From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751858AbdEJEiN (ORCPT ); Wed, 10 May 2017 00:38:13 -0400 Received: from smtp05.smtpout.orange.fr ([80.12.242.127]:48855 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751545AbdEJEiL (ORCPT ); Wed, 10 May 2017 00:38:11 -0400 X-ME-Helo: [192.168.1.23] X-ME-Date: Wed, 10 May 2017 06:38:09 +0200 X-ME-IP: 92.140.222.140 Subject: Re: [PATCH] net: dsa: loop: Check for memory allocation failure To: Joe Perches , Julia Lawall References: <20170506052945.2639-1-christophe.jaillet@wanadoo.fr> <063D6719AE5E284EB5DD2968C1650D6DCFFE715E@AcuExch.aculab.com> <1494265443.31950.62.camel@perches.com> <1494343107.20782.2.camel@perches.com> Cc: "linux-kernel@vger.kernel.org" , "kernel-janitors@vger.kernel.org" From: Christophe JAILLET Message-ID: <57023eee-a975-5984-dcc5-adee61235c47@wanadoo.fr> Date: Wed, 10 May 2017 06:38:05 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <1494343107.20782.2.camel@perches.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 09/05/2017 à 17:18, Joe Perches a écrit : > On Mon, 2017-05-08 at 17:35 -0700, Florian Fainelli wrote: >> On 05/08/2017 04:46 PM, Julia Lawall wrote: >>> On Mon, 8 May 2017, Joe Perches wrote: >>>> Each time -EPROBE_DEFER occurs, another set of calls to >>>> dsa_switch_alloc and dev_kzalloc also occurs. >>>> >>>> Perhaps it'd be better to do: >>>> >>>> if (ps->netdev) { >>>> devm_kfree(&devmdev->dev, ps); >>>> devm_kfree(&mdiodev->dev, ds); >>>> return -EPROBE_DEFER; >>>> } >>> Is EPROBE_DEFER handled differently than other kinds of errors? >> In the core device driver model, yes, EPROBE_DEFER is treated >> differently than other errors because it puts the driver on a retry queue. >> >> EPROBE_DEFER is already a slow and exceptional path, and this is a >> mock-up driver, so I am not sure what value there is in trying to >> balance devm_kzalloc() with corresponding devm_kfree()... > Example code should be as correct as possible. > Le 09/05/2017 à 17:18, Joe Perches a écrit : > On Mon, 2017-05-08 at 17:35 -0700, Florian Fainelli wrote: >> On 05/08/2017 04:46 PM, Julia Lawall wrote: >>> On Mon, 8 May 2017, Joe Perches wrote: >>>> Each time -EPROBE_DEFER occurs, another set of calls to >>>> dsa_switch_alloc and dev_kzalloc also occurs. >>>> >>>> Perhaps it'd be better to do: >>>> >>>> if (ps->netdev) { >>>> devm_kfree(&devmdev->dev, ps); >>>> devm_kfree(&mdiodev->dev, ds); >>>> return -EPROBE_DEFER; >>>> } >>> Is EPROBE_DEFER handled differently than other kinds of errors? >> In the core device driver model, yes, EPROBE_DEFER is treated >> differently than other errors because it puts the driver on a retry queue. >> >> EPROBE_DEFER is already a slow and exceptional path, and this is a >> mock-up driver, so I am not sure what value there is in trying to >> balance devm_kzalloc() with corresponding devm_kfree()... > Example code should be as correct as possible. > (* number of people/mailing list in copy has been reduced *) The coccinelle script below gives the following list of candidates for such improvement. char/hw_random/omap-rng.c clk/clk-si5351.c clk/clk-versaclock5.c crypto/mediatek/mtk-platform.c devfreq/rk3399_dmc.c dma/mv_xor_v2.c dma/omap-dma.c gpu/drm/arc/arcpgu_hdmi.c gpu/drm/bridge/dumb-vga-dac.c gpu/drm/bridge/lvds-encoder.c gpu/drm/exynos/exynos_dp.c gpu/drm/exynos/exynos_drm_dsi.c gpu/drm/imx/dw_hdmi-imx.c gpu/drm/mediatek/mtk_dpi.c gpu/drm/mediatek/mtk_drm_ddp_comp.c gpu/drm/mediatek/mtk_dsi.c gpu/drm/panel/panel-lvds.c gpu/drm/panel/panel-simple.c gpu/drm/panel/panel-sitronix-st7789v.c gpu/drm/rcar-du/rcar_du_lvdscon.c gpu/drm/rockchip/cdn-dp-core.c gpu/drm/rockchip/dw_hdmi-rockchip.c gpu/drm/sti/sti_hdmi.c gpu/drm/tegra/sor.c gpu/drm/tilcdc/tilcdc_panel.c gpu/drm/vc4/vc4_hdmi.c