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

Pull big execve/kernel_thread/fork unification series from Al Viro:
 "All architectures are converted to new model.  Quite a bit of that
  stuff is actually shared with architecture trees; in such cases it's
  literally shared branch pulled by both, not a cherry-pick.

  A lot of ugliness and black magic is gone (-3KLoC total in this one):

   - kernel_thread()/kernel_execve()/sys_execve() redesign.

     We don't do syscalls from kernel anymore for either kernel_thread()
     or kernel_execve():

     kernel_thread() is essentially clone(2) with callback run before we
     return to userland, the callbacks either never return or do
     successful do_execve() before returning.

     kernel_execve() is a wrapper for do_execve() - it doesn't need to
     do transition to user mode anymore.

     As a result kernel_thread() and kernel_execve() are
     arch-independent now - they live in kernel/fork.c and fs/exec.c
     resp.  sys_execve() is also in fs/exec.c and it's completely
     architecture-independent.

   - daemonize() is gone, along with its parts in fs/*.c

   - struct pt_regs * is no longer passed to do_fork/copy_process/
     copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump.

   - sys_fork()/sys_vfork()/sys_clone() unified; some architectures
     still need wrappers (ones with callee-saved registers not saved in
     pt_regs on syscall entry), but the main part of those suckers is in
     kernel/fork.c now."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits)
  do_coredump(): get rid of pt_regs argument
  print_fatal_signal(): get rid of pt_regs argument
  ptrace_signal(): get rid of unused arguments
  get rid of ptrace_signal_deliver() arguments
  new helper: signal_pt_regs()
  unify default ptrace_signal_deliver
  flagday: kill pt_regs argument of do_fork()
  death to idle_regs()
  don't pass regs to copy_process()
  flagday: don't pass regs to copy_thread()
  bfin: switch to generic vfork, get rid of pointless wrappers
  xtensa: switch to generic clone()
  openrisc: switch to use of generic fork and clone
  unicore32: switch to generic clone(2)
  score: switch to generic fork/vfork/clone
  c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone()
  take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h
  mn10300: switch to generic fork/vfork/clone
  h8300: switch to generic fork/vfork/clone
  tile: switch to generic clone()
  ...

