From: Dan Carpenter <dan.carpenter@oracle.com>
To: Nigel Christian <nigel.l.christian@gmail.com>
Cc: kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] mm: hugetlb: checking for IS_ERR() instead of NULL
Date: Wed, 2 Jun 2021 17:22:24 +0300 [thread overview]
Message-ID: <20210602142224.GH1955@kadam> (raw)
In-Reply-To: <20210601193419.GH24442@kadam>
On Tue, Jun 01, 2021 at 10:51:23PM +0300, Dan Carpenter wrote:
> Here is my next attempt at this check.
>
> Back in 2009, I used to write Smatch checks which were too complicated.
> Ideally, each Smatch check should only print one warning. The state
> engine should only have one custom state, and &undefined and &merged.
> That check I sent violated all those rules.
>
> The other thing which might be interesting is if you pass a NULL
> to IS_ERR() and then dereference the NULL then print a warning about
> that. This has a lot of overlaps with some of my existing checks, but
> it's still a new idea so it belongs in a separate check. It's fine and
> good even if one bug triggers a lot of different warnings. I'll write
> that, hang on, brb.
>
> regards,
> dan carpenter
>
This check worked decently enough. If you want to fix some of the bugs
here they are. I'll look at them in a couple weeks. I fixed a couple
of the first ones I looked at (not listed).
drivers/phy/microchip/sparx5_serdes.c:2474 sparx5_serdes_probe() warn: 'iomem' is not an error pointer
drivers/usb/musb/musb_core.c:2483 musb_init_controller() warn: 'musb->dma_controller' is not an error pointer
drivers/base/power/domain.c:2566 genpd_dev_pm_detach() warn: 'pd' is not an error pointer
drivers/base/power/domain.c:2599 genpd_dev_pm_sync() warn: 'pd' is not an error pointer
drivers/pci/controller/pci-ftpci100.c:496 faraday_pci_probe() warn: 'p->bus_clk' is not an error pointer
drivers/infiniband/core/cm.c:2348 ib_send_cm_rtu() warn: 'data' is not an error pointer
drivers/infiniband/core/cm.c:2761 ib_send_cm_drep() warn: 'data' is not an error pointer
drivers/infiniband/core/cm.c:3092 ib_send_cm_mra() warn: 'data' is not an error pointer
drivers/bluetooth/btqcomsmd.c:140 btqcomsmd_probe() warn: 'btq->acl_channel' is not an error pointer
drivers/bluetooth/btqcomsmd.c:145 btqcomsmd_probe() warn: 'btq->cmd_channel' is not an error pointer
drivers/media/platform/sti/bdisp/bdisp-v4l2.c:1402 bdisp_probe() warn: 'bdisp->clock' is not an error pointer
drivers/net/ipa/ipa_modem.c:360 ipa_modem_config() warn: 'notifier' is not an error pointer
drivers/net/wireless/ath/wcn36xx/main.c:1411 wcn36xx_probe() warn: 'wcn->smd_channel' is not an error pointer
drivers/net/can/spi/hi311x.c:854 hi3110_can_probe() warn: 'clk' is not an error pointer
drivers/net/can/spi/hi311x.c:941 hi3110_can_probe() warn: 'clk' is not an error pointer
net/bridge/br_forward.c:223 br_flood() warn: 'prev' is not an error pointer
net/bridge/br_forward.c:313 br_multicast_flood() warn: 'prev' is not an error pointer
One thing that I realized is that for functions the return NULL when
they are configured out like media_device_usb_allocate() is that these
are always a one liner:
struct foo *whatever(void) { return NULL; }
And they're always in the .h file so we have access to them and can add
a check for that.
static bool is_one_liner_function(struct expression *fn)
{
struct symbol *sym;
int lines;
if (fn->type != EXPR_SYMBOL || !fn->symbol)
return false;
sym = get_base_type(fn->symbol);
if (!sym)
return false;
if (sym->stmt && sym->stmt->type == STMT_COMPOUND)
lines = ptr_list_size((struct ptr_list *)sym->stmt->stmts);
else if (sym->inline_stmt && sym->inline_stmt->type == STMT_COMPOUND)
lines = ptr_list_size((struct ptr_list *)sym->inline_stmt->stmts);
else
return false;
if (lines == 1)
return true;
return false;
}
regards,
dan carpenter
next prev parent reply other threads:[~2021-06-02 14:22 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-01 9:25 [PATCH] mm: hugetlb: checking for IS_ERR() instead of NULL Dan Carpenter
2021-06-01 10:52 ` Mina Almasry
2021-06-01 17:54 ` Nigel Christian
2021-06-01 19:00 ` Dan Carpenter
2021-06-01 19:51 ` Dan Carpenter
2021-06-01 20:50 ` Dan Carpenter
2021-06-01 21:23 ` Nigel Christian
2021-06-02 6:11 ` Dan Carpenter
2021-06-02 14:47 ` Dan Carpenter
2021-06-02 16:01 ` Nigel Christian
2021-06-04 13:34 ` Dan Carpenter
2021-06-04 14:14 ` Nigel Christian
2021-06-04 14:21 ` Dan Carpenter
2021-06-02 14:22 ` Dan Carpenter [this message]
2021-06-02 15:57 ` Nigel Christian
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