Messages in this thread |  | | Subject | Re: [PATCH v2 19/21] treewide: add checks for the return value of memblock_alloc*() | From | Christophe Leroy <> | Date | Thu, 31 Jan 2019 07:44:14 +0100 |
| |
Le 31/01/2019 à 07:41, Mike Rapoport a écrit : > On Thu, Jan 31, 2019 at 07:07:46AM +0100, Christophe Leroy wrote: >> >> >> Le 21/01/2019 à 09:04, Mike Rapoport a écrit : >>> Add check for the return value of memblock_alloc*() functions and call >>> panic() in case of error. >>> The panic message repeats the one used by panicing memblock allocators with >>> adjustment of parameters to include only relevant ones. >>> >>> The replacement was mostly automated with semantic patches like the one >>> below with manual massaging of format strings. >>> >>> @@ >>> expression ptr, size, align; >>> @@ >>> ptr = memblock_alloc(size, align); >>> + if (!ptr) >>> + panic("%s: Failed to allocate %lu bytes align=0x%lx\n", __func__, >>> size, align); >>> >>> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> >>> Reviewed-by: Guo Ren <ren_guo@c-sky.com> # c-sky >>> Acked-by: Paul Burton <paul.burton@mips.com> # MIPS >>> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390 >>> Reviewed-by: Juergen Gross <jgross@suse.com> # Xen >>> --- >> >> [...] >> >>> diff --git a/mm/sparse.c b/mm/sparse.c >>> index 7ea5dc6..ad94242 100644 >>> --- a/mm/sparse.c >>> +++ b/mm/sparse.c >> >> [...] >> >>> @@ -425,6 +436,10 @@ static void __init sparse_buffer_init(unsigned long size, int nid) >>> memblock_alloc_try_nid_raw(size, PAGE_SIZE, >>> __pa(MAX_DMA_ADDRESS), >>> MEMBLOCK_ALLOC_ACCESSIBLE, nid); >>> + if (!sparsemap_buf) >>> + panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%lx\n", >>> + __func__, size, PAGE_SIZE, nid, __pa(MAX_DMA_ADDRESS)); >>> + >> >> memblock_alloc_try_nid_raw() does not panic (help explicitly says: Does not >> zero allocated memory, does not panic if request cannot be satisfied.). > > "Does not panic" does not mean it always succeeds.
I agree, but at least here you are changing the behaviour by making it panic explicitly. Are we sure there are not cases where the system could just continue functionning ? Maybe a WARN_ON() would be enough there ?
Christophe
> >> Stephen Rothwell reports a boot failure due to this change. > > Please see my reply on that thread. > >> Christophe >> >>> sparsemap_buf_end = sparsemap_buf + size; >>> } >>> >> >
|  |