staging: Android updates

index 052b43e..15a59c1 100644
@@ -212,7 +212,7 @@ static void __exit lowmem_exit(void)
 module_param_named(cost, lowmem_shrinker.seeks, int, S_IRUGO | S_IWUSR);
 module_param_array_named(adj, lowmem_adj, int, &lowmem_adj_size,
 			 S_IRUGO | S_IWUSR);
-module_param_array_named(minfree, lowmem_minfree, uint, &lowmem_minfree_size,
+module_param_array_named(minfree, lowmem_minfree, ulong, &lowmem_minfree_size,
 			 S_IRUGO | S_IWUSR);
 module_param_named(debug_level, lowmem_debug_level, uint, S_IRUGO | S_IWUSR);
 

index fabd398..f01a0c4 100644
@@ -143,7 +143,7 @@ ram_console_write(struct console *console, const char *s, unsigned int count)
 static struct console ram_console = {
 	.name	= "ram",
 	.write	= ram_console_write,
-	.flags	= CON_PRINTBUFFER | CON_ENABLED,
+	.flags	= CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME,
 	.index	= -1,
 };
 

index f01a0c4..2310a79 100644
@@ -42,6 +42,8 @@ static char __initdata
 #endif
 static char *ram_console_old_log;
 static size_t ram_console_old_log_size;
+static const char *bootinfo;
+static size_t bootinfo_size;
 
 static struct ram_console_buffer *ram_console_buffer;
 static size_t ram_console_buffer_size;

@@ -156,20 +158,13 @@ void ram_console_enable_console(int enabled)
 }
 
 static void __init
-ram_console_save_old(struct ram_console_buffer *buffer, const char *bootinfo,
-	char *dest)
+ram_console_save_old(struct ram_console_buffer *buffer, char *dest)
 {
 	size_t old_log_size = buffer->size;
-	size_t bootinfo_size = 0;
-	size_t total_size = old_log_size;
-	char *ptr;
-	const char *bootinfo_label = "Boot info:\n";
 
 #ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
 	uint8_t *block;
 	uint8_t *par;
-	char strbuf[80];
-	int strbuf_len = 0;
 
 	block = buffer->data;
 	par = ram_console_par_buffer;

@@ -195,24 +190,10 @@ ram_console_save_old(struct ram_console_buffer *buffer, const char *bootinfo,
 		block += ECC_BLOCK_SIZE;
 		par += ECC_SIZE;
 	}
-	if (ram_console_corrected_bytes || ram_console_bad_blocks)
-		strbuf_len = snprintf(strbuf, sizeof(strbuf),
-			"\n%d Corrected bytes, %d unrecoverable blocks\n",
-			ram_console_corrected_bytes, ram_console_bad_blocks);
-	else
-		strbuf_len = snprintf(strbuf, sizeof(strbuf),
-				      "\nNo errors detected\n");
-	if (strbuf_len >= sizeof(strbuf))
-		strbuf_len = sizeof(strbuf) - 1;
-	total_size += strbuf_len;
 #endif
 
-	if (bootinfo)
-		bootinfo_size = strlen(bootinfo) + strlen(bootinfo_label);
-	total_size += bootinfo_size;
-
 	if (dest == NULL) {
-		dest = kmalloc(total_size, GFP_KERNEL);
+		dest = kmalloc(old_log_size, GFP_KERNEL);
 		if (dest == NULL) {
 			printk(KERN_ERR
 			       "ram_console: failed to allocate buffer\n");

