Return to unwind.c CVS log

Up to [Development] / linux-2.6-xfs / arch / parisc / kernel

Update 2.6.x-xfs to 2.6.23-rc4.

Also update fs/xfs with external mainline changes.
There were 12 such missing commits that I detected:

--------
commit ad690ef9e690f6c31f7d310b09ef1314bcec9033
Author: Al Viro <viro@ftp.linux.org.uk>
    xfs ioctl __user annotations

commit 20c2df83d25c6a95affe6157a4c9cac4cf5ffaac
Author: Paul Mundt <lethal@linux-sh.org>
    mm: Remove slab destructors from kmem_cache_create().

commit d0217ac04ca6591841e5665f518e38064f4e65bd
Author: Nick Piggin <npiggin@suse.de>
    mm: fault feedback #1

commit 54cb8821de07f2ffcd28c380ce9b93d5784b40d7
Author: Nick Piggin <npiggin@suse.de>
    mm: merge populate and nopage into fault (fixes nonlinear)

commit d00806b183152af6d24f46f0c33f14162ca1262a
Author: Nick Piggin <npiggin@suse.de>
    mm: fix fault vs invalidate race for linear mappings

commit a569425512253992cc64ebf8b6d00a62f986db3e
Author: Christoph Hellwig <hch@infradead.org>
    knfsd: exportfs: add exportfs.h header

commit 831441862956fffa17b9801db37e6ea1650b0f69
Author: Rafael J. Wysocki <rjw@sisk.pl>
    Freezer: make kernel threads nonfreezable by default

commit 8e1f936b73150f5095448a0fee6d4f30a1f9001d
Author: Rusty Russell <rusty@rustcorp.com.au>
    mm: clean up and kernelify shrinker registration

commit 5ffc4ef45b3b0a57872f631b4e4ceb8ace0d7496
Author: Jens Axboe <jens.axboe@oracle.com>
    sendfile: remove .sendfile from filesystems that use generic_file_sendfile()

commit 8bb7844286fb8c9fce6f65d8288aeb09d03a5e0d
Author: Rafael J. Wysocki <rjw@sisk.pl>
    Add suspend-related notifications for CPU hotplug

commit 59c51591a0ac7568824f541f57de967e88adaa07
Author: Michael Opdenacker <michael@free-electrons.com>
    Fix occurrences of "the the "

commit 0ceb331433e8aad9c5f441a965d7c681f8b9046f
Author: Dmitriy Monakhov <dmonakhov@openvz.org>
    mm: move common segment checks to separate helper function
--------
Merge of 2.6.x-xfs-melb:linux:29656b by kenmcd.

/*
 * Kernel unwinding support
 *
 * (c) 2002-2004 Randolph Chung <tausq@debian.org>
 *
 * Derived partially from the IA64 implementation. The PA-RISC
 * Runtime Architecture Document is also a useful reference to
 * understand what is happening here
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/kallsyms.h>

#include <asm/uaccess.h>
#include <asm/assembly.h>
#include <asm/asm-offsets.h>
#include <asm/ptrace.h>

#include <asm/unwind.h>

/* #define DEBUG 1 */
#ifdef DEBUG
#define dbg(x...) printk(x)
#else
#define dbg(x...)
#endif

#define KERNEL_START (KERNEL_BINARY_TEXT_START - 0x1000)

extern struct unwind_table_entry __start___unwind[];
extern struct unwind_table_entry __stop___unwind[];

static spinlock_t unwind_lock;
/*
 * the kernel unwind block is not dynamically allocated so that
 * we can call unwind_init as early in the bootup process as 
 * possible (before the slab allocator is initialized)
 */
static struct unwind_table kernel_unwind_table __read_mostly;
static LIST_HEAD(unwind_tables);

static inline const struct unwind_table_entry *
find_unwind_entry_in_table(const struct unwind_table *table, unsigned long addr)
{
	const struct unwind_table_entry *e = NULL;
	unsigned long lo, hi, mid;

	lo = 0; 
	hi = table->length - 1; 
	
