Move the devkmsg_ functions and kmsg_fops declaration
to devkmsg.c.
Add devkmsg.o to Makefile.
Signed-off-by: Joe Perches <j...@perches.com>
---
kernel/printk/Makefile | 1 +
kernel/printk/devkmsg.c | 309 +++++++++++++++++++++++++++++++++++++++++++++++
kernel/printk/printk.c | 296 ---------------------------------------------
3 files changed, 310 insertions(+), 296 deletions(-)
create mode 100644 kernel/printk/devkmsg.c
diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile
index a692b68..bda335f 100644
--- a/kernel/printk/Makefile
+++ b/kernel/printk/Makefile
@@ -1,3 +1,4 @@
obj-y = printk.o
obj-y += printk_log.o
+obj-y += devkmsg.o
obj-$(CONFIG_A11Y_BRAILLE_CONSOLE) += braille.o
diff --git a/kernel/printk/devkmsg.c b/kernel/printk/devkmsg.c
new file mode 100644
index 0000000..af83290
--- /dev/null
+++ b/kernel/printk/devkmsg.c
@@ -0,0 +1,309 @@
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/kexec.h>
+#include <linux/slab.h>
+#include <linux/security.h>
+#include <linux/uaccess.h>
+#include <linux/poll.h>
+#include <linux/syslog.h>
+#include <linux/wait.h>
+#include <linux/uio.h>
+#include <linux/sched.h>
+
+#include "printk_log.h"
+
+/* /dev/kmsg - userspace message inject/listen interface */
+struct devkmsg_user {
+ u64 seq;
+ u32 idx;
+ enum printk_log_flags prev;
+ struct mutex lock;
+ char buf[8192];
+};
+
+static ssize_t devkmsg_writev(struct kiocb *iocb, const struct iovec *iv,
+ unsigned long count, loff_t pos)
+{
+ char *buf, *line;
+ int i;
+ int level = default_message_loglevel;
+ int facility = 1; /* LOG_USER */
+ size_t len = iov_length(iv, count);
+ ssize_t ret = len;
+
+ if (len > PRINTK_LOG_LINE_MAX)
+ return -EINVAL;
+ buf = kmalloc(len+1, GFP_KERNEL);
+ if (buf == NULL)
+ return -ENOMEM;
+
+ line = buf;
+ for (i = 0; i < count; i++) {
+ if (copy_from_user(line, iv[i].iov_base, iv[i].iov_len)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ line += iv[i].iov_len;
+ }
+
+ /*
+ * Extract and skip the syslog prefix <[0-9]*>. Coming from userspace
+ * the decimal value represents 32bit, the lower 3 bit are the log
+ * level, the rest are the log facility.
+ *
+ * If no prefix or no userspace facility is specified, we
+ * enforce LOG_USER, to be able to reliably distinguish
+ * kernel-generated messages from userspace-injected ones.
