9 files changed, 193 insertions, 25 deletions

diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
index 983d9510becc..916b8e23d968 100644
--- a/fs/pstore/Kconfig
+++ b/fs/pstore/Kconfig
@@ -21,6 +21,16 @@ config PSTORE_CONSOLE
           When the option is enabled, pstore will log all kernel
           messages, even if no oops or panic happened.
 
+config PSTORE_PMSG
+        bool "Log user space messages"
+        depends on PSTORE
+        help
+          When the option is enabled, pstore will export a character
+          interface /dev/pmsg0 to log user space messages. On reboot
+          data can be retrieved from /sys/fs/pstore/pmsg-ramoops-[ID].
+
+          If unsure, say N.
+
 config PSTORE_FTRACE
         bool "Persistent function tracer"
         depends on PSTORE
diff --git a/fs/pstore/Makefile b/fs/pstore/Makefile
index 4c9095c2781e..e647d8e81712 100644
--- a/fs/pstore/Makefile
+++ b/fs/pstore/Makefile
@@ -7,5 +7,7 @@ obj-y += pstore.o
 pstore-objs += inode.o platform.o
 obj-$(CONFIG_PSTORE_FTRACE)     += ftrace.o
 
+obj-$(CONFIG_PSTORE_PMSG)       += pmsg.o
+
 ramoops-objs += ram.o ram_core.o
 obj-$(CONFIG_PSTORE_RAM)        += ramoops.o
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 50416602774d..b32ce53d24ee 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -338,32 +338,38 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
 
         switch (type) {
         case PSTORE_TYPE_DMESG:
-                sprintf(name, "dmesg-%s-%lld%s", psname, id,
-                                                compressed ? ".enc.z" : "");
+                scnprintf(name, sizeof(name), "dmesg-%s-%lld%s",
+                          psname, id, compressed ? ".enc.z" : "");
                 break;
         case PSTORE_TYPE_CONSOLE:
-                sprintf(name, "console-%s-%lld", psname, id);
+                scnprintf(name, sizeof(name), "console-%s-%lld", psname, id);
                 break;
         case PSTORE_TYPE_FTRACE:
-                sprintf(name, "ftrace-%s-%lld", psname, id);
+                scnprintf(name, sizeof(name), "ftrace-%s-%lld", psname, id);
                 break;
         case PSTORE_TYPE_MCE:
-                sprintf(name, "mce-%s-%lld", psname, id);
+                scnprintf(name, sizeof(name), "mce-%s-%lld", psname, id);
                 break;
         case PSTORE_TYPE_PPC_RTAS:
-                sprintf(name, "rtas-%s-%lld", psname, id);
+                scnprintf(name, sizeof(name), "rtas-%s-%lld", psname, id);
                 break;
         case PSTORE_TYPE_PPC_OF:
-                sprintf(name, "powerpc-ofw-%s-%lld", psname, id);
+                scnprintf(name, sizeof(name), "powerpc-ofw-%s-%lld",
+                          psname, id);
                 break;
         case PSTORE_TYPE_PPC_COMMON:
-                sprintf(name, "powerpc-common-%s-%lld", psname, id);
+                scnprintf(name, sizeof(name), "powerpc-common-%s-%lld",
+                          psname, id);
+                break;
+        case PSTORE_TYPE_PMSG:
+                scnprintf(name, sizeof(name), "pmsg-%s-%lld", psname, id);
                 break;
         case PSTORE_TYPE_UNKNOWN:
-                sprintf(name, "unknown-%s-%lld", psname, id);
+                scnprintf(name, sizeof(name), "unknown-%s-%lld", psname, id);
                 break;
         default:
-                sprintf(name, "type%d-%s-%lld", type, psname, id);
+                scnprintf(name, sizeof(name), "type%d-%s-%lld",
+                          type, psname, id);
                 break;
         }
 
diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
index 3b3d305277c4..c36ba2cd0b5d 100644
--- a/fs/pstore/internal.h
+++ b/fs/pstore/internal.h
@@ -45,6 +45,12 @@ extern void pstore_register_ftrace(void);
 static inline void pstore_register_ftrace(void) {}
 #endif
 
