[PATCH] xfsprogs: xfs_db: Interpret inode's di_format field as unsigned

[PATCH] xfsprogs: xfs_db: Interpret inode's di_format field as unsigned

[Chandan Rajendra]

On a ppc64 big endian system, xfs_db would print the following,

xfs_db> p
core.magic = 0x494e
core.mode = 0100600
core.version = 3
core.format = -253

This is due to fp_dinode_fmt() interpretting the di_format field as
signed. This commit fixes the bug by passing BVUNSIGNED (instead of
BVSIGNED) as the argument to getbitval(). With this commit applied, we
now get,

xfs_db> p
core.magic = 0x494e
core.mode = 0100600
core.version = 3
core.format = 3 (btree)

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
---
 db/inode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/db/inode.c b/db/inode.c
index cac19fc..8b7a41e 100644
--- a/db/inode.c
+++ b/db/inode.c
@@ -238,7 +238,7 @@ fp_dinode_fmt(
 	int			i;
 
 	for (i = 0, bitpos = bit; i < count; i++, bitpos += size) {
-		f = (xfs_dinode_fmt_t)getbitval(obj, bitpos, size, BVSIGNED);
+		f = (xfs_dinode_fmt_t)getbitval(obj, bitpos, size, BVUNSIGNED);
 		if (array)
 			dbprintf("%d:", i + base);
 		if (f < 0 || f >= dinode_fmt_name_size)
-- 
2.5.5

Re: [PATCH] xfsprogs: xfs_db: Interpret inode's di_format field as unsigned

[Darrick J. Wong]

On Tue, Jan 24, 2017 at 06:27:53PM +0530, Chandan Rajendra wrote:
> On a ppc64 big endian system, xfs_db would print the following,
> 
> xfs_db> p
> core.magic = 0x494e
> core.mode = 0100600
> core.version = 3
> core.format = -253
> 
> This is due to fp_dinode_fmt() interpretting the di_format field as
> signed. This commit fixes the bug by passing BVUNSIGNED (instead of
> BVSIGNED) as the argument to getbitval(). With this commit applied, we
> now get,
> 
> xfs_db> p
> core.magic = 0x494e
> core.mode = 0100600
> core.version = 3
> core.format = 3 (btree)
> 
> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>

I hit this bug running fuzztests on ppc64, so
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
>  db/inode.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/db/inode.c b/db/inode.c
> index cac19fc..8b7a41e 100644
> --- a/db/inode.c
> +++ b/db/inode.c
> @@ -238,7 +238,7 @@ fp_dinode_fmt(
>  	int			i;
>  
>  	for (i = 0, bitpos = bit; i < count; i++, bitpos += size) {
> -		f = (xfs_dinode_fmt_t)getbitval(obj, bitpos, size, BVSIGNED);
> +		f = (xfs_dinode_fmt_t)getbitval(obj, bitpos, size, BVUNSIGNED);
>  		if (array)
>  			dbprintf("%d:", i + base);
>  		if (f < 0 || f >= dinode_fmt_name_size)
> -- 
> 2.5.5
> 
> --
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