	while (lo <= hi) {
		mid = (hi - lo) / 2 + lo;
		e = &table->table[mid];
		if (addr < e->region_start)
			hi = mid - 1;
		else if (addr > e->region_end)
			lo = mid + 1;
		else
			return e;
	}

	return NULL;
}

static const struct unwind_table_entry *
find_unwind_entry(unsigned long addr)
{
	struct unwind_table *table;
	const struct unwind_table_entry *e = NULL;

	if (addr >= kernel_unwind_table.start && 
	    addr <= kernel_unwind_table.end)
		e = find_unwind_entry_in_table(&kernel_unwind_table, addr);
	else 
		list_for_each_entry(table, &unwind_tables, list) {
			if (addr >= table->start && 
			    addr <= table->end)
				e = find_unwind_entry_in_table(table, addr);
			if (e)
				break;
		}

	return e;
}

static void
unwind_table_init(struct unwind_table *table, const char *name,
		  unsigned long base_addr, unsigned long gp,
		  void *table_start, void *table_end)
{
	struct unwind_table_entry *start = table_start;
	struct unwind_table_entry *end = 
		(struct unwind_table_entry *)table_end - 1;

	table->name = name;
	table->base_addr = base_addr;
	table->gp = gp;
	table->start = base_addr + start->region_start;
	table->end = base_addr + end->region_end;
	table->table = (struct unwind_table_entry *)table_start;
	table->length = end - start + 1;
	INIT_LIST_HEAD(&table->list);

	for (; start <= end; start++) {
		if (start < end && 
		    start->region_end > (start+1)->region_start) {
			printk("WARNING: Out of order unwind entry! %p and %p\n", start, start+1);
		}

		start->region_start += base_addr;
		start->region_end += base_addr;
	}
}

static void
unwind_table_sort(struct unwind_table_entry *start,
		  struct unwind_table_entry *finish)
{
	struct unwind_table_entry el, *p, *q;

	for (p = start + 1; p < finish; ++p) {
		if (p[0].region_start < p[-1].region_start) {
			el = *p;
			q = p;
			do {
				q[0] = q[-1];
				--q;
			} while (q > start && 
				 el.region_start < q[-1].region_start);
			*q = el;
		}
	}
}

struct unwind_table *
unwind_table_add(const char *name, unsigned long base_addr, 
		 unsigned long gp,
                 void *start, void *end)
{
	struct unwind_table *table;
	unsigned long flags;
	struct unwind_table_entry *s = (struct unwind_table_entry *)start;
	struct unwind_table_entry *e = (struct unwind_table_entry *)end;

	unwind_table_sort(s, e);

	table = kmalloc(sizeof(struct unwind_table), GFP_USER);
	if (table == NULL)
		return NULL;
	unwind_table_init(table, name, base_addr, gp, start, end);
	spin_lock_irqsave(&unwind_lock, flags);
	list_add_tail(&table->list, &unwind_tables);
	spin_unlock_irqrestore(&unwind_lock, flags);

	return table;
}

void unwind_table_remove(struct unwind_table *table)
{
	unsigned long flags;

	spin_lock_irqsave(&unwind_lock, flags);
	list_del(&table->list);
	spin_unlock_irqrestore(&unwind_lock, flags);

	kfree(table);
}

/* Called from setup_arch to import the kernel unwind info */
static int unwind_init(void)
{
	long start, stop;
	register unsigned long gp __asm__ ("r27");

	start = (long)&__start___unwind[0];
	stop = (long)&__stop___unwind[0];

	spin_lock_init(&unwind_lock);

	printk("unwind_init: start = 0x%lx, end = 0x%lx, entries = %lu\n", 
	    start, stop,
	    (stop - start) / sizeof(struct unwind_table_entry));

	unwind_table_init(&kernel_unwind_table, "kernel", KERNEL_START,
			  gp, 
			  &__start___unwind[0], &__stop___unwind[0]);
#if 0
	{
		int i;
		for (i = 0; i < 10; i++)
		{
			printk("region 0x%x-0x%x\n", 
				__start___unwind[i].region_start, 
				__start___unwind[i].region_end);
		}
	}
#endif
	return 0;
}

