Messages in this thread | | | Date | Tue, 26 Jun 2018 09:21:52 +0200 (CEST) | From | Julia Lawall <> | Subject | Re: [PATCH v2 net] nfp: cast sizeof() to int when comparing with error code |
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On Mon, 25 Jun 2018, Joe Perches wrote:
> On Tue, 2018-06-26 at 09:16 +0800, Chengguang Xu wrote: > > sizeof() will return unsigned value so in the error check > > negative error code will be always larger than sizeof(). > > This looks like a general class of error in the kernel > where a signed result that could be returning a -errno > is tested against < or <= sizeof() > > A couple examples: > > drivers/input/mouse/elan_i2c_smbus.c: > > len = i2c_smbus_read_block_data(client, > ETP_SMBUS_IAP_PASSWORD_READ, > val); > if (len < sizeof(u16)) { > > i2c_smbus_read_block_data can return a negative errno > > > net/smc/smc_clc.c: > > len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1, > sizeof(struct smc_clc_msg_decline)); > if (len < sizeof(struct smc_clc_msg_decline)) > > where kernel_sendmsg can return a negative errno > > There are probably others, I didn't look hard. > > Perhaps a cocci script to find these could be generated?
Currently there is a rule for comparison of unsigneds to 0. It would be reasonable to extend it for sizes. I will see what it gives.
julia
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