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Diffstat (limited to 'driver/gator_cookies.c')
-rw-r--r--driver/gator_cookies.c67
1 files changed, 38 insertions, 29 deletions
diff --git a/driver/gator_cookies.c b/driver/gator_cookies.c
index 5c7d842..c43cce8 100644
--- a/driver/gator_cookies.c
+++ b/driver/gator_cookies.c
@@ -7,8 +7,10 @@
*
*/
-#define COOKIEMAP_ENTRIES 1024 /* must be power of 2 */
-#define TRANSLATE_BUFFER_SIZE 512 // must be a power of 2 - 512/4 = 128 entries
+/* must be power of 2 */
+#define COOKIEMAP_ENTRIES 1024
+/* must be a power of 2 - 512/4 = 128 entries */
+#define TRANSLATE_BUFFER_SIZE 512
#define TRANSLATE_TEXT_SIZE 256
#define MAX_COLLISIONS 2
@@ -38,6 +40,7 @@ static uint32_t cookiemap_code(uint64_t value64)
{
uint32_t value = (uint32_t)((value64 >> 32) + value64);
uint32_t cookiecode = (value >> 24) & 0xff;
+
cookiecode = cookiecode * 31 + ((value >> 16) & 0xff);
cookiecode = cookiecode * 31 + ((value >> 8) & 0xff);
cookiecode = cookiecode * 31 + ((value >> 0) & 0xff);
@@ -52,9 +55,8 @@ static uint32_t gator_chksum_crc32(const char *data)
int i, length = strlen(data);
crc = 0xFFFFFFFF;
- for (i = 0; i < length; i++) {
+ for (i = 0; i < length; i++)
crc = ((crc >> 8) & 0x00FFFFFF) ^ gator_crc32_table[(crc ^ *block++) & 0xFF];
- }
return (crc ^ 0xFFFFFFFF);
}
@@ -72,11 +74,12 @@ static uint32_t cookiemap_exists(uint64_t key)
uint64_t *keys = &(per_cpu(cookie_keys, cpu)[cookiecode]);
uint32_t *values = &(per_cpu(cookie_values, cpu)[cookiecode]);
- // Can be called from interrupt handler or from work queue
+ /* Can be called from interrupt handler or from work queue */
local_irq_save(flags);
for (x = 0; x < MAX_COLLISIONS; x++) {
if (keys[x] == key) {
uint32_t value = values[x];
+
for (; x > 0; x--) {
keys[x] = keys[x - 1];
values[x] = values[x - 1];
@@ -126,7 +129,7 @@ static void translate_buffer_write_args(int cpu, struct task_struct *task, const
write = per_cpu(translate_buffer_write, cpu);
next_write = (write + 1) & translate_buffer_mask;
- // At least one entry must always remain available as when read == write, the queue is empty not full
+ /* At least one entry must always remain available as when read == write, the queue is empty not full */
if (next_write != per_cpu(translate_buffer_read, cpu)) {
args = &per_cpu(translate_buffer, cpu)[write];
args->task = task;
@@ -178,11 +181,11 @@ static void wq_cookie_handler(struct work_struct *unused)
static void app_process_wake_up_handler(unsigned long unused_data)
{
- // had to delay scheduling work as attempting to schedule work during the context switch is illegal in kernel versions 3.5 and greater
+ /* had to delay scheduling work as attempting to schedule work during the context switch is illegal in kernel versions 3.5 and greater */
schedule_work(&cookie_work);
}
-// Retrieve full name from proc/pid/cmdline for java processes on Android
+/* Retrieve full name from proc/pid/cmdline for java processes on Android */
static int translate_app_process(const char **text, int cpu, struct task_struct *task, bool from_wq)
{
void *maddr;
@@ -195,12 +198,16 @@ static int translate_app_process(const char **text, int cpu, struct task_struct
char *buf = per_cpu(translate_text, cpu);
#ifndef CONFIG_PREEMPT_RT_FULL
- // Push work into a work queue if in atomic context as the kernel functions below might sleep
- // Rely on the in_interrupt variable rather than in_irq() or in_interrupt() kernel functions, as the value of these functions seems
- // inconsistent during a context switch between android/linux versions
+ /* Push work into a work queue if in atomic context as the kernel
+ * functions below might sleep. Rely on the in_interrupt variable
+ * rather than in_irq() or in_interrupt() kernel functions, as the
+ * value of these functions seems inconsistent during a context
+ * switch between android/linux versions
+ */
if (!from_wq) {
- // Check if already in buffer
+ /* Check if already in buffer */
int pos = per_cpu(translate_buffer_read, cpu);
+
while (pos != per_cpu(translate_buffer_write, cpu)) {
if (per_cpu(translate_buffer, cpu)[pos].task == task)
goto out;
@@ -209,7 +216,7 @@ static int translate_app_process(const char **text, int cpu, struct task_struct
translate_buffer_write_args(cpu, task, *text);
