diff options
author | Damien Le Moal <damien.lemoal@wdc.com> | 2021-08-11 05:37:00 +0200 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2021-08-18 15:21:12 +0200 |
commit | ba05200fcce0a73fa8db16c514fbaa476d1d9399 (patch) | |
tree | b8d4a85dcb8c38149b887d60d12279ac8c135b57 /block/blk-pm.c | |
parent | block: change ioprio_valid() to an inline function (diff) | |
download | linux-ba05200fcce0a73fa8db16c514fbaa476d1d9399.tar.xz linux-ba05200fcce0a73fa8db16c514fbaa476d1d9399.zip |
block: fix IOPRIO_PRIO_CLASS() and IOPRIO_PRIO_VALUE() macros
The ki_ioprio field of struct kiocb is 16-bits (u16) but often handled
as an int in the block layer. E.g. ioprio_check_cap() takes an int as
argument.
With such implicit int casting function calls, the upper 16-bits of the
int argument may be left uninitialized by the compiler, resulting in
invalid values for the IOPRIO_PRIO_CLASS() macro (garbage upper bits)
and in an error return for functions such as ioprio_check_cap().
Fix this by masking the result of the shift by IOPRIO_CLASS_SHIFT bits
in the IOPRIO_PRIO_CLASS() macro. The new macro IOPRIO_CLASS_MASK
defines the 3-bits mask for the priority class.
Similarly, apply the IOPRIO_PRIO_MASK mask to the data argument of the
IOPRIO_PRIO_VALUE() macro to ignore the upper bits of the data value.
The IOPRIO_CLASS_MASK mask is also applied to the class argument of this
macro before shifting the result by IOPRIO_CLASS_SHIFT bits.
While at it, also change the argument name of the IOPRIO_PRIO_CLASS()
and IOPRIO_PRIO_DATA() macros from "mask" to "ioprio" to reflect the
fact that a priority value should be passed rather than a mask.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Link: https://lore.kernel.org/r/20210811033702.368488-5-damien.lemoal@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-pm.c')
0 files changed, 0 insertions, 0 deletions