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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-08-25 12:03:15 +0400 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-08-25 12:11:40 +0400 |
| commit | a849088aa1552b1a28eea3daff599ee22a734ae3 (patch) | |
| tree | 9df50901cafaca44eb1be1e97d1266a03c6913bc /arch/arm/mm | |
| parent | fea7a08acb13524b47711625eebea40a0ede69a0 (diff) | |
| download | linux-a849088aa1552b1a28eea3daff599ee22a734ae3.tar.xz | |
ARM: Fix ioremap() of address zero
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
19b52abe3c5d7 - 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>
Diffstat (limited to 'arch/arm/mm')
| -rw-r--r-- | arch/arm/mm/mm.h | 3 | ||||
| -rw-r--r-- | arch/arm/mm/mmu.c | 4 |
2 files changed, 5 insertions, 2 deletions
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h index 6776160618ef..a8ee92da3544 100644 --- a/arch/arm/mm/mm.h +++ b/arch/arm/mm/mm.h @@ -55,6 +55,9 @@ extern void __flush_dcache_page(struct address_space *mapping, struct page *page /* permanent static mappings from iotable_init() */ #define VM_ARM_STATIC_MAPPING 0x40000000 +/* empty mapping */ +#define VM_ARM_EMPTY_MAPPING 0x20000000 + /* mapping type (attributes) for permanent static mappings */ #define VM_ARM_MTYPE(mt) ((mt) << 20) #define VM_ARM_MTYPE_MASK (0x1f << 20) diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 4c2d0451e84a..eab94bc6f805 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -807,7 +807,7 @@ static void __init pmd_empty_section_gap(unsigned long addr) vm = early_alloc_aligned(sizeof(*vm), __alignof__(*vm)); vm->addr = (void *)addr; vm->size = SECTION_SIZE; - vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING; + vm->flags = VM_IOREMAP | VM_ARM_EMPTY_MAPPING; vm->caller = pmd_empty_section_gap; vm_area_add_early(vm); } @@ -820,7 +820,7 @@ static void __init fill_pmd_gaps(void) /* we're still single threaded hence no lock needed here */ for (vm = vmlist; vm; vm = vm->next) { - if (!(vm->flags & VM_ARM_STATIC_MAPPING)) + if (!(vm->flags & (VM_ARM_STATIC_MAPPING | VM_ARM_EMPTY_MAPPING))) continue; addr = (unsigned long)vm->addr; if (addr < next) |