#ifdef CONFIG_64BIT
#define get_func_addr(fptr) fptr[2]
#else
#define get_func_addr(fptr) fptr[0]
#endif

static int unwind_special(struct unwind_frame_info *info, unsigned long pc, int frame_size)
{
	void handle_interruption(int, struct pt_regs *);
	static unsigned long *hi = (unsigned long)&handle_interruption;

	if (pc == get_func_addr(hi)) {
		struct pt_regs *regs = (struct pt_regs *)(info->sp - frame_size - PT_SZ_ALGN);
		dbg("Unwinding through handle_interruption()\n");
		info->prev_sp = regs->gr[30];
		info->prev_ip = regs->iaoq[0];

		return 1;
	}

	return 0;
}

static void unwind_frame_regs(struct unwind_frame_info *info)
{
	const struct unwind_table_entry *e;
	unsigned long npc;
	unsigned int insn;
	long frame_size = 0;
	int looking_for_rp, rpoffset = 0;

	e = find_unwind_entry(info->ip);
	if (e == NULL) {
		unsigned long sp;
		extern char _stext[], _etext[];

		dbg("Cannot find unwind entry for 0x%lx; forced unwinding\n", info->ip);

#ifdef CONFIG_KALLSYMS
		/* Handle some frequent special cases.... */
		{
			char symname[KSYM_NAME_LEN];
			char *modname;

			kallsyms_lookup(info->ip, NULL, NULL, &modname,
				symname);

			dbg("info->ip = 0x%lx, name = %s\n", info->ip, symname);

			if (strcmp(symname, "_switch_to_ret") == 0) {
				info->prev_sp = info->sp - CALLEE_SAVE_FRAME_SIZE;
				info->prev_ip = *(unsigned long *)(info->prev_sp - RP_OFFSET);
				dbg("_switch_to_ret @ %lx - setting "
				    "prev_sp=%lx prev_ip=%lx\n", 
				    info->ip, info->prev_sp, 
				    info->prev_ip);
				return;
			} else if (strcmp(symname, "ret_from_kernel_thread") == 0 ||
				   strcmp(symname, "syscall_exit") == 0) {
				info->prev_ip = info->prev_sp = 0;
				return;
			}
		}
#endif

		/* Since we are doing the unwinding blind, we don't know if
		   we are adjusting the stack correctly or extracting the rp
		   correctly. The rp is checked to see if it belongs to the
		   kernel text section, if not we assume we don't have a 
		   correct stack frame and we continue to unwind the stack.
		   This is not quite correct, and will fail for loadable
		   modules. */
		sp = info->sp & ~63;
		do {
			unsigned long tmp;

			info->prev_sp = sp - 64;
			info->prev_ip = 0;
			if (get_user(tmp, (unsigned long *)(info->prev_sp - RP_OFFSET))) 
				break;
			info->prev_ip = tmp;
			sp = info->prev_sp;
		} while (info->prev_ip < (unsigned long)_stext ||
			 info->prev_ip > (unsigned long)_etext);

		info->rp = 0;

		dbg("analyzing func @ %lx with no unwind info, setting "
		    "prev_sp=%lx prev_ip=%lx\n", info->ip, 
		    info->prev_sp, info->prev_ip);
	} else {
		dbg("e->start = 0x%x, e->end = 0x%x, Save_SP = %d, "
		    "Save_RP = %d, Millicode = %d size = %u\n", 
		    e->region_start, e->region_end, e->Save_SP, e->Save_RP, 
		    e->Millicode, e->Total_frame_size);

		looking_for_rp = e->Save_RP;

		for (npc = e->region_start; 
		     (frame_size < (e->Total_frame_size << 3) || 
		      looking_for_rp) && 
		     npc < info->ip; 
		     npc += 4) {

			insn = *(unsigned int *)npc;

