[PATCH 1/3] viafb: Fix various resource leaks during module_init()

The current code executed from module_init() in viafb does not have
proper error checking and [partial] resoure release paths in case
an error happens half way through driver initialization.

This patch adresses the most obvious of those issues, such as a
leftover i2c bus if module_init (and thus module load) fails.

Signed-off-by: Harald Welte <redacted>
---
 drivers/video/via/viafbdev.c |   51 +++++++++++++++++++++++++++++++----------
 1 files changed, 38 insertions(+), 13 deletions(-)

diff --git a/drivers/video/via/viafbdev.c b/drivers/video/via/viafbdev.c
index a0fec29..61dcb13 100644
--- a/drivers/video/via/viafbdev.c
+++ b/drivers/video/via/viafbdev.c

@@ -1,5 +1,5 @@
 /*
- * Copyright 1998-2008 VIA Technologies, Inc. All Rights Reserved.
+ * Copyright 1998-2009 VIA Technologies, Inc. All Rights Reserved.
  * Copyright 2001-2008 S3 Graphics, Inc. All Rights Reserved.
 
  * This program is free software; you can redistribute it and/or

@@ -2106,7 +2106,7 @@ static int __devinit via_pci_probe(void)
 	unsigned long default_xres, default_yres;
 	char *tmpc, *tmpm;
 	char *tmpc_sec, *tmpm_sec;
-	int vmode_index;
+	int rc, vmode_index;
 	u32 tmds_length, lvds_length, crt_length, chip_length, viafb_par_length;
 
 	DEBUG_MSG(KERN_INFO "VIAFB PCI Probe!!\n");

@@ -2127,7 +2127,7 @@ static int __devinit via_pci_probe(void)
 	tmds_length + crt_length + chip_length, NULL);
 	if (!viafbinfo) {
 		printk(KERN_ERR"Could not allocate memory for viafb_info.\n");
-		return -ENODEV;
+		return -ENOMEM;
 	}
 
 	viaparinfo = (struct viafb_par *)viafbinfo->par;

@@ -2154,7 +2154,9 @@ static int __devinit via_pci_probe(void)
 		viafb_dual_fb = 0;
 
 	/* Set up I2C bus stuff */
-	viafb_create_i2c_bus(viaparinfo);
+	rc = viafb_create_i2c_bus(viaparinfo);
+	if (rc)
+		goto out_fb_release;
 
 	viafb_init_chip_info();
 	viafb_get_fb_info(&viaparinfo->fbmem, &viaparinfo->memsize);

@@ -2166,7 +2168,8 @@ static int __devinit via_pci_probe(void)
 
 	if (!viaparinfo->fbmem_virt) {
 		printk(KERN_INFO "ioremap failed\n");
-		return -1;
+		rc = -EIO;
+		goto out_delete_i2c;
 	}
 
 	viafb_get_mmio_info(&viaparinfo->mmio_base, &viaparinfo->mmio_len);

@@ -2279,7 +2282,7 @@ static int __devinit via_pci_probe(void)
 			printk(KERN_ERR
 			"allocate the second framebuffer struct error\n");
 			framebuffer_release(viafbinfo);
-			return -ENOMEM;
+			goto out_delete_i2c;
 		}
 		viaparinfo1 = viafbinfo1->par;
 		memcpy(viaparinfo1, viaparinfo, viafb_par_length);

@@ -2340,21 +2343,26 @@ static int __devinit via_pci_probe(void)
 	viafb_update_viafb_par(viafbinfo);
 	viafb_update_fix(&viafbinfo->fix, viafbinfo);
 	default_var.activate = FB_ACTIVATE_NOW;
-	fb_alloc_cmap(&viafbinfo->cmap, 256, 0);
+	rc = fb_alloc_cmap(&viafbinfo->cmap, 256, 0);
+	if (rc)
+		goto out_fb1_release;
 
 	if (viafb_dual_fb && (viafb_primary_dev == LCD_Device)
 	    && (viaparinfo->chip_info->gfx_chip_name == UNICHROME_CLE266)) {
-		if (register_framebuffer(viafbinfo1) < 0)
-			return -EINVAL;
+		rc = register_framebuffer(viafbinfo1);
+		if (rc)
+			goto out_dealloc_cmap;
 	}
-	if (register_framebuffer(viafbinfo) < 0)
-		return -EINVAL;
+	rc = register_framebuffer(viafbinfo);
+	if (rc)
+		goto out_fb1_unreg_lcd_cle266;
 
 	if (viafb_dual_fb && ((viafb_primary_dev != LCD_Device)
 			|| (viaparinfo->chip_info->gfx_chip_name !=
 			UNICHROME_CLE266))) {
-		if (register_framebuffer(viafbinfo1) < 0)
-			return -EINVAL;
+		rc = register_framebuffer(viafbinfo1);
+		if (rc)
+			goto out_fb_unreg;
 	}
 	DEBUG_MSG(KERN_INFO "fb%d: %s frame buffer device %dx%d-%dbpp\n",
 		  viafbinfo->node, viafbinfo->fix.id, default_var.xres,

