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[patch 3/3] add the clone64() and unshare64() syscalls [message #27035] Thu, 07 February 2008 10:31 Go to next message
Cedric Le Goater is currently offline  Cedric Le Goater
Messages: 443
Registered: February 2006
Senior Member
From: Cedric Le Goater <clg@fr.ibm.com>

This patch adds 2 new syscalls :

     long sys_clone64(unsigned long flags_high, unsigned long flags_low,
		unsigned long newsp);

     long sys_unshare64(unsigned long flags_high, unsigned long flags_low);

clone64() does not support CLONE_PARENT_SETTID and CLONE_CHILD_CLEARTID 
because we would exceed the 6 registers limit of some arches.

This is work in progress but already includes support for x86, x86_64, 
x86_64(32), ppc64, ppc64(32), s390x, s390x(31). 

ia64 already supports 64bits clone flags through the clone2() syscall.
should we harmonize the name to clone2 ?  

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>

---
 arch/powerpc/kernel/entry_32.S     |    8 ++++++++
 arch/powerpc/kernel/entry_64.S     |    5 +++++
 arch/powerpc/kernel/process.c      |   15 +++++++++++++++
 arch/s390/kernel/compat_linux.c    |   15 +++++++++++++++
 arch/s390/kernel/compat_wrapper.S  |    6 ++++++
 arch/s390/kernel/process.c         |   15 +++++++++++++++
 arch/s390/kernel/syscalls.S        |    2 ++
 arch/x86/ia32/ia32entry.S          |    4 ++++
 arch/x86/ia32/sys_ia32.c           |   12 ++++++++++++
 arch/x86/kernel/entry_64.S         |    1 +
 arch/x86/kernel/process_32.c       |   14 ++++++++++++++
 arch/x86/kernel/process_64.c       |   15 +++++++++++++++
 arch/x86/kernel/syscall_table_32.S |    2 ++
 include/asm-powerpc/systbl.h       |    2 ++
 include/asm-powerpc/unistd.h       |    4 +++-
 include/asm-s390/unistd.h          |    4 +++-
 include/asm-x86/unistd_32.h        |    2 ++
 include/asm-x86/unistd_64.h        |    4 ++++
 include/linux/syscalls.h           |    2 ++
 kernel/fork.c                      |    7 +++++++
 kernel/sys_ni.c                    |    3 +++
 21 files changed, 140 insertions(+), 2 deletions(-)

Index: 2.6.24-mm1/arch/s390/kernel/syscalls.S
===================================================================
--- 2.6.24-mm1.orig/arch/s390/kernel/syscalls.S
+++ 2.6.24-mm1/arch/s390/kernel/syscalls.S
@@ -327,3 +327,5 @@ SYSCALL(sys_utimensat,sys_utimensat,comp
 SYSCALL(sys_signalfd,sys_signalfd,compat_sys_signalfd_wrapper)
 NI_SYSCALL						/* 317 old sys_timer_fd */
 SYSCALL(sys_eventfd,sys_eventfd,sys_eventfd_wrapper)
+SYSCALL(sys_clone64,sys_clone64,sys32_clone64)
+SYSCALL(sys_unshare64,sys_unshare64,sys_unshare64_wrapper)
Index: 2.6.24-mm1/arch/x86/kernel/syscall_table_32.S
===================================================================
--- 2.6.24-mm1.orig/arch/x86/kernel/syscall_table_32.S
+++ 2.6.24-mm1/arch/x86/kernel/syscall_table_32.S
@@ -326,3 +326,5 @@ ENTRY(sys_call_table)
 	.long sys_fallocate
 	.long sys_timerfd_settime	/* 325 */
 	.long sys_timerfd_gettime
+	.long sys_clone64
+	.long sys_unshare64
Index: 2.6.24-mm1/include/asm-powerpc/systbl.h
===================================================================
--- 2.6.24-mm1.orig/include/asm-powerpc/systbl.h
+++ 2.6.24-mm1/include/asm-powerpc/systbl.h
@@ -314,3 +314,5 @@ SYSCALL_SPU(eventfd)
 COMPAT_SYS_SPU(sync_file_range2)
 COMPAT_SYS(fallocate)
 SYSCALL(subpage_prot)
+PPC_SYS(clone64)
+SYSCALL_SPU(unshare64)
Index: 2.6.24-mm1/include/asm-powerpc/unistd.h
===================================================================
--- 2.6.24-mm1.orig/include/asm-powerpc/unistd.h
+++ 2.6.24-mm1/include/asm-powerpc/unistd.h
@@ -333,10 +333,12 @@
 #define __NR_sync_file_range2	308
 #define __NR_fallocate		309
 #define __NR_subpage_prot	310
+#define __NR_clone64		311
+#define __NR_unshare64		312
 
