From 66c721e184e594d5761c5db804ade08fab81930d Mon Sep 17 00:00:00 2001 From: Milton Miller Date: Fri, 2 Jan 2009 10:46:15 +0000 Subject: [PATCH] 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 Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/machine_kexec.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c index b3abebb7ee64..d59e2b1bdcba 100644 --- a/arch/powerpc/kernel/machine_kexec.c +++ b/arch/powerpc/kernel/machine_kexec.c @@ -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; -- 2.20.1