x86, um: switch to generic fork/vfork/clone
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 88b725a..c763116 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -739,30 +739,12 @@
ENDPROC(ptregs_##name)
PTREGSCALL1(iopl)
-PTREGSCALL0(fork)
-PTREGSCALL0(vfork)
PTREGSCALL2(sigaltstack)
PTREGSCALL0(sigreturn)
PTREGSCALL0(rt_sigreturn)
PTREGSCALL2(vm86)
PTREGSCALL1(vm86old)
-/* Clone is an oddball. The 4th arg is in %edi */
-ENTRY(ptregs_clone)
- CFI_STARTPROC
- leal 4(%esp),%eax
- pushl_cfi %eax
- pushl_cfi PT_EDI(%eax)
- movl PT_EDX(%eax),%ecx
- movl PT_ECX(%eax),%edx
- movl PT_EBX(%eax),%eax
- call sys_clone
- addl $8,%esp
- CFI_ADJUST_CFA_OFFSET -8
- ret
- CFI_ENDPROC
-ENDPROC(ptregs_clone)
-
.macro FIXUP_ESPFIX_STACK
/*
* Switch back for ESPFIX stack to the normal zerobased stack
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 1328fe4..2363e82 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -845,9 +845,25 @@
END(\label)
.endm
- PTREGSCALL stub_clone, sys_clone, %r8
- PTREGSCALL stub_fork, sys_fork, %rdi
- PTREGSCALL stub_vfork, sys_vfork, %rdi
+ .macro FORK_LIKE func
+ENTRY(stub_\func)
+ CFI_STARTPROC
+ popq %r11 /* save return address */
+ PARTIAL_FRAME 0
+ SAVE_REST
+ pushq %r11 /* put it back on stack */
+ FIXUP_TOP_OF_STACK %r11, 8
+ DEFAULT_FRAME 0 8 /* offset 8: return address */
+ call sys_\func
+ RESTORE_TOP_OF_STACK %r11, 8
+ ret $REST_SKIP /* pop extended registers */
+ CFI_ENDPROC
+END(stub_\func)
+ .endm
+
+ FORK_LIKE clone
+ FORK_LIKE fork
+ FORK_LIKE vfork
PTREGSCALL stub_sigaltstack, sys_sigaltstack, %rdx
PTREGSCALL stub_iopl, sys_iopl, %rsi
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index b644e1c..fe94595 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -262,36 +262,6 @@
propagate_user_return_notify(prev_p, next_p);
}
-int sys_fork(struct pt_regs *regs)
-{
- return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
-}
-
-/*
- * This is trivial, and on the face of it looks like it
- * could equally well be done in user mode.
- *
- * Not so, for quite unobvious reasons - register pressure.
- * In user mode vfork() cannot have a stack frame, and if
- * done by calling the "clone()" system call directly, you
- * do not have enough call-clobbered registers to hold all
- * the information you need.
- */
-int sys_vfork(struct pt_regs *regs)
-{
- return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0,
- NULL, NULL);
-}
-
-long
-sys_clone(unsigned long clone_flags, unsigned long newsp,
- void __user *parent_tid, void __user *child_tid, struct pt_regs *regs)
-{
- if (!newsp)
- newsp = regs->sp;
- return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid);
-}
-
/*
* Idle related variables and functions
*/
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 44e0bff..16efa97 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -129,7 +129,7 @@
int copy_thread(unsigned long clone_flags, unsigned long sp,
unsigned long arg,
- struct task_struct *p, struct pt_regs *regs)
+ struct task_struct *p, struct pt_regs *unused)
{
struct pt_regs *childregs = task_pt_regs(p);
struct task_struct *tsk;
@@ -138,7 +138,7 @@
p->thread.sp = (unsigned long) childregs;
p->thread.sp0 = (unsigned long) (childregs+1);
- if (unlikely(!regs)) {
+ if (unlikely(p->flags & PF_KTHREAD)) {
/* kernel thread */
memset(childregs, 0, sizeof(struct pt_regs));
p->thread.ip = (unsigned long) ret_from_kernel_thread;
@@ -156,12 +156,13 @@
memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
return 0;
}
- *childregs = *regs;
+ *childregs = *current_pt_regs();
childregs->ax = 0;
- childregs->sp = sp;
+ if (sp)
+ childregs->sp = sp;
p->thread.ip = (unsigned long) ret_from_fork;
- task_user_gs(p) = get_user_gs(regs);
+ task_user_gs(p) = get_user_gs(current_pt_regs());
p->fpu_counter = 0;
p->thread.io_bitmap_ptr = NULL;
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 16c6365..74aac76 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -169,7 +169,7 @@
savesegment(ds, p->thread.ds);
memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
- if (unlikely(!regs)) {
+ if (unlikely(p->flags & PF_KTHREAD)) {
/* kernel thread */
memset(childregs, 0, sizeof(struct pt_regs));
childregs->sp = (unsigned long)childregs;
@@ -181,10 +181,11 @@
childregs->flags = X86_EFLAGS_IF | X86_EFLAGS_BIT1;
return 0;
}
- *childregs = *regs;
+ *childregs = *current_pt_regs();
childregs->ax = 0;
- childregs->sp = sp;
+ if (sp)
+ childregs->sp = sp;
err = -ENOMEM;
memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));