[PATCH 2/6] xfs_db: write command broken on 64 bit values

Dave Chinner
2014-07-04T05:57:33Z

From: Dave Chinner <dchinner@redhat.com>

convert_args() has problesm with 64 bit fields because it tries to
shift them by 64 bits. The result of doing so is undefined by the C
standard, and so results in the unexpected behaviour of the result
being being the original value unchanged rather than 0. Hence you
can't write 64 bit fields because the code thinks that all values
other than 0 are out of range.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
db/write.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/db/write.c b/db/write.c
index ca8bd0f..0157a44 100644
--- a/db/write.c
+++ b/db/write.c
@@ -565,7 +565,7 @@ convert_arg(
return NULL;

/* Does the value fit into the range of the destination bitfield? */
- if ((val >> bit_length) > 0)
+ if (bit_length < 64 && (val >> bit_length) > 0)
return NULL;
/*
* If the length of the field is not a multiple of a byte, push
--
2.0.0