path: root/arch/arm/mm/mm.h
diff options
authorRussell King <rmk+kernel@arm.linux.org.uk>2012-08-25 09:03:15 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-08-25 09:11:40 +0100
commita849088aa1552b1a28eea3daff599ee22a734ae3 (patch)
tree9df50901cafaca44eb1be1e97d1266a03c6913bc /arch/arm/mm/mm.h
parentfea7a08acb13524b47711625eebea40a0ede69a0 (diff)
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/mm.h')
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index 6776160618e..a8ee92da354 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)