Sending to lkml also.
Some drivers do not handle failure of misc_register.
Added return value checks appropriately in defaulting drivers
Tested with:
- allmodconfig
- Manually tweaking Kconfig/Makefiles to make sure that the changed
files compiles without any errors/warnings
Signed-off-by: Amol Lad <[email protected]>
---
arch/i386/kernel/apm.c | 23 +++++++++++++++++------
arch/um/drivers/mmapper_kern.c | 6 ++++--
arch/x86_64/kernel/mce.c | 6 +++++-
drivers/char/watchdog/ep93xx_wdt.c | 4 ++++
drivers/input/misc/hp_sdc_rtc.c | 7 ++++++-
drivers/macintosh/apm_emu.c | 8 +++++++-
drivers/macintosh/smu.c | 11 ++++++++---
drivers/macintosh/via-pmu.c | 11 ++++++++---
8 files changed, 59 insertions(+), 17 deletions(-)
---
diff -uprN -X linux-2.6.18-orig/Documentation/dontdiff linux-2.6.18-orig/arch/i386/kernel/apm.c linux-2.6.18/arch/i386/kernel/apm.c
--- linux-2.6.18-orig/arch/i386/kernel/apm.c 2006-09-21 10:15:25.000000000 +0530
+++ linux-2.6.18/arch/i386/kernel/apm.c 2006-09-25 13:59:53.000000000 +0530
@@ -2246,6 +2246,12 @@ static int __init apm_init(void)
return -ENODEV;
}
+ ret = misc_register(&apm_device);
+ if (ret != 0) {
+ printk(KERN_ERR "apm: cannot register misc device.\n");
+ return ret;
+ }
+
if (allow_ints)
apm_info.allow_ints = 1;
if (broken_psr)
@@ -2282,17 +2288,20 @@ static int __init apm_init(void)
if (apm_info.disabled) {
printk(KERN_NOTICE "apm: disabled on user request.\n");
- return -ENODEV;
+ ret = -ENODEV;
+ goto out_misc;
}
if ((num_online_cpus() > 1) && !power_off && !smp) {
printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
apm_info.disabled = 1;
- return -ENODEV;
+ ret = -ENODEV;
+ goto out_misc;
}
if (PM_IS_ACTIVE()) {
printk(KERN_NOTICE "apm: overridden by ACPI.\n");
apm_info.disabled = 1;
- return -ENODEV;
+ ret = -ENODEV;
+ goto out_misc;
}
#ifdef CONFIG_PM_LEGACY
pm_active = 1;
@@ -2339,7 +2348,8 @@ static int __init apm_init(void)
ret = kernel_thread(apm, NULL, CLONE_KERNEL | SIGCHLD);
if (ret < 0) {
printk(KERN_ERR "apm: disabled - Unable to start kernel thread.\n");
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto out_misc;
}
if (num_online_cpus() > 1 && !smp ) {
@@ -2348,8 +2358,6 @@ static int __init apm_init(void)
return 0;
}
- misc_register(&apm_device);
-
if (HZ != 100)
idle_period = (idle_period * HZ) / 100;
if (idle_threshold < 100) {
@@ -2359,6 +2367,9 @@ static int __init apm_init(void)
}
return 0;
+out_misc:
+ misc_deregister(&apm_device);
+ return ret;
}
static void __exit apm_exit(void)
diff -uprN -X linux-2.6.18-orig/Documentation/dontdiff linux-2.6.18-orig/arch/um/drivers/mmapper_kern.c linux-2.6.18/arch/um/drivers/mmapper_kern.c
--- linux-2.6.18-orig/arch/um/drivers/mmapper_kern.c 2006-08-24 02:46:33.000000000 +0530
+++ linux-2.6.18/arch/um/drivers/mmapper_kern.c 2006-09-25 13:23:46.000000000 +0530
@@ -103,7 +103,7 @@ static struct miscdevice mmapper_dev = {
static int __init mmapper_init(void)
{
- int err;
+ int err = 0;
printk(KERN_INFO "Mapper v0.1\n");
@@ -121,8 +121,10 @@ static int __init mmapper_init(void)
}
p_buf = __pa(v_buf);
-out:
+
return 0;
+out:
+ return err;
}
static void mmapper_exit(void)
diff -uprN -X linux-2.6.18-orig/Documentation/dontdiff linux-2.6.18-orig/arch/x86_64/kernel/mce.c linux-2.6.18/arch/x86_64/kernel/mce.c
--- linux-2.6.18-orig/arch/x86_64/kernel/mce.c 2006-09-21 10:15:31.000000000 +0530