+ */
+ line = buf;
+ if (line[0] == '<') {
+ char *endp = NULL;
+
+ i = simple_strtoul(line+1, &endp, 10);
+ if (endp && endp[0] == '>') {
+ level = i & 7;
+ if (i >> 3)
+ facility = i >> 3;
+ endp++;
+ len -= endp - line;
+ line = endp;
+ }
+ }
+ line[len] = '\0';
+
+ printk_emit(facility, level, NULL, 0, "%s", line);
+out:
+ kfree(buf);
+ return ret;
+}
+
+static ssize_t devkmsg_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct devkmsg_user *user = file->private_data;
+ struct printk_log *msg;
+ u64 ts_usec;
+ size_t i;
+ char cont = '-';
+ size_t len;
+ ssize_t ret;
+
+ if (!user)
+ return -EBADF;
+
+ ret = mutex_lock_interruptible(&user->lock);
+ if (ret)
+ return ret;
+ raw_spin_lock_irq(&printk_logbuf_lock);
+ while (user->seq == printk_log_next_seq) {
+ if (file->f_flags & O_NONBLOCK) {
+ ret = -EAGAIN;
+ raw_spin_unlock_irq(&printk_logbuf_lock);
+ goto out;
+ }
+
+ raw_spin_unlock_irq(&printk_logbuf_lock);
+ ret = wait_event_interruptible(printk_log_wait,
+ user->seq !=
printk_log_next_seq);
+ if (ret)
+ goto out;
+ raw_spin_lock_irq(&printk_logbuf_lock);
+ }
+
+ if (user->seq < printk_log_first_seq) {
+ /* our last seen message is gone, return error and reset */
+ user->idx = printk_log_first_idx;
+ user->seq = printk_log_first_seq;
+ ret = -EPIPE;
+ raw_spin_unlock_irq(&printk_logbuf_lock);
+ goto out;
+ }
+
+ msg = printk_log_from_idx(user->idx);
+ ts_usec = msg->ts_nsec;
+ do_div(ts_usec, 1000);
+
+ /*
+ * If we couldn't merge continuation line fragments during the print,
+ * export the stored flags to allow an optional external merge of the
+ * records. Merging the records isn't always neccessarily correct, like
+ * when we hit a race during printing. In most cases though, it produces
+ * better readable output. 'c' in the record flags mark the first
+ * fragment of a line, '+' the following.
+ */
+ if (msg->flags & LOG_CONT && !(user->prev & LOG_CONT))
+ cont = 'c';
+ else if ((msg->flags & LOG_CONT) ||
+ ((user->prev & LOG_CONT) && !(msg->flags & LOG_PREFIX)))
+ cont = '+';
+
+ len = sprintf(user->buf, "%u,%llu,%llu,%c;",
+ (msg->facility << 3) | msg->level,
+ user->seq, ts_usec, cont);
+ user->prev = msg->flags;
+
+ /* escape non-printable characters */
+ for (i = 0; i < msg->text_len; i++) {
+ unsigned char c = printk_log_text(msg)[i];
+
+ if (c < ' ' || c >= 127 || c == '\\')
+ len += sprintf(user->buf + len, "\\x%02x", c);
+ else
+ user->buf[len++] = c;
+ }
+ user->buf[len++] = '\n';
+
+ if (msg->dict_len) {
+ bool line = true;
+
+ for (i = 0; i < msg->dict_len; i++) {
+ unsigned char c = printk_log_dict(msg)[i];
+
+ if (line) {
+ user->buf[len++] = ' ';
+ line = false;
+ }
+
+ if (c == '\0') {
+ user->buf[len++] = '\n';
+ line = true;
+ continue;
+ }
+
+ if (c < ' ' || c >= 127 || c == '\\') {
+ len += sprintf(user->buf + len, "\\x%02x", c);
+ continue;
+ }
+
+ user->buf[len++] = c;
+ }
+ user->buf[len++] = '\n';
+ }
+
+ user->idx = printk_log_next(user->idx);
+ user->seq++;
+ raw_spin_unlock_irq(&printk_logbuf_lock);
+
+ if (len > count) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (copy_to_user(buf, user->buf, len)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ ret = len;
+out:
+ mutex_unlock(&user->lock);
+ return ret;
+}
+
+static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
+{
+ struct devkmsg_user *user = file->private_data;
+ loff_t ret = 0;
+
+ if (!user)
+ return -EBADF;
+ if (offset)
+ return -ESPIPE;
+
+ raw_spin_lock_irq(&printk_logbuf_lock);
+ switch (whence) {
+ case SEEK_SET:
+ /* the first record */
+ user->idx = printk_log_first_idx;
+ user->seq = printk_log_first_seq;
+ break;
+ case SEEK_DATA:
+ /*
+ * The first record after the last SYSLOG_ACTION_CLEAR,
+ * like issued by 'dmesg -c'. Reading /dev/kmsg itself
+ * changes no global state, and does not clear anything.
