nalika / rpms / grub2

Forked from rpms/grub2 2 years ago
Clone

Blame SOURCES/0052-bz1374141-fix-incorrect-mask-for-ppc64.patch

8e15ce
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
8e15ce
From: Masahiro Matsuya <mmatsuya@redhat.com>
8e15ce
Date: Sat, 29 Oct 2016 08:35:26 +0900
8e15ce
Subject: [PATCH] bz1374141 fix incorrect mask for ppc64
8e15ce
8e15ce
The netmask configured in firmware is not respected on ppc64 (big endian).
8e15ce
When 255.255.252.0 is set as netmask in firmware, the following is the value of bootpath string in grub_ieee1275_parse_bootpath().
8e15ce
8e15ce
 /vdevice/l-lan@30000002:speed=auto,duplex=auto,192.168.88.10,,192.168.89.113,192.168.88.1,5,5,255.255.252.0,512
8e15ce
8e15ce
The netmask in this bootpath is no problem, since it's a value specified in firmware. But,
8e15ce
The value of 'subnet_mask.ipv4' was set with 0xfffffc00, and __builtin_ctz (~grub_le_to_cpu32 (subnet_mask.ipv4)) returned 16 (not 22).
8e15ce
As a result, 16 was used for netmask wrongly.
8e15ce
8e15ce
1111 1111 1111 1111 1111 1100 0000 0000 # subnet_mask.ipv4 (=0xfffffc00)
8e15ce
0000 0000 1111 1100 1111 1111 1111 1111 # grub_le_to_cpu32 (subnet_mask.ipv4)
8e15ce
1111 1111 0000 0011 0000 0000 0000 0000 # ~grub_le_to_cpu32 (subnet_mask.ipv4)
8e15ce
8e15ce
And, the count of zero with __builtin_ctz can be 16.
8e15ce
This patch changes it as below.
8e15ce
8e15ce
1111 1111 1111 1111 1111 1100 0000 0000 # subnet_mask.ipv4 (=0xfffffc00)
8e15ce
0000 0000 1111 1100 1111 1111 1111 1111 # grub_le_to_cpu32 (subnet_mask.ipv4)
8e15ce
1111 1111 1111 1111 1111 1100 0000 0000 # grub_swap_bytes32(grub_le_to_cpu32 (subnet_mask.ipv4))
8e15ce
0000 0000 0000 0000 0000 0011 1111 1111 # ~grub_swap_bytes32(grub_le_to_cpu32 (subnet_mask.ipv4))
8e15ce
8e15ce
The count of zero with __builtin_clz can be 22. (clz counts the number of one bits preceding the most significant zero bit)
8e15ce
---
8e15ce
 grub-core/net/drivers/ieee1275/ofnet.c | 3 +--
8e15ce
 1 file changed, 1 insertion(+), 2 deletions(-)
8e15ce
8e15ce
diff --git a/grub-core/net/drivers/ieee1275/ofnet.c b/grub-core/net/drivers/ieee1275/ofnet.c
8e15ce
index ac4e62a95c9..3860b6f78d8 100644
8e15ce
--- a/grub-core/net/drivers/ieee1275/ofnet.c
8e15ce
+++ b/grub-core/net/drivers/ieee1275/ofnet.c
8e15ce
@@ -220,8 +220,7 @@ grub_ieee1275_parse_bootpath (const char *devpath, char *bootpath,
8e15ce
                                  flags);
8e15ce
       inter->vlantag = vlantag;
8e15ce
       grub_net_add_ipv4_local (inter,
8e15ce
-                          __builtin_ctz (~grub_le_to_cpu32 (subnet_mask.ipv4)));
8e15ce
-
8e15ce
+                          __builtin_clz (~grub_swap_bytes32(grub_le_to_cpu32 (subnet_mask.ipv4))));
8e15ce
     }
8e15ce
 
8e15ce
   if (gateway_addr.ipv4 != 0)