@@ -221,27 +202,15 @@ ram_console_save_old(struct ram_console_buffer *buffer, const char *bootinfo,
 	}
 
 	ram_console_old_log = dest;
-	ram_console_old_log_size = total_size;
+	ram_console_old_log_size = old_log_size;
 	memcpy(ram_console_old_log,
 	       &buffer->data[buffer->start], buffer->size - buffer->start);
 	memcpy(ram_console_old_log + buffer->size - buffer->start,
 	       &buffer->data[0], buffer->start);
-	ptr = ram_console_old_log + old_log_size;
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
-	memcpy(ptr, strbuf, strbuf_len);
-	ptr += strbuf_len;
-#endif
-	if (bootinfo) {
-		memcpy(ptr, bootinfo_label, strlen(bootinfo_label));
-		ptr += strlen(bootinfo_label);
-		memcpy(ptr, bootinfo, bootinfo_size);
-		ptr += bootinfo_size;
-	}
 }
 
 static int __init ram_console_init(struct ram_console_buffer *buffer,
-				   size_t buffer_size, const char *bootinfo,
-				   char *old_buf)
+				   size_t buffer_size, char *old_buf)
 {
 #ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
 	int numerr;

@@ -308,7 +277,7 @@ static int __init ram_console_init(struct ram_console_buffer *buffer,
 			printk(KERN_INFO "ram_console: found existing buffer, "
 			       "size %d, start %d\n",
 			       buffer->size, buffer->start);
-			ram_console_save_old(buffer, bootinfo, old_buf);
+			ram_console_save_old(buffer, old_buf);
 		}
 	} else {
 		printk(KERN_INFO "ram_console: no valid data in buffer "

@@ -326,6 +295,24 @@ static int __init ram_console_init(struct ram_console_buffer *buffer,
 	return 0;
 }
 
+static ssize_t ram_console_ecc_string(char *str, size_t len)
+{
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+	ssize_t ret;
+
+	if (ram_console_corrected_bytes || ram_console_bad_blocks)
+		ret = snprintf(str, len, ""
+			"\n%d Corrected bytes, %d unrecoverable blocks\n",
+			ram_console_corrected_bytes, ram_console_bad_blocks);
+	else
+		ret = snprintf(str, len, "\nNo errors detected\n");
+
+	return ret;
+#else
+	return 0;
+#endif
+}
+
 #ifdef CONFIG_ANDROID_RAM_CONSOLE_EARLY_INIT
 static int __init ram_console_early_init(void)
 {

@@ -342,7 +329,6 @@ static int ram_console_driver_probe(struct platform_device *pdev)
 	size_t start;
 	size_t buffer_size;
 	void *buffer;
-	const char *bootinfo = NULL;
 	struct ram_console_platform_data *pdata = pdev->dev.platform_data;
 
 	if (res == NULL || pdev->num_resources != 1 ||

@@ -361,10 +347,13 @@ static int ram_console_driver_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
-	if (pdata)
-		bootinfo = pdata->bootinfo;
+	if (pdata) {
+		bootinfo = kstrdup(pdata->bootinfo, GFP_KERNEL);
+		if (bootinfo)
+			bootinfo_size = strlen(bootinfo);
+	}
 
-	return ram_console_init(buffer, buffer_size, bootinfo, NULL/* allocate */);
+	return ram_console_init(buffer, buffer_size, NULL/* allocate */);
 }
 
 static struct platform_driver ram_console_driver = {

@@ -387,14 +376,46 @@ static ssize_t ram_console_read_old(struct file *file, char __user *buf,
 {
 	loff_t pos = *offset;
 	ssize_t count;
+	char *str;
+	int ret;
+
+	/* Main last_kmsg log */
+	if (pos < ram_console_old_log_size) {
+		count = min(len, (size_t)(ram_console_old_log_size - pos));
+		if (copy_to_user(buf, ram_console_old_log + pos, count))
+			return -EFAULT;
+		goto out;
+	}
 
-	if (pos >= ram_console_old_log_size)
-		return 0;
+	/* ECC correction notice */
+	pos -= ram_console_old_log_size;
+	count = ram_console_ecc_string(NULL, 0);
+	if (pos < count) {
+		str = kmalloc(count, GFP_KERNEL);
+		if (!str)
+			return -ENOMEM;
+		ram_console_ecc_string(str, count + 1);
+		count = min(len, (size_t)(count - pos));
+		ret = copy_to_user(buf, str + pos, count);
+		kfree(str);
+		if (ret)
+			return -EFAULT;
+		goto out;
+	}
 