 #ifdef __KERNEL__
 
-#define __NR_syscalls		311
+#define __NR_syscalls		313
 
 #define __NR__exit __NR_exit
 #define NR_syscalls	__NR_syscalls
Index: 2.6.24-mm1/include/asm-s390/unistd.h
===================================================================
--- 2.6.24-mm1.orig/include/asm-s390/unistd.h
+++ 2.6.24-mm1/include/asm-s390/unistd.h
@@ -256,7 +256,9 @@
 #define __NR_signalfd		316
 #define __NR_timerfd		317
 #define __NR_eventfd		318
-#define NR_syscalls 319
+#define __NR_clone64		319
+#define __NR_unshare64		320
+#define NR_syscalls 321
 
 /* 
  * There are some system calls that are not present on 64 bit, some
Index: 2.6.24-mm1/include/asm-x86/unistd_32.h
===================================================================
--- 2.6.24-mm1.orig/include/asm-x86/unistd_32.h
+++ 2.6.24-mm1/include/asm-x86/unistd_32.h
@@ -332,6 +332,8 @@
 #define __NR_fallocate		324
 #define __NR_timerfd_settime	325
 #define __NR_timerfd_gettime	326
+#define __NR_clone64		327
+#define __NR_unshare64		328
 
 #ifdef __KERNEL__
 
Index: 2.6.24-mm1/include/asm-x86/unistd_64.h
===================================================================
--- 2.6.24-mm1.orig/include/asm-x86/unistd_64.h
+++ 2.6.24-mm1/include/asm-x86/unistd_64.h
@@ -639,6 +639,10 @@ __SYSCALL(__NR_fallocate, sys_fallocate)
 __SYSCALL(__NR_timerfd_settime, sys_timerfd_settime)
 #define __NR_timerfd_gettime			287
 __SYSCALL(__NR_timerfd_gettime, sys_timerfd_gettime)
+#define __NR_clone64		288
+__SYSCALL(__NR_clone64, stub_clone64)
+#define __NR_unshare64		289
+__SYSCALL(__NR_unshare64,	sys_unshare64)
 
 
 #ifndef __NO_STUBS
Index: 2.6.24-mm1/include/linux/syscalls.h
===================================================================
--- 2.6.24-mm1.orig/include/linux/syscalls.h
+++ 2.6.24-mm1/include/linux/syscalls.h
@@ -615,6 +615,8 @@ asmlinkage long sys_timerfd_gettime(int 
 asmlinkage long sys_eventfd(unsigned int count);
 asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len);
 
+asmlinkage long sys_unshare64(unsigned long clone_flags_high, unsigned long clone_flags_low);
+
 int kernel_execve(const char *filename, char *const argv[], char *const envp[]);
 
