linux/arch/s390/kernel/process.c

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/*
* This file handles the architecture dependent parts of process handling.
*
* Copyright IBM Corp. 1999,2009
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
* Hartmut Penner <hp@de.ibm.com>,
* Denis Joseph Barrow,
*/
#include <linux/compiler.h>
#include <linux/cpu.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
Remove fs.h from mm.h Remove fs.h from mm.h. For this, 1) Uninline vma_wants_writenotify(). It's pretty huge anyway. 2) Add back fs.h or less bloated headers (err.h) to files that need it. As result, on x86_64 allyesconfig, fs.h dependencies cut down from 3929 files rebuilt down to 3444 (-12.3%). Cross-compile tested without regressions on my two usual configs and (sigh): alpha arm-mx1ads mips-bigsur powerpc-ebony alpha-allnoconfig arm-neponset mips-capcella powerpc-g5 alpha-defconfig arm-netwinder mips-cobalt powerpc-holly alpha-up arm-netx mips-db1000 powerpc-iseries arm arm-ns9xxx mips-db1100 powerpc-linkstation arm-assabet arm-omap_h2_1610 mips-db1200 powerpc-lite5200 arm-at91rm9200dk arm-onearm mips-db1500 powerpc-maple arm-at91rm9200ek arm-picotux200 mips-db1550 powerpc-mpc7448_hpc2 arm-at91sam9260ek arm-pleb mips-ddb5477 powerpc-mpc8272_ads arm-at91sam9261ek arm-pnx4008 mips-decstation powerpc-mpc8313_rdb arm-at91sam9263ek arm-pxa255-idp mips-e55 powerpc-mpc832x_mds arm-at91sam9rlek arm-realview mips-emma2rh powerpc-mpc832x_rdb arm-ateb9200 arm-realview-smp mips-excite powerpc-mpc834x_itx arm-badge4 arm-rpc mips-fulong powerpc-mpc834x_itxgp arm-carmeva arm-s3c2410 mips-ip22 powerpc-mpc834x_mds arm-cerfcube arm-shannon mips-ip27 powerpc-mpc836x_mds arm-clps7500 arm-shark mips-ip32 powerpc-mpc8540_ads arm-collie arm-simpad mips-jazz powerpc-mpc8544_ds arm-corgi arm-spitz mips-jmr3927 powerpc-mpc8560_ads arm-csb337 arm-trizeps4 mips-malta powerpc-mpc8568mds arm-csb637 arm-versatile mips-mipssim powerpc-mpc85xx_cds arm-ebsa110 i386 mips-mpc30x powerpc-mpc8641_hpcn arm-edb7211 i386-allnoconfig mips-msp71xx powerpc-mpc866_ads arm-em_x270 i386-defconfig mips-ocelot powerpc-mpc885_ads arm-ep93xx i386-up mips-pb1100 powerpc-pasemi arm-footbridge ia64 mips-pb1500 powerpc-pmac32 arm-fortunet ia64-allnoconfig mips-pb1550 powerpc-ppc64 arm-h3600 ia64-bigsur mips-pnx8550-jbs powerpc-prpmc2800 arm-h7201 ia64-defconfig mips-pnx8550-stb810 powerpc-ps3 arm-h7202 ia64-gensparse mips-qemu powerpc-pseries arm-hackkit ia64-sim mips-rbhma4200 powerpc-up arm-integrator ia64-sn2 mips-rbhma4500 s390 arm-iop13xx ia64-tiger mips-rm200 s390-allnoconfig arm-iop32x ia64-up mips-sb1250-swarm s390-defconfig arm-iop33x ia64-zx1 mips-sead s390-up arm-ixp2000 m68k mips-tb0219 sparc arm-ixp23xx m68k-amiga mips-tb0226 sparc-allnoconfig arm-ixp4xx m68k-apollo mips-tb0287 sparc-defconfig arm-jornada720 m68k-atari mips-workpad sparc-up arm-kafa m68k-bvme6000 mips-wrppmc sparc64 arm-kb9202 m68k-hp300 mips-yosemite sparc64-allnoconfig arm-ks8695 m68k-mac parisc sparc64-defconfig arm-lart m68k-mvme147 parisc-allnoconfig sparc64-up arm-lpd270 m68k-mvme16x parisc-defconfig um-x86_64 arm-lpd7a400 m68k-q40 parisc-up x86_64 arm-lpd7a404 m68k-sun3 powerpc x86_64-allnoconfig arm-lubbock m68k-sun3x powerpc-cell x86_64-defconfig arm-lusl7200 mips powerpc-celleb x86_64-up arm-mainstone mips-atlas powerpc-chrp32 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-29 22:36:13 +00:00
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/stddef.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/vmalloc.h>
#include <linux/user.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/tick.h>
#include <linux/elfcore.h>
#include <linux/kernel_stat.h>
#include <linux/syscalls.h>
#include <linux/compat.h>
#include <asm/compat.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/irq.h>
#include <asm/timer.h>
#include <asm/nmi.h>
