From e5880d76aea443b04e07da19830da0f6f7494eef Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Tue, 27 Jul 2010 11:56:04 -0400 Subject: ext4: fix potential NULL dereference while tracing The allocation_context pointer can be NULL. Signed-off-by: "Theodore Ts'o" --- include/trace/events/ext4.h | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) (limited to 'include/trace') diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h index f3865c7b4166..01e9e0076a92 100644 --- a/include/trace/events/ext4.h +++ b/include/trace/events/ext4.h @@ -395,11 +395,12 @@ DEFINE_EVENT(ext4__mb_new_pa, ext4_mb_new_group_pa, ); TRACE_EVENT(ext4_mb_release_inode_pa, - TP_PROTO(struct ext4_allocation_context *ac, + TP_PROTO(struct super_block *sb, + struct ext4_allocation_context *ac, struct ext4_prealloc_space *pa, unsigned long long block, unsigned int count), - TP_ARGS(ac, pa, block, count), + TP_ARGS(sb, ac, pa, block, count), TP_STRUCT__entry( __field( dev_t, dev ) @@ -410,8 +411,9 @@ TRACE_EVENT(ext4_mb_release_inode_pa, ), TP_fast_assign( - __entry->dev = ac->ac_sb->s_dev; - __entry->ino = ac->ac_inode->i_ino; + __entry->dev = sb->s_dev; + __entry->ino = (ac && ac->ac_inode) ? + ac->ac_inode->i_ino : 0; __entry->block = block; __entry->count = count; ), @@ -422,10 +424,11 @@ TRACE_EVENT(ext4_mb_release_inode_pa, ); TRACE_EVENT(ext4_mb_release_group_pa, - TP_PROTO(struct ext4_allocation_context *ac, + TP_PROTO(struct super_block *sb, + struct ext4_allocation_context *ac, struct ext4_prealloc_space *pa), - TP_ARGS(ac, pa), + TP_ARGS(sb, ac, pa), TP_STRUCT__entry( __field( dev_t, dev ) @@ -436,8 +439,9 @@ TRACE_EVENT(ext4_mb_release_group_pa, ), TP_fast_assign( - __entry->dev = ac->ac_sb->s_dev; - __entry->ino = ac->ac_inode->i_ino; + __entry->dev = sb->s_dev; + __entry->ino = (ac && ac->ac_inode) ? + ac->ac_inode->i_ino : 0; __entry->pa_pstart = pa->pa_pstart; __entry->pa_len = pa->pa_len; ), -- cgit v1.2.2