 #endif
Index: 2.6.24-mm1/kernel/sys_ni.c
===================================================================
--- 2.6.24-mm1.orig/kernel/sys_ni.c
+++ 2.6.24-mm1/kernel/sys_ni.c
@@ -161,3 +161,6 @@ cond_syscall(sys_timerfd_gettime);
 cond_syscall(compat_sys_timerfd_settime);
 cond_syscall(compat_sys_timerfd_gettime);
 cond_syscall(sys_eventfd);
+
+cond_syscall(sys_clone64);
+cond_syscall(sys_unshare64);
Index: 2.6.24-mm1/arch/x86/kernel/process_32.c
===================================================================
--- 2.6.24-mm1.orig/arch/x86/kernel/process_32.c
+++ 2.6.24-mm1/arch/x86/kernel/process_32.c
@@ -768,6 +768,20 @@ asmlinkage int sys_clone(struct pt_regs 
 	return do_fork(clone_flags, newsp, &regs, 0, parent_tidptr, child_tidptr);
 }
 
+asmlinkage int sys_clone64(struct pt_regs regs)
+{
+	u64 clone_flags;
+	unsigned long newsp;
+
+	clone_flags = ((u64) regs.bx << 32 | regs.cx);
+	clone_flags &= ~(CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID);
+
+	newsp = regs.dx;
+	if (!newsp)
+		newsp = regs.sp;
+	return do_fork(clone_flags, newsp, &regs, 0, NULL, NULL);
+}
+
 /*
  * This is trivial, and on the face of it looks like it
  * could equally well be done in user mode.
Index: 2.6.24-mm1/arch/x86/kernel/process_64.c
===================================================================
--- 2.6.24-mm1.orig/arch/x86/kernel/process_64.c
+++ 2.6.24-mm1/arch/x86/kernel/process_64.c
@@ -772,6 +772,21 @@ sys_clone(unsigned long clone_flags, uns
 	return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid);
 }
 
+asmlinkage long
+sys_clone64(unsigned long clone_flags_high, unsigned long clone_flags_low,
+	  unsigned long newsp, struct pt_regs *regs)
+{
+	u64 clone_flags;
+
+	clone_flags = ((u64) clone_flags_high << 32 | clone_flags_low);
+	clone_flags &= ~(CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID);
+
+	if (!newsp)
+		newsp = regs->sp;
+	return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
+}
+
+
 /*
  * This is trivial, and on the face of it looks like it
  * could equally well be done in user mode.
Index: 2.6.24-mm1/arch/s390/kernel/compat_linux.c
===================================================================
--- 2.6.24-mm1.orig/arch/s390/kernel/compat_linux.c
+++ 2.6.24-mm1/arch/s390/kernel/compat_linux.c
@@ -940,6 +940,21 @@ asmlinkage long sys32_clone(void)
 		       parent_tidptr, child_tidptr);
 }
 
+asmlinkage long sys32_clone64(void)
+{
+	struct pt_regs *regs = task_pt_regs(current);
+	u64 clone_flags;
+	unsigned long newsp;
+
+	clone_flags = ((u64) (regs->orig_gpr2  & 0xffffffffUL) << 32 |  (regs->gprs[3]  & 0xffffffffUL));
+	clone_flags &= ~(CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID);
+
+	newsp = regs->gprs[4] & 0x7fffffffUL;
+	if (!newsp)
+		newsp = regs->gprs[15];
+	return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
+}
+
 /*
  * 31 bit emulation wrapper functions for sys_fadvise64/fadvise64_64.
  * These need to rewrite the advise values for POSIX_FADV_{DONTNEED,NOREUSE}
Index: 2.6.24-mm1/arch/s390/kernel/process.c
===================================================================
--- 2.6.24-mm1.orig/arch/s390/kernel/process.c
+++ 2.6.24-mm1/arch/s390/kernel/process.c
@@ -323,6 +323,21 @@ asmlinkage long sys_clone(void)
 		       parent_tidptr, child_tidptr);
 }
 