+ */
+ user->idx = printk_log_clear_idx;
+ user->seq = printk_log_clear_seq;
+ break;
+ case SEEK_END:
+ /* after the last record */
+ user->idx = printk_log_next_idx;
+ user->seq = printk_log_next_seq;
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ raw_spin_unlock_irq(&printk_logbuf_lock);
+ return ret;
+}
+
+static unsigned int devkmsg_poll(struct file *file, poll_table *wait)
+{
+ struct devkmsg_user *user = file->private_data;
+ int ret = 0;
+
+ if (!user)
+ return POLLERR|POLLNVAL;
+
+ poll_wait(file, &printk_log_wait, wait);
+
+ raw_spin_lock_irq(&printk_logbuf_lock);
+ if (user->seq < printk_log_next_seq) {
+ /* return error when data has vanished underneath us */
+ if (user->seq < printk_log_first_seq)
+ ret = POLLIN|POLLRDNORM|POLLERR|POLLPRI;
+ ret = POLLIN|POLLRDNORM;
+ }
+ raw_spin_unlock_irq(&printk_logbuf_lock);
+
+ return ret;
+}
+
+static int devkmsg_open(struct inode *inode, struct file *file)
+{
+ struct devkmsg_user *user;
+ int err;
+
+ /* write-only does not need any file context */
+ if ((file->f_flags & O_ACCMODE) == O_WRONLY)
+ return 0;
+
+ err = security_syslog(SYSLOG_ACTION_READ_ALL);
+ if (err)
+ return err;
+
+ user = kmalloc(sizeof(struct devkmsg_user), GFP_KERNEL);
+ if (!user)
+ return -ENOMEM;
+
+ mutex_init(&user->lock);
+
+ raw_spin_lock_irq(&printk_logbuf_lock);
+ user->idx = printk_log_first_idx;
+ user->seq = printk_log_first_seq;
+ raw_spin_unlock_irq(&printk_logbuf_lock);
+
+ file->private_data = user;
+ return 0;
+}
+
+static int devkmsg_release(struct inode *inode, struct file *file)
+{
+ struct devkmsg_user *user = file->private_data;
+
+ if (!user)
+ return 0;
+
+ mutex_destroy(&user->lock);
+ kfree(user);
+ return 0;
+}
+
+const struct file_operations kmsg_fops = {
+ .open = devkmsg_open,
+ .read = devkmsg_read,
+ .aio_write = devkmsg_writev,
+ .llseek = devkmsg_llseek,
+ .poll = devkmsg_poll,
+ .release = devkmsg_release,
+};
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 988d048..5e30343 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -136,302 +136,6 @@ static enum printk_log_flags console_prev;
/* cpu currently holding printk_logbuf_lock */
static volatile unsigned int logbuf_cpu = UINT_MAX;
-/* /dev/kmsg - userspace message inject/listen interface */
-struct devkmsg_user {
- u64 seq;
- u32 idx;
- enum printk_log_flags prev;
- struct mutex lock;
- char buf[8192];
-};
-
-static ssize_t devkmsg_writev(struct kiocb *iocb, const struct iovec *iv,
- unsigned long count, loff_t pos)
-{
- char *buf, *line;
- int i;
- int level = default_message_loglevel;
- int facility = 1; /* LOG_USER */
- size_t len = iov_length(iv, count);
- ssize_t ret = len;
-
- if (len > PRINTK_LOG_LINE_MAX)
- return -EINVAL;
- buf = kmalloc(len+1, GFP_KERNEL);
- if (buf == NULL)
- return -ENOMEM;
-
- line = buf;
- for (i = 0; i < count; i++) {
- if (copy_from_user(line, iv[i].iov_base, iv[i].iov_len)) {
- ret = -EFAULT;
- goto out;
- }
- line += iv[i].iov_len;
- }
-
- /*
- * Extract and skip the syslog prefix <[0-9]*>. Coming from userspace
- * the decimal value represents 32bit, the lower 3 bit are the log
- * level, the rest are the log facility.