-	count = min(len, (size_t)(ram_console_old_log_size - pos));
-	if (copy_to_user(buf, ram_console_old_log + pos, count))
-		return -EFAULT;
+	/* Boot info passed through pdata */
+	pos -= count;
+	if (pos < bootinfo_size) {
+		count = min(len, (size_t)(bootinfo_size - pos));
+		if (copy_to_user(buf, bootinfo + pos, count))
+			return -EFAULT;
+		goto out;
+	}
+
+	/* EOF */
+	return 0;
 
+out:
 	*offset += count;
 	return count;
 }

index 2310a79..ed7827b 100644
@@ -36,10 +36,6 @@ struct ram_console_buffer {
 
 #define RAM_CONSOLE_SIG (0x43474244) /* DBGC */
 
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_EARLY_INIT
-static char __initdata
-	ram_console_old_log_init_buffer[CONFIG_ANDROID_RAM_CONSOLE_EARLY_SIZE];
-#endif
 static char *ram_console_old_log;
 static size_t ram_console_old_log_size;
 static const char *bootinfo;

@@ -313,16 +309,6 @@ static ssize_t ram_console_ecc_string(char *str, size_t len)
 #endif
 }
 
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_EARLY_INIT
-static int __init ram_console_early_init(void)
-{
-	return ram_console_init((struct ram_console_buffer *)
-		CONFIG_ANDROID_RAM_CONSOLE_EARLY_ADDR,
-		CONFIG_ANDROID_RAM_CONSOLE_EARLY_SIZE,
-		NULL,
-		ram_console_old_log_init_buffer);
-}
-#else
 static int ram_console_driver_probe(struct platform_device *pdev)
 {
 	struct resource *res = pdev->resource;

@@ -369,7 +355,6 @@ static int __init ram_console_module_init(void)
 	err = platform_driver_register(&ram_console_driver);
 	return err;
 }
-#endif
 
 static ssize_t ram_console_read_old(struct file *file, char __user *buf,
 				    size_t len, loff_t *offset)

@@ -431,16 +416,6 @@ static int __init ram_console_late_init(void)
 
 	if (ram_console_old_log == NULL)
 		return 0;
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_EARLY_INIT
-	ram_console_old_log = kmemdup(ram_console_old_log_init_buffer,
-					ram_console_old_log_size, GFP_KERNEL);
-	if (ram_console_old_log == NULL) {
-		printk(KERN_ERR
-		       "ram_console: failed to allocate buffer for old log\n");
-		ram_console_old_log_size = 0;
-		return 0;
-	}
-#endif
 	entry = create_proc_entry("last_kmsg", S_IFREG | S_IRUGO, NULL);
 	if (!entry) {
 		printk(KERN_ERR "ram_console: failed to create proc entry\n");

@@ -454,10 +429,6 @@ static int __init ram_console_late_init(void)
 	return 0;
 }
 
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_EARLY_INIT
-console_initcall(ram_console_early_init);
-#else
 postcore_initcall(ram_console_module_init);
-#endif
 late_initcall(ram_console_late_init);
 

index ed7827b..73215e2 100644
@@ -285,9 +285,6 @@ static int __init ram_console_init(struct ram_console_buffer *buffer,
 	buffer->size = 0;
 
 	register_console(&ram_console);
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_ENABLE_VERBOSE
-	console_verbose();
-#endif
 	return 0;
 }
 

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index f73fb08..ab3995c 100644
@@ -24,13 +24,19 @@ struct persistent_ram_zone {
 	struct list_head node;
 	struct persistent_ram_buffer *buffer;
 	size_t buffer_size;
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+
+	/* ECC correction */
+	bool ecc;
 	char *par_buffer;
 	char *par_header;
 	struct rs_control *rs_decoder;
 	int corrected_bytes;
 	int bad_blocks;
-#endif
+	int ecc_block_size;
+	int ecc_size;
+	int ecc_symsize;
+	int ecc_poly;
+
 	char *old_log;
 	size_t old_log_size;
 	size_t old_log_footer_size;

