Commit 42859eea authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

Pull generic execve() changes from Al Viro:
 "This introduces the generic kernel_thread() and kernel_execve()
  functions, and switches x86, arm, alpha, um and s390 over to them."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits)
  s390: convert to generic kernel_execve()
  s390: switch to generic kernel_thread()
  s390: fold kernel_thread_helper() into ret_from_fork()
  s390: fold execve_tail() into start_thread(), convert to generic sys_execve()
  um: switch to generic kernel_thread()
  x86, um/x86: switch to generic sys_execve and kernel_execve
  x86: split ret_from_fork
  alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
  alpha: switch to generic kernel_thread()
  alpha: switch to generic sys_execve()
  arm: get rid of execve wrapper, switch to generic execve() implementation
  arm: optimized current_pt_regs()
  arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
  arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk]
  generic sys_execve()
  generic kernel_execve()
  new helper: current_pt_regs()
  preparation for generic kernel_thread()
  um: kill thread->forking
  um: let signal_delivered() do SIGTRAP on singlestepping into handler
  ...
parents f59b51fe f322220d
......@@ -271,6 +271,9 @@ config ARCH_WANT_OLD_COMPAT_IPC
select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
bool
config GENERIC_KERNEL_THREAD
bool
config HAVE_ARCH_SECCOMP_FILTER
bool
help
......
......@@ -20,6 +20,7 @@ config ALPHA
select GENERIC_CMOS_UPDATE
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
select GENERIC_KERNEL_THREAD
help
The Alpha is a 64-bit general-purpose processor designed and
marketed by the Digital Equipment Corporation of blessed memory,
......
......@@ -10,3 +10,4 @@ header-y += pal.h
header-y += reg.h
header-y += regdef.h
header-y += sysinfo.h
generic-y += exec.h
#ifndef __ALPHA_EXEC_H
#define __ALPHA_EXEC_H
#define arch_align_stack(x) (x)
#endif /* __ALPHA_EXEC_H */
......@@ -49,9 +49,6 @@ extern void start_thread(struct pt_regs *, unsigned long, unsigned long);
/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);
/* Create a kernel thread without removing it from tasklists. */
extern long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc)
......
......@@ -481,6 +481,8 @@
#define __ARCH_WANT_SYS_OLDUMOUNT
#define __ARCH_WANT_SYS_SIGPENDING
#define __ARCH_WANT_SYS_RT_SIGSUSPEND
#define __ARCH_WANT_SYS_EXECVE
#define __ARCH_WANT_KERNEL_EXECVE
/* "Conditional" syscalls. What we want is
......
......@@ -50,9 +50,6 @@ EXPORT_SYMBOL(alpha_read_fp_reg_s);
EXPORT_SYMBOL(alpha_write_fp_reg);
EXPORT_SYMBOL(alpha_write_fp_reg_s);
/* entry.S */
EXPORT_SYMBOL(kernel_thread);
/* Networking helper routines. */
EXPORT_SYMBOL(csum_tcpudp_magic);
EXPORT_SYMBOL(ip_compute_csum);
......
......@@ -609,59 +609,35 @@ ret_from_fork:
.end ret_from_fork
/*
* kernel_thread(fn, arg, clone_flags)
* ... and new kernel threads - here
*/
.align 4
.globl kernel_thread
.ent kernel_thread
kernel_thread:
/* We can be called from a module. */
ldgp $gp, 0($27)
.prologue 1
subq $sp, SP_OFF+6*8, $sp
br $1, 2f /* load start address */
/* We've now "returned" from a fake system call. */
unop
blt $0, 1f /* error? */
ldi $1, 0x3fff
beq $20, 1f /* parent or child? */
bic $sp, $1, $8 /* in child. */
jsr $26, ($27)
.globl ret_from_kernel_thread
.ent ret_from_kernel_thread
ret_from_kernel_thread:
mov $17, $16
jsr $26, schedule_tail
mov $9, $27
mov $10, $16
jsr $26, ($9)
ldgp $gp, 0($26)
mov $0, $16
mov $31, $26
jmp $31, sys_exit
.end ret_from_kernel_thread
1: ret /* in parent. */
.align 4
2: /* Fake a system call stack frame, as we can't do system calls
from kernel space. Note that we store FN and ARG as they
need to be set up in the child for the call. Also store $8
and $26 for use in the parent. */
stq $31, SP_OFF($sp) /* ps */
stq $1, SP_OFF+8($sp) /* pc */
stq $gp, SP_OFF+16($sp) /* gp */
stq $16, 136($sp) /* $27; FN for child */
stq $17, SP_OFF+24($sp) /* $16; ARG for child */
stq $8, 64($sp) /* $8 */
stq $26, 128($sp) /* $26 */
.globl ret_from_kernel_execve
.align 4
.ent ret_from_kernel_execve
ret_from_kernel_execve:
mov $16, $sp
/* Avoid the HAE being gratuitously wrong, to avoid restoring it. */
ldq $2, alpha_mv+HAE_CACHE
stq $2, 152($sp) /* HAE */
mov $31, $19 /* to disable syscall restarts */
br $31, ret_to_user
/* Shuffle FLAGS to the front; add CLONE_VM. */
ldi $1, CLONE_VM|CLONE_UNTRACED
or $18, $1, $16
bsr $26, sys_clone
/* We don't actually care for a3 success widgetry in the kernel.