- *
- * If no prefix or no userspace facility is specified, we
- * enforce LOG_USER, to be able to reliably distinguish
- * kernel-generated messages from userspace-injected ones.
- */
- line = buf;
- if (line[0] == '<') {
- char *endp = NULL;
-
- i = simple_strtoul(line+1, &endp, 10);
- if (endp && endp[0] == '>') {
- level = i & 7;
- if (i >> 3)
- facility = i >> 3;
- endp++;
- len -= endp - line;
- line = endp;
- }
- }
- line[len] = '\0';
-
- printk_emit(facility, level, NULL, 0, "%s", line);
-out:
- kfree(buf);
- return ret;
-}
-
-static ssize_t devkmsg_read(struct file *file, char __user *buf,
- size_t count, loff_t *ppos)
-{
- struct devkmsg_user *user = file->private_data;
- struct printk_log *msg;
- u64 ts_usec;
- size_t i;
- char cont = '-';
- size_t len;
- ssize_t ret;
-
- if (!user)
- return -EBADF;
-
- ret = mutex_lock_interruptible(&user->lock);
- if (ret)
- return ret;
- raw_spin_lock_irq(&printk_logbuf_lock);
- while (user->seq == printk_log_next_seq) {
- if (file->f_flags & O_NONBLOCK) {
- ret = -EAGAIN;
- raw_spin_unlock_irq(&printk_logbuf_lock);
- goto out;
- }
-
- raw_spin_unlock_irq(&printk_logbuf_lock);
- ret = wait_event_interruptible(printk_log_wait,
- user->seq !=
printk_log_next_seq);
- if (ret)
- goto out;
- raw_spin_lock_irq(&printk_logbuf_lock);
- }
-
- if (user->seq < printk_log_first_seq) {
- /* our last seen message is gone, return error and reset */
- user->idx = printk_log_first_idx;
- user->seq = printk_log_first_seq;
- ret = -EPIPE;
- raw_spin_unlock_irq(&printk_logbuf_lock);
- goto out;
- }
-
- msg = printk_log_from_idx(user->idx);
- ts_usec = msg->ts_nsec;
- do_div(ts_usec, 1000);
-
- /*
- * If we couldn't merge continuation line fragments during the print,
- * export the stored flags to allow an optional external merge of the
- * records. Merging the records isn't always neccessarily correct, like
- * when we hit a race during printing. In most cases though, it produces
- * better readable output. 'c' in the record flags mark the first
- * fragment of a line, '+' the following.
- */
- if (msg->flags & LOG_CONT && !(user->prev & LOG_CONT))
- cont = 'c';
- else if ((msg->flags & LOG_CONT) ||
- ((user->prev & LOG_CONT) && !(msg->flags & LOG_PREFIX)))
- cont = '+';
-
- len = sprintf(user->buf, "%u,%llu,%llu,%c;",
- (msg->facility << 3) | msg->level,
- user->seq, ts_usec, cont);
- user->prev = msg->flags;
-
- /* escape non-printable characters */
- for (i = 0; i < msg->text_len; i++) {
- unsigned char c = printk_log_text(msg)[i];
-
- if (c < ' ' || c >= 127 || c == '\\')
- len += sprintf(user->buf + len, "\\x%02x", c);
- else
- user->buf[len++] = c;
- }
- user->buf[len++] = '\n';
-
- if (msg->dict_len) {
- bool line = true;
-
- for (i = 0; i < msg->dict_len; i++) {
- unsigned char c = printk_log_dict(msg)[i];
-
- if (line) {
- user->buf[len++] = ' ';
- line = false;
- }
-
- if (c == '\0') {
- user->buf[len++] = '\n';
- line = true;
- continue;
- }
-
- if (c < ' ' || c >= 127 || c == '\\') {
- len += sprintf(user->buf + len, "\\x%02x", c);
