github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-13 15:40:03 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

mm/sparse: panic on memmap and usemap allocation failure

Browse Source 
When vmemmap or usemap allocation fails, sparse_init_nid() currently marks
the section non-present and continues.  Later boot-time code can still
walk PFNs in that section without checking for this partial setup, which
leads to invalid accesses.  subsection_map_init() can also touch an
unallocated usemap.

Auditing and fixing all early PFN walkers for this case is not worth the
complexity.  These allocation failures are expected to be fatal anyway,
and other memory models already treat them that way.

Make memmap and usemap allocation failures panic immediately instead of
trying to recover and crashing later in less obvious ways.  This is also
consistent with how other memory model configurations handle memmap
allocation failures.

Link: https://lore.kernel.org/20260612035903.2468601-7-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Frank van der Linden <fvdl@google.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador (SUSE) <osalvador@kernel.org>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Muchun Song 2026-06-12 11:58:50 +08:00 committed by Andrew Morton
parent 9c29f83d88
commit b3ef855262
1 changed files with 9 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
mm/sparse.c
View File

@ -239,15 +239,8 @@ struct page __init *__populate_section_memmap(unsigned long pfn,
struct dev_pagemap *pgmap)
{
unsigned long size = section_map_size();
struct page *map;
phys_addr_t addr = __pa(MAX_DMA_ADDRESS);
map = memmap_alloc(size, size, addr, nid, false);
if (!map)
panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%pa\n",
__func__, size, PAGE_SIZE, nid, &addr);
return map;
return memmap_alloc(size, size, __pa(MAX_DMA_ADDRESS), nid, false);
}
#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
@ -300,17 +293,14 @@ static void __init sparse_init_nid(int nid, unsigned long pnum_begin,
unsigned long map_count)
{
unsigned long pnum;
struct page *map;
struct mem_section *ms;
if (sparse_usage_init(nid, map_count)) {
pr_err("%s: node[%d] usemap allocation failed", __func__, nid);
goto failed;
}
if (sparse_usage_init(nid, map_count))
panic("Failed to allocate usemap for node %d\n", nid);
sparse_vmemmap_init_nid_early(nid);
for_each_present_section_nr(pnum_begin, pnum) {
struct mem_section *ms;
unsigned long pfn = section_nr_to_pfn(pnum);
if (pnum >= pnum_end)
@ -318,34 +308,18 @@ static void __init sparse_init_nid(int nid, unsigned long pnum_begin,
ms = __nr_to_section(pnum);
if (!preinited_vmemmap_section(ms)) {
struct page *map;
map = __populate_section_memmap(pfn, PAGES_PER_SECTION,
nid, NULL, NULL);
if (!map) {
pr_err("%s: node[%d] memory map backing failed. Some memory will not be available.",
__func__, nid);
pnum_begin = pnum;
sparse_usage_fini();
goto failed;
}
nid, NULL, NULL);
if (!map)
panic("Failed to allocate memmap for section %lu\n", pnum);
memmap_boot_pages_add(DIV_ROUND_UP(PAGES_PER_SECTION * sizeof(struct page),
PAGE_SIZE));
sparse_init_early_section(nid, map, pnum, 0);
}
}
sparse_usage_fini();
return;
failed:
/*
* We failed to allocate, mark all the following pnums as not present,
* except the ones already initialized earlier.
*/
for_each_present_section_nr(pnum_begin, pnum) {
if (pnum >= pnum_end)
break;
ms = __nr_to_section(pnum);
if (!preinited_vmemmap_section(ms))
ms->section_mem_map = 0;
}
}
/*