- // Not safe to call in RT-Preempt full in schedule switch context
+ /* Not safe to call in RT-Preempt full in schedule switch context */
mod_timer(&app_process_wake_up_timer, jiffies + 1);
goto out;
}
@@ -239,7 +246,8 @@ static int translate_app_process(const char **text, int cpu, struct task_struct
copy_from_user_page(page_vma, page, addr, buf, maddr + offset, bytes);
- kunmap(page); // release page allocated by get_user_pages()
+ /* release page allocated by get_user_pages() */
+ kunmap(page);
page_cache_release(page);
len -= bytes;
@@ -250,7 +258,7 @@ static int translate_app_process(const char **text, int cpu, struct task_struct
retval = 1;
}
- // On app_process startup, /proc/pid/cmdline is initially "zygote" then "<pre-initialized>" but changes after an initial startup period
+ /* On app_process startup, /proc/pid/cmdline is initially "zygote" then "<pre-initialized>" but changes after an initial startup period */
if (strcmp(*text, "zygote") == 0 || strcmp(*text, "<pre-initialized>") == 0)
retval = 0;
@@ -262,6 +270,8 @@ out:
return retval;
}
+static const char APP_PROCESS[] = "app_process";
+
static uint32_t get_cookie(int cpu, struct task_struct *task, const char *text, bool from_wq)
{
unsigned long flags, cookie;
@@ -271,16 +281,16 @@ static uint32_t get_cookie(int cpu, struct task_struct *task, const char *text,
key = (key << 32) | (uint32_t)task->tgid;
cookie = cookiemap_exists(key);
- if (cookie) {
+ if (cookie)
return cookie;
- }
- if (strcmp(text, "app_process") == 0) {
+ /* On 64-bit android app_process can be app_process32 or app_process64 */
+ if (strncmp(text, APP_PROCESS, sizeof(APP_PROCESS) - 1) == 0) {
if (!translate_app_process(&text, cpu, task, from_wq))
return UNRESOLVED_COOKIE;
}
- // Can be called from interrupt handler or from work queue or from scheduler trace
+ /* Can be called from interrupt handler or from work queue or from scheduler trace */
local_irq_save(flags);
cookie = UNRESOLVED_COOKIE;
@@ -300,7 +310,7 @@ static int get_exec_cookie(int cpu, struct task_struct *task)
struct mm_struct *mm = task->mm;
const char *text;
- // kernel threads have no address space
+ /* kernel threads have no address space */
if (!mm)
return NO_COOKIE;
@@ -355,7 +365,7 @@ static int cookies_initialize(void)
per_cpu(cookie_next_key, cpu) = nr_cpu_ids + cpu;
size = COOKIEMAP_ENTRIES * MAX_COLLISIONS * sizeof(uint64_t);
- per_cpu(cookie_keys, cpu) = (uint64_t *)kmalloc(size, GFP_KERNEL);
+ per_cpu(cookie_keys, cpu) = kmalloc(size, GFP_KERNEL);
if (!per_cpu(cookie_keys, cpu)) {
err = -ENOMEM;
goto cookie_setup_error;
@@ -363,14 +373,14 @@ static int cookies_initialize(void)
memset(per_cpu(cookie_keys, cpu), 0, size);
size = COOKIEMAP_ENTRIES * MAX_COLLISIONS * sizeof(uint32_t);
- per_cpu(cookie_values, cpu) = (uint32_t *)kmalloc(size, GFP_KERNEL);
+ per_cpu(cookie_values, cpu) = kmalloc(size, GFP_KERNEL);
if (!per_cpu(cookie_values, cpu)) {
err = -ENOMEM;
goto cookie_setup_error;
}
memset(per_cpu(cookie_values, cpu), 0, size);
- per_cpu(translate_buffer, cpu) = (struct cookie_args *)kmalloc(TRANSLATE_BUFFER_SIZE, GFP_KERNEL);
+ per_cpu(translate_buffer, cpu) = kmalloc(TRANSLATE_BUFFER_SIZE, GFP_KERNEL);
if (!per_cpu(translate_buffer, cpu)) {
err = -ENOMEM;
goto cookie_setup_error;
@@ -379,16 +389,16 @@ static int cookies_initialize(void)
per_cpu(translate_buffer_write, cpu) = 0;
per_cpu(translate_buffer_read, cpu) = 0;
- per_cpu(translate_text, cpu) = (char *)kmalloc(TRANSLATE_TEXT_SIZE, GFP_KERNEL);
+ per_cpu(translate_text, cpu) = kmalloc(TRANSLATE_TEXT_SIZE, GFP_KERNEL);
if (!per_cpu(translate_text, cpu)) {
err = -ENOMEM;
goto cookie_setup_error;
}
}
- // build CRC32 table
+ /* build CRC32 table */
poly = 0x04c11db7;
- gator_crc32_table = (uint32_t *)kmalloc(256 * sizeof(uint32_t), GFP_KERNEL);
+ gator_crc32_table = kmalloc(256 * sizeof(*gator_crc32_table), GFP_KERNEL);
if (!gator_crc32_table) {
err = -ENOMEM;
goto cookie_setup_error;
@@ -396,11 +406,10 @@ static int cookies_initialize(void)
for (i = 0; i < 256; i++) {
crc = i;
for (j = 8; j > 0; j--) {
- if (crc & 1) {
+ if (crc & 1)
crc = (crc >> 1) ^ poly;
- } else {
+ else
crc >>= 1;
- }
}
gator_crc32_table[i] = crc;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-24 06:17:36 +0000