+++ linux-2.6.18/arch/x86_64/kernel/mce.c 2006-09-25 14:00:39.000000000 +0530
@@ -663,7 +663,11 @@ static __init int mce_init_device(void)
}
register_hotcpu_notifier(&mce_cpu_notifier);
- misc_register(&mce_log_device);
+
+ err = misc_register(&mce_log_device);
+ if (err != 0)
+ printk(KERN_ERR "MCE: cannot register misc device.\n");
+
return err;
}
diff -uprN -X linux-2.6.18-orig/Documentation/dontdiff linux-2.6.18-orig/drivers/char/watchdog/ep93xx_wdt.c linux-2.6.18/drivers/char/watchdog/ep93xx_wdt.c
--- linux-2.6.18-orig/drivers/char/watchdog/ep93xx_wdt.c 2006-09-21 10:15:32.000000000 +0530
+++ linux-2.6.18/drivers/char/watchdog/ep93xx_wdt.c 2006-09-25 13:23:46.000000000 +0530
@@ -215,6 +215,10 @@ static int __init ep93xx_wdt_init(void)
int err;
err = misc_register(&ep93xx_wdt_miscdev);
+ if (err != 0) {
+ printk(KERN_ERR PFX "cannot register misc device.\n");
+ return err;
+ }
boot_status = __raw_readl(EP93XX_WDT_WATCHDOG) & 0x01 ? 1 : 0;
diff -uprN -X linux-2.6.18-orig/Documentation/dontdiff linux-2.6.18-orig/drivers/input/misc/hp_sdc_rtc.c linux-2.6.18/drivers/input/misc/hp_sdc_rtc.c
--- linux-2.6.18-orig/drivers/input/misc/hp_sdc_rtc.c 2006-08-24 02:46:33.000000000 +0530
+++ linux-2.6.18/drivers/input/misc/hp_sdc_rtc.c 2006-09-25 14:01:36.000000000 +0530
@@ -695,7 +695,12 @@ static int __init hp_sdc_rtc_init(void)
if ((ret = hp_sdc_request_timer_irq(&hp_sdc_rtc_isr)))
return ret;
- misc_register(&hp_sdc_rtc_dev);
+
+ ret = misc_register(&hp_sdc_rtc_dev);
+ if (ret != 0) {
+ printk(KERN_ERR "HP i8042 SDC + MSM-58321 RTC: cannot register misc device.\n");
+ return ret;
+ }
create_proc_read_entry ("driver/rtc", 0, 0,
hp_sdc_rtc_read_proc, NULL);
diff -uprN -X linux-2.6.18-orig/Documentation/dontdiff linux-2.6.18-orig/drivers/macintosh/apm_emu.c linux-2.6.18/drivers/macintosh/apm_emu.c
--- linux-2.6.18-orig/drivers/macintosh/apm_emu.c 2006-09-21 10:15:33.000000000 +0530
+++ linux-2.6.18/drivers/macintosh/apm_emu.c 2006-09-25 14:02:04.000000000 +0530
@@ -519,6 +519,7 @@ static struct miscdevice apm_device = {
static int __init apm_emu_init(void)
{
struct proc_dir_entry *apm_proc;
+ int ret;
if (sys_ctrler != SYS_CTRLER_PMU) {
printk(KERN_INFO "apm_emu: Requires a machine with a PMU.\n");
@@ -529,7 +530,12 @@ static int __init apm_emu_init(void)
if (apm_proc)
apm_proc->owner = THIS_MODULE;
- misc_register(&apm_device);
+ ret = misc_register(&apm_device);
+ if (ret != 0) {
+ printk(KERN_ERR "apm_emu: cannot register misc device.\n");
+ remove_proc_entry("apm", NULL);
+ return ret;
+ }
pmu_register_sleep_notifier(&apm_sleep_notifier);
diff -uprN -X linux-2.6.18-orig/Documentation/dontdiff linux-2.6.18-orig/drivers/macintosh/smu.c linux-2.6.18/drivers/macintosh/smu.c
--- linux-2.6.18-orig/drivers/macintosh/smu.c 2006-09-21 10:15:33.000000000 +0530
+++ linux-2.6.18/drivers/macintosh/smu.c 2006-09-25 14:02:32.000000000 +0530
@@ -1292,10 +1292,15 @@ static struct miscdevice pmu_device = {
static int smu_device_init(void)
{
+ int ret = 0;
+
if (!smu)
return -ENODEV;
- if (misc_register(&pmu_device) < 0)
- printk(KERN_ERR "via-pmu: cannot register misc device.\n");
- return 0;
+
+ ret = misc_register(&pmu_device);
+ if (ret != 0)
+ printk(KERN_ERR "SMU: cannot register misc device.\n");
+
+ return ret;
}
device_initcall(smu_device_init);
diff -uprN -X linux-2.6.18-orig/Documentation/dontdiff linux-2.6.18-orig/drivers/macintosh/via-pmu.c linux-2.6.18/drivers/macintosh/via-pmu.c
