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Message-ID: <20240131125907.1006760-1-liuyongqiang13@huawei.com>
Date: Wed, 31 Jan 2024 20:59:07 +0800
From: Yongqiang Liu <liuyongqiang13@...wei.com>
To: <linux-arm-kernel@...ts.infradead.org>
CC: <yanaijie@...wei.com>, <zhangxiaoxu5@...wei.com>,
<wangkefeng.wang@...wei.com>, <sunnanyong@...wei.com>,
<linux@...linux.org.uk>, <rppt@...ux.ibm.com>,
<linux-kernel@...r.kernel.org>, <keescook@...omium.org>, <arnd@...db.de>,
<m.szyprowski@...sung.com>, <willy@...radead.org>,
<liuyongqiang13@...wei.com>
Subject: [PATCH] arm: flush: don't abuse pfn_valid() to check if pfn is in RAM
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. __sync_icache_dcache() should use
memblock_is_map_memory() instead of pfn_valid() to check if a PFN is in
RAM or not.In Some uio case we will get a crash on a system 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
Fixes: a4d5613c4dc6 ("arm: extend pfn_valid to take into account freed memory map alignment")
Signed-off-by: Yongqiang Liu <liuyongqiang13@...wei.com>
---
arch/arm/mm/flush.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index d19d140a10c7..11ec6c5ff5fc 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -15,6 +15,7 @@
#include <asm/smp_plat.h>
#include <asm/tlbflush.h>
#include <linux/hugetlb.h>
+#include <linux/memblock.h>
#include "mm.h"
@@ -292,7 +293,7 @@ void __sync_icache_dcache(pte_t pteval)
/* only flush non-aliasing VIPT caches for exec mappings */
return;
pfn = pte_pfn(pteval);
- if (!pfn_valid(pfn))
+ if (!memblock_is_map_memory(PFN_PHYS(pfn)))
return;
folio = page_folio(pfn_to_page(pfn));
--
2.25.1
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