From 3b8cb427e9281790f36e847e46cb1d005a50cec0 Mon Sep 17 00:00:00 2001 From: Chen Gong Date: Mon, 14 Dec 2009 09:42:28 +0800 Subject: acpi_pad: fix error checks There are some fixes listed below: 1. When met a bogus BIOS, the return value of cpu number maybe is a negative value so that acpi_pad_pur get an unexpected result. 2. the return value of function acpi_pad_idle_cpus is useless. 3. enhance the process of create_power_saving_task/destroy_power_saving_task 4. Add more error checks when evaluating _PUR object. 5. one typo fix Signed-off-by: Chen Gong Acked-by: Shaohua Li Signed-off-by: Len Brown --- drivers/acpi/acpi_pad.c | 37 ++++++++++++++++++++----------------- 1 file changed, 20 insertions(+), 17 deletions(-) (limited to 'drivers/acpi/acpi_pad.c') diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c index 0d2cdb86158b..a7bd49f0f01f 100644 --- a/drivers/acpi/acpi_pad.c +++ b/drivers/acpi/acpi_pad.c @@ -207,7 +207,7 @@ static int power_saving_thread(void *data) * the mechanism only works when all CPUs have RT task running, * as if one CPU hasn't RT task, RT task from other CPUs will * borrow CPU time from this CPU and cause RT task use > 95% - * CPU time. To make 'avoid staration' work, takes a nap here. + * CPU time. To make 'avoid starvation' work, takes a nap here. */ if (do_sleep) schedule_timeout_killable(HZ * idle_pct / 100); @@ -221,14 +221,18 @@ static struct task_struct *ps_tsks[NR_CPUS]; static unsigned int ps_tsk_num; static int create_power_saving_task(void) { + int rc = -ENOMEM; + ps_tsks[ps_tsk_num] = kthread_run(power_saving_thread, (void *)(unsigned long)ps_tsk_num, "power_saving/%d", ps_tsk_num); - if (ps_tsks[ps_tsk_num]) { + rc = IS_ERR(ps_tsks[ps_tsk_num]) ? PTR_ERR(ps_tsks[ps_tsk_num]) : 0; + if (!rc) ps_tsk_num++; - return 0; - } - return -EINVAL; + else + ps_tsks[ps_tsk_num] = NULL; + + return rc; } static void destroy_power_saving_task(void) @@ -236,6 +240,7 @@ static void destroy_power_saving_task(void) if (ps_tsk_num > 0) { ps_tsk_num--; kthread_stop(ps_tsks[ps_tsk_num]); + ps_tsks[ps_tsk_num] = NULL; } } @@ -252,7 +257,7 @@ static void set_power_saving_task_num(unsigned int num) } } -static int acpi_pad_idle_cpus(unsigned int num_cpus) +static void acpi_pad_idle_cpus(unsigned int num_cpus) { get_online_cpus(); @@ -260,7 +265,6 @@ static int acpi_pad_idle_cpus(unsigned int num_cpus) set_power_saving_task_num(num_cpus); put_online_cpus(); - return 0; } static uint32_t acpi_pad_idle_cpus_num(void) @@ -368,19 +372,21 @@ static void acpi_pad_remove_sysfs(struct acpi_device *device) static int acpi_pad_pur(acpi_handle handle, int *num_cpus) { struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; - acpi_status status; union acpi_object *package; int rev, num, ret = -EINVAL; - status = acpi_evaluate_object(handle, "_PUR", NULL, &buffer); - if (ACPI_FAILURE(status)) + if (ACPI_FAILURE(acpi_evaluate_object(handle, "_PUR", NULL, &buffer))) + return -EINVAL; + + if (!buffer.length || !buffer.pointer) return -EINVAL; + package = buffer.pointer; if (package->type != ACPI_TYPE_PACKAGE || package->package.count != 2) goto out; rev = package->package.elements[0].integer.value; num = package->package.elements[1].integer.value; - if (rev != 1) + if (rev != 1 || num < 0) goto out; *num_cpus = num; ret = 0; @@ -409,7 +415,7 @@ static void acpi_pad_ost(acpi_handle handle, int stat, static void acpi_pad_handle_notify(acpi_handle handle) { - int num_cpus, ret; + int num_cpus; uint32_t idle_cpus; mutex_lock(&isolated_cpus_lock); @@ -417,12 +423,9 @@ static void acpi_pad_handle_notify(acpi_handle handle) mutex_unlock(&isolated_cpus_lock); return; } - ret = acpi_pad_idle_cpus(num_cpus); + acpi_pad_idle_cpus(num_cpus); idle_cpus = acpi_pad_idle_cpus_num(); - if (!ret) - acpi_pad_ost(handle, 0, idle_cpus); - else - acpi_pad_ost(handle, 1, 0); + acpi_pad_ost(handle, 0, idle_cpus); mutex_unlock(&isolated_cpus_lock); } -- cgit v1.2.3-58-ga151