Conflicts:
	arch/microblaze/include/asm/Kbuild
This commit is contained in:
Linus Torvalds
2012-12-12 12:22:13 -08:00
273 changed files with 1385 additions and 4231 deletions
+2 -1
View File
@@ -16,7 +16,7 @@ obj-y := debugtraps.o dma-nommu.o dumpstack.o \
machvec.o nmi_debug.o process.o \
process_$(BITS).o ptrace.o ptrace_$(BITS).o \
reboot.o return_address.o \
setup.o signal_$(BITS).o sys_sh.o sys_sh$(BITS).o \
setup.o signal_$(BITS).o sys_sh.o \
syscalls_$(BITS).o time.o topology.o traps.o \
traps_$(BITS).o unwinder.o
@@ -25,6 +25,7 @@ obj-y += iomap.o
obj-$(CONFIG_HAS_IOPORT) += ioport.o
endif
obj-$(CONFIG_SUPERH32) += sys_sh32.o
obj-y += cpu/
obj-$(CONFIG_VSYSCALL) += vsyscall/
obj-$(CONFIG_SMP) += smp.o
+19
View File
@@ -1228,6 +1228,25 @@ ret_from_fork:
pta ret_from_syscall, tr0
blink tr0, ZERO
.global ret_from_kernel_thread
ret_from_kernel_thread:
movi schedule_tail,r5
ori r5, 1, r5
ptabs r5, tr0
blink tr0, LINK
ld.q SP, FRAME_R(2), r2
ld.q SP, FRAME_R(3), r3
ptabs r3, tr0
blink tr0, LINK
ld.q SP, FRAME_S(FSPC), r2
addi r2, 4, r2 /* Move PC, being pre-execution event */
st.q SP, FRAME_S(FSPC), r2
pta ret_from_syscall, tr0
blink tr0, ZERO
syscall_allowed:
/* Use LINK to deflect the exit point, default is syscall_ret */
pta syscall_ret, tr0
+13
View File
@@ -297,6 +297,19 @@ ret_from_fork:
mov r0, r4
bra syscall_exit
nop
.align 2
.globl ret_from_kernel_thread
ret_from_kernel_thread:
mov.l 1f, r8
jsr @r8
mov r0, r4
mov.l @(OFF_R5,r15), r5 ! fn
jsr @r5
mov.l @(OFF_R4,r15), r4 ! arg
bra syscall_exit
nop
.align 2
1: .long schedule_tail
+20 -114
View File
@@ -68,38 +68,6 @@ void show_regs(struct pt_regs * regs)
show_code(regs);
}
/*
* Create a kernel thread
*/
__noreturn void kernel_thread_helper(void *arg, int (*fn)(void *))
{
do_exit(fn(arg));
}
/* Don't use this in BL=1(cli). Or else, CPU resets! */
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
struct pt_regs regs;
int pid;
memset(&regs, 0, sizeof(regs));
regs.regs[4] = (unsigned long)arg;
regs.regs[5] = (unsigned long)fn;
regs.pc = (unsigned long)kernel_thread_helper;
regs.sr = SR_MD;
#if defined(CONFIG_SH_FPU)
regs.sr |= SR_FD;
#endif
/* Ok, create the new process.. */
pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
&regs, 0, NULL, NULL);
return pid;
}
EXPORT_SYMBOL(kernel_thread);
void start_thread(struct pt_regs *regs, unsigned long new_pc,
unsigned long new_sp)
{
@@ -157,10 +125,10 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
EXPORT_SYMBOL(dump_fpu);
asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long unused,
struct task_struct *p, struct pt_regs *regs)
unsigned long arg, struct task_struct *p)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs;
@@ -177,29 +145,35 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
}
#endif
childregs = task_pt_regs(p);
*childregs = *regs;
memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
if (user_mode(regs)) {
childregs->regs[15] = usp;
ti->addr_limit = USER_DS;
} else {
childregs->regs[15] = (unsigned long)childregs;
childregs = task_pt_regs(p);
p->thread.sp = (unsigned long) childregs;
if (unlikely(p->flags & PF_KTHREAD)) {
memset(childregs, 0, sizeof(struct pt_regs));
p->thread.pc = (unsigned long) ret_from_kernel_thread;
childregs->regs[4] = arg;
childregs->regs[5] = usp;
childregs->sr = SR_MD;
#if defined(CONFIG_SH_FPU)
childregs->sr |= SR_FD;
#endif
ti->addr_limit = KERNEL_DS;
ti->status &= ~TS_USEDFPU;
p->fpu_counter = 0;
return 0;
}
*childregs = *current_pt_regs();
if (usp)
childregs->regs[15] = usp;
ti->addr_limit = USER_DS;
if (clone_flags & CLONE_SETTLS)
childregs->gbr = childregs->regs[0];
childregs->regs[0] = 0; /* Set return value for child */
p->thread.sp = (unsigned long) childregs;
p->thread.pc = (unsigned long) ret_from_fork;
memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
return 0;
}
@@ -243,74 +217,6 @@ __switch_to(struct task_struct *prev, struct task_struct *next)
return prev;
}
asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs __regs)
{
#ifdef CONFIG_MMU
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL);
#else
/* fork almost works, enough to trick you into looking elsewhere :-( */
return -EINVAL;
#endif
}
asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
unsigned long parent_tidptr,
unsigned long child_tidptr,
struct pt_regs __regs)
{
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
if (!newsp)
newsp = regs->regs[15];
return do_fork(clone_flags, newsp, regs, 0,
(int __user *)parent_tidptr,
(int __user *)child_tidptr);
}
/*
* 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.
*/
asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs __regs)
{
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs,
0, NULL, NULL);
}
/*
* sys_execve() executes a new program.
*/
asmlinkage int sys_execve(const char __user *ufilename,
const char __user *const __user *uargv,
const char __user *const __user *uenvp,
unsigned long r7, struct pt_regs __regs)
{
struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
int error;
struct filename *filename;
filename = getname(ufilename);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename->name, uargv, uenvp, regs);
putname(filename);
out:
return error;
}
unsigned long get_wchan(struct task_struct *p)
{
unsigned long pc;
+19 -108
View File
@@ -284,39 +284,6 @@ void show_regs(struct pt_regs *regs)
}
}
/*
* Create a kernel thread
*/
__noreturn void kernel_thread_helper(void *arg, int (*fn)(void *))
{
do_exit(fn(arg));
}
/*
* This is the mechanism for creating a new kernel thread.
*
* NOTE! Only a kernel-only process(ie the swapper or direct descendants
* who haven't done an "execve()") should use this: it will work within
