[PATCH] x86/crash: Update the stale comment in reserve_crashkernel()

[Xunlei Pang]

CRASH_KERNEL_ADDR_MAX was missing for a long time, update it
with more detailed explanation.

Cc: Robert LeBlanc <robert at leblancnet.us>
Cc: Baoquan He <bhe at redhat.com>
Signed-off-by: Xunlei Pang <xlpang at redhat.com>
---
 arch/x86/kernel/setup.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 9c337b0..79ee507 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -575,7 +575,10 @@ static void __init reserve_crashkernel(void)
 	/* 0 means: find the address automatically */
 	if (crash_base <= 0) {
 		/*
-		 *  kexec want bzImage is below CRASH_KERNEL_ADDR_MAX
+		 * Set CRASH_ADDR_LOW_MAX upper bound for crash range
+		 * as old kexec-tools loads bzImage below that, unless
+		 * "size,high" or "size at offset"(nonzero offset, see the
+		 * else leg below) is specified.
 		 */
 		crash_base = memblock_find_in_range(CRASH_ALIGN,
 						    high ? CRASH_ADDR_HIGH_MAX
-- 
1.8.3.1