@@ -2363,6 +2371,23 @@ static int __devinit via_pci_probe(void)
 	viafb_init_proc(&viaparinfo->proc_entry);
 	viafb_init_dac(IGA2);
 	return 0;
+
+out_fb_unreg:
+	unregister_framebuffer(viafbinfo);
+out_fb1_unreg_lcd_cle266:
+	if (viafbinfo1 && (viafb_primary_dev == LCD_Device)
+            && (viaparinfo->chip_info->gfx_chip_name == UNICHROME_CLE266))
+		unregister_framebuffer(viafbinfo1);
+out_dealloc_cmap:
+	fb_dealloc_cmap(&viafbinfo->cmap);
+out_fb1_release:
+	if (viafbinfo1)
+		framebuffer_release(viafbinfo1);
+out_delete_i2c:
+	viafb_delete_i2c_buss(viaparinfo);
+out_fb_release:
+	framebuffer_release(viafbinfo);
+	return rc;
 }
 
 static void __devexit via_pci_remove(void)

-- 
1.6.2.4

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Hi Harald,

On Tue, 19 May 2009 11:51:05 +0800
Harald Welte [off-list ref] wrote:

I strongly recommend not to duplicate standard fields: fb_info.fix.smem_base and 
fb_info.fix.smem_len  (and fb_info.screen_base and fb_info.screen_size).

I would like to see conversion:
viainfo->fbmem => viaifbnfo->screen_base (physical address)
? => viafbinfo->screen_size (physical size)
viaparinfo->fbmem_virt => viafbinfo->fix.smem_start (virtual address)
viaparinfo->memsize => viafbinfo->fix.smem_len (virtual size)

You may try dropping the global viaparinfo pointer as well (and just get it
as viafbinfo->par if needed).

These changes should be sent as a separate patch.

The framebuffer_release(viafbinfo) will be called twice now.

The condition here differs from the condition used during viafbinfo1 register
(viafb_dual_fb vs. viafbinfo1).

+out_dealloc_cmap:
+	fb_dealloc_cmap(&viafbinfo->cmap);
+out_fb1_release:
+	if (viafbinfo1)
+		framebuffer_release(viafbinfo1);
+out_delete_i2c:
+	viafb_delete_i2c_buss(viaparinfo);
+out_fb_release:
+	framebuffer_release(viafbinfo);
+	return rc;
 }
 
 static void __devexit via_pci_remove(void)
-- 
1.6.2.4

Kind regards,
Krzysztof

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Hi Krysztof,

thanks for your feedback.

On Tue, May 19, 2009 at 10:00:43AM +0200, Krzysztof Helt wrote:

I strongly recommend not to duplicate standard fields: fb_info.fix.smem_base and 
fb_info.fix.smem_len  (and fb_info.screen_base and fb_info.screen_size).

of course.  I have just started to dig into viafb, and there is a long list of
issues that I'd like to improve over time. getting rid of a lot of global
variables, duplicated fields, bringing it more in line with the kernel
infrastructure as well as improving the overall code structure...

I would like to see conversion:
viainfo->fbmem => viaifbnfo->screen_base (physical address)
? => viafbinfo->screen_size (physical size)
viaparinfo->fbmem_virt => viafbinfo->fix.smem_start (virtual address)
viaparinfo->memsize => viafbinfo->fix.smem_len (virtual size)

You may try dropping the global viaparinfo pointer as well (and just get it
as viafbinfo->par if needed).

These changes should be sent as a separate patch.

yes, I will do this as a cleanup patch on top of my current work.

quoted

 	viafb_get_mmio_info(&viaparinfo->mmio_base, &viaparinfo->mmio_len);

@@ -2279,7 +2282,7 @@ static int __devinit via_pci_probe(void)
 			printk(KERN_ERR
 			"allocate the second framebuffer struct error\n");
 			framebuffer_release(viafbinfo);
-			return -ENOMEM;
+			goto out_delete_i2c;
 		}

The framebuffer_release(viafbinfo) will be called twice now.

good catch, fixed in my tree now.

quoted

+
+out_fb_unreg:
+	unregister_framebuffer(viafbinfo);
+out_fb1_unreg_lcd_cle266:
+	if (viafbinfo1 && (viafb_primary_dev == LCD_Device)
+            && (viaparinfo->chip_info->gfx_chip_name == UNICHROME_CLE266))
+		unregister_framebuffer(viafbinfo1);

The condition here differs from the condition used during viafbinfo1 register
(viafb_dual_fb vs. viafbinfo1).

thanks.  This was actually intentional, since it only makes sense to unregister
viafbinfo1 if it actually exists.  But in any case, it doesn't make a practical
difference, so I have altered it to check for viafb_dual_info

-- 
- Harald Welte [off-list ref]	    http://linux.via.com.tw/
============================================================================
VIA Open Source Liaison

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