[PATCH] ofmem: restrict ofmem_claim() allocations to RAM size

[Mark Cave-Ayland]

As OFMEM memory ranges don't provide an explicit upper limit, we must manually
check that CIF claim calls lie within a valid maxmimum range if attempting to
allocate a specific address. Since the claim method provides a 1:1 mapping between
physical and virtual addresses, the valid maximum address is therefore equivalent
to the machine RAM size.

This fixes booting yaboot 1.3.17 which implements a top-down search using claim to
find the next free memory region to locate its heap. Without this fix we blindly
accept a claim for physical addresses far above the available RAM which fails
silently when we try to use the mapping later.

Signed-off-by: Mark Cave-Ayland 
---
 libopenbios/ofmem_common.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libopenbios/ofmem_common.c b/libopenbios/ofmem_common.c
index 217bd9b..fc19d27 100644
--- a/libopenbios/ofmem_common.c
+++ b/libopenbios/ofmem_common.c
@@ -623,7 +623,7 @@ ucell ofmem_claim( ucell addr, ucell size, ucell align )
    virt = phys = 0;
    if( !align ) {
    	if( is_free(addr, size, ofmem->virt_range) &&
-		    is_free(addr, size, ofmem->phys_range) ) {
+		    is_free(addr, size, ofmem->phys_range) && addr < get_ram_size() ) {
    		ofmem_claim_phys_( addr, size, 0, 0, 0, 0 );
    		ofmem_claim_virt_( addr, size, 0, 0, 0, 0 );
    		virt = phys = addr;

[Mark Cave-Ayland]

On 13/02/18 22:41, Mark Cave-Ayland wrote:
> As OFMEM memory ranges don't provide an explicit upper limit, we must manually
> check that CIF claim calls lie within a valid maxmimum range if attempting to
> allocate a specific address. Since the claim method provides a 1:1 mapping between
> physical and virtual addresses, the valid maximum address is therefore equivalent
> to the machine RAM size.
>
> This fixes booting yaboot 1.3.17 which implements a top-down search using claim to
> find the next free memory region to locate its heap. Without this fix we blindly
> accept a claim for physical addresses far above the available RAM which fails
> silently when we try to use the mapping later.
> Signed-off-by: Mark Cave-Ayland
>
> libopenbios/ofmem_common.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/libopenbios/ofmem_common.c b/libopenbios/ofmem_common.c
> index 217bd9b..fc19d27 100644
> --- a/libopenbios/ofmem_common.c
> +++ b/libopenbios/ofmem_common.c
> @@ -623,7 +623,7 @@ ucell ofmem_claim( ucell addr, ucell size, ucell align )
>    virt = phys = 0;
>    if( !align ) {
>    	if( is_free(addr, size, ofmem->virt_range) &&
>     is_free(addr, size, ofmem->phys_range) ) {
>     is_free(addr, size, ofmem->phys_range) && addr < get_ram_size() ) {
> ofmem_claim_phys_( addr, size, 0, 0, 0, 0 );
> ofmem_claim_virt_( addr, size, 0, 0, 0, 0 );
> virt = phys = addr;

Applied to master.

ATB,

Mark.