On Wed, May 25, 2016 at 01:30:44PM +0530, Pratyush Anand wrote:
> On Tue, May 3, 2016 at 3:52 PM, Russell King <rmk at arm.linux.org.uk> wrote:
> > +int mem_regions_exclude(struct memory_ranges *ranges,
> > + const struct memory_range *range)
> > +{
> > + int i;
> > +
> > + for (i = 0; i < ranges->size; i++) {
> > + struct memory_range *r = ranges->ranges + i;
> > +
> > + /*
> > + * We assume that crash area is fully contained in
> > + * some larger memory area.
> > + */
> > + if (r->start <= range->start && r->end >= range->end) {
> > + if (r->start == range->start) {
> > + /* Shrink the start of this memory range */
> > + r->start = range->end + 1;
> > + } else if (r->end == range->end) {
> > + /* Shrink the end of this memory range */
> > + r->end = range->start - 1;
>
> What if r->start == range->start) && (r->end == range->end)?
I suppose that could happen, so what about this patch on top (untested).
This isn't something I'd be able to test on real hardware, it needs a
separate test-suite to be written to do modular testing...
kexec/mem_regions.c | 94 +++++++++++++++++++++++++++++++----------------------
1 file changed, 55 insertions(+), 39 deletions(-)
diff --git a/kexec/mem_regions.c b/kexec/mem_regions.c
index c6ba942..4e7061b 100644
--- a/kexec/mem_regions.c
+++ b/kexec/mem_regions.c
@@ -29,6 +29,50 @@ void mem_regions_sort(struct memory_ranges *ranges)
}
/**
+ * mem_regions_add() - add a memory region to a set of ranges
+ * @ranges: ranges to add the memory region to
+ * @max: maximum number of entries in memory region
+ * @base: base address of memory region
+ * @length: length of memory region in bytes
+ * @type: type of memory region
+ *
+ * Add the memory region to the set of ranges, and return %0 if successful,
+ * or %-1 if we ran out of space.
+ */
+int mem_regions_add(struct memory_ranges *ranges, unsigned long long base,
+ unsigned long long length, int type)
+{
+ struct memory_range *range;
+
+ if (ranges->size >= ranges->max_size)
+ return -1;
+
+ range = ranges->ranges + ranges->size++;
+ range->start = base;
+ range->end = base + length - 1;
+ range->type = type;
+
+ return 0;
+}
+
+static void mem_regions_remove(struct memory_ranges *ranges, int index)
+{
+ int tail_entries;
+
+ /* we are assured to have at least one entry */
+ ranges->size -= 1;
+
+ /* if we have following entries, shuffle them down one place */
+ tail_entries = ranges->size - index;
+ if (tail_entries)
+ memmove(ranges->ranges + index, ranges->ranges + index + 1,
+ tail_entries * sizeof(*ranges->ranges));
+
+ /* zero the new tail entry */
+ memset(ranges->ranges + ranges->size, 0, sizeof(*ranges->ranges));
+}
+
+/**
* mem_regions_exclude() - excludes a memory region from a set of memory ranges
* @ranges: memory ranges to exclude the region from
* @range: memory range to exclude
@@ -40,7 +84,7 @@ void mem_regions_sort(struct memory_ranges *ranges)
int mem_regions_exclude(struct memory_ranges *ranges,
const struct memory_range *range)
{
- int i;
+ int i, ret;
for (i = 0; i < ranges->size; i++) {
struct memory_range *r = ranges->ranges + i;
@@ -51,25 +95,25 @@ int mem_regions_exclude(struct memory_ranges *ranges,
*/
if (r->start <= range->start && r->end >= range->end) {
if (r->start == range->start) {
- /* Shrink the start of this memory range */
- r->start = range->end + 1;
+ if (r->end == range->end)
+ /* Remove this entry */
+ mem_regions_remove(ranges, i);
+ else
+ /* Shrink the start of this memory range */
+ r->start = range->end + 1;
} else if (r->end == range->end) {
/* Shrink the end of this memory range */
r->end = range->start - 1;
} else {
- struct memory_range *new;
-
/*
* Split this area into 2 smaller ones and
* remove excluded range from between. First
* create new entry for the remaining area.
*/
- if (ranges->size >= ranges->max_size)
- return -1;
-
- new = ranges->ranges + ranges->size++;
- new->start = range->end + 1;
- new->end = r->end;
+ ret = mem_regions_add(ranges, range->end + 1,
+ r->end, 0);
+ if (ret < 0)
+ return ret;
/*
* Update this area to end before excluded
@@ -82,31 +126,3 @@ int mem_regions_exclude(struct memory_ranges *ranges,
}
return 0;
}
-
-/**
- * mem_regions_add() - add a memory region to a set of ranges
- * @ranges: ranges to add the memory region to
- * @max: maximum number of entries in memory region
- * @base: base address of memory region
- * @length: length of memory region in bytes
- * @type: type of memory region
- *
- * Add the memory region to the set of ranges, and return %0 if successful,
- * or %-1 if we ran out of space.
- */
-int mem_regions_add(struct memory_ranges *ranges, unsigned long long base,
- unsigned long long length, int type)
-{
- struct memory_range *range;
-
- if (ranges->size >= ranges->max_size)
- return -1;
-
- range = ranges->ranges + ranges->size++;
- range->start = base;
- range->end = base + length - 1;
- range->type = type;
-
- return 0;
-}
-
--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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