#include "entry.h"
asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
/*
* Return saved PC of a blocked thread. used in kernel/sched.
* resume in entry.S does not create a new stack frame, it
* just stores the registers %r6-%r15 to the frame given by
* schedule. We want to return the address of the caller of
* schedule, so we have to walk the backchain one time to
* find the frame schedule() store its return address.
*/
unsigned long thread_saved_pc(struct task_struct *tsk)
{
struct stack_frame *sf, *low, *high;
if (!tsk || !task_stack_page(tsk))
return 0;
low = task_stack_page(tsk);
high = (struct stack_frame *) task_pt_regs(tsk);
sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN);
if (sf <= low || sf > high)
return 0;
sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
if (sf <= low || sf > high)
return 0;
return sf->gprs[8];
}
/*
* The idle loop on a S390...
*/
static void default_idle(void)
{
[PATCH] sched: resched and cpu_idle rework Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce confusion, and make their semantics rigid. Improves efficiency of resched_task and some cpu_idle routines. * In resched_task: - TIF_NEED_RESCHED is only cleared with the task's runqueue lock held, and as we hold it during resched_task, then there is no need for an atomic test and set there. The only other time this should be set is when the task's quantum expires, in the timer interrupt - this is protected against because the rq lock is irq-safe. - If TIF_NEED_RESCHED is set, then we don't need to do anything. It won't get unset until the task get's schedule()d off. - If we are running on the same CPU as the task we resched, then set TIF_NEED_RESCHED and no further action is required. - If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set after TIF_NEED_RESCHED has been set, then we need to send an IPI. Using these rules, we are able to remove the test and set operation in resched_task, and make clear the previously vague semantics of POLLING_NRFLAG. * In idle routines: - Enter cpu_idle with preempt disabled. When the need_resched() condition becomes true, explicitly call schedule(). This makes things a bit clearer (IMO), but haven't updated all architectures yet. - Many do a test and clear of TIF_NEED_RESCHED for some reason. According to the resched_task rules, this isn't needed (and actually breaks the assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock held). So remove that. Generally one less locked memory op when switching to the idle thread. - Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner most polling idle loops. The above resched_task semantics allow it to be set until before the last time need_resched() is checked before going into a halt requiring interrupt wakeup. Many idle routines simply never enter such a halt, and so POLLING_NRFLAG can be always left set, completely eliminating resched IPIs when rescheduling the idle task. POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Con Kolivas <kernel@kolivas.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 05:39:04 +00:00
/* CPU is going idle. */
#ifdef CONFIG_HOTPLUG_CPU
if (cpu_is_offline(smp_processor_id())) {
preempt_enable_no_resched();
cpu_die();
}
#endif
local_irq_disable();
if (need_resched()) {
local_irq_enable();
return;
}
local_mcck_disable();
if (test_thread_flag(TIF_MCCK_PENDING)) {
local_mcck_enable();
local_irq_enable();
s390_handle_mcck();
return;
}
trace_hardirqs_on();
/* Don't trace preempt off for idle. */
stop_critical_timings();
/* Stop virtual timer and halt the cpu. */
vtime_stop_cpu();
/* Reenable preemption tracer. */
start_critical_timings();
}
void cpu_idle(void)
{
for (;;) {
tick_nohz_stop_sched_tick(1);
while (!need_resched())
default_idle();
tick_nohz_restart_sched_tick();
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
extern void kernel_thread_starter(void);