@@ -38,7 +44,7 @@ struct persistent_ram_zone {
 };
 
 int persistent_ram_init_ringbuffer(struct persistent_ram_zone *prz,
-	void __iomem *buffer, size_t buffer_size);
+	void __iomem *buffer, size_t buffer_size, bool ecc);
 
 int persistent_ram_write(struct persistent_ram_zone *prz, const void *s,
 	unsigned int count);

index 689c3dc..d920bd7 100644
@@ -76,7 +76,7 @@ static int ram_console_driver_probe(struct platform_device *pdev)
 	}
 
 	ret = persistent_ram_init_ringbuffer(&ram_console_zone, buffer,
-					     buffer_size);
+					     buffer_size, true);
 	if (ret)
 		goto err;
 

index 35c57a0..81950e6 100644
@@ -12,12 +12,17 @@
  *
  */
 
+#include <linux/device.h>
+#include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/io.h>
+#include <linux/list.h>
+#include <linux/memblock.h>
 #include <linux/rslib.h>
 #include <linux/slab.h>
+#include <linux/vmalloc.h>
 #include "persistent_ram.h"
 
 struct persistent_ram_buffer {

@@ -29,7 +34,7 @@ struct persistent_ram_buffer {
 
 #define PERSISTENT_RAM_SIG (0x43474244) /* DBGC */
 
-static LIST_HEAD(zone_list);
+static __initdata LIST_HEAD(persistent_ram_list);
 
 static void persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
 	uint8_t *data, size_t len, uint8_t *ecc)

@@ -270,54 +275,134 @@ void persistent_ram_free_old(struct persistent_ram_zone *prz)
 	prz->old_log_size = 0;
 }
 
-static int __init __persistent_ram_init(struct persistent_ram_zone *prz,
-			       void __iomem *mem, size_t buffer_size, bool ecc)
+static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size,
+		struct persistent_ram_zone *prz)
 {
-	struct persistent_ram_buffer *buffer = mem;
+	struct page **pages;
+	phys_addr_t page_start;
+	unsigned int page_count;
+	pgprot_t prot;
+	unsigned int i;
+
+	page_start = start - offset_in_page(start);
+	page_count = DIV_ROUND_UP(size + offset_in_page(start), PAGE_SIZE);
+
+	prot = pgprot_noncached(PAGE_KERNEL);
+
+	pages = kmalloc(sizeof(struct page *) * page_count, GFP_KERNEL);
+	if (!pages) {
+		pr_err("%s: Failed to allocate array for %u pages\n", __func__,
+			page_count);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < page_count; i++) {
+		phys_addr_t addr = page_start + i * PAGE_SIZE;
+		pages[i] = pfn_to_page(addr >> PAGE_SHIFT);
+	}
+	prz->vaddr = vmap(pages, page_count, VM_MAP, prot);
+	kfree(pages);
+	if (!prz->vaddr) {
+		pr_err("%s: Failed to map %u pages\n", __func__, page_count);
+		return -ENOMEM;
+	}
+
+	prz->buffer = prz->vaddr + offset_in_page(start);
+	prz->buffer_size = size - sizeof(struct persistent_ram_buffer);
+
+	return 0;
+}
+
+static int __init persistent_ram_buffer_init(const char *name,
+		struct persistent_ram_zone *prz)
+{
+	int i;
+	struct persistent_ram *ram;
+	struct persistent_ram_descriptor *desc;
+	phys_addr_t start;
+
+	list_for_each_entry(ram, &persistent_ram_list, node) {
+		start = ram->start;
+		for (i = 0; i < ram->num_descs; i++) {
+			desc = &ram->descs[i];
+			if (!strcmp(desc->name, name))
+				return persistent_ram_buffer_map(start,
+						desc->size, prz);
+			start += desc->size;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static  __init
+struct persistent_ram_zone *__persistent_ram_init(struct device *dev, bool ecc)
+{
+	struct persistent_ram_zone *prz;
 	int ret;
 