+#ifdef CONFIG_PSTORE_PMSG
+extern void pstore_register_pmsg(void);
+#else
+static inline void pstore_register_pmsg(void) {}
+#endif
+
 extern struct pstore_info *psinfo;
 
 extern void     pstore_set_kmsg_bytes(int);
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 0a9b72cdfeca..c4c9a10c5760 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -301,7 +301,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
 
                 if (big_oops_buf) {
                         dst = big_oops_buf;
-                        hsize = sprintf(dst, "%s#%d Part%d\n", why,
+                        hsize = sprintf(dst, "%s#%d Part%u\n", why,
                                                         oopscount, part);
                         size = big_oops_buf_sz - hsize;
 
@@ -321,7 +321,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
                         }
                 } else {
                         dst = psinfo->buf;
-                        hsize = sprintf(dst, "%s#%d Part%d\n", why, oopscount,
+                        hsize = sprintf(dst, "%s#%d Part%u\n", why, oopscount,
                                                                         part);
                         size = psinfo->bufsize - hsize;
                         dst += hsize;
@@ -447,6 +447,7 @@ int pstore_register(struct pstore_info *psi)
         if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) {
                 pstore_register_console();
                 pstore_register_ftrace();
+                pstore_register_pmsg();
         }
 
         if (pstore_update_ms >= 0) {
diff --git a/fs/pstore/pmsg.c b/fs/pstore/pmsg.c
new file mode 100644
index 000000000000..feb5dd2948b4
--- /dev/null
+++ b/fs/pstore/pmsg.c
@@ -0,0 +1,114 @@
+/*
+ * Copyright 2014  Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+#include "internal.h"
+
+static DEFINE_MUTEX(pmsg_lock);
+#define PMSG_MAX_BOUNCE_BUFFER_SIZE (2*PAGE_SIZE)
+
+static ssize_t write_pmsg(struct file *file, const char __user *buf,
+                          size_t count, loff_t *ppos)
+{
+        size_t i, buffer_size;
+        char *buffer;
+
+        if (!count)
+                return 0;
+
+        if (!access_ok(VERIFY_READ, buf, count))
+                return -EFAULT;
+
+        buffer_size = count;
+        if (buffer_size > PMSG_MAX_BOUNCE_BUFFER_SIZE)
+                buffer_size = PMSG_MAX_BOUNCE_BUFFER_SIZE;
+        buffer = vmalloc(buffer_size);
+
+        mutex_lock(&pmsg_lock);
+        for (i = 0; i < count; ) {
+                size_t c = min(count - i, buffer_size);
+                u64 id;
+                long ret;
+
+                ret = __copy_from_user(buffer, buf + i, c);
+                if (unlikely(ret != 0)) {
+                        mutex_unlock(&pmsg_lock);
+                        vfree(buffer);
+                        return -EFAULT;
+                }
+                psinfo->write_buf(PSTORE_TYPE_PMSG, 0, &id, 0, buffer, 0, c,
+                                  psinfo);
+
+                i += c;
+        }
+
+        mutex_unlock(&pmsg_lock);
+        vfree(buffer);
+        return count;
+}
+
+static const struct file_operations pmsg_fops = {
+        .owner          = THIS_MODULE,
+        .llseek         = noop_llseek,
+        .write          = write_pmsg,
+};
+
+static struct class *pmsg_class;
+static int pmsg_major;
+#define PMSG_NAME "pmsg"
+#undef pr_fmt
+#define pr_fmt(fmt) PMSG_NAME ": " fmt
+
+static char *pmsg_devnode(struct device *dev, umode_t *mode)
+{
+        if (mode)
+                *mode = 0220;
+        return NULL;
+}
+
+void pstore_register_pmsg(void)
+{
+        struct device *pmsg_device;
+
+        pmsg_major = register_chrdev(0, PMSG_NAME, &pmsg_fops);
+        if (pmsg_major < 0) {
+                pr_err("register_chrdev failed\n");
+                goto err;
+        }
+
+        pmsg_class = class_create(THIS_MODULE, PMSG_NAME);
+        if (IS_ERR(pmsg_class)) {
+                pr_err("device class file already in use\n");
+                goto err_class;
+        }
+        pmsg_class->devnode = pmsg_devnode;
+
+        pmsg_device = device_create(pmsg_class, NULL, MKDEV(pmsg_major, 0),
+                                        NULL, "%s%d", PMSG_NAME, 0);
+        if (IS_ERR(pmsg_device)) {
+                pr_err("failed to create device\n");
+                goto err_device;
+        }
+        return;
+
+err_device:
+        class_destroy(pmsg_class);
+err_class:
+        unregister_chrdev(pmsg_major, PMSG_NAME);
+err:
+        return;
+}
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 8613e5b35c22..39d1373128e9 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -51,6 +51,10 @@ static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
 