asm(
".align 4\n"
"kernel_thread_starter:\n"
" la 2,0(10)\n"
" basr 14,9\n"
" la 2,0\n"
" br 11\n");
int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
struct pt_regs regs;
memset(&regs, 0, sizeof(regs));
[S390] noexec protection This provides a noexec protection on s390 hardware. Our hardware does not have any bits left in the pte for a hw noexec bit, so this is a different approach using shadow page tables and a special addressing mode that allows separate address spaces for code and data. As a special feature of our "secondary-space" addressing mode, separate page tables can be specified for the translation of data addresses (storage operands) and instruction addresses. The shadow page table is used for the instruction addresses and the standard page table for the data addresses. The shadow page table is linked to the standard page table by a pointer in page->lru.next of the struct page corresponding to the page that contains the standard page table (since page->private is not really private with the pte_lock and the page table pages are not in the LRU list). Depending on the software bits of a pte, it is either inserted into both page tables or just into the standard (data) page table. Pages of a vma that does not have the VM_EXEC bit set get mapped only in the data address space. Any try to execute code on such a page will cause a page translation exception. The standard reaction to this is a SIGSEGV with two exceptions: the two system call opcodes 0x0a77 (sys_sigreturn) and 0x0aad (sys_rt_sigreturn) are allowed. They are stored by the kernel to the signal stack frame. Unfortunately, the signal return mechanism cannot be modified to use an SA_RESTORER because the exception unwinding code depends on the system call opcode stored behind the signal stack frame. This feature requires that user space is executed in secondary-space mode and the kernel in home-space mode, which means that the addressing modes need to be switched and that the noexec protection only works for user space. After switching the addressing modes, we cannot use the mvcp/mvcs instructions anymore to copy between kernel and user space. A new mvcos instruction has been added to the z9 EC/BC hardware which allows to copy between arbitrary address spaces, but on older hardware the page tables need to be walked manually. Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-02-05 20:18:17 +00:00
regs.psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
regs.psw.addr = (unsigned long) kernel_thread_starter | PSW_ADDR_AMODE;
regs.gprs[9] = (unsigned long) fn;
regs.gprs[10] = (unsigned long) arg;
regs.gprs[11] = (unsigned long) do_exit;
regs.orig_gpr2 = -1;
/* 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..
*/
void exit_thread(void)
{
}
void flush_thread(void)
{
}
void release_thread(struct task_struct *dead_task)
{
}
int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
unsigned long unused,
struct task_struct *p, struct pt_regs *regs)
{
struct thread_info *ti;
struct fake_frame
{
struct stack_frame sf;
struct pt_regs childregs;
} *frame;
frame = container_of(task_pt_regs(p), struct fake_frame, childregs);
p->thread.ksp = (unsigned long) frame;
/* Store access registers to kernel stack of new process. */
frame->childregs = *regs;
frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */
frame->childregs.gprs[15] = new_stackp;
frame->sf.back_chain = 0;
/* new return point is ret_from_fork */
frame->sf.gprs[8] = (unsigned long) ret_from_fork;
/* fake return stack for resume(), don't go back to schedule */
frame->sf.gprs[9] = (unsigned long) frame;
/* Save access registers to new thread structure. */
save_access_regs(&p->thread.acrs[0]);
#ifndef CONFIG_64BIT
/*
* save fprs to current->thread.fp_regs to merge them with
* the emulated registers and then copy the result to the child.
