lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 19 May 2021 09:50:46 +0800 From: Kefeng Wang <wangkefeng.wang@...wei.com> To: Mike Rapoport <rppt@...nel.org> CC: <linux-arm-kernel@...ts.infradead.org>, Andrew Morton <akpm@...ux-foundation.org>, Mike Rapoport <rppt@...ux.ibm.com>, Russell King <linux@...linux.org.uk>, <linux-kernel@...r.kernel.org>, <linux-mm@...ck.org> Subject: Re: [PATCH 3/3] arm: extend pfn_valid to take into accound freed memory map alignment On 2021/5/18 23:52, Mike Rapoport wrote: > On Tue, May 18, 2021 at 08:49:43PM +0800, Kefeng Wang wrote: >> >> >> On 2021/5/18 17:06, Mike Rapoport wrote: >>> From: Mike Rapoport <rppt@...ux.ibm.com> >>> >>> When unused memory map is freed the preserved part of the memory map is >>> extended to match pageblock boundaries because lots of core mm >>> functionality relies on homogeneity of the memory map within pageblock >>> boundaries. >>> >>> Since pfn_valid() is used to check whether there is a valid memory map >>> entry for a PFN, make it return true also for PFNs that have memory map >>> entries even if there is no actual memory populated there. >>> >>> Signed-off-by: Mike Rapoport <rppt@...ux.ibm.com> >>> --- >>> arch/arm/mm/init.c | 15 ++++++++++++++- >>> 1 file changed, 14 insertions(+), 1 deletion(-) >>> >>> diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c >>> index 9d4744a632c6..bb678c0ba143 100644 >>> --- a/arch/arm/mm/init.c >>> +++ b/arch/arm/mm/init.c >>> @@ -125,11 +125,24 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max_low, >>> int pfn_valid(unsigned long pfn) >>> { >>> phys_addr_t addr = __pfn_to_phys(pfn); >>> + unsigned long pageblock_size = PAGE_SIZE * pageblock_nr_pages; >>> if (__phys_to_pfn(addr) != pfn) >>> return 0; >>> - return memblock_is_map_memory(addr); >>> + if (memblock_is_map_memory(addr)) >>> + return 1; >>> + >>> + /* >>> + * If address less than pageblock_size bytes away from a present >>> + * memory chunk there still will be a memory map entry for it >>> + * because we round freed memory map to the pageblock boundaries >>> + */ >>> + if (memblock_is_map_memory(ALIGN(addr + 1, pageblock_size)) || >>> + memblock_is_map_memory(ALIGN_DOWN(addr, pageblock_size))) >>> + return 1; >> >> Hi Mike, with patch3, the system won't boot. > > Hmm, apparently I've miscalculated the ranges... > > Can you please check with the below patch on top of this series: Yes, it works, On node 0 totalpages: 311551 Normal zone: 1230 pages used for memmap Normal zone: 0 pages reserved Normal zone: 157440 pages, LIFO batch:31 Normal zone: 17152 pages in unavailable ranges HighMem zone: 154111 pages, LIFO batch:31 HighMem zone: 513 pages in unavailable ranges and the oom testcase could pass. Tested-by: Kefeng Wang <wangkefeng.wang@...wei.com> There is memblock_is_region_reserved(check if a region intersects reserved memory), it also checks the size, should we add a similar func? > > diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c > index bb678c0ba143..2fafbbc8e73b 100644 > --- a/arch/arm/mm/init.c > +++ b/arch/arm/mm/init.c > @@ -138,8 +138,9 @@ int pfn_valid(unsigned long pfn) > * memory chunk there still will be a memory map entry for it > * because we round freed memory map to the pageblock boundaries > */ > - if (memblock_is_map_memory(ALIGN(addr + 1, pageblock_size)) || > - memblock_is_map_memory(ALIGN_DOWN(addr, pageblock_size))) > + if (memblock_overlaps_region(&memblock.memory, > + ALIGN_DOWN(addr, pageblock_size), > + pageblock_size); > return 1; > > return 0; >
Powered by blists - more mailing lists