From: Yongqiang Liu <liuyongqiang13@huawei.com>
To: <linux-arm-kernel@lists.infradead.org>
Cc: <yanaijie@huawei.com>, <zhangxiaoxu5@huawei.com>,
<wangkefeng.wang@huawei.com>, <sunnanyong@huawei.com>,
<linux@armlinux.org.uk>, <rppt@linux.ibm.com>,
<linux-kernel@vger.kernel.org>, <keescook@chromium.org>,
<arnd@arndb.de>, <m.szyprowski@samsung.com>,
<willy@infradead.org>, <liuyongqiang13@huawei.com>
Subject: [PATCH v2] arm: flush: check if the folio is reserved for no-mapping addresses
Date: Fri, 23 Feb 2024 14:36:08 +0800 [thread overview]
Message-ID: <20240223063608.2605736-1-liuyongqiang13@huawei.com> (raw)
Since commit a4d5613c4dc6 ("arm: extend pfn_valid to take into account
freed memory map alignment") changes the semantics of pfn_valid() to check
presence of the memory map for a PFN. A valid page for an address which
is reserved but not mapped by the kernel[1], the system crashed during
some uio test with the following memory layout:
node 0: [mem 0x00000000c0a00000-0x00000000cc8fffff]
node 0: [mem 0x00000000d0000000-0x00000000da1fffff]
the uio layout is:0xc0900000, 0x100000
the crash backtrace like:
Unable to handle kernel paging request at virtual address bff00000
[...]
CPU: 1 PID: 465 Comm: startapp.bin Tainted: G O 5.10.0 #1
Hardware name: Generic DT based system
PC is at b15_flush_kern_dcache_area+0x24/0x3c
LR is at __sync_icache_dcache+0x6c/0x98
[...]
(b15_flush_kern_dcache_area) from (__sync_icache_dcache+0x6c/0x98)
(__sync_icache_dcache) from (set_pte_at+0x28/0x54)
(set_pte_at) from (remap_pfn_range+0x1a0/0x274)
(remap_pfn_range) from (uio_mmap+0x184/0x1b8 [uio])
(uio_mmap [uio]) from (__mmap_region+0x264/0x5f4)
(__mmap_region) from (__do_mmap_mm+0x3ec/0x440)
(__do_mmap_mm) from (do_mmap+0x50/0x58)
(do_mmap) from (vm_mmap_pgoff+0xfc/0x188)
(vm_mmap_pgoff) from (ksys_mmap_pgoff+0xac/0xc4)
(ksys_mmap_pgoff) from (ret_fast_syscall+0x0/0x5c)
Code: e0801001 e2423001 e1c00003 f57ff04f (ee070f3e)
---[ end trace 09cf0734c3805d52 ]---
Kernel panic - not syncing: Fatal exception
So check if PG_reserved was set to solve this issue.
[1]: https://lore.kernel.org/lkml/Zbtdue57RO0QScJM@linux.ibm.com/
Fixes: a4d5613c4dc6 ("arm: extend pfn_valid to take into account freed memory map alignment")
Suggested-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>
---
v1 -> v2
- Improve commit message
- Use helpers instead of PG_reserved
- drop the unnecessary include headers
arch/arm/mm/flush.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index d19d140a10c7..0749cf8a6637 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -296,6 +296,9 @@ void __sync_icache_dcache(pte_t pteval)
return;
folio = page_folio(pfn_to_page(pfn));
+ if (folio_test_reserved(folio))
+ return;
+
if (cache_is_vipt_aliasing())
mapping = folio_flush_mapping(folio);
else
--
2.25.1
next reply other threads:[~2024-02-23 6:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-23 6:36 Yongqiang Liu [this message]
2024-02-26 7:03 ` [PATCH v2] arm: flush: check if the folio is reserved for no-mapping addresses Jinjiang Tu
[not found] <788c8a64-09ed-96fd-9878-ed126b09c683@huawei.com>
2024-02-26 11:57 ` Russell King (Oracle)
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