*/
save_fp_regs(&current->thread.fp_regs);
memcpy(&p->thread.fp_regs, &current->thread.fp_regs,
sizeof(s390_fp_regs));
/* Set a new TLS ? */
if (clone_flags & CLONE_SETTLS)
p->thread.acrs[0] = regs->gprs[6];
#else /* CONFIG_64BIT */
/* Save the fpu registers to new thread structure. */
save_fp_regs(&p->thread.fp_regs);
/* Set a new TLS ? */
if (clone_flags & CLONE_SETTLS) {
if (is_compat_task()) {
p->thread.acrs[0] = (unsigned int) regs->gprs[6];
} else {
p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32);
p->thread.acrs[1] = (unsigned int) regs->gprs[6];
}
}
#endif /* CONFIG_64BIT */
/* start new process with ar4 pointing to the correct address space */
p->thread.mm_segment = get_fs();
/* Don't copy debug registers */
memset(&p->thread.per_info, 0, sizeof(p->thread.per_info));
clear_tsk_thread_flag(p, TIF_SINGLE_STEP);
/* Initialize per thread user and system timer values */
ti = task_thread_info(p);
ti->user_timer = 0;
ti->system_timer = 0;
return 0;
}
SYSCALL_DEFINE0(fork)
{
struct pt_regs *regs = task_pt_regs(current);
return do_fork(SIGCHLD, regs->gprs[15], regs, 0, NULL, NULL);
}
SYSCALL_DEFINE4(clone, unsigned long, newsp, unsigned long, clone_flags,
int __user *, parent_tidptr, int __user *, child_tidptr)
{
struct pt_regs *regs = task_pt_regs(current);
if (!newsp)
newsp = regs->gprs[15];
return do_fork(clone_flags, newsp, regs, 0,
parent_tidptr, 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.
*/
SYSCALL_DEFINE0(vfork)
{
struct pt_regs *regs = task_pt_regs(current);
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
regs->gprs[15], regs, 0, NULL, NULL);
}
asmlinkage void execve_tail(void)
{
current->thread.fp_regs.fpc = 0;
if (MACHINE_HAS_IEEE)
asm volatile("sfpc %0,%0" : : "d" (0));
}
/*
* sys_execve() executes a new program.
*/
SYSCALL_DEFINE3(execve, const char __user *, name,
const char __user *const __user *, argv,
const char __user *const __user *, envp)
{
struct pt_regs *regs = task_pt_regs(current);
char *filename;
long rc;
filename = getname(name);
rc = PTR_ERR(filename);
if (IS_ERR(filename))
return rc;
rc = do_execve(filename, argv, envp, regs);
if (rc)
goto out;
execve_tail();
rc = regs->gprs[2];
out:
putname(filename);
return rc;
}
/*
* fill in the FPU structure for a core dump.
*/
int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
{
#ifndef CONFIG_64BIT
/*
* save fprs to current->thread.fp_regs to merge them with
* the emulated registers and then copy the result to the dump.
*/
save_fp_regs(&current->thread.fp_regs);
memcpy(fpregs, &current->thread.fp_regs, sizeof(s390_fp_regs));
#else /* CONFIG_64BIT */
save_fp_regs(fpregs);
#endif /* CONFIG_64BIT */
return 1;
}
EXPORT_SYMBOL(dump_fpu);
unsigned long get_wchan(struct task_struct *p)
{
struct stack_frame *sf, *low, *high;
unsigned long return_address;
int count;
if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p))
return 0;
low = task_stack_page(p);
high = (struct stack_frame *) task_pt_regs(p);
sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN);
if (sf <= low || sf > high)
return 0;
for (count = 0; count < 16; count++) {
sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
if (sf <= low || sf > high)
return 0;
return_address = sf->gprs[8] & PSW_ADDR_INSN;
if (!in_sched_functions(return_address))
return return_address;
}
return 0;
}