The patch titled
Subject: mm/cma.c: fail if fixed declaration can't be honored
has been removed from the -mm tree. Its filename was
cma-fail-if-fixed-declaration-cant-be-honored.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Doug Berger <opendmb@xxxxxxxxx>
Subject: mm/cma.c: fail if fixed declaration can't be honored
The description of cma_declare_contiguous() indicates that if the 'fixed'
argument is true the reserved contiguous area must be exactly at the
address of the 'base' argument.
However, the function currently allows the 'base', 'size', and 'limit'
arguments to be silently adjusted to meet alignment constraints. This
commit enforces the documented behavior through explicit checks that
return an error if the region does not fit within a specified region.
Link: http://lkml.kernel.org/r/1561422051-16142-1-git-send-email-opendmb@xxxxxxxxx
Fixes: 5ea3b1b2f8ad ("cma: add placement specifier for "cma=" kernel parameter")
Signed-off-by: Doug Berger <opendmb@xxxxxxxxx>
Acked-by: Michal Nazarewicz <mina86@xxxxxxxxxx>
Cc: Yue Hu <huyue2@xxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Cc: Laura Abbott <labbott@xxxxxxxxxx>
Cc: Peng Fan <peng.fan@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/cma.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
--- a/mm/cma.c~cma-fail-if-fixed-declaration-cant-be-honored
+++ a/mm/cma.c
@@ -278,6 +278,12 @@ int __init cma_declare_contiguous(phys_a
*/
alignment = max(alignment, (phys_addr_t)PAGE_SIZE <<
max_t(unsigned long, MAX_ORDER - 1, pageblock_order));
+ if (fixed && base & (alignment - 1)) {
+ ret = -EINVAL;
+ pr_err("Region at %pa must be aligned to %pa bytes\n",
+ &base, &alignment);
+ goto err;
+ }
base = ALIGN(base, alignment);
size = ALIGN(size, alignment);
limit &= ~(alignment - 1);
@@ -308,6 +314,13 @@ int __init cma_declare_contiguous(phys_a
if (limit == 0 || limit > memblock_end)
limit = memblock_end;
+ if (base + size > limit) {
+ ret = -EINVAL;
+ pr_err("Size (%pa) of region at %pa exceeds limit (%pa)\n",
+ &size, &base, &limit);
+ goto err;
+ }
+
/* Reserve memory */
if (fixed) {
if (memblock_is_region_reserved(base, size) ||
_
Patches currently in -mm which might be from opendmb@xxxxxxxxx are
