diff options
| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2011-02-21 06:57:33 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2011-02-23 16:14:25 +0000 |
| commit | 3572bea8cbc57f0bef1e0f4580c01717df7026d8 (patch) | |
| tree | aa48782419dad9dbd005783ff7af349e980b1de4 /arch/arm/kernel/setup.c | |
| parent | dce72dd08c976c9e5e1367bf994b306b15ae87fe (diff) | |
ARM: 6748/1: ignore mdesc->boot_params if out of range
The initial MMU table created in head.S contains a 1 MB mapping at the
start of memory to let the early kernel boot code access the boot params
specified by mdesc->boot_params.
When using CONFIG_ARM_PATCH_PHYS_VIRT it is possible for the kernel to
have a different idea of where the start of memory is at run time, making
the compile-time determined mdesc->boot_params pointing to a memory area
which is not mapped. Any access to the boot params in that case will
fault and silently hang the kernel at that point. It is therefore a
better idea to simply ignore mdesc->boot_params in that case and give
the kernel a chance to print some diagnostic on the console later.
If the bootloader provides a valid pointer in r2 to the kernel then this
is used instead of mdesc->boot_params, and an explicit mapping is already
created in the initial MMU table for it. It is therefore a good idea to
use that facility when using a relocated kernel.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/setup.c')
| -rw-r--r-- | arch/arm/kernel/setup.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 6ce80106316..f43f041a097 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -839,8 +839,25 @@ void __init setup_arch(char **cmdline_p) if (__atags_pointer) tags = phys_to_virt(__atags_pointer); - else if (mdesc->boot_params) - tags = phys_to_virt(mdesc->boot_params); + else if (mdesc->boot_params) { +#ifdef CONFIG_MMU + /* + * We still are executing with a minimal MMU mapping created + * with the presumption that the machine default for this + * is located in the first MB of RAM. Anything else will + * fault and silently hang the kernel at this point. + */ + if (mdesc->boot_params < PHYS_OFFSET || + mdesc->boot_params >= PHYS_OFFSET + SZ_1M) { + printk(KERN_WARNING + "Default boot params at physical 0x%08lx out of reach\n", + mdesc->boot_params); + } else +#endif + { + tags = phys_to_virt(mdesc->boot_params); + } + } #if defined(CONFIG_DEPRECATED_PARAM_STRUCT) /* |