-	INIT_LIST_HEAD(&prz->node);
+	prz = kzalloc(sizeof(struct persistent_ram_zone), GFP_KERNEL);
+	if (!prz) {
+		pr_err("persistent_ram: failed to allocate persistent ram zone\n");
+		return ERR_PTR(-ENOMEM);
+	}
 
-	prz->buffer = buffer;
-	prz->buffer_size = buffer_size - sizeof(struct persistent_ram_buffer);
+	INIT_LIST_HEAD(&prz->node);
 
-	if (prz->buffer_size > buffer_size) {
-		pr_err("persistent_ram: buffer %p, invalid size %zu, datasize %zu\n",
-		       buffer, buffer_size, prz->buffer_size);
-		return -EINVAL;
+	ret = persistent_ram_buffer_init(dev_name(dev), prz);
+	if (ret) {
+		pr_err("persistent_ram: failed to initialize buffer\n");
+		return ERR_PTR(ret);
 	}
 
 	prz->ecc = ecc;
-	ret = persistent_ram_init_ecc(prz, buffer_size);
+	ret = persistent_ram_init_ecc(prz, prz->buffer_size);
 	if (ret)
-		return ret;
+		return ERR_PTR(ret);
 
-	if (buffer->sig == PERSISTENT_RAM_SIG) {
-		if (buffer->size > prz->buffer_size
-		    || buffer->start > buffer->size)
+	if (prz->buffer->sig == PERSISTENT_RAM_SIG) {
+		if (prz->buffer->size > prz->buffer_size
+		    || prz->buffer->start > prz->buffer->size)
 			pr_info("persistent_ram: found existing invalid buffer, size %d, start %d\n",
-			       buffer->size, buffer->start);
+			       prz->buffer->size, prz->buffer->start);
 		else {
 			pr_info("persistent_ram: found existing buffer, size %d, start %d\n",
-			       buffer->size, buffer->start);
+			       prz->buffer->size, prz->buffer->start);
 			persistent_ram_save_old(prz);
 		}
 	} else {
 		pr_info("persistent_ram: no valid data in buffer (sig = 0x%08x)\n",
-			buffer->sig);
+			prz->buffer->sig);
 	}
 
-	buffer->sig = PERSISTENT_RAM_SIG;
-	buffer->start = 0;
-	buffer->size = 0;
+	prz->buffer->sig = PERSISTENT_RAM_SIG;
+	prz->buffer->start = 0;
+	prz->buffer->size = 0;
 
-	list_add_tail(&prz->node, &zone_list);
+	return prz;
+}
 
-	return 0;
+struct persistent_ram_zone * __init
+persistent_ram_init_ringbuffer(struct device *dev, bool ecc)
+{
+	return __persistent_ram_init(dev, ecc);
 }
 
-int __init persistent_ram_init_ringbuffer(struct persistent_ram_zone *prz,
-			       void __iomem *mem, size_t buffer_size, bool ecc)
+int __init persistent_ram_early_init(struct persistent_ram *ram)
 {
-	return __persistent_ram_init(prz, mem, buffer_size, true);
+	int ret;
+
+	ret = memblock_reserve(ram->start, ram->size);
+	if (ret) {
+		pr_err("Failed to reserve persistent memory from %08lx-%08lx\n",
+			(long)ram->start, (long)(ram->start + ram->size - 1));
+		return ret;
+	}
+
+	list_add_tail(&ram->node, &persistent_ram_list);
+
+	pr_info("Initialized persistent memory from %08lx-%08lx\n",
+		(long)ram->start, (long)(ram->start + ram->size - 1));
+
+	return 0;
 }

index ab3995c..f41e208 100644
@@ -15,13 +15,31 @@
 #ifndef __LINUX_PERSISTENT_RAM_H__
 #define __LINUX_PERSISTENT_RAM_H__
 
+#include <linux/device.h>
 #include <linux/kernel.h>
+#include <linux/list.h>
 #include <linux/types.h>
 
 struct persistent_ram_buffer;
 
