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authorMilton Miller <miltonm@bga.com>2009-01-02 10:46:15 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-01-13 14:47:59 +1100
commit66c721e184e594d5761c5db804ade08fab81930d (patch)
tree5f1832ed0eb95c55b4a3c650b541c0aecd6d8aec
parente16459c6b7e9c1390020a3e2a033b5383d1c4f3b (diff)
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>
-rw-r--r--arch/powerpc/kernel/machine_kexec.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c
index b3abebb7ee6..d59e2b1bdcb 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;