#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/spinlock.h>
+#include <linux/key.h>
#include <linux/personality.h>
#include <linux/binfmts.h>
#include <linux/swap.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/rmap.h>
+#include <linux/acct.h>
#include <linux/vs_memory.h>
#include <asm/uaccess.h>
/* The maximal length of core_pattern is also specified in sysctl.c */
static struct linux_binfmt *formats;
-static rwlock_t binfmt_lock = RW_LOCK_UNLOCKED;
+static DEFINE_RWLOCK(binfmt_lock);
int register_binfmt(struct linux_binfmt * fmt)
{
argv++;
if(++i > max)
return -E2BIG;
+ cond_resched();
}
}
return i;
{
struct mm_struct *mm = vma->vm_mm;
pgd_t * pgd;
+ pud_t * pud;
pmd_t * pmd;
pte_t * pte;
pgd = pgd_offset(mm, address);
spin_lock(&mm->page_table_lock);
- pmd = pmd_alloc(mm, pgd, address);
+ pud = pud_alloc(mm, pgd, address);
+ if (!pud)
+ goto out;
+ pmd = pmd_alloc(mm, pud, address);
if (!pmd)
goto out;
pte = pte_alloc_map(mm, pmd, address);
force_sig(SIGKILL, current);
}
-int setup_arg_pages(struct linux_binprm *bprm, int executable_stack)
+#define EXTRA_STACK_VM_PAGES 20 /* random */
+
+int setup_arg_pages(struct linux_binprm *bprm,
+ unsigned long stack_top,
+ int executable_stack)
{
unsigned long stack_base;
struct vm_area_struct *mpnt;
struct mm_struct *mm = current->mm;
- int i;
+ int i, ret;
long arg_size;
#ifdef CONFIG_STACK_GROWSUP
memmove(to, to + offset, PAGE_SIZE - offset);
kunmap(bprm->page[j - 1]);
- /* Adjust bprm->p to point to the end of the strings. */
- bprm->p = PAGE_SIZE * i - offset;
-
/* Limit stack size to 1GB */
- stack_base = current->rlim[RLIMIT_STACK].rlim_max;
+ stack_base = current->signal->rlim[RLIMIT_STACK].rlim_max;
if (stack_base > (1 << 30))
stack_base = 1 << 30;
- stack_base = PAGE_ALIGN(STACK_TOP - stack_base);
+ stack_base = PAGE_ALIGN(stack_top - stack_base);
+
+ /* Adjust bprm->p to point to the end of the strings. */
+ bprm->p = stack_base + PAGE_SIZE * i - offset;
mm->arg_start = stack_base;
arg_size = i << PAGE_SHIFT;
while (i < MAX_ARG_PAGES)
bprm->page[i++] = NULL;
#else
- stack_base = STACK_TOP - MAX_ARG_PAGES * PAGE_SIZE;
- mm->arg_start = bprm->p + stack_base;
- arg_size = STACK_TOP - (PAGE_MASK & (unsigned long) mm->arg_start);
+ stack_base = stack_top - MAX_ARG_PAGES * PAGE_SIZE;
+ bprm->p += stack_base;
+ mm->arg_start = bprm->p;
+ arg_size = stack_top - (PAGE_MASK & (unsigned long) mm->arg_start);
#endif
- bprm->p += stack_base;
+ arg_size += EXTRA_STACK_VM_PAGES * PAGE_SIZE;
+
if (bprm->loader)
bprm->loader += stack_base;
bprm->exec += stack_base;
mpnt->vm_mm = mm;
#ifdef CONFIG_STACK_GROWSUP
mpnt->vm_start = stack_base;
- mpnt->vm_end = PAGE_MASK &
- (PAGE_SIZE - 1 + (unsigned long) bprm->p);
+ mpnt->vm_end = stack_base + arg_size;
#else
- mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
- mpnt->vm_end = STACK_TOP;
+ mpnt->vm_end = stack_top;
+ mpnt->vm_start = mpnt->vm_end - arg_size;
#endif
/* Adjust stack execute permissions; explicitly enable
* for EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X
mpnt->vm_flags = VM_STACK_FLAGS;
mpnt->vm_flags |= mm->def_flags;
mpnt->vm_page_prot = protection_map[mpnt->vm_flags & 0x7];
- insert_vm_struct(mm, mpnt);
+ if ((ret = insert_vm_struct(mm, mpnt))) {
+ up_write(&mm->mmap_sem);
+ kmem_cache_free(vm_area_cachep, mpnt);
+ return ret;
+ }
// mm->stack_vm = mm->total_vm = vma_pages(mpnt);
vx_vmpages_sub(mm, mm->total_vm - vma_pages(mpnt));
mm->stack_vm = mm->total_vm;
struct task_struct *tsk;
struct mm_struct * old_mm, *active_mm;
- /* Add it to the list of mm's */
- spin_lock(&mmlist_lock);
- list_add(&mm->mmlist, &init_mm.mmlist);
- mmlist_nr++;
- spin_unlock(&mmlist_lock);
-
/* Notify parent that we're no longer interested in the old VM */
tsk = current;
old_mm = current->mm;
mm_release(tsk, old_mm);
+ if (old_mm) {
+ /*
+ * Make sure that if there is a core dump in progress
+ * for the old mm, we get out and die instead of going
+ * through with the exec. We must hold mmap_sem around
+ * checking core_waiters and changing tsk->mm. The
+ * core-inducing thread will increment core_waiters for
+ * each thread whose ->mm == old_mm.
