Commit ca05f333 authored by Vincent Whitchurch's avatar Vincent Whitchurch Committed by Rob Herring

of: Fix reserved-memory overlap detection

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: default avatarVincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/ded6fd6b47b58741aabdcc6967f73eca6a3f311e.1603273666.git-series.vincent.whitchurch@axis.comSigned-off-by: default avatarRob Herring <robh@kernel.org>
parent f83b03fc
...@@ -200,6 +200,16 @@ static int __init __rmem_cmp(const void *a, const void *b) ...@@ -200,6 +200,16 @@ static int __init __rmem_cmp(const void *a, const void *b)
if (ra->base > rb->base) if (ra->base > rb->base)
return 1; 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; return 0;
} }
...@@ -217,8 +227,7 @@ static void __init __rmem_check_for_overlap(void) ...@@ -217,8 +227,7 @@ static void __init __rmem_check_for_overlap(void)
this = &reserved_mem[i]; this = &reserved_mem[i];
next = &reserved_mem[i + 1]; next = &reserved_mem[i + 1];
if (!(this->base && next->base))
continue;
if (this->base + this->size > next->base) { if (this->base + this->size > next->base) {
phys_addr_t this_end, next_end; phys_addr_t this_end, next_end;
......
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