+struct persistent_ram_descriptor {
+	const char	*name;
+	phys_addr_t	size;
+};
+
+struct persistent_ram {
+	phys_addr_t	start;
+	phys_addr_t	size;
+
+	int					num_descs;
+	struct persistent_ram_descriptor	*descs;
+
+	struct list_head node;
+};
+
 struct persistent_ram_zone {
 	struct list_head node;
+	void *vaddr;
 	struct persistent_ram_buffer *buffer;
 	size_t buffer_size;
 

@@ -43,8 +61,10 @@ struct persistent_ram_zone {
 	bool early;
 };
 
-int persistent_ram_init_ringbuffer(struct persistent_ram_zone *prz,
-	void __iomem *buffer, size_t buffer_size, bool ecc);
+int persistent_ram_early_init(struct persistent_ram *ram);
+
+struct persistent_ram_zone *persistent_ram_init_ringbuffer(struct device *dev,
+		bool ecc);
 
 int persistent_ram_write(struct persistent_ram_zone *prz, const void *s,
 	unsigned int count);

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index 81950e6..3eb2fb4 100644
@@ -27,8 +27,8 @@
 
 struct persistent_ram_buffer {
 	uint32_t    sig;
-	uint32_t    start;
-	uint32_t    size;
+	atomic_t    start;
+	atomic_t    size;
 	uint8_t     data[0];
 };
 

@@ -36,6 +36,66 @@ struct persistent_ram_buffer {
 
 static __initdata LIST_HEAD(persistent_ram_list);
 
+static inline size_t buffer_size(struct persistent_ram_zone *prz)
+{
+	return atomic_read(&prz->buffer->size);
+}
+
+static inline size_t buffer_start(struct persistent_ram_zone *prz)
+{
+	return atomic_read(&prz->buffer->start);
+}
+
+/* increase and wrap the start pointer, returning the old value */
+static inline size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
+{
+	int old;
+	int new;
+
+	do {
+		old = atomic_read(&prz->buffer->start);
+		new = old + a;
+		while (unlikely(new > prz->buffer_size))
+			new -= prz->buffer_size;
+	} while (atomic_cmpxchg(&prz->buffer->start, old, new) != old);
+
+	return old;
+}
+
+/* increase the size counter until it hits the max size */
+static inline void buffer_size_add(struct persistent_ram_zone *prz, size_t a)
+{
+	size_t old;
+	size_t new;
+
+	if (atomic_read(&prz->buffer->size) == prz->buffer_size)
+		return;
+
+	do {
+		old = atomic_read(&prz->buffer->size);
+		new = old + a;
+		if (new > prz->buffer_size)
+			new = prz->buffer_size;
+	} while (atomic_cmpxchg(&prz->buffer->size, old, new) != old);
+}
+
+/* increase the size counter, retuning an error if it hits the max size */
+static inline ssize_t buffer_size_add_clamp(struct persistent_ram_zone *prz,
+	size_t a)
+{
+	size_t old;
+	size_t new;
+
+	do {
+		old = atomic_read(&prz->buffer->size);
+		new = old + a;
+		if (new > prz->buffer_size)
+			return -ENOMEM;
+	} while (atomic_cmpxchg(&prz->buffer->size, old, new) != old);
+
+	return 0;
+}
+
 static void persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
 	uint8_t *data, size_t len, uint8_t *ecc)
 {

@@ -62,7 +122,7 @@ static int persistent_ram_decode_rs8(struct persistent_ram_zone *prz,
 }
 
 static void persistent_ram_update_ecc(struct persistent_ram_zone *prz,
-	unsigned int count)
+	unsigned int start, unsigned int count)
 {
 	struct persistent_ram_buffer *buffer = prz->buffer;
 	uint8_t *buffer_end = buffer->data + prz->buffer_size;

@@ -75,16 +135,16 @@ static void persistent_ram_update_ecc(struct persistent_ram_zone *prz,
 	if (!prz->ecc)
 		return;
 
