![Russell King](/assets/img/avatar_default.png)
Murali Nalajala reports a regression that ioremapping address zero
results in an oops dump:
Unable to handle kernel paging request at virtual address fa200000
pgd = d4f80000
[fa200000] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 Tainted: G W (3.4.0-g3b5f728-00009-g638207a #13)
PC is at msm_pm_config_rst_vector_before_pc+0x8/0x30
LR is at msm_pm_boot_config_before_pc+0x18/0x20
pc : [<c0078f84>] lr : [<c007903c>] psr: a0000093
sp : c0837ef0 ip : cfe00000 fp : 0000000d
r10: da7efc17 r9 : 225c4278 r8 : 00000006
r7 : 0003c000 r6 : c085c824 r5 : 00000001 r4 : fa101000
r3 : fa200000 r2 : c095080c r1 : 002250fc r0 : 00000000
Flags: NzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel
Control: 10c5387d Table: 25180059 DAC: 00000015
[<c0078f84>] (msm_pm_config_rst_vector_before_pc+0x8/0x30) from [<c007903c>] (msm_pm_boot_config_before_pc+0x18/0x20)
[<c007903c>] (msm_pm_boot_config_before_pc+0x18/0x20) from [<c007a55c>] (msm_pm_power_collapse+0x410/0xb04)
[<c007a55c>] (msm_pm_power_collapse+0x410/0xb04) from [<c007b17c>] (arch_idle+0x294/0x3e0)
[<c007b17c>] (arch_idle+0x294/0x3e0) from [<c000eed8>] (default_idle+0x18/0x2c)
[<c000eed8>] (default_idle+0x18/0x2c) from [<c000f254>] (cpu_idle+0x90/0xe4)
[<c000f254>] (cpu_idle+0x90/0xe4) from [<c057231c>] (rest_init+0x88/0xa0)
[<c057231c>] (rest_init+0x88/0xa0) from [<c07ff890>] (start_kernel+0x3a8/0x40c)
Code: c0704256 e12fff1e e59f2020 e5923000 (e5930000)
This is caused by the 'reserved' entries which we insert (see
19b52abe3c
- ARM: 7438/1: fill possible PMD empty section gaps)
which get matched for physical address zero.
Resolve this by marking these reserved entries with a different flag.
Cc: <stable@vger.kernel.org>
Tested-by: Murali Nalajala <mnalajal@codeaurora.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
81 lines
1.9 KiB
C
81 lines
1.9 KiB
C
#ifdef CONFIG_MMU
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/* the upper-most page table pointer */
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extern pmd_t *top_pmd;
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/*
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* 0xffff8000 to 0xffffffff is reserved for any ARM architecture
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* specific hacks for copying pages efficiently, while 0xffff4000
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* is reserved for VIPT aliasing flushing by generic code.
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*
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* Note that we don't allow VIPT aliasing caches with SMP.
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*/
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#define COPYPAGE_MINICACHE 0xffff8000
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#define COPYPAGE_V6_FROM 0xffff8000
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#define COPYPAGE_V6_TO 0xffffc000
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/* PFN alias flushing, for VIPT caches */
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#define FLUSH_ALIAS_START 0xffff4000
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static inline void set_top_pte(unsigned long va, pte_t pte)
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{
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pte_t *ptep = pte_offset_kernel(top_pmd, va);
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set_pte_ext(ptep, pte, 0);
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local_flush_tlb_kernel_page(va);
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}
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static inline pte_t get_top_pte(unsigned long va)
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{
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pte_t *ptep = pte_offset_kernel(top_pmd, va);
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return *ptep;
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}
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static inline pmd_t *pmd_off_k(unsigned long virt)
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{
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return pmd_offset(pud_offset(pgd_offset_k(virt), virt), virt);
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}
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struct mem_type {
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pteval_t prot_pte;
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pmdval_t prot_l1;
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pmdval_t prot_sect;
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unsigned int domain;
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};
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const struct mem_type *get_mem_type(unsigned int type);
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extern void __flush_dcache_page(struct address_space *mapping, struct page *page);
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/*
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* ARM specific vm_struct->flags bits.
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*/
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/* (super)section-mapped I/O regions used by ioremap()/iounmap() */
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#define VM_ARM_SECTION_MAPPING 0x80000000
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/* permanent static mappings from iotable_init() */
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#define VM_ARM_STATIC_MAPPING 0x40000000
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/* empty mapping */
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#define VM_ARM_EMPTY_MAPPING 0x20000000
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/* mapping type (attributes) for permanent static mappings */
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#define VM_ARM_MTYPE(mt) ((mt) << 20)
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#define VM_ARM_MTYPE_MASK (0x1f << 20)
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/* consistent regions used by dma_alloc_attrs() */
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#define VM_ARM_DMA_CONSISTENT 0x20000000
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#endif
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#ifdef CONFIG_ZONE_DMA
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extern phys_addr_t arm_dma_limit;
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#else
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#define arm_dma_limit ((phys_addr_t)~0)
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#endif
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extern phys_addr_t arm_lowmem_limit;
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void __init bootmem_init(void);
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void arm_mm_memblock_reserve(void);
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void dma_contiguous_remap(void);
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