Re: [PATCH 6/7] md/raid10, LLVM: get rid of variable length array
From: Peter Zijlstra <peterz@infradead.org>
Date: 2017-03-17 12:10:00
Also in:
linux-crypto, linux-kbuild, lkml
From: Peter Zijlstra <peterz@infradead.org>
Date: 2017-03-17 12:10:00
Also in:
linux-crypto, linux-kbuild, lkml
On Thu, Mar 16, 2017 at 05:15:19PM -0700, Michael Davidson wrote:
Replace a variable length array in a struct by allocating the memory for the entire struct in a char array on the stack. Signed-off-by: Michael Davidson <redacted> --- drivers/md/raid10.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 063c43d83b72..158ebdff782c 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c@@ -4654,11 +4654,10 @@ static int handle_reshape_read_error(struct mddev *mddev, /* Use sync reads to get the blocks from somewhere else */ int sectors = r10_bio->sectors; struct r10conf *conf = mddev->private; - struct { - struct r10bio r10_bio; - struct r10dev devs[conf->copies]; - } on_stack; - struct r10bio *r10b = &on_stack.r10_bio; + char on_stack_r10_bio[sizeof(struct r10bio) + + conf->copies * sizeof(struct r10dev)] + __aligned(__alignof__(struct r10bio)); + struct r10bio *r10b = (struct r10bio *)on_stack_r10_bio; int slot = 0; int idx = 0; struct bio_vec *bvec = r10_bio->master_bio->bi_io_vec;
That's disgusting. Why not fix LLVM to support this?