| Message ID | 20230624032607.921173-1-songshuaishuai@tinylab.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | memblock: report failures when memblock_can_resize is not set | expand |
On Sat, Jun 24, 2023 at 11:26:07AM +0800, Song Shuai wrote: > The callers of memblock_reserve() do not check the return value > presuming that memblock_reserve() always succeeds, but there are > cases where it may fail. > > Having numerous memblock reservations at early boot where > memblock_can_resize is unset may exhaust the INIT_MEMBLOCK_REGIONS sized > memblock.reserved regions array and an attempt to double this array via > memblock_double_array() will fail and will return -1 to the caller. > > When this happens the system crashes anyway, but it's hard to identify > the reason for the crash. > > Add a panic message to memblock_double_array() to aid debugging of the > cases when too many regions are reserved before memblock can resize > memblock.reserved array. > > Link: https://lore.kernel.org/linux-kernel/20230614131746.3670303-1-songshuaishuai@tinylab.org/ > Signed-off-by: Song Shuai <songshuaishuai@tinylab.org> This is queued now, it will appear in memblock/for-next after the merge window closes. Thanks! > --- > mm/memblock.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/memblock.c b/mm/memblock.c > index 3feafea06ab2..1b8e902490e5 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -419,7 +419,7 @@ static int __init_memblock memblock_double_array(struct memblock_type *type, > * of memory that aren't suitable for allocation > */ > if (!memblock_can_resize) > - return -1; > + panic("memblock: cannot resize %s array\n", type->name); > > /* Calculate new doubled size */ > old_size = type->max * sizeof(struct memblock_region); > -- > 2.20.1 > >
diff --git a/mm/memblock.c b/mm/memblock.c index 3feafea06ab2..1b8e902490e5 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -419,7 +419,7 @@ static int __init_memblock memblock_double_array(struct memblock_type *type, * of memory that aren't suitable for allocation */ if (!memblock_can_resize) - return -1; + panic("memblock: cannot resize %s array\n", type->name); /* Calculate new doubled size */ old_size = type->max * sizeof(struct memblock_region);
The callers of memblock_reserve() do not check the return value presuming that memblock_reserve() always succeeds, but there are cases where it may fail. Having numerous memblock reservations at early boot where memblock_can_resize is unset may exhaust the INIT_MEMBLOCK_REGIONS sized memblock.reserved regions array and an attempt to double this array via memblock_double_array() will fail and will return -1 to the caller. When this happens the system crashes anyway, but it's hard to identify the reason for the crash. Add a panic message to memblock_double_array() to aid debugging of the cases when too many regions are reserved before memblock can resize memblock.reserved array. Link: https://lore.kernel.org/linux-kernel/20230614131746.3670303-1-songshuaishuai@tinylab.org/ Signed-off-by: Song Shuai <songshuaishuai@tinylab.org> --- mm/memblock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)