+asmlinkage long sys_clone64(void)
+{
+	struct pt_regs *regs = task_pt_regs(current);
+	u64 clone_flags;
+	unsigned long newsp;
+
+	clone_flags = ((u64) regs->orig_gpr2 << 32 |  regs->gprs[3]);
+	clone_flags &= ~(CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID);
+
+	newsp = regs->gprs[4];
+	if (!newsp)
+		newsp = regs->gprs[15];
+	return do_fork(clone_flags, newsp, regs, 0, NULL, NULL);
+}
+
 /*
  * This is trivial, and on the face of it looks like it
  * could equally well be done in user mode.
Index: 2.6.24-mm1/arch/powerpc/kernel/process.c
===================================================================
--- 2.6.24-mm1.orig/arch/powerpc/kernel/process.c
+++ 2.6.24-mm1/arch/powerpc/kernel/process.c
@@ -829,6 +829,21 @@ int sys_clone(unsigned long clone_flags,
  	return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
 }
 
+int sys_clone64(unsigned long clone_flags_high, unsigned long clone_flags_low,
+		unsigned long usp, unsigned long p4, unsigned long p5,
+		unsigned long p6,
...

Re: [PATCH 3/3] add the clone64() and unshare64() syscalls [message #29271 is a reply to message #27035] Thu, 10 April 2008 02:15 Go to previous messageGo to next message
Sukadev Bhattiprolu is currently offline  Sukadev Bhattiprolu
Messages: 413
Registered: August 2006
Senior Member
Jakub Jelinek [jakub@redhat.com] wrote:
| On Wed, Apr 09, 2008 at 03:34:59PM -0700, sukadev@us.ibm.com wrote:
| > From: Cedric Le Goater <clg@fr.ibm.com>
| > Subject: [PATCH 3/3] add the clone64() and unshare64() syscalls
| > 
| > This patch adds 2 new syscalls :
| > 
| >      long sys_clone64(unsigned long flags_high, unsigned long flags_low,
| > 		unsigned long newsp);
| > 
| >      long sys_unshare64(unsigned long flags_high, unsigned long flags_low);
| 
| Can you explain why are you adding it for 64-bit arches too?  unsigned long
| is there already 64-bit, and both sys_clone and sys_unshare have unsigned
| long flags, rather than unsigned int.

Hmm,

By simply resuing clone() on 64 bit and adding a new call for 32-bit won't
the semantics of clone() differ between the two ?

i.e clone() on 64 bit supports say CLONE_NEWPTS clone() on 32bit does not ?

Wouldn't it be simpler/cleaner if clone() and clone64() behaved the same
on both 32 and 64 bit systems ?

Sukadev
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Re: [PATCH 3/3] add the clone64() and unshare64() syscalls [message #29274 is a reply to message #29271] Thu, 10 April 2008 03:40 Go to previous message
hpa is currently offline  hpa
Messages: 38
Registered: January 2007
Member
sukadev@us.ibm.com wrote:
> Jakub Jelinek [jakub@redhat.com] wrote:
> | On Wed, Apr 09, 2008 at 03:34:59PM -0700, sukadev@us.ibm.com wrote:
> | > From: Cedric Le Goater <clg@fr.ibm.com>
> | > Subject: [PATCH 3/3] add the clone64() and unshare64() syscalls
> | > 
> | > This patch adds 2 new syscalls :
> | > 
> | >      long sys_clone64(unsigned long flags_high, unsigned long flags_low,
> | > 		unsigned long newsp);
> | > 
> | >      long sys_unshare64(unsigned long flags_high, unsigned long flags_low);
> | 
> | Can you explain why are you adding it for 64-bit arches too?  unsigned long
> | is there already 64-bit, and both sys_clone and sys_unshare have unsigned
> | long flags, rather than unsigned int.
> 
> Hmm,
> 
> By simply resuing clone() on 64 bit and adding a new call for 32-bit won't
> the semantics of clone() differ between the two ?
> 
> i.e clone() on 64 bit supports say CLONE_NEWPTS clone() on 32bit does not ?
> 
> Wouldn't it be simpler/cleaner if clone() and clone64() behaved the same
> on both 32 and 64 bit systems ?
> 

No, not really.  The way this work on the libc side is pretty much "use 
clone64 if it exists, otherwise use clone".

	-hpa
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