- continue;
- }
-
- user->buf[len++] = c;
- }
- user->buf[len++] = '\n';
- }
-
- user->idx = printk_log_next(user->idx);
- user->seq++;
- raw_spin_unlock_irq(&printk_logbuf_lock);
-
- if (len > count) {
- ret = -EINVAL;
- goto out;
- }
-
- if (copy_to_user(buf, user->buf, len)) {
- ret = -EFAULT;
- goto out;
- }
- ret = len;
-out:
- mutex_unlock(&user->lock);
- return ret;
-}
-
-static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
-{
- struct devkmsg_user *user = file->private_data;
- loff_t ret = 0;
-
- if (!user)
- return -EBADF;
- if (offset)
- return -ESPIPE;
-
- raw_spin_lock_irq(&printk_logbuf_lock);
- switch (whence) {
- case SEEK_SET:
- /* the first record */
- user->idx = printk_log_first_idx;
- user->seq = printk_log_first_seq;
- break;
- case SEEK_DATA:
- /*
- * The first record after the last SYSLOG_ACTION_CLEAR,
- * like issued by 'dmesg -c'. Reading /dev/kmsg itself
- * changes no global state, and does not clear anything.
- */
- user->idx = printk_log_clear_idx;
- user->seq = printk_log_clear_seq;
- break;
- case SEEK_END:
- /* after the last record */
- user->idx = printk_log_next_idx;
- user->seq = printk_log_next_seq;
- break;
- default:
- ret = -EINVAL;
- }
- raw_spin_unlock_irq(&printk_logbuf_lock);
- return ret;
-}
-
-static unsigned int devkmsg_poll(struct file *file, poll_table *wait)
-{
- struct devkmsg_user *user = file->private_data;
- int ret = 0;
-
- if (!user)
- return POLLERR|POLLNVAL;
-
- poll_wait(file, &printk_log_wait, wait);
-
- raw_spin_lock_irq(&printk_logbuf_lock);
- if (user->seq < printk_log_next_seq) {
- /* return error when data has vanished underneath us */
- if (user->seq < printk_log_first_seq)
- ret = POLLIN|POLLRDNORM|POLLERR|POLLPRI;
- ret = POLLIN|POLLRDNORM;
- }
- raw_spin_unlock_irq(&printk_logbuf_lock);
-
- return ret;
-}
-
-static int devkmsg_open(struct inode *inode, struct file *file)
-{
- struct devkmsg_user *user;
- int err;
-
- /* write-only does not need any file context */
- if ((file->f_flags & O_ACCMODE) == O_WRONLY)
- return 0;
-
- err = security_syslog(SYSLOG_ACTION_READ_ALL);
- if (err)
- return err;
-
- user = kmalloc(sizeof(struct devkmsg_user), GFP_KERNEL);
- if (!user)
- return -ENOMEM;
-
- mutex_init(&user->lock);
-
- raw_spin_lock_irq(&printk_logbuf_lock);
- user->idx = printk_log_first_idx;
- user->seq = printk_log_first_seq;
- raw_spin_unlock_irq(&printk_logbuf_lock);
-
- file->private_data = user;
- return 0;
-}
-
-static int devkmsg_release(struct inode *inode, struct file *file)
-{
- struct devkmsg_user *user = file->private_data;
-
- if (!user)
- return 0;
-
- mutex_destroy(&user->lock);
- kfree(user);
- return 0;
-}
-
-const struct file_operations kmsg_fops = {
- .open = devkmsg_open,
- .read = devkmsg_read,
- .aio_write = devkmsg_writev,
- .llseek = devkmsg_llseek,
- .poll = devkmsg_poll,
- .release = devkmsg_release,
-};
-
#ifdef CONFIG_KEXEC
/*
* This appends the listed symbols to /proc/vmcoreinfo
--
1.7.8.112.g3fd21
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