+ */
+ down_read(&old_mm->mmap_sem);
+ if (unlikely(old_mm->core_waiters)) {
+ up_read(&old_mm->mmap_sem);
+ return -EINTR;
+ }
+ }
task_lock(tsk);
active_mm = tsk->active_mm;
tsk->mm = mm;
task_unlock(tsk);
arch_pick_mmap_layout(mm);
if (old_mm) {
+ up_read(&old_mm->mmap_sem);
if (active_mm != old_mm) BUG();
mmput(old_mm);
return 0;
*/
static inline int de_thread(struct task_struct *tsk)
{
- struct signal_struct *newsig, *oldsig = tsk->signal;
+ struct signal_struct *sig = tsk->signal;
struct sighand_struct *newsighand, *oldsighand = tsk->sighand;
spinlock_t *lock = &oldsighand->siglock;
int count;
* If we don't share sighandlers, then we aren't sharing anything
* and we can just re-use it all.
*/
- if (atomic_read(&oldsighand->count) <= 1)
+ if (atomic_read(&oldsighand->count) <= 1) {
+ BUG_ON(atomic_read(&sig->count) != 1);
+ exit_itimers(sig);
return 0;
+ }
newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
if (!newsighand)
return -ENOMEM;
- spin_lock_init(&newsighand->siglock);
- atomic_set(&newsighand->count, 1);
- memcpy(newsighand->action, oldsighand->action, sizeof(newsighand->action));
-
- /*
- * See if we need to allocate a new signal structure
- */
- newsig = NULL;
- if (atomic_read(&oldsig->count) > 1) {
- newsig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);
- if (!newsig) {
- kmem_cache_free(sighand_cachep, newsighand);
- return -ENOMEM;
- }
- atomic_set(&newsig->count, 1);
- newsig->group_exit = 0;
- newsig->group_exit_code = 0;
- newsig->group_exit_task = NULL;
- newsig->group_stop_count = 0;
- newsig->curr_target = NULL;
- init_sigpending(&newsig->shared_pending);
- INIT_LIST_HEAD(&newsig->posix_timers);
-
- newsig->tty = oldsig->tty;
- newsig->pgrp = oldsig->pgrp;
- newsig->session = oldsig->session;
- newsig->leader = oldsig->leader;
- newsig->tty_old_pgrp = oldsig->tty_old_pgrp;
- }
-
if (thread_group_empty(current))
goto no_thread_group;
*/
read_lock(&tasklist_lock);
spin_lock_irq(lock);
- if (oldsig->group_exit) {
+ if (sig->flags & SIGNAL_GROUP_EXIT) {
/*
* Another group action in progress, just
* return so that the signal is processed.
spin_unlock_irq(lock);
read_unlock(&tasklist_lock);
kmem_cache_free(sighand_cachep, newsighand);
- if (newsig)
- kmem_cache_free(signal_cachep, newsig);
return -EAGAIN;
}
- oldsig->group_exit = 1;
zap_other_threads(current);
read_unlock(&tasklist_lock);
* Account for the thread group leader hanging around:
*/
count = 2;
- if (current->pid == current->tgid)
+ if (thread_group_leader(current))
count = 1;
- while (atomic_read(&oldsig->count) > count) {
- oldsig->group_exit_task = current;
- oldsig->notify_count = count;
+ while (atomic_read(&sig->count) > count) {
+ sig->group_exit_task = current;
+ sig->notify_count = count;
__set_current_state(TASK_UNINTERRUPTIBLE);
spin_unlock_irq(lock);
schedule();
spin_lock_irq(lock);
}
+ sig->group_exit_task = NULL;
+ sig->notify_count = 0;
spin_unlock_irq(lock);
/*
* do is to wait for the thread group leader to become inactive,
* and to assume its PID:
*/
- if (current->pid != current->tgid) {
+ if (!thread_group_leader(current)) {
struct task_struct *leader = current->group_leader, *parent;
struct dentry *proc_dentry1, *proc_dentry2;
- unsigned long state, ptrace;
+ unsigned long exit_state, ptrace;
/*
* Wait for the thread group leader to be a zombie.