gpu/ipu-v3/ipu-common.c gpu/ipu-v3/ipu-pre.c gpu/ipu-v3/ipu-prg.c hwtracing/coresight/coresight-stm.c i2c/busses/i2c-designware-platdrv.c i2c/busses/i2c-mv64xxx.c i2c/muxes/i2c-mux-gpio.c i2c/muxes/i2c-mux-pinctrl.c i2c/muxes/i2c-mux-reg.c iommu/mtk_iommu.c iommu/mtk_iommu_v1.c irqchip/qcom-irq-combiner.c mailbox/mailbox-test.c media/i2c/mt9m111.c media/i2c/ov2640.c media/i2c/ov7670.c media/i2c/smiapp/smiapp-core.c media/i2c/soc_camera/imx074.c media/platform/coda/coda-common.c media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c media/platform/mtk-vcodec/mtk_vcodec_enc_drv.c media/platform/s5p-cec/s5p_cec.c media/platform/sti/cec/stih-cec.c memory/tegra/tegra124-emc.c mfd/twl6040.c mtd/nand/lpc32xx_mlc.c mtd/nand/lpc32xx_slc.c net/dsa/dsa_loop.c net/ethernet/mediatek/mtk_eth_soc.c net/phy/xilinx_gmii2rgmii.c net/wireless/ti/wlcore/spi.c pci/host/pcie-iproc-platform.c phy/phy-exynos5250-sata.c phy/phy-mt65xx-usb3.c phy/phy-qcom-qusb2.c phy/phy-sun4i-usb.c pinctrl/core.c pinctrl/pinctrl-at91.c platform/x86/intel_cht_int33fe.c power/supply/act8945a_charger.c power/supply/axp20x_ac_power.c power/supply/axp20x_battery.c power/supply/axp288_charger.c power/supply/bq24190_charger.c power/supply/cpcap-charger.c power/supply/gpio-charger.c soc/bcm/raspberrypi-power.c thermal/samsung/exynos_tmu.c tty/serial/8250/8250_dw.c tty/serial/max310x.c tty/serial/sccnxp.c usb/chipidea/ci_hdrc_msm.c usb/gadget/udc/mv_udc_core.c usb/host/xhci-mtk.c usb/mtu3/mtu3_plat.c usb/musb/sunxi.c usb/phy/phy-am335x.c usb/phy/phy-generic.c usb/phy/phy-twl6030-usb.c video/backlight/hx8357.c video/backlight/lp855x_bl.c video/fbdev/simplefb.c Coccinelle script : ================= // find calls to kmalloc or equivalent function @call@ expression ptr; position p; @@ ( * ptr@p = kmalloc(...) | * ptr@p = kzalloc(...) | * ptr@p = kcalloc(...) | * ptr@p = kmalloc_array(...) | * ptr@p = devm_kmalloc(...) | * ptr@p = devm_kzalloc(...) | * ptr@p = devm_kcalloc(...) | * ptr@p = devm_kmalloc_array(...) ) ... * return -EPROBE_DEFER; From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christophe JAILLET Date: Wed, 10 May 2017 04:38:05 +0000 Subject: Re: [PATCH] net: dsa: loop: Check for memory allocation failure Message-Id: <57023eee-a975-5984-dcc5-adee61235c47@wanadoo.fr> List-Id: References: <20170506052945.2639-1-christophe.jaillet@wanadoo.fr> <063D6719AE5E284EB5DD2968C1650D6DCFFE715E@AcuExch.aculab.com> <1494265443.31950.62.camel@perches.com> <1494343107.20782.2.camel@perches.com> In-Reply-To: <1494343107.20782.2.camel@perches.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: Joe Perches , Julia Lawall Cc: "linux-kernel@vger.kernel.org" , "kernel-janitors@vger.kernel.org" Le 09/05/2017 =E0 17:18, Joe Perches a =E9crit : > On Mon, 2017-05-08 at 17:35 -0700, Florian Fainelli wrote: >> On 05/08/2017 04:46 PM, Julia Lawall wrote: >>> On Mon, 8 May 2017, Joe Perches wrote: >>>> Each time -EPROBE_DEFER occurs, another set of calls to >>>> dsa_switch_alloc and dev_kzalloc also occurs. >>>> >>>> Perhaps it'd be better to do: >>>> >>>> if (ps->netdev) { >>>> devm_kfree(&devmdev->dev, ps); >>>> devm_kfree(&mdiodev->dev, ds); >>>> return -EPROBE_DEFER; >>>> } >>> Is EPROBE_DEFER handled differently than other kinds of errors? >> In the core device driver model, yes, EPROBE_DEFER is treated >> differently than other errors because it puts the driver on a retry queu= e. >> >> EPROBE_DEFER is already a slow and exceptional path, and this is a >> mock-up driver, so I am not sure what value there is in trying to >> balance devm_kzalloc() with corresponding devm_kfree()... > Example code should be as correct as possible. > Le 09/05/2017 =E0 17:18, Joe Perches a =E9crit : > On Mon, 2017-05-08 at 17:35 -0700, Florian Fainelli wrote: >> On 05/08/2017 04:46 PM, Julia