| Message ID | 1354984288-773-1-git-send-email-Julia.Lawall@lip6.fr (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, 2012-12-08 at 17:31 +0100, Julia Lawall wrote: > From: Julia Lawall <Julia.Lawall@lip6.fr> > > The various devm_ functions allocate memory that is released when a driver > detaches. This patch uses these functions for data that is allocated in > the probe function of a platform device and is only freed in the remove > function. > > The patch makes some other cleanups. First, the original code used > devm_kzalloc, but kfree. This would lead to a double free. The problem > was found using the following semantic match (http://coccinelle.lip6.fr/): > > // <smpl> > @@ > expression x,e; > @@ > x = devm_kzalloc(...) > ... when != x = e > ?-kfree(x,...); > // </smpl> > > The error-handling code for the call to dma_alloc_coherent is copied to the > end of the function, like the other error-handling code. Given the > introduction of the devm functions, this is just for uniformity, because > the label at the end of the function now just returns the error code. > > A semicolon is removed at the end of this error handling code. > > The call platform_set_drvdata(pdev, NULL); is moved up under the label > failed_free_cmap, because platform_set_drvdata(pdev, fbi); doesn't happen > in the function until after gotos to this label are reached. > > The initializations of fbi and ret are not necessary and are removed. > > Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> > > --- > drivers/video/wm8505fb.c | 44 ++++++++------------------------------------ > 1 file changed, 8 insertions(+), 36 deletions(-) > > diff --git a/drivers/video/wm8505fb.c b/drivers/video/wm8505fb.c > index 77539c1..3bad805 100644 > --- a/drivers/video/wm8505fb.c > +++ b/drivers/video/wm8505fb.c > @@ -274,9 +274,6 @@ static int __devinit wm8505fb_probe(struct platform_device *pdev) > unsigned long fb_mem_len; > void *fb_mem_virt; > > - ret = -ENOMEM; > - fbi = NULL; > - > fbi = devm_kzalloc(&pdev->dev, sizeof(struct wm8505fb_info) + > sizeof(u32) * 16, GFP_KERNEL); > if (!fbi) { > @@ -308,31 +305,19 @@ static int __devinit wm8505fb_probe(struct platform_device *pdev) > fbi->fb.pseudo_palette = addr; > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > - if (res == NULL) { > - dev_err(&pdev->dev, "no I/O memory resource defined\n"); > - ret = -ENODEV; > - goto failed_fbi; > - } > - > - res = request_mem_region(res->start, resource_size(res), DRIVER_NAME); > - if (res == NULL) { > - dev_err(&pdev->dev, "failed to request I/O memory\n"); > - ret = -EBUSY; > - goto failed_fbi; > - } > > - fbi->regbase = ioremap(res->start, resource_size(res)); > + fbi->regbase = devm_request_and_ioremap(&pdev->dev, res); > if (fbi->regbase == NULL) { > dev_err(&pdev->dev, "failed to map I/O memory\n"); > ret = -EBUSY; > - goto failed_free_res; > + goto failed; > } > > np = of_parse_phandle(pdev->dev.of_node, "default-mode", 0); > if (!np) { > pr_err("%s: No display description in Device Tree\n", __func__); > ret = -EINVAL; > - goto failed_free_res; > + goto failed; > } > > /* > @@ -351,7 +336,7 @@ static int __devinit wm8505fb_probe(struct platform_device *pdev) > ret |= of_property_read_u32(np, "bpp", &bpp); > if (ret) { > pr_err("%s: Unable to read display properties\n", __func__); > - goto failed_free_res; > + goto failed; > } > > of_mode.vmode = FB_VMODE_NONINTERLACED; > @@ -369,8 +354,9 @@ static int __devinit wm8505fb_probe(struct platform_device *pdev) > GFP_KERNEL); > if (!fb_mem_virt) { > pr_err("%s: Failed to allocate framebuffer\n", __func__); > - return -ENOMEM; > - }; > + ret = -ENOMEM; > + goto failed; > + } > > fbi->fb.var.xres_virtual = of_mode.xres; > fbi->fb.var.yres_virtual = of_mode.yres * 2; > @@ -384,7 +370,7 @@ static int __devinit wm8505fb_probe(struct platform_device *pdev) > if (fb_alloc_cmap(&fbi->fb.cmap, 256, 0) < 0) { > dev_err(&pdev->dev, "Failed to allocate color map\n"); > ret = -ENOMEM; > - goto failed_free_io; > + goto failed; > } > > wm8505fb_init_hw(&fbi->fb); > @@ -420,13 +406,7 @@ static int __devinit wm8505fb_probe(struct platform_device *pdev) > failed_free_cmap: > if (fbi->fb.cmap.len) > fb_dealloc_cmap(&fbi->fb.cmap); > -failed_free_io: > - iounmap(fbi->regbase); > -failed_free_res: > - release_mem_region(res->start, resource_size(res)); > -failed_fbi: > platform_set_drvdata(pdev, NULL); > - kfree(fbi); > failed: > return ret; > } > @@ -434,7 +414,6 @@ failed: > static int __devexit wm8505fb_remove(struct platform_device *pdev) > { > struct wm8505fb_info *fbi = platform_get_drvdata(pdev); > - struct resource *res; > > device_remove_file(&pdev->dev, &dev_attr_contrast); > > @@ -445,13 +424,6 @@ static int __devexit wm8505fb_remove(struct platform_device *pdev) > if (fbi->fb.cmap.len) > fb_dealloc_cmap(&fbi->fb.cmap); > > - iounmap(fbi->regbase); > - > - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > - release_mem_region(res->start, resource_size(res)); > - > - kfree(fbi); > - > return 0; > } > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel Julia, Thanks for the cleanup on this driver. Perhaps I could suggest just one additional thing. There are only two paths which lead to failed_free_cmap. Moving ... fbi->contrast = 0x80; ret = wm8505fb_set_par(&fbi->fb); if (ret) { dev_err(&pdev->dev, "Failed to set parameters\n"); goto failed_free_cmap; } ... above the following line removes the need to have the failed_free_cmap path at all. ... if (fb_alloc_cmap(&fbi->fb.cmap, 256, 0) < 0) { ... If that is done, only this code leads to the failed_free_cmap path: ... ret = register_framebuffer(&fbi->fb); if (ret < 0) { dev_err(&pdev->dev, "Failed to register framebuffer device: %d\n", ret); goto failed_free_cmap; } ... Rather than the goto, add the fail path code in directly, and return. ret = register_framebuffer(&fbi->fb); if (ret < 0) { dev_err(&pdev->dev, "Failed to register framebuffer device: %d\n", ret); if (fbi->fb.cmap.len) fb_dealloc_cmap(&fbi->fb.cmap); return ret; } Now there is no need for any goto commands, and all the rest can be replaced with 'return ret' or equiv. Regards Tony P
> Rather than the goto, add the fail path code in directly, and return. > > > ret = register_framebuffer(&fbi->fb); > if (ret < 0) { > dev_err(&pdev->dev, > "Failed to register framebuffer device: %d\n", ret); > if (fbi->fb.cmap.len) > fb_dealloc_cmap(&fbi->fb.cmap); > return ret; > } So there is no need for the platform_set_drvdata(pdev, NULL); ? Also, do you know if it is correct that the original code does not include a call to dma_free_coherent? thanks, julia
On Sun, 2012-12-09 at 08:21 +0100, Julia Lawall wrote: > > Rather than the goto, add the fail path code in directly, and return. > > > > > > ret = register_framebuffer(&fbi->fb); > > if (ret < 0) { > > dev_err(&pdev->dev, > > "Failed to register framebuffer device: %d\n", ret); > > if (fbi->fb.cmap.len) > > fb_dealloc_cmap(&fbi->fb.cmap); > > return ret; > > } > > So there is no need for the platform_set_drvdata(pdev, NULL); ? Unless there is some kind of reference counting, I can't see any reason for this. > > Also, do you know if it is correct that the original code does not include > a call to dma_free_coherent? No, that is not correct - there definitely should be a dma_free_coherent, both in the fail path and in the remove(). Appears they are both missing. Regards Tony P
