powerpc/kexec: Check crash_base for relocatable kernel

Enforce that the crash kernel region never overlaps the current kernel,
as it will be written directly on kexec load.

Also, default to the previous KDUMP_KERNELBASE if the start is 0.

Other architectures (x86, ia64) state that specifying the start address
0 (or omitting it) will result in the kernel allocating it.  Before the
relocatable patch in 2.6.28, powerpc would adjust any other start value
to the hardcoded KDUMP_KERNELBASE of 32M.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Milton Miller 2009-01-02 10:46:15 +00:00 committed by Benjamin Herrenschmidt
parent e16459c6b7
commit 66c721e184

View File

@ -93,10 +93,35 @@ void __init reserve_crashkernel(void)
KDUMP_KERNELBASE);
crashk_res.start = KDUMP_KERNELBASE;
#else
if (!crashk_res.start) {
/*
* unspecified address, choose a region of specified size
* can overlap with initrd (ignoring corruption when retained)
* ppc64 requires kernel and some stacks to be in first segemnt
*/
crashk_res.start = KDUMP_KERNELBASE;
}
crash_base = PAGE_ALIGN(crashk_res.start);
if (crash_base != crashk_res.start) {
printk("Crash kernel base must be aligned to 0x%lx\n",
PAGE_SIZE);
crashk_res.start = crash_base;
}
#endif
crash_size = PAGE_ALIGN(crash_size);
crashk_res.end = crashk_res.start + crash_size - 1;
/* The crash region must not overlap the current kernel */
if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
printk(KERN_WARNING
"Crash kernel can not overlap current kernel\n");
crashk_res.start = crashk_res.end = 0;
return;
}
/* Crash kernel trumps memory limit */
if (memory_limit && memory_limit <= crashk_res.end) {
memory_limit = crashk_res.end + 1;