Lawall wrote: >>> On Mon, 8 May 2017, Joe Perches wrote: >>>> Each time -EPROBE_DEFER occurs, another set of calls to >>>> dsa_switch_alloc and dev_kzalloc also occurs. >>>> >>>> Perhaps it'd be better to do: >>>> >>>> if (ps->netdev) { >>>> devm_kfree(&devmdev->dev, ps); >>>> devm_kfree(&mdiodev->dev, ds); >>>> return -EPROBE_DEFER; >>>> } >>> Is EPROBE_DEFER handled differently than other kinds of errors? >> In the core device driver model, yes, EPROBE_DEFER is treated >> differently than other errors because it puts the driver on a retry queu= e. >> >> EPROBE_DEFER is already a slow and exceptional path, and this is a >> mock-up driver, so I am not sure what value there is in trying to >> balance devm_kzalloc() with corresponding devm_kfree()... > Example code should be as correct as possible. > (* number of people/mailing list in copy has been reduced *) The coccinelle script below gives the following list of candidates for=20 such improvement. char/hw_random/omap-rng.c clk/clk-si5351.c clk/clk-versaclock5.c crypto/mediatek/mtk-platform.c devfreq/rk3399_dmc.c dma/mv_xor_v2.c dma/omap-dma.c gpu/drm/arc/arcpgu_hdmi.c gpu/drm/bridge/dumb-vga-dac.c gpu/drm/bridge/lvds-encoder.c gpu/drm/exynos/exynos_dp.c gpu/drm/exynos/exynos_drm_dsi.c gpu/drm/imx/dw_hdmi-imx.c gpu/drm/mediatek/mtk_dpi.c gpu/drm/mediatek/mtk_drm_ddp_comp.c gpu/drm/mediatek/mtk_dsi.c gpu/drm/panel/panel-lvds.c gpu/drm/panel/panel-simple.c gpu/drm/panel/panel-sitronix-st7789v.c gpu/drm/rcar-du/rcar_du_lvdscon.c gpu/drm/rockchip/cdn-dp-core.c gpu/drm/rockchip/dw_hdmi-rockchip.c gpu/drm/sti/sti_hdmi.c gpu/drm/tegra/sor.c gpu/drm/tilcdc/tilcdc_panel.c gpu/drm/vc4/vc4_hdmi.c gpu/ipu-v3/ipu-common.c gpu/ipu-v3/ipu-pre.c gpu/ipu-v3/ipu-prg.c hwtracing/coresight/coresight-stm.c i2c/busses/i2c-designware-platdrv.c i2c/busses/i2c-mv64xxx.c i2c/muxes/i2c-mux-gpio.c i2c/muxes/i2c-mux-pinctrl.c i2c/muxes/i2c-mux-reg.c iommu/mtk_iommu.c iommu/mtk_iommu_v1.c irqchip/qcom-irq-combiner.c mailbox/mailbox-test.c media/i2c/mt9m111.c media/i2c/ov2640.c media/i2c/ov7670.c media/i2c/smiapp/smiapp-core.c media/i2c/soc_camera/imx074.c media/platform/coda/coda-common.c media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c media/platform/mtk-vcodec/mtk_vcodec_enc_drv.c media/platform/s5p-cec/s5p_cec.c media/platform/sti/cec/stih-cec.c memory/tegra/tegra124-emc.c mfd/twl6040.c mtd/nand/lpc32xx_mlc.c mtd/nand/lpc32xx_slc.c net/dsa/dsa_loop.c net/ethernet/mediatek/mtk_eth_soc.c net/phy/xilinx_gmii2rgmii.c net/wireless/ti/wlcore/spi.c pci/host/pcie-iproc-platform.c phy/phy-exynos5250-sata.c phy/phy-mt65xx-usb3.c phy/phy-qcom-qusb2.c phy/phy-sun4i-usb.c pinctrl/core.c pinctrl/pinctrl-at91.c platform/x86/intel_cht_int33fe.c power/supply/act8945a_charger.c power/supply/axp20x_ac_power.c power/supply/axp20x_battery.c power/supply/axp288_charger.c power/supply/bq24190_charger.c power/supply/cpcap-charger.c power/supply/gpio-charger.c soc/bcm/raspberrypi-power.c thermal/samsung/exynos_tmu.c tty/serial/8250/8250_dw.c tty/serial/max310x.c tty/serial/sccnxp.c usb/chipidea/ci_hdrc_msm.c usb/gadget/udc/mv_udc_core.c usb/host/xhci-mtk.c usb/mtu3/mtu3_plat.c usb/musb/sunxi.c usb/phy/phy-am335x.c usb/phy/phy-generic.c usb/phy/phy-twl6030-usb.c video/backlight/hx8357.c video/backlight/lp855x_bl.c video/fbdev/simplefb.c Coccinelle script : =3D=3D=3D=3D=3D=3D=3D=3D// find calls to kmalloc or equivalent function @call@ expression ptr; position p; @@ ( * ptr@p =3D kmalloc(...) | * ptr@p =3D kzalloc(...) | * ptr@p =3D kcalloc(...) | * ptr@p =3D kmalloc_array(...) | * ptr@p =3D devm_kmalloc(...) | * ptr@p =3D devm_kzalloc(...) | * ptr@p =3D devm_kcalloc(...) | * ptr@p =3D devm_kmalloc_array(...) ) ... * return -EPROBE_DEFER; -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html