Not for positive errno values. */
stq $0, 0($sp) /* $0 */
br ret_to_kernel
.end kernel_thread
.end ret_from_kernel_execve
/*
......@@ -744,15 +720,6 @@ sys_rt_sigreturn:
br ret_from_sys_call
.end sys_rt_sigreturn
.align 4
.globl sys_execve
.ent sys_execve
sys_execve:
.prologue 0
mov $sp, $19
jmp $31, do_sys_execve
.end sys_execve
.align 4
.globl alpha_ni_syscall
.ent alpha_ni_syscall
......
......@@ -263,33 +263,35 @@ alpha_vfork(struct pt_regs *regs)
/*
* Copy an alpha thread..
*
* Note the "stack_offset" stuff: when returning to kernel mode, we need
* to have some extra stack-space for the kernel stack that still exists
* after the "ret_from_fork". When returning to user mode, we only want
* the space needed by the syscall stack frame (ie "struct pt_regs").
* Use the passed "regs" pointer to determine how much space we need
* for a kernel fork().
*/
int
copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long unused,
unsigned long arg,
struct task_struct * p, struct pt_regs * regs)
{
extern void ret_from_fork(void);
extern void ret_from_kernel_thread(void);
struct thread_info *childti = task_thread_info(p);
struct pt_regs * childregs;
struct switch_stack * childstack, *stack;
unsigned long stack_offset, settls;
stack_offset = PAGE_SIZE - sizeof(struct pt_regs);
if (!(regs->ps & 8))
stack_offset = (PAGE_SIZE-1) & (unsigned long) regs;
childregs = (struct pt_regs *)
(stack_offset + PAGE_SIZE + task_stack_page(p));
struct pt_regs *childregs = task_pt_regs(p);
struct switch_stack *childstack, *stack;
unsigned long settls;
childstack = ((struct switch_stack *) childregs) - 1;
if (unlikely(!regs)) {
/* kernel thread */
memset(childstack, 0,
sizeof(struct switch_stack) + sizeof(struct pt_regs));
childstack->r26 = (unsigned long) ret_from_kernel_thread;
childstack->r9 = usp; /* function */
childstack->r10 = arg;
childregs->hae = alpha_mv.hae_cache,
childti->pcb.usp = 0;
childti->pcb.ksp = (unsigned long) childstack;
childti->pcb.flags = 1; /* set FEN, clear everything else */
return 0;
}
*childregs = *regs;
settls = regs->r20;
childregs->r0 = 0;
......@@ -297,7 +299,6 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
childregs->r20 = 1; /* OSF/1 has some strange fork() semantics. */
regs->r20 = 0;
stack = ((struct switch_stack *) regs) - 1;
childstack = ((struct switch_stack *) childregs) - 1;
*childstack = *stack;
childstack->r26 = (unsigned long) ret_from_fork;
childti->pcb.usp = usp;
......@@ -385,27 +386,6 @@ dump_elf_task_fp(elf_fpreg_t *dest, struct task_struct *task)
}
EXPORT_SYMBOL(dump_elf_task_fp);
/*
* sys_execve() executes a new program.
