a/eclone/clone_args.h b/eclone/clone_args.h
> new file mode 100644
> index 0000000..393f139
> --- /dev/null
> +++ b/eclone/clone_args.h
> @@ -0,0 +1,37 @@
> +#include <errno.h>
> +
> +#define __NR_clone_with_pids 337
> +#define __NR_clone3 337
> +#define __NR_eclone 337
> +#define __NR_clone 120
> +#define __NR_exit 1
> +#define __NR_getpid 20
> +
> +#define CLONE_NEWPID 0x20000000
> +#define CLONE_CHILD_SETTID 0x01000000
> +#define CLONE_PARENT_SETTID 0x00100000
> +#define CLONE_UNUSED 0x00001000
> +
> +#define STACKSIZE 8192
> +
> +typedef unsigned long long u64;
> +typedef unsigned int u32;
> +typedef int pid_t;
> +struct clone_args {
> + u64 clone_flags_high;
> +
> + u64 child_stack_base;
> + u64 child_stack_size;
> +
> + u64 parent_tid_ptr;
> + u64 child_tid_ptr;
> +
> + u32 nr_pids;
> +
> + u32 reserved0;
> +};
> +
> +void *setup_stack(int (*child_fn)(void *), void *child_arg, int stack_size);
> +int eclone(int flags_low, struct clone_args *clone_args, int args_size,
> + int *pids);
> +int gettid();
> diff --git a/eclone/eclone-1.c b/eclone/eclone-1.c
> new file mode 100644
> index 0000000..06a10f9
> --- /dev/null
> +++ b/eclone/eclone-1.c
> @@ -0,0 +1,121 @@
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <errno.h>
> +#include <unistd.h>
> +#include <signal.h>
> +#include <string.h>
> +#include <sys/types.h>
> +#include <sys/wait.h>
> +#include <sys/syscall.h>
> +#include "clone_args.h"
> +
> +int verbose = 0;
> +int child_tid, parent_tid;
> +
> +#define CHILD_TID1 377
> +#define CHILD_TID2 399
> +#define CHILD_ARG (void *)0x979797
> +
> +pid_t pids_list[] = { CHILD_TID1, CHILD_TID2 };
> +
> +int do_child(void *arg)
> +{
> + sleep(3);
> +
> + if (arg != CHILD_ARG) {
> + printf("ERROR: Expected arg %p, actual %p\n", CHILD_ARG, arg);
> + exit(1);
> + }
> +
> + if (gettid() != CHILD_TID1) {
> + printf("FAIL: Child expected pid %d, actual %d\n", CHILD_TID1,
> + getpid());
> + exit(2);
> + } else {
> + printf("PASS: Child got expected pid %d\n", CHILD_TID1);
> + exit(0);
> + }
> +
> +}
> +
> +static int myclone(int (*child_fn)(void *), void *child_arg,
> + unsigned int flags_low, int nr_pids, pid_t *pids_list)
> +{
> + int rc;
> + void *stack;
> + struct clone_args ca;
> + int args_size;
> +
> + stack = setup_stack(child_fn, child_arg, STACKSIZE);
> + if (!stack) {
> + printf("ERROR: setup_stack returns NULL for size %d\n",
> + STACKSIZE);
> + exit(1);
> + }
> +
> + memset(&ca, 0, sizeof(ca));
> + ca.child_stack_base = (u64)(int)stack;
> + ca.child_stack_size = (u64)0;
> + ca.parent_tid_ptr = (u64)((int)&parent_tid);
> + ca.child_tid_ptr = (u64)((int)&child_tid);
> + ca.nr_pids = nr_pids;
> +
> + if (verbose) {
> + printf("[%d, %d]: Parent:\n\t child_stack 0x%p, ptidp %llx, "
> + "ctidp %llx, pids %p\n", getpid(), gettid(),
> + stack, ca.parent_tid_ptr, ca.child_tid_ptr,
> + pids_list);
> + }
> +
> + args_size = sizeof(struct clone_args);
> + rc = eclone(flags_low, &ca, args_size, pids_list);
> +
> + if (verbose) {
> + printf("[%d, %d]: eclone() returned %d, error %d\n", getpid(),
> + gettid(), rc, errno);
> + fflush(stdout);
> + }
> +
> + if (rc < 0) {
> + printf("ERROR: ");
> + exit(1);
> + }
> +
> + return rc;
> +}
> +
> +int main()