-	block = buffer->data + (buffer->start & ~(ecc_block_size - 1));
-	par = prz->par_buffer +
-	      (buffer->start / ecc_block_size) * prz->ecc_size;
+	block = buffer->data + (start & ~(ecc_block_size - 1));
+	par = prz->par_buffer + (start / ecc_block_size) * prz->ecc_size;
+
 	do {
 		if (block + ecc_block_size > buffer_end)
 			size = buffer_end - block;
 		persistent_ram_encode_rs8(prz, block, size, par);
 		block += ecc_block_size;
 		par += ecc_size;
-	} while (block < buffer->data + buffer->start + count);
+	} while (block < buffer->data + start + count);
 }
 
 static void persistent_ram_update_header_ecc(struct persistent_ram_zone *prz)

@@ -109,7 +169,7 @@ static void persistent_ram_ecc_old(struct persistent_ram_zone *prz)
 
 	block = buffer->data;
 	par = prz->par_buffer;
-	while (block < buffer->data + buffer->size) {
+	while (block < buffer->data + buffer_size(prz)) {
 		int numerr;
 		int size = prz->ecc_block_size;
 		if (block + size > buffer->data + prz->buffer_size)

@@ -199,34 +259,33 @@ ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
 }
 
 static void persistent_ram_update(struct persistent_ram_zone *prz,
-	const void *s, unsigned int count)
+	const void *s, unsigned int start, unsigned int count)
 {
 	struct persistent_ram_buffer *buffer = prz->buffer;
-	memcpy(buffer->data + buffer->start, s, count);
-	persistent_ram_update_ecc(prz, count);
+	memcpy(buffer->data + start, s, count);
+	persistent_ram_update_ecc(prz, start, count);
 }
 
 static void __init
 persistent_ram_save_old(struct persistent_ram_zone *prz)
 {
 	struct persistent_ram_buffer *buffer = prz->buffer;
-	size_t old_log_size = buffer->size;
+	size_t size = buffer_size(prz);
+	size_t start = buffer_start(prz);
 	char *dest;
 
 	persistent_ram_ecc_old(prz);
 
-	dest = kmalloc(old_log_size, GFP_KERNEL);
+	dest = kmalloc(size, GFP_KERNEL);
 	if (dest == NULL) {
 		pr_err("persistent_ram: failed to allocate buffer\n");
 		return;
 	}
 
 	prz->old_log = dest;
-	prz->old_log_size = old_log_size;
-	memcpy(prz->old_log,
-	       &buffer->data[buffer->start], buffer->size - buffer->start);
-	memcpy(prz->old_log + buffer->size - buffer->start,
-	       &buffer->data[0], buffer->start);
+	prz->old_log_size = size;
+	memcpy(prz->old_log, &buffer->data[start], size - start);
+	memcpy(prz->old_log + size - start, &buffer->data[0], start);
 }
 
 int persistent_ram_write(struct persistent_ram_zone *prz,

@@ -234,25 +293,26 @@ int persistent_ram_write(struct persistent_ram_zone *prz,
 {
 	int rem;
 	int c = count;
-	struct persistent_ram_buffer *buffer = prz->buffer;
+	size_t start;
 
-	if (c > prz->buffer_size) {
+	if (unlikely(c > prz->buffer_size)) {
 		s += c - prz->buffer_size;
 		c = prz->buffer_size;
 	}
-	rem = prz->buffer_size - buffer->start;
-	if (rem < c) {
-		persistent_ram_update(prz, s, rem);
+
+	buffer_size_add_clamp(prz, c);
+
+	start = buffer_start_add(prz, c);
+
+	rem = prz->buffer_size - start;
+	if (unlikely(rem < c)) {
+		persistent_ram_update(prz, s, start, rem);
 		s += rem;
 		c -= rem;
-		buffer->start = 0;
-		buffer->size = prz->buffer_size;
+		start = 0;
 	}
-	persistent_ram_update(prz, s, c);
+	persistent_ram_update(prz, s, start, c);
 
-	buffer->start += c;
-	if (buffer->size < prz->buffer_size)
-		buffer->size += c;
 	persistent_ram_update_header_ecc(prz);
 
 	return count;