*/
asmlinkage int
do_sys_execve(const char __user *ufilename,
const char __user *const __user *argv,
const char __user *const __user *envp, struct pt_regs *regs)
{
int error;
char *filename;
filename = getname(ufilename);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename, argv, envp, regs);
putname(filename);
out:
return error;
}
/*
* Return saved PC of a blocked thread. This assumes the frame
* pointer is the 6th saved long on the kernel stack and that the
......@@ -459,22 +439,3 @@ get_wchan(struct task_struct *p)
}
return pc;
}
int kernel_execve(const char *path, const char *const argv[], const char *const envp[])
{
/* Avoid the HAE being gratuitously wrong, which would cause us
to do the whole turn off interrupts thing and restore it. */
struct pt_regs regs = {.hae = alpha_mv.hae_cache};
int err = do_execve(path, argv, envp, &regs);
if (!err) {
struct pt_regs *p = current_pt_regs();
/* copy regs to normal position and off to userland we go... */
*p = regs;
__asm__ __volatile__ (
"mov %0, $sp;"
"br $31, ret_from_sys_call"
: : "r"(p));
}
return err;
}
EXPORT_SYMBOL(kernel_execve);
......@@ -52,6 +52,7 @@ config ARM
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
select DCACHE_WORD_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && !CPU_BIG_ENDIAN
select GENERIC_KERNEL_THREAD
help
The ARM series is a line of low-power-consumption RISC chip designs
licensed by ARM Ltd and targeted at embedded applications and
......
......@@ -85,11 +85,6 @@ unsigned long get_wchan(struct task_struct *p);
#define cpu_relax() barrier()
#endif
/*
* Create a new kernel thread
*/
extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
#define task_pt_regs(p) \
((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)
......
......@@ -254,6 +254,11 @@ static inline unsigned long user_stack_pointer(struct pt_regs *regs)
return regs->ARM_sp;
}
#define current_pt_regs(void) ({ \
register unsigned long sp asm ("sp"); \
(struct pt_regs *)((sp | (THREAD_SIZE - 1)) - 7) - 1; \
})
#endif /* __KERNEL__ */
#endif /* __ASSEMBLY__ */
......
......@@ -2,7 +2,6 @@
#include <asm/barrier.h>
#include <asm/compiler.h>
#include <asm/cmpxchg.h>
#include <asm/exec.h>
#include <asm/switch_to.h>
#include <asm/system_info.h>
#include <asm/system_misc.h>
......@@ -478,6 +478,8 @@
#define __ARCH_WANT_OLD_READDIR
#define __ARCH_WANT_SYS_SOCKETCALL
#endif
#define __ARCH_WANT_SYS_EXECVE
#define __ARCH_WANT_KERNEL_EXECVE
/*
* "Conditional" syscalls
......
......@@ -20,7 +20,7 @@
CALL(sys_creat)
CALL(sys_link)
/* 10 */ CALL(sys_unlink)
CALL(sys_execve_wrapper)
CALL(sys_execve)
CALL(sys_chdir)
CALL(OBSOLETE(sys_time)) /* used by libc4 */
CALL(sys_mknod)
......
......@@ -91,6 +91,30 @@ ENTRY(ret_from_fork)
b ret_slow_syscall
ENDPROC(ret_from_fork)
ENTRY(ret_from_kernel_thread)
UNWIND(.fnstart)
UNWIND(.cantunwind)
bl schedule_tail
mov r0, r4
adr lr, BSYM(1f) @ kernel threads should not exit
mov pc, r5
1: bl do_exit
nop
UNWIND(.fnend)
ENDPROC(ret_from_kernel_thread)
/*
* turn a kernel thread into userland process
* use: ret_from_kernel_execve(struct pt_regs *normal)
*/
ENTRY(ret_from_kernel_execve)
mov why, #0 @ not a syscall
str why, [r0, #S_R0] @ ... and we want 0 in ->ARM_r0 as well
get_thread_info tsk @ thread structure
mov sp, r0 @ stack pointer just under pt_regs
b ret_slow_syscall
ENDPROC(ret_from_kernel_execve)
.equ NR_syscalls,0
#define CALL(x) .equ NR_syscalls,NR_syscalls+1
#include "calls.S"
......@@ -517,11 +541,6 @@ sys_vfork_wrapper:
b sys_vfork
ENDPROC(sys_vfork_wrapper)
sys_execve_wrapper:
add r3, sp, #S_OFF
b sys_execve
ENDPROC(sys_execve_wrapper)
sys_clone_wrapper:
add ip, sp, #S_OFF
str ip, [sp, #4]
......