> +{
> + int rc, pid, status;
> + unsigned long flags;
> + int nr_pids = 1;
> +
> + flags = SIGCHLD|CLONE_PARENT_SETTID|CLONE_CHILD_SETTID;
> +
> + pid = myclone(do_child, (void *)CHILD_ARG, flags, nr_pids, pids_list);
> +
> + if (verbose) {
> + printf("[%d, %d]: Parent waiting for %d\n", getpid(),
> + gettid(), pid);
> + }
> +
> + rc = waitpid(pid, &status, __WALL);
> + if (rc < 0) {
> + printf("ERROR: ");
> + verbose = 1;
> + }
> +
> + if (verbose) {
> + printf("\twaitpid(): child %d, rc %d, error %d, status 0x%x\n",
> + getpid(), rc, errno, status);
> + if (rc >=0) {
> + if (WIFEXITED(status)) {
> + printf("\t EXITED, %d\n", WEXITSTATUS(status));
> + } else if (WIFSIGNALED(status)) {
> + printf("\t SIGNALED, %d\n", WTERMSIG(status));
> + }
> + }
> + }
> +
> + return 0;
> +}
> diff --git a/eclone/eclone-lib.c b/eclone/eclone-lib.c
> new file mode 100644
> index 0000000..f547945
> --- /dev/null
> +++ b/eclone/eclone-lib.c
> @@ -0,0 +1,85 @@
> +#define _GNU_SOURCE
> +#include <stdio.h>
> +#include <errno.h>
> +#include <stdlib.h>
> +#include <unistd.h>
> +#include <sys/syscall.h>
> +#include "clone_args.h"
> +
> +/* From Oren Laadan */
> +
> +#if defined(__i386__) && defined(__NR_eclone)
> +/*
> + * libc doesn't support eclone() yet...
> + * (see: http://lkml.indiana.edu/hypermail/linux/kernel/9604.3/0204.html)
> + */
> +
> +int eclone(int flags_low, struct clone_args *clone_args, int args_size,
> + int *pids)
> +{
> + long retval;
> +
> + __asm__ __volatile__(
> + "movl %3, %%ebx\n\t" /* flags_low -> 1st (ebx) */
> + "movl %4, %%ecx\n\t" /* clone_args -> 2nd (ecx) */
> + "movl %5, %%edx\n\t" /* args_size -> 3rd (edx) */
> + "movl %6, %%esi\n\t" /* pids -> 4th (esi) */
> +
> + "pushl %%ebp\n\t" /* save value of ebp */
> + "int $0x80\n\t" /* Linux/i386 system call */
> + "testl %0,%0\n\t" /* check return value */
> + "jne 1f\n\t" /* jump if parent */
> + "popl %%esi\n\t" /* get subthread function */
> + "call *%%esi\n\t" /* start subthread function */
> + "movl %2,%0\n\t"
> + "int $0x80\n" /* exit system call: exit subthread */
> + "1:\n\t"
> + "popl %%ebp\t" /* restore parent's ebp */
> +
> + :"=a" (retval)
> +
> + :"0" (__NR_clone3),
> + "i" (__NR_exit),
> + "b" (flags_low),
> + "c" (clone_args),
> + "d" (args_size),
> + "D" (pids)
> + );
> +
> + if (retval < 0) {
> + errno = -retval;
> + retval = -1;
> + }
> + return retval;
> +}
> +
> +void *setup_stack(int (*child_fn)(void *), void *child_arg, int size)
> +{
> + void *stack_base;
> + void **stack_top;
> +
> + stack_base = malloc(size);
> + if (!stack_base)
> + return NULL;
> +
> + stack_top = (void **)((char *)stack_base + (size - 4));
> + *--stack_top = child_arg;
> + *--stack_top = child_fn;
> +
> + return stack_top;
> +}
> +
> +#endif
> +
> +/* gettid() is a bit more useful than getpid() when messing with clone() */
> +int gettid()
> +{
> + int rc;
> +
> + rc = syscall(__NR_gettid, 0, 0, 0);
> + if (rc < 0) {
> + printf("rc %d, errno %d\n", rc, errno);
> + exit(1);
> + }
> + return rc;
> +}
> --
> 1.6.6.1
_______________________________________________
Containers mailing list
Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linux-foundation.org/mailman/listinfo/containers
