From 1d4b4b2994b5fc208963c0b795291f8c1f18becf Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 22 Oct 2012 22:34:11 -0400 Subject: x86, um: switch to generic fork/vfork/clone Signed-off-by: Al Viro --- arch/x86/kernel/entry_32.S | 18 ------------------ arch/x86/kernel/entry_64.S | 22 +++++++++++++++++++--- arch/x86/kernel/process.c | 30 ------------------------------ arch/x86/kernel/process_32.c | 11 ++++++----- arch/x86/kernel/process_64.c | 7 ++++--- 5 files changed, 29 insertions(+), 59 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 88b725aa1d52..c763116c5359 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -739,30 +739,12 @@ ENTRY(ptregs_##name) ; \ 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 1328fe49a3f1..2363e820ed68 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -845,9 +845,25 @@ ENTRY(\label) 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 b644e1c765dc..fe9459593257 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -262,36 +262,6 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, 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 44e0bff38e72..16efa974532b 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -129,7 +129,7 @@ void release_thread(struct task_struct *dead_task) 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 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, 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 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, 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 16c6365e2b86..74aac76c6e34 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -169,7 +169,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, 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 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, 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)); -- cgit v1.2.1 From afa86fc426ff7e7f5477f15da9c405d08d5cf790 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 22 Oct 2012 22:51:14 -0400 Subject: flagday: don't pass regs to copy_thread() Signed-off-by: Al Viro --- arch/x86/kernel/process_32.c | 3 +-- arch/x86/kernel/process_64.c | 3 +-- 2 files changed, 2 insertions(+), 4 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 16efa974532b..b5a8905785e6 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -128,8 +128,7 @@ void release_thread(struct task_struct *dead_task) } int copy_thread(unsigned long clone_flags, unsigned long sp, - unsigned long arg, - struct task_struct *p, struct pt_regs *unused) + unsigned long arg, struct task_struct *p) { struct pt_regs *childregs = task_pt_regs(p); struct task_struct *tsk; diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 74aac76c6e34..6e68a6194965 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -146,8 +146,7 @@ static inline u32 read_32bit_tls(struct task_struct *t, int tls) } int copy_thread(unsigned long clone_flags, unsigned long sp, - unsigned long arg, - struct task_struct *p, struct pt_regs *regs) + unsigned long arg, struct task_struct *p) { int err; struct pt_regs *childregs; -- cgit v1.2.1 From 18c26c27ae0abe82253cb2e2363df465dbbb657e Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 22 Oct 2012 22:53:20 -0400 Subject: death to idle_regs() Signed-off-by: Al Viro --- arch/x86/kernel/cpu/common.c | 9 --------- 1 file changed, 9 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 7505f7b13e71..6a6432cf89de 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1173,15 +1173,6 @@ DEFINE_PER_CPU(struct task_struct *, fpu_owner_task); DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary); #endif -/* Make sure %fs and %gs are initialized properly in idle threads */ -struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs) -{ - memset(regs, 0, sizeof(struct pt_regs)); - regs->fs = __KERNEL_PERCPU; - regs->gs = __KERNEL_STACK_CANARY; - - return regs; -} #endif /* CONFIG_X86_64 */ /* -- cgit v1.2.1