[PATCH 1/2] mtdpart: Avoid divide-by-zero on out-of-reach path
Jörn Engel
joern at logfs.org
Wed Jun 18 13:52:53 EDT 2008
On Wed, 18 June 2008 19:40:34 +0200, Jörn Engel wrote:
> On Wed, 18 June 2008 11:19:07 +0900, Atsushi Nemoto wrote:
>
> > Putting 'goto somewhere' or 'slave->mtd.erasesize = master->erasesize'
> > in the above 'if' block can be an alternative fix.
>
> That seems a better idea.
I've had a quick go at it. Three cleanup patches first, then the goto.
Patches have been compile-tested, but not more. Would these work?
Jörn
--
I can say that I spend most of my time fixing bugs even if I have lots
of new features to implement in mind, but I give bugs more priority.
-- Andrea Arcangeli, 2000
[PATCH 1/4] [MTD][MTDPART] Seperate main loop from per-partition code in add_mtd_partition
add_mtd_partition was a 150+ line monster consisting mostly of a single
loop. Seperate the loop from most of the body. Now it should be
obvious which variables are carried around from iteration to iteration.
Signed-off-by: Joern Engel <joern at logfs.org>
---
drivers/mtd/mtdpart.c | 327 +++++++++++++++++++++++++------------------------
1 files changed, 168 insertions(+), 159 deletions(-)
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index 07c7011..f0d0430 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -322,184 +322,193 @@ int del_mtd_partitions(struct mtd_info *master)
return 0;
}
-/*
- * This function, given a master MTD object and a partition table, creates
- * and registers slave MTD objects which are bound to the master according to
- * the partition definitions.
- * (Q: should we register the master MTD object as well?)
- */
-
-int add_mtd_partitions(struct mtd_info *master,
- const struct mtd_partition *parts,
- int nbparts)
+static int add_one_partition(struct mtd_info *master,
+ const struct mtd_partition *part, int partno,
+ u_int32_t cur_offset)
{
struct mtd_part *slave;
- u_int32_t cur_offset = 0;
- int i;
-
- printk (KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
-
- for (i = 0; i < nbparts; i++) {
- /* allocate the partition structure */
- slave = kzalloc (sizeof(*slave), GFP_KERNEL);
- if (!slave) {
- printk ("memory allocation error while creating partitions for \"%s\"\n",
- master->name);
- del_mtd_partitions(master);
- return -ENOMEM;
- }
- list_add(&slave->list, &mtd_partitions);
+ /* allocate the partition structure */
+ slave = kzalloc (sizeof(*slave), GFP_KERNEL);
+ if (!slave) {
+ printk("memory allocation error while creating partitions for \"%s\"\n",
+ master->name);
+ del_mtd_partitions(master);
+ return -ENOMEM;
+ }
+ list_add(&slave->list, &mtd_partitions);
- /* set up the MTD object for this partition */
- slave->mtd.type = master->type;
- slave->mtd.flags = master->flags & ~parts[i].mask_flags;
- slave->mtd.size = parts[i].size;
- slave->mtd.writesize = master->writesize;
- slave->mtd.oobsize = master->oobsize;
- slave->mtd.oobavail = master->oobavail;
- slave->mtd.subpage_sft = master->subpage_sft;
+ /* set up the MTD object for this partition */
+ slave->mtd.type = master->type;
+ slave->mtd.flags = master->flags & ~part->mask_flags;
+ slave->mtd.size = part->size;
+ slave->mtd.writesize = master->writesize;
+ slave->mtd.oobsize = master->oobsize;
+ slave->mtd.oobavail = master->oobavail;
+ slave->mtd.subpage_sft = master->subpage_sft;
- slave->mtd.name = parts[i].name;
- slave->mtd.owner = master->owner;
+ slave->mtd.name = part->name;
+ slave->mtd.owner = master->owner;
- slave->mtd.read = part_read;
- slave->mtd.write = part_write;
+ slave->mtd.read = part_read;
+ slave->mtd.write = part_write;
- if (master->panic_write)
- slave->mtd.panic_write = part_panic_write;
+ if (master->panic_write)
+ slave->mtd.panic_write = part_panic_write;
- if(master->point && master->unpoint){
- slave->mtd.point = part_point;
- slave->mtd.unpoint = part_unpoint;
- }
+ if(master->point && master->unpoint){
+ slave->mtd.point = part_point;
+ slave->mtd.unpoint = part_unpoint;
+ }
- if (master->read_oob)
- slave->mtd.read_oob = part_read_oob;
- if (master->write_oob)
- slave->mtd.write_oob = part_write_oob;
- if(master->read_user_prot_reg)
- slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
- if(master->read_fact_prot_reg)
- slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
- if(master->write_user_prot_reg)
- slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
- if(master->lock_user_prot_reg)
- slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
- if(master->get_user_prot_info)
- slave->mtd.get_user_prot_info = part_get_user_prot_info;
- if(master->get_fact_prot_info)
- slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
- if (master->sync)
- slave->mtd.sync = part_sync;
- if (!i && master->suspend && master->resume) {
- slave->mtd.suspend = part_suspend;
- slave->mtd.resume = part_resume;
+ if (master->read_oob)
+ slave->mtd.read_oob = part_read_oob;
+ if (master->write_oob)
+ slave->mtd.write_oob = part_write_oob;
+ if(master->read_user_prot_reg)
+ slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
+ if(master->read_fact_prot_reg)
+ slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
+ if(master->write_user_prot_reg)
+ slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
+ if(master->lock_user_prot_reg)
+ slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
+ if(master->get_user_prot_info)
+ slave->mtd.get_user_prot_info = part_get_user_prot_info;
+ if(master->get_fact_prot_info)
+ slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
+ if (master->sync)
+ slave->mtd.sync = part_sync;
+ if (!partno && master->suspend && master->resume) {
+ slave->mtd.suspend = part_suspend;
+ slave->mtd.resume = part_resume;
+ }
+ if (master->writev)
+ slave->mtd.writev = part_writev;
+ if (master->lock)
+ slave->mtd.lock = part_lock;
+ if (master->unlock)
+ slave->mtd.unlock = part_unlock;
+ if (master->block_isbad)
+ slave->mtd.block_isbad = part_block_isbad;
+ if (master->block_markbad)
+ slave->mtd.block_markbad = part_block_markbad;
+ slave->mtd.erase = part_erase;
+ slave->master = master;
+ slave->offset = part->offset;
+ slave->index = partno;
+
+ if (slave->offset == MTDPART_OFS_APPEND)
+ slave->offset = cur_offset;
+ if (slave->offset == MTDPART_OFS_NXTBLK) {
+ slave->offset = cur_offset;
+ if ((cur_offset % master->erasesize) != 0) {
+ /* Round up to next erasesize */
+ slave->offset = ((cur_offset / master->erasesize) + 1) * master->erasesize;
+ printk(KERN_NOTICE "Moving partition %d: "
+ "0x%08x -> 0x%08x\n", partno,
+ cur_offset, slave->offset);
}
- if (master->writev)
- slave->mtd.writev = part_writev;
- if (master->lock)
- slave->mtd.lock = part_lock;
- if (master->unlock)
- slave->mtd.unlock = part_unlock;
- if (master->block_isbad)
- slave->mtd.block_isbad = part_block_isbad;
- if (master->block_markbad)
- slave->mtd.block_markbad = part_block_markbad;
- slave->mtd.erase = part_erase;
- slave->master = master;
- slave->offset = parts[i].offset;
- slave->index = i;
-
- if (slave->offset == MTDPART_OFS_APPEND)
- slave->offset = cur_offset;
- if (slave->offset == MTDPART_OFS_NXTBLK) {
- slave->offset = cur_offset;
- if ((cur_offset % master->erasesize) != 0) {
- /* Round up to next erasesize */
- slave->offset = ((cur_offset / master->erasesize) + 1) * master->erasesize;
- printk(KERN_NOTICE "Moving partition %d: "
- "0x%08x -> 0x%08x\n", i,
- cur_offset, slave->offset);
+ }
+ if (slave->mtd.size == MTDPART_SIZ_FULL)
+ slave->mtd.size = master->size - slave->offset;
+
+ printk (KERN_NOTICE "0x%08x-0x%08x : \"%s\"\n", slave->offset,
+ slave->offset + slave->mtd.size, slave->mtd.name);
+
+ /* let's do some sanity checks */
+ if (slave->offset >= master->size) {
+ /* let's register it anyway to preserve ordering */
+ slave->offset = 0;
+ slave->mtd.size = 0;
+ printk ("mtd: partition \"%s\" is out of reach -- disabled\n",
+ part->name);
+ }
+ if (slave->offset + slave->mtd.size > master->size) {
+ slave->mtd.size = master->size - slave->offset;
+ printk ("mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#x\n",
+ part->name, master->name, slave->mtd.size);
+ }
+ if (master->numeraseregions>1) {
+ /* Deal with variable erase size stuff */
+ int i;
+ struct mtd_erase_region_info *regions = master->eraseregions;
+
+ /* Find the first erase regions which is part of this partition. */
+ for (i=0; i < master->numeraseregions && regions[i].offset <= slave->offset; i++)
+ ;
+
+ for (i--; i < master->numeraseregions && regions[i].offset < slave->offset + slave->mtd.size; i++) {
+ if (slave->mtd.erasesize < regions[i].erasesize) {
+ slave->mtd.erasesize = regions[i].erasesize;
}
}
- if (slave->mtd.size == MTDPART_SIZ_FULL)