--- linux-2.6.18-orig/drivers/macintosh/via-pmu.c 2006-09-21 10:15:33.000000000 +0530
+++ linux-2.6.18/drivers/macintosh/via-pmu.c 2006-09-25 14:03:02.000000000 +0530
@@ -2678,11 +2678,16 @@ static struct miscdevice pmu_device = {
static int pmu_device_init(void)
{
+ int ret = 0;
+
if (!via)
return 0;
- if (misc_register(&pmu_device) < 0)
- printk(KERN_ERR "via-pmu: cannot register misc device.\n");
- return 0;
+
+ ret = misc_register(&pmu_device);
+ if (ret != 0)
+ printk(KERN_ERR "pmu: cannot register misc device.\n");
+
+ return ret;
}
device_initcall(pmu_device_init);
On Mon, 25 Sep 2006 14:13:01 +0530 Amol Lad <[email protected]> wrote:
>
> diff -uprN -X linux-2.6.18-orig/Documentation/dontdiff linux-2.6.18-orig/arch/i386/kernel/apm.c linux-2.6.18/arch/i386/kernel/apm.c
> --- linux-2.6.18-orig/arch/i386/kernel/apm.c 2006-09-21 10:15:25.000000000 +0530
> +++ linux-2.6.18/arch/i386/kernel/apm.c 2006-09-25 13:59:53.000000000 +0530
> @@ -2246,6 +2246,12 @@ static int __init apm_init(void)
> return -ENODEV;
> }
>
> + ret = misc_register(&apm_device);
> + if (ret != 0) {
> + printk(KERN_ERR "apm: cannot register misc device.\n");
> + return ret;
> + }
> +
NAK. (This has been NAKed at least twice - I guess we need to add a
comment - see patch below) The apm module can still do useful work even
if the misc_register() fails.
> if (allow_ints)
> apm_info.allow_ints = 1;
> if (broken_psr)
> @@ -2282,17 +2288,20 @@ static int __init apm_init(void)
>
> if (apm_info.disabled) {
> printk(KERN_NOTICE "apm: disabled on user request.\n");
> - return -ENODEV;
> + ret = -ENODEV;
> + goto out_misc;
> }
> if ((num_online_cpus() > 1) && !power_off && !smp) {
> printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
> apm_info.disabled = 1;
> - return -ENODEV;
> + ret = -ENODEV;
> + goto out_misc;
> }
> if (PM_IS_ACTIVE()) {
> printk(KERN_NOTICE "apm: overridden by ACPI.\n");
> apm_info.disabled = 1;
> - return -ENODEV;
> + ret = -ENODEV;
> + goto out_misc;
> }
> #ifdef CONFIG_PM_LEGACY
> pm_active = 1;
> @@ -2339,7 +2348,8 @@ static int __init apm_init(void)
> ret = kernel_thread(apm, NULL, CLONE_KERNEL | SIGCHLD);
> if (ret < 0) {
> printk(KERN_ERR "apm: disabled - Unable to start kernel thread.\n");
> - return -ENOMEM;
> + ret = -ENOMEM;
> + goto out_misc;
> }
>
> if (num_online_cpus() > 1 && !smp ) {
> @@ -2348,8 +2358,6 @@ static int __init apm_init(void)
> return 0;
> }
>
> - misc_register(&apm_device);
> -
> if (HZ != 100)
> idle_period = (idle_period * HZ) / 100;
> if (idle_threshold < 100) {
> @@ -2359,6 +2367,9 @@ static int __init apm_init(void)
> }
>
> return 0;
> +out_misc:
> + misc_deregister(&apm_device);
> + return ret;
> }
So the rest is unnecessary as well ...
--
Cheers,
Stephen Rothwell [email protected]
http://www.canb.auug.org.au/~sfr/
Note that we don't need to check the misc_register() return value in apm.c
Signed-off-by: Stephen Rothwell <[email protected]>
diff --git a/arch/i386/kernel/apm.c b/arch/i386/kernel/apm.c
index 8591f2f..b74ebf1 100644
--- a/arch/i386/kernel/apm.c
+++ b/arch/i386/kernel/apm.c
@@ -2348,6 +2348,11 @@ #endif
return 0;
}
+ /*
+ * We don't check the return value of misc_register() because
+ * the driver can still do very useful work even without the
+ * user mode access provided by the misc device.
+ */
misc_register(&apm_device);
if (HZ != 100)