Commit f400e198 authored by Sukadev Bhattiprolu's avatar Sukadev Bhattiprolu Committed by Linus Torvalds
Browse files

[PATCH] pidspace: is_init()

This is an updated version of Eric Biederman's is_init() patch.
(http://lkml.org/lkml/2006/2/6/280

).  It applies cleanly to 2.6.18-rc3 and
replaces a few more instances of ->pid == 1 with is_init().

Further, is_init() checks pid and thus removes dependency on Eric's other
patches for now.

Eric's original description:

	There are a lot of places in the kernel where we test for init
	because we give it special properties.  Most  significantly init
	must not die.  This results in code all over the kernel test
	->pid == 1.

	Introduce is_init to capture this case.

	With multiple pid spaces for all of the cases affected we are
	looking for only the first process on the system, not some other
	process that has pid == 1.
Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: default avatarSukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: <lxc-devel@lists.sourceforge.net>
Acked-by: default avatarPaul Mackerras <paulus@samba.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 959ed340
......@@ -193,7 +193,7 @@ do_page_fault(unsigned long address, unsigned long mmcsr,
/* We ran out of memory, or some other thing happened to us that
made us unable to handle the page fault gracefully. */
out_of_memory:
if (current->pid == 1) {
if (is_init(current)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
......
......@@ -198,7 +198,7 @@ __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
return fault;
}
if (tsk->pid != 1)
if (!is_init(tsk))
goto out;
/*
......
......@@ -185,7 +185,7 @@ __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
}
fault = -3; /* out of memory */
if (tsk->pid != 1)
if (!is_init(tsk))
goto out;
/*
......
......@@ -739,7 +739,7 @@ unsigned long __copy_to_user_ll(void __user *to, const void *from,
retval = get_user_pages(current, current->mm,
(unsigned long )to, 1, 1, 0, &pg, NULL);
if (retval == -ENOMEM && current->pid == 1) {
if (retval == -ENOMEM && is_init(current)) {
up_read(&current->mm->mmap_sem);
blk_congestion_wait(WRITE, HZ/50);
goto survive;
......
......@@ -589,7 +589,7 @@ fastcall void __kprobes do_page_fault(struct pt_regs *regs,
*/
out_of_memory:
up_read(&mm->mmap_sem);
if (tsk->pid == 1) {
if (is_init(tsk)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
......
......@@ -280,7 +280,7 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
out_of_memory:
up_read(&mm->mmap_sem);
if (current->pid == 1) {
if (is_init(current)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
......
......@@ -299,7 +299,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code,
*/
out_of_memory:
up_read(&mm->mmap_sem);
if (tsk->pid == 1) {
if (is_init(tsk)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
......
......@@ -181,7 +181,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
*/
out_of_memory:
up_read(&mm->mmap_sem);
if (current->pid == 1) {
if (is_init(current)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
......
......@@ -171,7 +171,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
*/
out_of_memory:
up_read(&mm->mmap_sem);
if (tsk->pid == 1) {
if (is_init(tsk)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
......
......@@ -386,7 +386,7 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
*/
out_of_memory:
up_read(&mm->mmap_sem);
if (current->pid == 1) {
if (is_init(current)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
......
......@@ -337,7 +337,7 @@ static int recover_mce(struct pt_regs *regs, struct rtas_error_log * err)
err->disposition == RTAS_DISP_NOT_RECOVERED &&
err->target == RTAS_TARGET_MEMORY &&
err->type == RTAS_TYPE_ECC_UNCORR &&
!(current->pid == 0 || current->pid == 1)) {
!(current->pid == 0 || is_init(current))) {
/* Kill off a user process with an ECC error */
printk(KERN_ERR "MCE: uncorrectable ecc error for pid %d\n",
current->pid);
......
......@@ -119,7 +119,7 @@ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
* generate the same exception over and over again and we get
* nowhere. Better to kill it and let the kernel panic.
*/
if (current->pid == 1) {
if (is_init(current)) {
__sighandler_t handler;
spin_lock_irq(&current->sighand->siglock);
......
......@@ -291,7 +291,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
*/
out_of_memory:
up_read(&mm->mmap_sem);
if (current->pid == 1) {
if (is_init(current)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
......
......@@ -353,7 +353,7 @@ do_exception(struct pt_regs *regs, unsigned long error_code, int is_protection)
*/
out_of_memory:
up_read(&mm->mmap_sem);
if (tsk->pid == 1) {
if (is_init(tsk)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
......
......@@ -149,7 +149,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long writeaccess,
*/
out_of_memory:
up_read(&mm->mmap_sem);
if (current->pid == 1) {
if (is_init(current)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
......
......@@ -277,7 +277,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long writeaccess,
show_regs(regs);
#endif
}
if (tsk->pid == 1) {
if (is_init(tsk)) {
panic("INIT had user mode bad_area\n");
}
tsk->thread.address = address;
......@@ -319,14 +319,14 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long writeaccess,
* us unable to handle the page fault gracefully.
*/
out_of_memory:
if (current->pid == 1) {
if (is_init(current)) {
panic("INIT out of memory\n");
yield();
goto survive;
}
printk("fault:Out of memory\n");
up_read(&mm->mmap_sem);
if (current->pid == 1) {
if (is_init(current)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
......
......@@ -120,7 +120,7 @@ int handle_page_fault(unsigned long address, unsigned long ip,
* us unable to handle the page fault gracefully.
*/
out_of_memory:
if (current->pid == 1) {
if (is_init(current)) {
up_read(&mm->mmap_sem);
yield();
down_read(&mm->mmap_sem);
......
......@@ -244,7 +244,7 @@ static int is_errata93(struct pt_regs *regs, unsigned long address)
int unhandled_signal(struct task_struct *tsk, int sig)
{
if (tsk->pid == 1)
if (is_init(tsk))
return 1;
if (tsk->ptrace & PT_PTRACED)
return 0;
......@@ -580,7 +580,7 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
*/
out_of_memory:
up_read(&mm->mmap_sem);
if (current->pid == 1) {
if (is_init(current)) {
yield();
goto again;
}
......
......@@ -144,7 +144,7 @@ void do_page_fault(struct pt_regs *regs)
*/
out_of_memory:
up_read(&mm->mmap_sem);
if (current->pid == 1) {
if (is_init(current)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
......
......@@ -208,7 +208,7 @@ static void send_sig_all(int sig)
struct task_struct *p;
for_each_process(p) {
if (p->mm && p->pid != 1)
if (p->mm && !is_init(p))
/* Not swapper, init nor kernel thread */
force_sig(sig, p);
}
......
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