[C/R v20][PATCH 09/96] eclone (9/11): Implement sys_eclone for s390

From: Oren Laadan
Date: Wed Mar 17 2010 - 12:34:34 EST


From: Serge E. Hallyn <serue@xxxxxxxxxx>

Implement the s390 hook for sys_eclone().

Changelog:
Nov 24: Removed user-space code from commit log. See user-cr git tree.
Nov 17: remove redundant flags_high check
Nov 13: As suggested by Heiko, convert eclone to take its
parameters via registers.

Signed-off-by: Serge E. Hallyn <serue@xxxxxxxxxx>
---
arch/s390/include/asm/unistd.h | 3 ++-
arch/s390/kernel/compat_linux.c | 17 +++++++++++++++++
arch/s390/kernel/compat_wrapper.S | 8 ++++++++
arch/s390/kernel/process.c | 37 +++++++++++++++++++++++++++++++++++++
arch/s390/kernel/syscalls.S | 1 +
5 files changed, 65 insertions(+), 1 deletions(-)

diff --git a/arch/s390/include/asm/unistd.h b/arch/s390/include/asm/unistd.h
index 6e9f049..2250950 100644
--- a/arch/s390/include/asm/unistd.h
+++ b/arch/s390/include/asm/unistd.h
@@ -269,7 +269,8 @@
#define __NR_pwritev 329
#define __NR_rt_tgsigqueueinfo 330
#define __NR_perf_event_open 331
-#define NR_syscalls 332
+#define __NR_eclone 332
+#define NR_syscalls 333

/*
* There are some system calls that are not present on 64 bit, some
diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index 11c3aba..f9e8983 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -663,6 +663,23 @@ asmlinkage long sys32_write(unsigned int fd, char __user * buf, size_t count)
return sys_write(fd, buf, count);
}

+asmlinkage long sys32_clone(void)
+{
+ struct pt_regs *regs = task_pt_regs(current);
+ unsigned long clone_flags;
+ unsigned long newsp;
+ int __user *parent_tidptr, *child_tidptr;
+
+ clone_flags = regs->gprs[3] & 0xffffffffUL;
+ newsp = regs->orig_gpr2 & 0x7fffffffUL;
+ parent_tidptr = compat_ptr(regs->gprs[4]);
+ child_tidptr = compat_ptr(regs->gprs[5]);
+ if (!newsp)
+ newsp = regs->gprs[15];
+ return do_fork(clone_flags, newsp, regs, 0,
+ parent_tidptr, child_tidptr);
+}
+
/*
* 31 bit emulation wrapper functions for sys_fadvise64/fadvise64_64.
* These need to rewrite the advise values for POSIX_FADV_{DONTNEED,NOREUSE}
diff --git a/arch/s390/kernel/compat_wrapper.S b/arch/s390/kernel/compat_wrapper.S
index 30de2d0..cfa227e 100644
--- a/arch/s390/kernel/compat_wrapper.S
+++ b/arch/s390/kernel/compat_wrapper.S
@@ -1847,6 +1847,14 @@ sys_clone_wrapper:
llgtr %r5,%r5 # int *
jg sys_clone # branch to system call

+ .globl sys_eclone_wrapper
+sys_eclone_wrapper:
+ llgfr %r2,%r2 # unsigned int
+ llgtr %r3,%r3 # struct clone_args *
+ lgfr %r4,%r4 # int
+ llgtr %r5,%r5 # pid_t *
+ jg sys_eclone # branch to system call
+
.globl sys32_execve_wrapper
sys32_execve_wrapper:
llgtr %r2,%r2 # char *
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 00b6d1d..5b0729a 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -240,6 +240,43 @@ SYSCALL_DEFINE4(clone, unsigned long, newsp, unsigned long, clone_flags,
parent_tidptr, child_tidptr);
}

+SYSCALL_DEFINE4(eclone, unsigned int, flags_low, struct clone_args __user *,
+ uca, int, args_size, pid_t __user *, pids)
+{
+ int rc;
+ struct pt_regs *regs = task_pt_regs(current);
+ struct clone_args kca;
+ int __user *parent_tid_ptr;
+ int __user *child_tid_ptr;
+ unsigned long flags;
+ unsigned long __user child_stack;
+ unsigned long stack_size;
+
+ rc = fetch_clone_args_from_user(uca, args_size, &kca);
+ if (rc)
+ return rc;
+
+ flags = flags_low;
+ parent_tid_ptr = (int __user *) kca.parent_tid_ptr;
+ child_tid_ptr = (int __user *) kca.child_tid_ptr;
+
+ stack_size = (unsigned long) kca.child_stack_size;
+ if (stack_size)
+ return -EINVAL;
+
+ child_stack = (unsigned long) kca.child_stack;
+ if (!child_stack)
+ child_stack = regs->gprs[15];
+
+ /*
+ * TODO: On 32-bit systems, clone_flags is passed in as 32-bit value
+ * to several functions. Need to convert clone_flags to 64-bit.
+ */
+ return do_fork_with_pids(flags, child_stack, regs, stack_size,
+ parent_tid_ptr, child_tid_ptr, kca.nr_pids,
+ pids);
+}
+
/*
* This is trivial, and on the face of it looks like it
* could equally well be done in user mode.
diff --git a/arch/s390/kernel/syscalls.S b/arch/s390/kernel/syscalls.S
index 30eca07..fb8708d 100644
--- a/arch/s390/kernel/syscalls.S
+++ b/arch/s390/kernel/syscalls.S
@@ -340,3 +340,4 @@ SYSCALL(sys_preadv,sys_preadv,compat_sys_preadv_wrapper)
SYSCALL(sys_pwritev,sys_pwritev,compat_sys_pwritev_wrapper)
SYSCALL(sys_rt_tgsigqueueinfo,sys_rt_tgsigqueueinfo,compat_sys_rt_tgsigqueueinfo_wrapper) /* 330 */
SYSCALL(sys_perf_event_open,sys_perf_event_open,sys_perf_event_open_wrapper)
+SYSCALL(sys_eclone,sys_eclone,sys_eclone_wrapper)
--
1.6.3.3

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