* It should already be zombie at this point, most
* of the time.
*/
- while (leader->state != TASK_ZOMBIE)
+ while (leader->exit_state != EXIT_ZOMBIE)
yield();
spin_lock(&leader->proc_lock);
*/
ptrace = leader->ptrace;
parent = leader->parent;
+ if (unlikely(ptrace) && unlikely(parent == current)) {
+ /*
+ * Joker was ptracing his own group leader,
+ * and now he wants to be his own parent!
+ * We can't have that.
+ */
+ ptrace = 0;
+ }
ptrace_unlink(current);
ptrace_unlink(leader);
list_del(¤t->tasks);
list_add_tail(¤t->tasks, &init_task.tasks);
current->exit_signal = SIGCHLD;
- state = leader->state;
+ exit_state = leader->exit_state;
write_unlock_irq(&tasklist_lock);
spin_unlock(&leader->proc_lock);
proc_pid_flush(proc_dentry1);
proc_pid_flush(proc_dentry2);
- if (state != TASK_ZOMBIE)
+ if (exit_state != EXIT_ZOMBIE)
BUG();
release_task(leader);
}
+ /*
+ * Now there are really no other threads at all,
+ * so it's safe to stop telling them to kill themselves.
+ */
+ sig->flags = 0;
+
no_thread_group:
+ BUG_ON(atomic_read(&sig->count) != 1);
+ exit_itimers(sig);
- write_lock_irq(&tasklist_lock);
- spin_lock(&oldsighand->siglock);
- spin_lock(&newsighand->siglock);
-
- if (current == oldsig->curr_target)
- oldsig->curr_target = next_thread(current);
- if (newsig)
- current->signal = newsig;
- current->sighand = newsighand;
- init_sigpending(¤t->pending);
- recalc_sigpending();
-
- spin_unlock(&newsighand->siglock);
- spin_unlock(&oldsighand->siglock);
- write_unlock_irq(&tasklist_lock);
-
- if (newsig && atomic_dec_and_test(&oldsig->count)) {
- exit_itimers(oldsig);
- kmem_cache_free(signal_cachep, oldsig);
- }
+ if (atomic_read(&oldsighand->count) == 1) {
+ /*
+ * Now that we nuked the rest of the thread group,
+ * it turns out we are not sharing sighand any more either.
+ * So we can just keep it.
+ */
+ kmem_cache_free(sighand_cachep, newsighand);
+ } else {
+ /*
+ * Move our state over to newsighand and switch it in.
+ */
+ spin_lock_init(&newsighand->siglock);
+ atomic_set(&newsighand->count, 1);
+ memcpy(newsighand->action, oldsighand->action,
+ sizeof(newsighand->action));
+
+ write_lock_irq(&tasklist_lock);
+ spin_lock(&oldsighand->siglock);
+ spin_lock(&newsighand->siglock);
- if (atomic_dec_and_test(&oldsighand->count))
- kmem_cache_free(sighand_cachep, oldsighand);
+ current->sighand = newsighand;
+ recalc_sigpending();
+
+ spin_unlock(&newsighand->siglock);
+ spin_unlock(&oldsighand->siglock);
+ write_unlock_irq(&tasklist_lock);
+
+ if (atomic_dec_and_test(&oldsighand->count))
+ kmem_cache_free(sighand_cachep, oldsighand);
+ }
if (!thread_group_empty(current))
BUG();
- if (current->tgid != current->pid)
+ if (!thread_group_leader(current))
BUG();
return 0;
}
{
/* buf must be at least sizeof(tsk->comm) in size */
task_lock(tsk);
- memcpy(buf, tsk->comm, sizeof(tsk->comm));
+ strncpy(buf, tsk->comm, sizeof(tsk->comm));
task_unlock(tsk);
}
if (bprm->e_uid != current->euid || bprm->e_gid != current->egid ||
permission(bprm->file->f_dentry->d_inode,MAY_READ, NULL) ||
- (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP))
+ (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) {
+ suid_keys(current);
current->mm->dumpable = 0;
+ }
/* An exec changes our domain. We are no longer part of the thread
group */
mode = inode->i_mode;
/*
* Check execute perms again - if the caller has CAP_DAC_OVERRIDE,
- * vfs_permission lets a non-executable through
+ * generic_permission lets a non-executable through
*/
if (!(mode & 0111)) /* with at least _one_ execute bit set */