+static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
+module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
+MODULE_PARM_DESC(pmsg_size, "size of user space message log");
+
 static ulong mem_address;
 module_param(mem_address, ulong, 0400);
 MODULE_PARM_DESC(mem_address,
@@ -82,12 +86,14 @@ struct ramoops_context {
         struct persistent_ram_zone **przs;
         struct persistent_ram_zone *cprz;
         struct persistent_ram_zone *fprz;
+        struct persistent_ram_zone *mprz;
         phys_addr_t phys_addr;
         unsigned long size;
         unsigned int memtype;
         size_t record_size;
         size_t console_size;
         size_t ftrace_size;
+        size_t pmsg_size;
         int dump_oops;
         struct persistent_ram_ecc_info ecc_info;
         unsigned int max_dump_cnt;
@@ -96,6 +102,7 @@ struct ramoops_context {
         unsigned int dump_read_cnt;
         unsigned int console_read_cnt;
         unsigned int ftrace_read_cnt;
+        unsigned int pmsg_read_cnt;
         struct pstore_info pstore;
 };
 
@@ -109,6 +116,7 @@ static int ramoops_pstore_open(struct pstore_info *psi)
         cxt->dump_read_cnt = 0;
         cxt->console_read_cnt = 0;
         cxt->ftrace_read_cnt = 0;
+        cxt->pmsg_read_cnt = 0;
         return 0;
 }
 
@@ -164,6 +172,12 @@ static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
         return header_length;
 }
 
+static bool prz_ok(struct persistent_ram_zone *prz)
+{
+        return !!prz && !!(persistent_ram_old_size(prz) +
+                           persistent_ram_ecc_string(prz, NULL, 0));
+}
+
 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
                                    int *count, struct timespec *time,
                                    char **buf, bool *compressed,
@@ -178,13 +192,16 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
         prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
                                    cxt->max_dump_cnt, id, type,
                                    PSTORE_TYPE_DMESG, 1);
-        if (!prz)
+        if (!prz_ok(prz))
                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
                                            1, id, type, PSTORE_TYPE_CONSOLE, 0);
-        if (!prz)
+        if (!prz_ok(prz))
                 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
                                            1, id, type, PSTORE_TYPE_FTRACE, 0);
-        if (!prz)
+        if (!prz_ok(prz))
+                prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
+                                           1, id, type, PSTORE_TYPE_PMSG, 0);
+        if (!prz_ok(prz))
                 return 0;
 
         if (!persistent_ram_old(prz))
@@ -252,6 +269,11 @@ static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
                         return -ENOMEM;
                 persistent_ram_write(cxt->fprz, buf, size);
                 return 0;
+        } else if (type == PSTORE_TYPE_PMSG) {
+                if (!cxt->mprz)
+                        return -ENOMEM;
+                persistent_ram_write(cxt->mprz, buf, size);
+                return 0;
         }
 