			if ((insn & 0xffffc000) == 0x37de0000 ||
			    (insn & 0xffe00000) == 0x6fc00000) {
				/* ldo X(sp), sp, or stwm X,D(sp) */
				frame_size += (insn & 0x1 ? -1 << 13 : 0) | 
					((insn & 0x3fff) >> 1);
				dbg("analyzing func @ %lx, insn=%08x @ "
				    "%lx, frame_size = %ld\n", info->ip,
				    insn, npc, frame_size);
			} else if ((insn & 0xffe00008) == 0x73c00008) {
				/* std,ma X,D(sp) */
				frame_size += (insn & 0x1 ? -1 << 13 : 0) | 
					(((insn >> 4) & 0x3ff) << 3);
				dbg("analyzing func @ %lx, insn=%08x @ "
				    "%lx, frame_size = %ld\n", info->ip,
				    insn, npc, frame_size);
			} else if (insn == 0x6bc23fd9) { 
				/* stw rp,-20(sp) */
				rpoffset = 20;
				looking_for_rp = 0;
				dbg("analyzing func @ %lx, insn=stw rp,"
				    "-20(sp) @ %lx\n", info->ip, npc);
			} else if (insn == 0x0fc212c1) {
				/* std rp,-16(sr0,sp) */
				rpoffset = 16;
				looking_for_rp = 0;
				dbg("analyzing func @ %lx, insn=std rp,"
				    "-16(sp) @ %lx\n", info->ip, npc);
			}
		}

		if (!unwind_special(info, e->region_start, frame_size)) {
			info->prev_sp = info->sp - frame_size;
			if (e->Millicode)
				info->rp = info->r31;
			else if (rpoffset)
				info->rp = *(unsigned long *)(info->prev_sp - rpoffset);
			info->prev_ip = info->rp;
			info->rp = 0;
		}

		dbg("analyzing func @ %lx, setting prev_sp=%lx "
		    "prev_ip=%lx npc=%lx\n", info->ip, info->prev_sp, 
		    info->prev_ip, npc);
	}
}

void unwind_frame_init(struct unwind_frame_info *info, struct task_struct *t, 
		       struct pt_regs *regs)
{
	memset(info, 0, sizeof(struct unwind_frame_info));
	info->t = t;
	info->sp = regs->gr[30];
	info->ip = regs->iaoq[0];
	info->rp = regs->gr[2];
	info->r31 = regs->gr[31];

	dbg("(%d) Start unwind from sp=%08lx ip=%08lx\n", 
	    t ? (int)t->pid : -1, info->sp, info->ip);
}

void unwind_frame_init_from_blocked_task(struct unwind_frame_info *info, struct task_struct *t)
{
	struct pt_regs *r = &t->thread.regs;
	struct pt_regs *r2;

	r2 = kmalloc(sizeof(struct pt_regs), GFP_KERNEL);
	if (!r2)
		return;
	*r2 = *r;
	r2->gr[30] = r->ksp;
	r2->iaoq[0] = r->kpc;
	unwind_frame_init(info, t, r2);
	kfree(r2);
}

void unwind_frame_init_running(struct unwind_frame_info *info, struct pt_regs *regs)
{
	unwind_frame_init(info, current, regs);
}

int unwind_once(struct unwind_frame_info *next_frame)
{
	unwind_frame_regs(next_frame);

	if (next_frame->prev_sp == 0 ||
	    next_frame->prev_ip == 0)
		return -1;

	next_frame->sp = next_frame->prev_sp;
	next_frame->ip = next_frame->prev_ip;
	next_frame->prev_sp = 0;
	next_frame->prev_ip = 0;

	dbg("(%d) Continue unwind to sp=%08lx ip=%08lx\n", 
	    next_frame->t ? (int)next_frame->t->pid : -1, 
	    next_frame->sp, next_frame->ip);

	return 0;
}

int unwind_to_user(struct unwind_frame_info *info)
{
	int ret;
	
	do {
		ret = unwind_once(info);
	} while (!ret && !(info->ip & 3));

	return ret;
}

module_init(unwind_init);