From: Vincent Whitchurch vincent.whitchurch@axis.com
[ Upstream commit ca05f33316559a04867295dd49f85aeedbfd6bfd ]
The reserved-memory overlap detection code fails to detect overlaps if either of the regions starts at address 0x0. The code explicitly checks for and ignores such regions, apparently in order to ignore dynamically allocated regions which have an address of 0x0 at this point. These dynamically allocated regions also have a size of 0x0 at this point, so fix this by removing the check and sorting the dynamically allocated regions ahead of any static regions at address 0x0.
For example, there are two overlaps in this case but they are not currently reported:
foo@0 { reg = <0x0 0x2000>; };
bar@0 { reg = <0x0 0x1000>; };
baz@1000 { reg = <0x1000 0x1000>; };
quux { size = <0x1000>; };
but they are after this patch:
OF: reserved mem: OVERLAP DETECTED! bar@0 (0x00000000--0x00001000) overlaps with foo@0 (0x00000000--0x00002000) OF: reserved mem: OVERLAP DETECTED! foo@0 (0x00000000--0x00002000) overlaps with baz@1000 (0x00001000--0x00002000)
Signed-off-by: Vincent Whitchurch vincent.whitchurch@axis.com Link: https://lore.kernel.org/r/ded6fd6b47b58741aabdcc6967f73eca6a3f311e.160327366... Signed-off-by: Rob Herring robh@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/of/of_reserved_mem.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c index 6bd610ee2cd73..3fb5d8caffd53 100644 --- a/drivers/of/of_reserved_mem.c +++ b/drivers/of/of_reserved_mem.c @@ -200,6 +200,16 @@ static int __init __rmem_cmp(const void *a, const void *b) if (ra->base > rb->base) return 1;
+ /* + * Put the dynamic allocations (address == 0, size == 0) before static + * allocations at address 0x0 so that overlap detection works + * correctly. + */ + if (ra->size < rb->size) + return -1; + if (ra->size > rb->size) + return 1; + return 0; }
@@ -217,8 +227,7 @@ static void __init __rmem_check_for_overlap(void)
this = &reserved_mem[i]; next = &reserved_mem[i + 1]; - if (!(this->base && next->base)) - continue; + if (this->base + this->size > next->base) { phys_addr_t this_end, next_end;