......@@ -373,6 +373,7 @@ void release_thread(struct task_struct *dead_task)
}
asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");
int
copy_thread(unsigned long clone_flags, unsigned long stack_start,
......@@ -381,13 +382,20 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start,
struct thread_info *thread = task_thread_info(p);
struct pt_regs *childregs = task_pt_regs(p);
*childregs = *regs;
childregs->ARM_r0 = 0;
childregs->ARM_sp = stack_start;
memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
if (likely(regs)) {
*childregs = *regs;
childregs->ARM_r0 = 0;
childregs->ARM_sp = stack_start;
thread->cpu_context.pc = (unsigned long)ret_from_fork;
} else {
thread->cpu_context.r4 = stk_sz;
thread->cpu_context.r5 = stack_start;
thread->cpu_context.pc = (unsigned long)ret_from_kernel_thread;
childregs->ARM_cpsr = SVC_MODE;
}
thread->cpu_context.sp = (unsigned long)childregs;
thread->cpu_context.pc = (unsigned long)ret_from_fork;
clear_ptrace_hw_breakpoint(p);
......@@ -423,63 +431,6 @@ int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
}
EXPORT_SYMBOL(dump_fpu);
/*
* Shuffle the argument into the correct register before calling the
* thread function. r4 is the thread argument, r5 is the pointer to
* the thread function, and r6 points to the exit function.
*/
extern void kernel_thread_helper(void);
asm( ".pushsection .text\n"
" .align\n"
" .type kernel_thread_helper, #function\n"
"kernel_thread_helper:\n"
#ifdef CONFIG_TRACE_IRQFLAGS
" bl trace_hardirqs_on\n"
#endif
" msr cpsr_c, r7\n"
" mov r0, r4\n"
" mov lr, r6\n"
" mov pc, r5\n"
" .size kernel_thread_helper, . - kernel_thread_helper\n"
" .popsection");
#ifdef CONFIG_ARM_UNWIND
extern void kernel_thread_exit(long code);
asm( ".pushsection .text\n"
" .align\n"
" .type kernel_thread_exit, #function\n"
"kernel_thread_exit:\n"
" .fnstart\n"
" .cantunwind\n"
" bl do_exit\n"
" nop\n"
" .fnend\n"
" .size kernel_thread_exit, . - kernel_thread_exit\n"
" .popsection");
#else
#define kernel_thread_exit do_exit
#endif
/*
* Create a kernel thread.
*/
pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
struct pt_regs regs;
memset(&regs, 0, sizeof(regs));
regs.ARM_r4 = (unsigned long)arg;
regs.ARM_r5 = (unsigned long)fn;
regs.ARM_r6 = (unsigned long)kernel_thread_exit;
regs.ARM_r7 = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE;
regs.ARM_pc = (unsigned long)kernel_thread_helper;
regs.ARM_cpsr = regs.ARM_r7 | PSR_I_BIT;
return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
}
EXPORT_SYMBOL(kernel_thread);
unsigned long get_wchan(struct task_struct *p)
{
struct stackframe frame;
......
......@@ -59,69 +59,6 @@ asmlinkage int sys_vfork(struct pt_regs *regs)
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
}
/* sys_execve() executes a new program.
* This is called indirectly via a small wrapper
*/
asmlinkage int sys_execve(const char __user *filenamei,
const char __user *const __user *argv,
const char __user *const __user *envp, struct pt_regs *regs)
{
int error;
char * filename;
filename = getname(filenamei);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename, argv, envp, regs);
putname(filename);
out:
return error;
}
int kernel_execve(const char *filename,
const char *const argv[],
const char *const envp[])
{
struct pt_regs regs;
int ret;
memset(&regs, 0, sizeof(struct pt_regs));
ret = do_execve(filename,
(const char __user *const __user *)argv,
(const char __user *const __user *)envp, &regs);
if (ret < 0)
goto out;
/*
* Save argc to the register structure for userspace.
*/
regs.ARM_r0 = ret;
/*
* We were successful. We won't be returning to our caller, but
* instead to user space by manipulating the kernel stack.
