Messages in this thread Patch in this message | | | From | Christoffer Dall <> | Subject | [C/R ARM][PATCH 2/3] ARM: Add the eclone system call | Date | Sun, 21 Mar 2010 21:06:04 -0400 |
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In addition to doing everything that clone() system call does, the eclone() system call:
- allows additional clone flags (31 of 32 bits in the flags parameter to clone() are in use)
- allows user to specify a pid for the child process in its active and ancestor pid namespaces.
Eclone is needed for restarting a process from a checkpoint. See more in Documentation/eclone and refer to the original LKML posting: http://lkml.org/lkml/2009/11/11/361
The new system call for ARM has number 366.
Cc: rmk@arm.linux.org.uk Cc: libc-ports <libc-ports@sourceware.org> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Christoffer Dall <christofferdall@christofferdall.dk> Acked-by: Oren Laadan <orenl@cs.columbia.edu> --- arch/arm/include/asm/unistd.h | 1 + arch/arm/kernel/calls.S | 1 + arch/arm/kernel/entry-common.S | 6 ++++++ arch/arm/kernel/sys_arm.c | 39 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 47 insertions(+), 0 deletions(-)
diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h index cf9cdaa..f295a6c 100644 --- a/arch/arm/include/asm/unistd.h +++ b/arch/arm/include/asm/unistd.h @@ -392,6 +392,7 @@ #define __NR_rt_tgsigqueueinfo (__NR_SYSCALL_BASE+363) #define __NR_perf_event_open (__NR_SYSCALL_BASE+364) #define __NR_recvmmsg (__NR_SYSCALL_BASE+365) +#define __NR_eclone (__NR_SYSCALL_BASE+366) /* * The following SWIs are ARM private. diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S index 9314a2d..5ef0b03 100644 --- a/arch/arm/kernel/calls.S +++ b/arch/arm/kernel/calls.S @@ -375,6 +375,7 @@ CALL(sys_rt_tgsigqueueinfo) CALL(sys_perf_event_open) /* 365 */ CALL(sys_recvmmsg) + CALL(sys_eclone_wrapper) #ifndef syscalls_counted .equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls #define syscalls_counted diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index f694f4d..9ead15d 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -386,6 +386,12 @@ sys_clone_wrapper: b sys_clone ENDPROC(sys_clone_wrapper) +sys_eclone_wrapper: + add ip, sp, #S_OFF + str ip, [sp, #0] + b sys_eclone +ENDPROC(sys_eclone_wrapper) + sys_sigreturn_wrapper: add r0, sp, #S_OFF b sys_sigreturn diff --git a/arch/arm/kernel/sys_arm.c b/arch/arm/kernel/sys_arm.c index ae4027b..fd8199d 100644 --- a/arch/arm/kernel/sys_arm.c +++ b/arch/arm/kernel/sys_arm.c @@ -183,6 +183,45 @@ asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr); } +asmlinkage int sys_eclone(unsigned flags_low, struct clone_args __user *uca, + int args_size, pid_t __user *pids, + struct pt_regs *regs) +{ + int rc; + struct clone_args kca; + unsigned long flags; + int __user *parent_tidp; + int __user *child_tidp; + unsigned long __user stack; + unsigned long stack_size; + + rc = fetch_clone_args_from_user(uca, args_size, &kca); + if (rc) + return rc; + + /* + * TODO: Convert 'clone-flags' to 64-bits on all architectures. + * TODO: When ->clone_flags_high is non-zero, copy it in to the + * higher word(s) of 'flags': + * + * flags = (kca.clone_flags_high << 32) | flags_low; + */ + flags = flags_low; + parent_tidp = (int *)(unsigned long)kca.parent_tid_ptr; + child_tidp = (int *)(unsigned long)kca.child_tid_ptr; + + stack_size = (unsigned long)kca.child_stack_size; + if (stack_size) + return -EINVAL; + + stack = (unsigned long)kca.child_stack; + if (!stack) + stack = regs->ARM_sp; + + return do_fork_with_pids(flags, stack, regs, stack_size, parent_tidp, + child_tidp, kca.nr_pids, pids); +} + asmlinkage int sys_vfork(struct pt_regs *regs) { return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL); -- 1.5.6.5
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