x86: fix alloc_mptable()

Fix the conditions when we stop updating the mptable due to
running out of slots.

[ Impact: fix memory corruption / non-working update_mptable boot parameter ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Len Brown <lenb@kernel.org>
LKML-Reference: <4A01C3BB.1000609@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 9 insertions, 16 deletions

diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index 70fd7e414c15..cd2a41a7c45c 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -870,24 +870,17 @@ static
 inline void __init check_irq_src(struct mpc_intsrc *m, int *nr_m_spare) {}
 #endif /* CONFIG_X86_IO_APIC */
 
-static int check_slot(unsigned long mpc_new_phys, unsigned long mpc_new_length,
-                      int count)
+static int
+check_slot(unsigned long mpc_new_phys, unsigned long mpc_new_length, int count)
 {
-        if (!mpc_new_phys) {
-                pr_info("No spare slots, try to append...take your risk, "
-                        "new mpc_length %x\n", count);
-        } else {
-                if (count <= mpc_new_length)
-                        pr_info("No spare slots, try to append..., "
-                                "new mpc_length %x\n", count);
-                else {
-                        pr_err("mpc_new_length %lx is too small\n",
-                                mpc_new_length);
-                        return -1;
-                }
+        int ret = 0;
+
+        if (!mpc_new_phys || count <= mpc_new_length) {
+                WARN(1, "update_mptable: No spare slots (length: %x)\n", count);
+                return -1;
         }
 
-        return 0;
+        return ret;
 }
 
 static int  __init replace_intsrc_all(struct mpc_table *mpc,
@@ -946,7 +939,7 @@ static int  __init replace_intsrc_all(struct mpc_table *mpc,
                 } else {
                         struct mpc_intsrc *m = (struct mpc_intsrc *)mpt;
                         count += sizeof(struct mpc_intsrc);
-                        if (!check_slot(mpc_new_phys, mpc_new_length, count))
+                        if (check_slot(mpc_new_phys, mpc_new_length, count) < 0)
                                 goto out;
                         assign_to_mpc_intsrc(&mp_irqs[i], m);
                         mpc->length = count;