[tip:x86/apic] x86: uv - prevent NULL dereference in uv_system_init()

[tip-bot for Cyrill Gorcunov <gorcunov@gmail.com>]

Commit-ID:  9a8709d44139748fe2e0ab56d20d8c384c8b65ad
Gitweb:     http://git.kernel.org/tip/9a8709d44139748fe2e0ab56d20d8c384c8b65ad
Author:     Cyrill Gorcunov <gorcunov@gmail.com>
AuthorDate: Sat, 2 May 2009 00:25:11 +0400
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Sun, 3 May 2009 10:49:31 +0200

x86: uv - prevent NULL dereference in uv_system_init()

We may reach NULL dereference oops if kmalloc failed.
Prevent it with explicit BUG_ON.

[ Impact: more controlled assert in 'impossible' scenario ]

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Jack Steiner <steiner@sgi.com>
LKML-Reference: <20090501202511.GE4633@lenovo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


---
 arch/x86/kernel/apic/x2apic_uv_x.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index 873bf71..9d9e228 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -569,15 +569,18 @@ void __init uv_system_init(void)
 
 	bytes = sizeof(struct uv_blade_info) * uv_num_possible_blades();
 	uv_blade_info = kmalloc(bytes, GFP_KERNEL);
+	BUG_ON(!uv_blade_info);
 
 	get_lowmem_redirect(&lowmem_redir_base, &lowmem_redir_size);
 
 	bytes = sizeof(uv_node_to_blade[0]) * num_possible_nodes();
 	uv_node_to_blade = kmalloc(bytes, GFP_KERNEL);
+	BUG_ON(!uv_node_to_blade);
 	memset(uv_node_to_blade, 255, bytes);
 
 	bytes = sizeof(uv_cpu_to_blade[0]) * num_possible_cpus();
 	uv_cpu_to_blade = kmalloc(bytes, GFP_KERNEL);
+	BUG_ON(!uv_cpu_to_blade);
 	memset(uv_cpu_to_blade, 255, bytes);
 
 	blade = 0;