diff --git a/drivers/video/wm8505fb.c b/drivers/video/wm8505fb.c index 77539c1..3bad805 100644 --- a/drivers/video/wm8505fb.c +++ b/drivers/video/wm8505fb.c @@ -274,9 +274,6 @@ static int __devinit wm8505fb_probe(struct platform_device *pdev) unsigned long fb_mem_len; void *fb_mem_virt; - ret = -ENOMEM; - fbi = NULL; - fbi = devm_kzalloc(&pdev->dev, sizeof(struct wm8505fb_info) + sizeof(u32) * 16, GFP_KERNEL); if (!fbi) { @@ -308,31 +305,19 @@ static int __devinit wm8505fb_probe(struct platform_device *pdev) fbi->fb.pseudo_palette = addr; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (res == NULL) { - dev_err(&pdev->dev, "no I/O memory resource defined\n"); - ret = -ENODEV; - goto failed_fbi; - } - - res = request_mem_region(res->start, resource_size(res), DRIVER_NAME); - if (res == NULL) { - dev_err(&pdev->dev, "failed to request I/O memory\n"); - ret = -EBUSY; - goto failed_fbi; - } - fbi->regbase = ioremap(res->start, resource_size(res)); + fbi->regbase = devm_request_and_ioremap(&pdev->dev, res); if (fbi->regbase == NULL) { dev_err(&pdev->dev, "failed to map I/O memory\n"); ret = -EBUSY; - goto failed_free_res; + goto failed; } np = of_parse_phandle(pdev->dev.of_node, "default-mode", 0); if (!np) { pr_err("%s: No display description in Device Tree\n", __func__); ret = -EINVAL; - goto failed_free_res; + goto failed; } /* @@ -351,7 +336,7 @@ static int __devinit wm8505fb_probe(struct platform_device *pdev) ret |= of_property_read_u32(np, "bpp", &bpp); if (ret) { pr_err("%s: Unable to read display properties\n", __func__); - goto failed_free_res; + goto failed; } of_mode.vmode = FB_VMODE_NONINTERLACED; @@ -369,8 +354,9 @@ static int __devinit wm8505fb_probe(struct platform_device *pdev) GFP_KERNEL); if (!fb_mem_virt) { pr_err("%s: Failed to allocate framebuffer\n", __func__); - return -ENOMEM; - }; + ret = -ENOMEM; + goto failed; + } fbi->fb.var.xres_virtual = of_mode.xres; fbi->fb.var.yres_virtual = of_mode.yres * 2; @@ -384,7 +370,7 @@ static int __devinit wm8505fb_probe(struct platform_device *pdev) if (fb_alloc_cmap(&fbi->fb.cmap, 256, 0) < 0) { dev_err(&pdev->dev, "Failed to allocate color map\n"); ret = -ENOMEM; - goto failed_free_io; + goto failed; } wm8505fb_init_hw(&fbi->fb); @@ -420,13 +406,7 @@ static int __devinit wm8505fb_probe(struct platform_device *pdev) failed_free_cmap: if (fbi->fb.cmap.len) fb_dealloc_cmap(&fbi->fb.cmap); -failed_free_io: - iounmap(fbi->regbase); -failed_free_res: - release_mem_region(res->start, resource_size(res)); -failed_fbi: platform_set_drvdata(pdev, NULL); - kfree(fbi); failed: return ret; } @@ -434,7 +414,6 @@ failed: static int __devexit wm8505fb_remove(struct platform_device *pdev) { struct wm8505fb_info *fbi = platform_get_drvdata(pdev); - struct resource *res; device_remove_file(&pdev->dev, &dev_attr_contrast); @@ -445,13 +424,6 @@ static int __devexit wm8505fb_remove(struct platform_device *pdev) if (fbi->fb.cmap.len) fb_dealloc_cmap(&fbi->fb.cmap); - iounmap(fbi->regbase); - - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - release_mem_region(res->start, resource_size(res)); - - kfree(fbi); - return 0; }