Write permissions on the /dev/udmabuf device file are not required to issue ioctls and allocate udmabufs. Applications should be opening this file as O_RDONLY. The BPF dmabuf_iter selftest already does this. [1]
Remove the write access mode from the drivers/dma-buf/udmabuf.c and drivers/net/hw/ncdevmem.c selftests. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c?h=v7.1#n49 Signed-off-by: T.J. Mercier <[email protected]> --- tools/testing/selftests/drivers/dma-buf/udmabuf.c | 2 +- tools/testing/selftests/drivers/net/hw/ncdevmem.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/drivers/dma-buf/udmabuf.c b/tools/testing/selftests/drivers/dma-buf/udmabuf.c index d78aec662586..ced0b95c876c 100644 --- a/tools/testing/selftests/drivers/dma-buf/udmabuf.c +++ b/tools/testing/selftests/drivers/dma-buf/udmabuf.c @@ -140,7 +140,7 @@ int main(int argc, char *argv[]) ksft_print_header(); ksft_set_plan(7); - devfd = open("/dev/udmabuf", O_RDWR); + devfd = open("/dev/udmabuf", O_RDONLY); if (devfd < 0) { ksft_print_msg( "%s: [skip,no-udmabuf: Unable to access DMA buffer device file]\n", diff --git a/tools/testing/selftests/drivers/net/hw/ncdevmem.c b/tools/testing/selftests/drivers/net/hw/ncdevmem.c index e098d6534c3c..8114a29692fd 100644 --- a/tools/testing/selftests/drivers/net/hw/ncdevmem.c +++ b/tools/testing/selftests/drivers/net/hw/ncdevmem.c @@ -149,7 +149,7 @@ static struct memory_buffer *udmabuf_alloc(size_t size) ctx->size = size; - ctx->devfd = open("/dev/udmabuf", O_RDWR); + ctx->devfd = open("/dev/udmabuf", O_RDONLY); if (ctx->devfd < 0) { pr_err("[skip,no-udmabuf: Unable to access DMA buffer device file]"); goto err_free_ctx; -- 2.55.0.rc0.799.gd6f94ed593-goog