return -EACCES;
void compute_creds(struct linux_binprm *bprm)
{
int unsafe;
+
+ if (bprm->e_uid != current->uid)
+ suid_keys(current);
+ exec_keys(current);
+
task_lock(current);
unsafe = unsafe_exec(current);
security_bprm_apply_creds(bprm, unsafe);
task_unlock(current);
+ security_bprm_post_apply_creds(bprm);
}
EXPORT_SYMBOL(compute_creds);
*/
int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
{
- int try,retval=0;
+ int try,retval;
struct linux_binfmt *fmt;
#ifdef __alpha__
/* handle /sbin/loader.. */
/* kernel module loader fixup */
/* so we don't try to load run modprobe in kernel space. */
set_fs(USER_DS);
+ retval = -ENOENT;
for (try=0; try<2; try++) {
read_lock(&binfmt_lock);
for (fmt = formats ; fmt ; fmt = fmt->next) {
int retval;
int i;
- file = open_exec(filename);
-
- retval = PTR_ERR(file);
- if (IS_ERR(file))
- return retval;
-
- sched_exec();
-
retval = -ENOMEM;
bprm = kmalloc(sizeof(*bprm), GFP_KERNEL);
if (!bprm)
goto out_ret;
memset(bprm, 0, sizeof(*bprm));
+ file = open_exec(filename);
+ retval = PTR_ERR(file);
+ if (IS_ERR(file))
+ goto out_kfree;
+
+ sched_exec();
+
bprm->p = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *);
bprm->file = file;
bprm->filename = filename;
bprm->interp = filename;
bprm->mm = mm_alloc();
+ retval = -ENOMEM;
if (!bprm->mm)
goto out_file;
/* execve success */
security_bprm_free(bprm);
+ acct_update_integrals();
+ update_mem_hiwater();
kfree(bprm);
return retval;
}
allow_write_access(bprm->file);
fput(bprm->file);
}
+
+out_kfree:
kfree(bprm);
out_ret:
return retval;
}
-EXPORT_SYMBOL(do_execve);
-
int set_binfmt(struct linux_binfmt *new)
{
struct linux_binfmt *old = current->binfmt;
struct task_struct *g, *p;
struct task_struct *tsk = current;
struct completion *vfork_done = tsk->vfork_done;
+ int traced = 0;
/*
* Make sure nobody is waiting for us to release the VM,
if (mm == p->mm && p != tsk) {
force_sig_specific(SIGKILL, p);
mm->core_waiters++;
+ if (unlikely(p->ptrace) &&
+ unlikely(p->parent->mm == mm))
+ traced = 1;
}
while_each_thread(g,p);
read_unlock(&tasklist_lock);
+
+ if (unlikely(traced)) {
+ /*
+ * We are zapping a thread and the thread it ptraces.
+ * If the tracee went into a ptrace stop for exit tracing,
+ * we could deadlock since the tracer is waiting for this
+ * coredump to finish. Detach them so they can both die.
+ */
+ write_lock_irq(&tasklist_lock);
+ do_each_thread(g,p) {
+ if (mm == p->mm && p != tsk &&
+ p->ptrace && p->parent->mm == mm) {
+ __ptrace_unlink(p);
+ }
+ } while_each_thread(g,p);
+ write_unlock_irq(&tasklist_lock);
+ }
}
static void coredump_wait(struct mm_struct *mm)
}
mm->dumpable = 0;
init_completion(&mm->core_done);
- current->signal->group_exit = 1;
+ spin_lock_irq(¤t->sighand->siglock);
+ current->signal->flags = SIGNAL_GROUP_EXIT;
current->signal->group_exit_code = exit_code;
+ spin_unlock_irq(¤t->sighand->siglock);
coredump_wait(mm);
- if (current->rlim[RLIMIT_CORE].rlim_cur < binfmt->min_coredump)
+ /*
+ * Clear any false indication of pending signals that might
+ * be seen by the filesystem code called to write the core file.
+ */
+ current->signal->group_stop_count = 0;
+ clear_thread_flag(TIF_SIGPENDING);
+
+ if (current->signal->rlim[RLIMIT_CORE].rlim_cur < binfmt->min_coredump)
goto fail_unlock;
/*
retval = binfmt->core_dump(signr, regs, file);
- current->signal->group_exit_code |= 0x80;
+ if (retval)
+ current->signal->group_exit_code |= 0x80;
close_fail:
filp_close(file, NULL);
fail_unlock:
git://git.onelab.eu / linux-2.6.git / blobdiff