@@ -361,23 +421,25 @@ struct persistent_ram_zone *__persistent_ram_init(struct device *dev, bool ecc)
 		return ERR_PTR(ret);
 
 	if (prz->buffer->sig == PERSISTENT_RAM_SIG) {
-		if (prz->buffer->size > prz->buffer_size
-		    || prz->buffer->start > prz->buffer->size)
-			pr_info("persistent_ram: found existing invalid buffer, size %d, start %d\n",
-			       prz->buffer->size, prz->buffer->start);
+		if (buffer_size(prz) > prz->buffer_size ||
+		    buffer_start(prz) > buffer_size(prz))
+			pr_info("persistent_ram: found existing invalid buffer,"
+				" size %ld, start %ld\n",
+			       buffer_size(prz), buffer_start(prz));
 		else {
-			pr_info("persistent_ram: found existing buffer, size %d, start %d\n",
-			       prz->buffer->size, prz->buffer->start);
+			pr_info("persistent_ram: found existing buffer,"
+				" size %ld, start %ld\n",
+			       buffer_size(prz), buffer_start(prz));
 			persistent_ram_save_old(prz);
 		}
 	} else {
-		pr_info("persistent_ram: no valid data in buffer (sig = 0x%08x)\n",
-			prz->buffer->sig);
+		pr_info("persistent_ram: no valid data in buffer"
+			" (sig = 0x%08x)\n", prz->buffer->sig);
 	}
 
 	prz->buffer->sig = PERSISTENT_RAM_SIG;
-	prz->buffer->start = 0;
-	prz->buffer->size = 0;
+	atomic_set(&prz->buffer->start, 0);
+	atomic_set(&prz->buffer->size, 0);
 
 	return prz;
 }

index 3eb2fb4..e08f257 100644
@@ -96,7 +96,7 @@ static inline ssize_t buffer_size_add_clamp(struct persistent_ram_zone *prz,
 	return 0;
 }
 
-static void persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
+static void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
 	uint8_t *data, size_t len, uint8_t *ecc)
 {
 	int i;

@@ -121,7 +121,7 @@ static int persistent_ram_decode_rs8(struct persistent_ram_zone *prz,
 				NULL, 0, NULL, 0, NULL);
 }
 
-static void persistent_ram_update_ecc(struct persistent_ram_zone *prz,
+static void notrace persistent_ram_update_ecc(struct persistent_ram_zone *prz,
 	unsigned int start, unsigned int count)
 {
 	struct persistent_ram_buffer *buffer = prz->buffer;

@@ -258,7 +258,7 @@ ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
 	return ret;
 }
 
-static void persistent_ram_update(struct persistent_ram_zone *prz,
+static void notrace persistent_ram_update(struct persistent_ram_zone *prz,
 	const void *s, unsigned int start, unsigned int count)
 {
 	struct persistent_ram_buffer *buffer = prz->buffer;

@@ -288,7 +288,7 @@ persistent_ram_save_old(struct persistent_ram_zone *prz)
 	memcpy(prz->old_log + size - start, &buffer->data[0], start);
 }
 
-int persistent_ram_write(struct persistent_ram_zone *prz,
+int notrace persistent_ram_write(struct persistent_ram_zone *prz,
 	const void *s, unsigned int count)
 {
 	int rem;

242 lines not on this page · raw message

index 29d347e..d956b84 100644
@@ -150,6 +150,9 @@ static int __init ram_console_late_init(void)
 	struct proc_dir_entry *entry;
 	struct persistent_ram_zone *prz = ram_console_zone;
 
+	if (!prz)
+		return 0;
+
 	if (persistent_ram_old_size(prz) == 0)
 		return 0;
 

index d956b84..b242be2 100644
@@ -99,6 +99,9 @@ static ssize_t ram_console_read_old(struct file *file, char __user *buf,
 	char *str;
 	int ret;
 
+	if (dmesg_restrict && !capable(CAP_SYSLOG))
+		return -EPERM;
+
 	/* Main last_kmsg log */
 	if (pos < old_log_size) {
 		count = min(len, (size_t)(old_log_size - pos));