- slave->mtd.size = master->size - slave->offset;
- cur_offset = slave->offset + slave->mtd.size;
+ } else {
+ /* Single erase size */
+ slave->mtd.erasesize = master->erasesize;
+ }
- printk (KERN_NOTICE "0x%08x-0x%08x : \"%s\"\n", slave->offset,
- slave->offset + slave->mtd.size, slave->mtd.name);
+ if ((slave->mtd.flags & MTD_WRITEABLE) &&
+ (slave->offset % slave->mtd.erasesize)) {
+ /* Doesn't start on a boundary of major erase size */
+ /* FIXME: Let it be writable if it is on a boundary of _minor_ erase size though */
+ slave->mtd.flags &= ~MTD_WRITEABLE;
+ printk ("mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
+ part->name);
+ }
+ if ((slave->mtd.flags & MTD_WRITEABLE) &&
+ (slave->mtd.size % slave->mtd.erasesize)) {
+ slave->mtd.flags &= ~MTD_WRITEABLE;
+ printk ("mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
+ part->name);
+ }
- /* let's do some sanity checks */
- if (slave->offset >= master->size) {
- /* let's register it anyway to preserve ordering */
- slave->offset = 0;
- slave->mtd.size = 0;
- printk ("mtd: partition \"%s\" is out of reach -- disabled\n",
- parts[i].name);
- }
- if (slave->offset + slave->mtd.size > master->size) {
- slave->mtd.size = master->size - slave->offset;
- printk ("mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#x\n",
- parts[i].name, master->name, slave->mtd.size);
- }
- if (master->numeraseregions>1) {
- /* Deal with variable erase size stuff */
- int i;
- struct mtd_erase_region_info *regions = master->eraseregions;
-
- /* Find the first erase regions which is part of this partition. */
- for (i=0; i < master->numeraseregions && slave->offset >= regions[i].offset; i++)
- ;
-
- for (i--; i < master->numeraseregions && slave->offset + slave->mtd.size > regions[i].offset; i++) {
- if (slave->mtd.erasesize < regions[i].erasesize) {
- slave->mtd.erasesize = regions[i].erasesize;
- }
- }
- } else {
- /* Single erase size */
- slave->mtd.erasesize = master->erasesize;
- }
+ slave->mtd.ecclayout = master->ecclayout;
+ if (master->block_isbad) {
+ uint32_t offs = 0;
- if ((slave->mtd.flags & MTD_WRITEABLE) &&
- (slave->offset % slave->mtd.erasesize)) {
- /* Doesn't start on a boundary of major erase size */
- /* FIXME: Let it be writable if it is on a boundary of _minor_ erase size though */
- slave->mtd.flags &= ~MTD_WRITEABLE;
- printk ("mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
- parts[i].name);
- }
- if ((slave->mtd.flags & MTD_WRITEABLE) &&
- (slave->mtd.size % slave->mtd.erasesize)) {
- slave->mtd.flags &= ~MTD_WRITEABLE;
- printk ("mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
- parts[i].name);
+ while(offs < slave->mtd.size) {
+ if (master->block_isbad(master,
+ offs + slave->offset))
+ slave->mtd.ecc_stats.badblocks++;
+ offs += slave->mtd.erasesize;
}
+ }
- slave->mtd.ecclayout = master->ecclayout;
- if (master->block_isbad) {
- uint32_t offs = 0;
+ if(part->mtdp) { /* store the object pointer (caller may or may not register it */
+ *part->mtdp = &slave->mtd;
+ slave->registered = 0;
+ } else {
+ /* register our partition */
+ add_mtd_device(&slave->mtd);
+ slave->registered = 1;
+ }
+ return 0;
+}
- while(offs < slave->mtd.size) {
- if (master->block_isbad(master,
- offs + slave->offset))
- slave->mtd.ecc_stats.badblocks++;
- offs += slave->mtd.erasesize;
- }
- }
+/*
+ * This function, given a master MTD object and a partition table, creates
+ * and registers slave MTD objects which are bound to the master according to
+ * the partition definitions.
+ * (Q: should we register the master MTD object as well?)
+ */
- if(parts[i].mtdp)
- { /* store the object pointer (caller may or may not register it */
- *parts[i].mtdp = &slave->mtd;
- slave->registered = 0;
- }
- else
- {
- /* register our partition */
- add_mtd_device(&slave->mtd);
- slave->registered = 1;
- }
+int add_mtd_partitions(struct mtd_info *master,
+ const struct mtd_partition *parts,
+ int nbparts)
+{
+ struct mtd_part *slave;
+ u_int32_t cur_offset = 0;
+ int i, err;
+
+ printk (KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
+
+ for (i = 0; i < nbparts; i++) {
+ err = add_one_partition(master, parts + i, i, cur_offset);
+ if (err)
+ return err;
+ slave = PART(parts[i].mtdp);
+ cur_offset = slave->offset + slave->mtd.size;
}
return 0;
--
1.5.3.5
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