*/
asm( "add r0, %0, %1\n\t"
"mov r1, %2\n\t"
"mov r2, %3\n\t"
"bl memmove\n\t" /* copy regs to top of stack */
"mov r8, #0\n\t" /* not a syscall */
"mov r9, %0\n\t" /* thread structure */
"mov sp, r0\n\t" /* reposition stack pointer */
"b ret_to_user"
:
: "r" (current_thread_info()),
"Ir" (THREAD_START_SP - sizeof(regs)),
"r" (&regs),
"Ir" (sizeof(regs))
: "r0", "r1", "r2", "r3", "r8", "r9", "ip", "lr", "memory");
out:
return ret;
}
EXPORT_SYMBOL(kernel_execve);
/*
* Since loff_t is a 64 bit type we avoid a lot of ABI hassle
* with a different argument ordering.
......
include include/asm-generic/Kbuild.asm
generic-y += clkdev.h
generic-y += exec.h
header-y += cachectl.h
/*
* Copyright (C) 2004-2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_AVR32_EXEC_H
#define __ASM_AVR32_EXEC_H
#define arch_align_stack(x) (x)
#endif /* __ASM_AVR32_EXEC_H */
......@@ -12,6 +12,7 @@ generic-y += div64.h
generic-y += dma.h
generic-y += emergency-restart.h
generic-y += errno.h
generic-y += exec.h
generic-y += fb.h
generic-y += fcntl.h
generic-y += futex.h
......
#ifndef _ASM_C6X_EXEC_H
#define _ASM_C6X_EXEC_H
#define arch_align_stack(x) (x)
#endif /* _ASM_C6X_EXEC_H */
......@@ -9,3 +9,4 @@ header-y += rs485.h
header-y += sync_serial.h
generic-y += clkdev.h
generic-y += exec.h
#ifndef __ASM_CRIS_EXEC_H
#define __ASM_CRIS_EXEC_H
#define arch_align_stack(x) (x)
#endif /* __ASM_CRIS_EXEC_H */
......@@ -3,3 +3,4 @@ include include/asm-generic/Kbuild.asm
header-y += registers.h
header-y += termios.h
generic-y += clkdev.h
generic-y += exec.h
/* FR-V CPU executable handling
*
* Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _ASM_EXEC_H
#define _ASM_EXEC_H
#define arch_align_stack(x) (x)
#endif /* _ASM_EXEC_H */
include include/asm-generic/Kbuild.asm
generic-y += clkdev.h
generic-y += clkdev.h
generic-y += exec.h
#ifndef _H8300_EXEC_H
#define _H8300_EXEC_H
#define arch_align_stack(x) (x)
#endif /* _H8300_EXEC_H */
......@@ -87,4 +87,3 @@ int kernel_execve(const char *filename,
return retval;
}
EXPORT_SYMBOL(kernel_execve);
......@@ -14,3 +14,4 @@ header-y += rse.h
header-y += ucontext.h
header-y += ustack.h
generic-y += clkdev.h
generic-y += exec.h
/*
* Process execution defines.
*
* Copyright (C) 1998-2003 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
* Copyright (C) 1999 Asit Mallick <asit.k.mallick@intel.com>
* Copyright (C) 1999 Don Dugger <don.dugger@intel.com>
*/
#ifndef _ASM_IA64_EXEC_H
#define _ASM_IA64_EXEC_H
#define arch_align_stack(x) (x)
#endif /* _ASM_IA64_EXEC_H */
include include/asm-generic/Kbuild.asm
generic-y += clkdev.h
generic-y += clkdev.h
generic-y += exec.h
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 Hiroyuki Kondo, Hirokazu Takata, and Hitoshi Yamamoto
* Copyright (C) 2004, 2006 Hirokazu Takata <takata at linux-m32r.org>
*/
#ifndef _ASM_M32R_EXEC_H
#define _ASM_M32R_EXEC_H
#define arch_align_stack(x) (x)
#endif /* _ASM_M32R_EXEC_H */
......@@ -7,6 +7,7 @@ generic-y += cputime.h
generic-y += device.h
generic-y += emergency-restart.h
generic-y += errno.h
generic-y += exec.h
generic-y += futex.h
generic-y += ioctl.h
generic-y += ipcbuf.h
......