         if (type != PSTORE_TYPE_DMESG)
@@ -309,6 +331,9 @@ static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
         case PSTORE_TYPE_FTRACE:
                 prz = cxt->fprz;
                 break;
+        case PSTORE_TYPE_PMSG:
+                prz = cxt->mprz;
+                break;
         default:
                 return -EINVAL;
         }
@@ -435,7 +460,7 @@ static int ramoops_probe(struct platform_device *pdev)
                 goto fail_out;
 
         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
-                        !pdata->ftrace_size)) {
+                        !pdata->ftrace_size && !pdata->pmsg_size)) {
                 pr_err("The memory size and the record/console size must be "
                         "non-zero\n");
                 goto fail_out;
@@ -447,6 +472,8 @@ static int ramoops_probe(struct platform_device *pdev)
                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
+        if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
+                pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
 
         cxt->size = pdata->mem_size;
         cxt->phys_addr = pdata->mem_address;
@@ -454,12 +481,14 @@ static int ramoops_probe(struct platform_device *pdev)
         cxt->record_size = pdata->record_size;
         cxt->console_size = pdata->console_size;
         cxt->ftrace_size = pdata->ftrace_size;
+        cxt->pmsg_size = pdata->pmsg_size;
         cxt->dump_oops = pdata->dump_oops;
         cxt->ecc_info = pdata->ecc_info;
 
         paddr = cxt->phys_addr;
 
-        dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size;
+        dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
+                        - cxt->pmsg_size;
         err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
         if (err)
                 goto fail_out;
@@ -474,13 +503,9 @@ static int ramoops_probe(struct platform_device *pdev)
         if (err)
                 goto fail_init_fprz;
 
-        if (!cxt->przs && !cxt->cprz && !cxt->fprz) {
-                pr_err("memory size too small, minimum is %zu\n",
-                        cxt->console_size + cxt->record_size +
-                        cxt->ftrace_size);
-                err = -EINVAL;
-                goto fail_cnt;
-        }
+        err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0);
+        if (err)
+                goto fail_init_mprz;
 
         cxt->pstore.data = cxt;
         /*
@@ -525,7 +550,8 @@ fail_buf:
         kfree(cxt->pstore.buf);
 fail_clear:
         cxt->pstore.bufsize = 0;
-fail_cnt:
+        kfree(cxt->mprz);
+fail_init_mprz:
         kfree(cxt->fprz);
 fail_init_fprz:
         kfree(cxt->cprz);
@@ -583,6 +609,7 @@ static void ramoops_register_dummy(void)
         dummy_data->record_size = record_size;
         dummy_data->console_size = ramoops_console_size;
         dummy_data->ftrace_size = ramoops_ftrace_size;
+        dummy_data->pmsg_size = ramoops_pmsg_size;
         dummy_data->dump_oops = dump_oops;
         /*
          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index ece0c6bbfcc5..8884f6e507f7 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -39,6 +39,7 @@ enum pstore_type_id {
         PSTORE_TYPE_PPC_RTAS    = 4,
         PSTORE_TYPE_PPC_OF      = 5,
         PSTORE_TYPE_PPC_COMMON  = 6,
+        PSTORE_TYPE_PMSG        = 7,
         PSTORE_TYPE_UNKNOWN     = 255
 };
 
diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h
index 4af3fdc85b01..9c9d6c154c8e 100644
--- a/include/linux/pstore_ram.h
+++ b/include/linux/pstore_ram.h
@@ -81,6 +81,7 @@ struct ramoops_platform_data {
         unsigned long   record_size;
         unsigned long   console_size;
         unsigned long   ftrace_size;
+        unsigned long   pmsg_size;
         int             dump_oops;
         struct persistent_ram_ecc_info ecc_info;
 };