Piteball/android_kernel_samsung_msm8976
1
1
Fork 0
mirror of https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git synced 2024-11-01 02:21:16 +00:00
Code Issues Projects Releases Wiki Activity

memblock: memblock should be able to handle zero length operations

Browse source 
Commit 24aa07882b ("memblock, x86: Replace memblock_x86_reserve/
free_range() with generic ones") replaced x86 specific memblock
operations with the generic ones; unfortunately, it lost zero length
operation handling in the process making the kernel panic if somebody
tries to reserve zero length area.

There isn't much to be gained by being cranky to zero length operations
and panicking is almost the worst response.  Drop the BUG_ON() in
memblock_reserve() and update memblock_add_region/isolate_range() so
that all zero length operations are handled as noops.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Reported-by: Valere Monseur <valere.monseur@ymail.com>
Bisected-by: Joseph Freeman <jfree143dev@gmail.com>
Tested-by: Joseph Freeman <jfree143dev@gmail.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43098
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Tejun Heo 2012-04-20 08:31:34 -07:00 committed by Linus Torvalds
parent 310eb77650
commit b3dc627cab
1 changed files with 6 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
mm/memblock.c
View file

@ -330,6 +330,9 @@ static int __init_memblock memblock_add_region(struct memblock_type *type,
phys_addr_t end = base + memblock_cap_size(base, &size); phys_addr_t end = base + memblock_cap_size(base, &size);
int i, nr_new; int i, nr_new;
if (!size)
return 0;
/* special case for empty array */ /* special case for empty array */
if (type->regions[0].size == 0) { if (type->regions[0].size == 0) {
WARN_ON(type->cnt != 1 || type->total_size); WARN_ON(type->cnt != 1 || type->total_size);
@ -430,6 +433,9 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type,
*start_rgn = *end_rgn = 0; *start_rgn = *end_rgn = 0;
if (!size)
return 0;
/* we'll create at most two more regions */ /* we'll create at most two more regions */
while (type->cnt + 2 > type->max) while (type->cnt + 2 > type->max)
if (memblock_double_array(type) < 0) if (memblock_double_array(type) < 0)
@ -514,7 +520,6 @@ int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size)
(unsigned long long)base, (unsigned long long)base,
(unsigned long long)base + size, (unsigned long long)base + size,
(void *)_RET_IP_); (void *)_RET_IP_);
BUG_ON(0 == size);
return memblock_add_region(_rgn, base, size, MAX_NUMNODES); return memblock_add_region(_rgn, base, size, MAX_NUMNODES);
} }