From: "Alastair D'Silva" <alastair@au1.ibm.com>
To: alastair@d-silva.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@redhat.com>,
Oscar Salvador <osalvador@suse.com>,
Michal Hocko <mhocko@suse.com>,
Pavel Tatashin <pasha.tatashin@soleen.com>,
Wei Yang <richard.weiyang@gmail.com>, Qian Cai <cai@lca.pw>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Jiri Kosina <jkosina@suse.cz>, Mukesh Ojha <mojha@codeaurora.org>,
Arun KS <arunks@codeaurora.org>,
Mike Rapoport <rppt@linux.vnet.ibm.com>,
Baoquan He <bhe@redhat.com>,
Logan Gunthorpe <logang@deltatee.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [PATCH 1/5] mm: Trigger bug on if a section is not found in __section_nr
Date: Mon, 17 Jun 2019 14:36:27 +1000 [thread overview]
Message-ID: <20190617043635.13201-2-alastair@au1.ibm.com> (raw)
In-Reply-To: <20190617043635.13201-1-alastair@au1.ibm.com>
From: Alastair D'Silva <alastair@d-silva.org>
If a memory section comes in where the physical address is greater than
that which is managed by the kernel, this function would not trigger the
bug and instead return a bogus section number.
This patch tracks whether the section was actually found, and triggers the
bug if not.
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
---
mm/sparse.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/mm/sparse.c b/mm/sparse.c
index fd13166949b5..104a79fedd00 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -105,20 +105,23 @@ static inline int sparse_index_init(unsigned long section_nr, int nid)
int __section_nr(struct mem_section* ms)
{
unsigned long root_nr;
- struct mem_section *root = NULL;
+ struct mem_section *found = NULL;
+ struct mem_section *root;
for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
if (!root)
continue;
- if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
- break;
+ if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT))) {
+ found = root;
+ break;
+ }
}
- VM_BUG_ON(!root);
+ VM_BUG_ON(!found);
- return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
+ return (root_nr * SECTIONS_PER_ROOT) + (ms - found);
}
#else
int __section_nr(struct mem_section* ms)
--
2.21.0
next prev parent reply other threads:[~2019-06-17 4:38 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-17 4:36 [PATCH 0/5] mm: Cleanup & allow modules to hotplug memory Alastair D'Silva
2019-06-17 4:36 ` Alastair D'Silva [this message]
2019-06-17 6:46 ` [PATCH 1/5] mm: Trigger bug on if a section is not found in __section_nr Mike Rapoport
2019-06-17 4:36 ` [PATCH 2/5] mm: don't hide potentially null memmap pointer in sparse_remove_one_section Alastair D'Silva
2019-06-17 6:49 ` Mike Rapoport
2019-06-17 7:26 ` David Hildenbrand
2019-06-17 4:36 ` [PATCH 3/5] mm: Don't manually decrement num_poisoned_pages Alastair D'Silva
2019-06-17 6:52 ` Mike Rapoport
2019-06-17 7:17 ` David Hildenbrand
2019-06-17 4:36 ` [PATCH 4/5] mm/hotplug: Avoid RCU stalls when removing large amounts of memory Alastair D'Silva
2019-06-17 6:53 ` Mike Rapoport
2019-06-17 6:58 ` Alastair D'Silva
2019-06-17 7:47 ` Michal Hocko
2019-06-17 7:57 ` Alastair D'Silva
2019-06-17 8:21 ` Michal Hocko
2019-06-17 15:49 ` Oscar Salvador
2019-06-17 4:36 ` [PATCH 5/5] mm/hotplug: export try_online_node Alastair D'Silva
2019-06-17 6:59 ` Peter Zijlstra
2019-06-17 7:05 ` Alastair D'Silva
2019-06-17 7:15 ` Christoph Hellwig
2019-06-17 8:00 ` Alastair D'Silva
2019-06-17 13:14 ` 'Christoph Hellwig'
2019-06-17 7:16 ` Michal Hocko
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