* a system call from a "real" process, but the process memory space will
* not be freed until both the parent and the child have exited.
*/
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
struct pt_regs regs;
memset(&regs, 0, sizeof(regs));
regs.regs[2] = (unsigned long)arg;
regs.regs[3] = (unsigned long)fn;
regs.pc = (unsigned long)kernel_thread_helper;
regs.sr = (1 << 30);
/* Ok, create the new process.. */
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
&regs, 0, NULL, NULL);
}
EXPORT_SYMBOL(kernel_thread);
/*
* Free current thread data structures etc..
*/
@@ -401,26 +368,37 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
EXPORT_SYMBOL(dump_fpu);
asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long unused,
struct task_struct *p, struct pt_regs *regs)
unsigned long arg, struct task_struct *p)
{
struct pt_regs *childregs;
struct pt_regs *childregs, *regs = current_pt_regs();
#ifdef CONFIG_SH_FPU
if(last_task_used_math == current) {
/* can't happen for a kernel thread */
if (last_task_used_math == current) {
enable_fpu();
save_fpu(current);
disable_fpu();
last_task_used_math = NULL;
regs->sr |= SR_FD;
current_pt_regs()->sr |= SR_FD;
}
#endif
/* Copy from sh version */
childregs = (struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1;
p->thread.sp = (unsigned long) childregs;
*childregs = *regs;
if (unlikely(p->flags & PF_KTHREAD)) {
memset(childregs, 0, sizeof(struct pt_regs));
childregs->regs[2] = (unsigned long)arg;
childregs->regs[3] = (unsigned long)fn;
childregs->sr = (1 << 30); /* not user_mode */
childregs->sr |= SR_FD; /* Invalidate FPU flag */
p->thread.pc = (unsigned long) ret_from_kernel_thread;
return 0;
}
*childregs = *current_pt_regs();
/*
* Sign extend the edited stack.
@@ -428,85 +406,18 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
* 32-bit wide and context switch must take care
* of NEFF sign extension.
*/
if (user_mode(regs)) {
if (usp)
childregs->regs[15] = neff_sign_extend(usp);
p->thread.uregs = childregs;
} else {
childregs->regs[15] =
neff_sign_extend((unsigned long)task_stack_page(p) +
THREAD_SIZE);
}
p->thread.uregs = childregs;
childregs->regs[9] = 0; /* Set return value for child */
childregs->sr |= SR_FD; /* Invalidate FPU flag */
p->thread.sp = (unsigned long) childregs;
p->thread.pc = (unsigned long) ret_from_fork;
return 0;
}
asmlinkage int sys_fork(unsigned long r2, unsigned long r3,
unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs *pregs)
{
return do_fork(SIGCHLD, pregs->regs[15], pregs, 0, 0, 0);
}
asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs *pregs)
{
if (!newsp)
newsp = pregs->regs[15];
return do_fork(clone_flags, newsp, pregs, 0, 0, 0);
}
/*
* 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.
*/
asmlinkage int sys_vfork(unsigned long r2, unsigned long r3,
unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs *pregs)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, pregs->regs[15], pregs, 0, 0, 0);
}
/*
* sys_execve() executes a new program.
*/
asmlinkage int sys_execve(const char *ufilename, char **uargv,
char **uenvp, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs *pregs)
{
int error;
struct filename *filename;
filename = getname((char __user *)ufilename);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename->name,
(const char __user *const __user *)uargv,
(const char __user *const __user *)uenvp,
pregs);
putname(filename);
out:
return error;
}
#ifdef CONFIG_FRAME_POINTER
static int in_sh64_switch_to(unsigned long pc)
{
-24
View File
@@ -60,27 +60,3 @@ asmlinkage int sys_fadvise64_64_wrapper(int fd, u32 offset0, u32 offset1,
(u64)len0 << 32 | len1, advice);
#endif
}
#if defined(CONFIG_CPU_SH2) || defined(CONFIG_CPU_SH2A)
#define SYSCALL_ARG3 "trapa #0x23"
#else
#define SYSCALL_ARG3 "trapa #0x13"
#endif
/*
* Do a system call from kernel instead of calling sys_execve so we
* end up with proper pt_regs.
*/
int kernel_execve(const char *filename,
const char *const argv[],
const char *const envp[])
{
register long __sc0 __asm__ ("r3") = __NR_execve;
register long __sc4 __asm__ ("r4") = (long) filename;
register long __sc5 __asm__ ("r5") = (long) argv;
register long __sc6 __asm__ ("r6") = (long) envp;
__asm__ __volatile__ (SYSCALL_ARG3 : "=z" (__sc0)
: "0" (__sc0), "r" (__sc4), "r" (__sc5), "r" (__sc6)
: "memory");
return __sc0;
}
-50
View File
@@ -1,50 +0,0 @@
/*
* arch/sh/kernel/sys_sh64.c
*
* Copyright (C) 2000, 2001 Paolo Alberelli
*
* This file contains various random system calls that
* have a non-standard calling sequence on the Linux/SH5
* platform.
*
* 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.
*/
#include <linux/errno.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
#include <linux/mman.h>
#include <linux/file.h>
#include <linux/syscalls.h>
#include <linux/ipc.h>
#include <asm/uaccess.h>
#include <asm/ptrace.h>
#include <asm/unistd.h>
/*
* Do a system call from kernel instead of calling sys_execve so we
* end up with proper pt_regs.
*/
int kernel_execve(const char *filename,
const char *const argv[],
const char *const envp[])
{
register unsigned long __sc0 __asm__ ("r9") = ((0x13 << 16) | __NR_execve);
register unsigned long __sc2 __asm__ ("r2") = (unsigned long) filename;
register unsigned long __sc3 __asm__ ("r3") = (unsigned long) argv;
register unsigned long __sc4 __asm__ ("r4") = (unsigned long) envp;
__asm__ __volatile__ ("trapa %1 !\t\t\t execve(%2,%3,%4)"
: "=r" (__sc0)
: "r" (__sc0), "r" (__sc2), "r" (__sc3), "r" (__sc4) );
__asm__ __volatile__ ("!dummy %0 %1 %2 %3"
: : "r" (__sc0), "r" (__sc2), "r" (__sc3), "r" (__sc4) : "memory");
return __sc0;
}