Messages in this thread Patch in this message | | | From | Yongqiang Liu <> | Subject | [PATCH] arm: flush: don't abuse pfn_valid() to check if pfn is in RAM | Date | Wed, 31 Jan 2024 20:59:07 +0800 |
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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@huawei.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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