diff mbox

[v3,1/2] printk: Add function to return log buffer address and size

Message ID 20140809054424.17676.1090.stgit@hegdevasant.in.ibm.com (mailing list archive)
State Accepted
Commit 14c4000a88afaaa2d0877cc86d42a74fde0f35e0
Headers show

Commit Message

Vasant Hegde Aug. 9, 2014, 5:45 a.m. UTC 
Platforms like IBM Power Systems supports service processor
assisted dump. It provides interface to add memory region to
be captured when system is crashed.

During initialization/running we can add kernel memory region
to be collected.

Presently we don't have a way to get the log buffer base address
and size. This patch adds support to return log buffer address
and size.

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

---
Next patch extends arch specific code to add log buffer to platform
dump.

Changes in v3:
  As Andrew suggested changed function names and return type.
  (https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-August/119802.html).

Ben,
  - This patchset applies cleanly on powerpc next branch.
  - Andrew Morton suggested to include this patch in powerpc tree.
    (https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-August/119802.html)


 include/linux/printk.h |    3 +++
 kernel/printk/printk.c |   12 ++++++++++++
 2 files changed, 15 insertions(+)

Comments

Benjamin Herrenschmidt Aug. 11, 2014, 1:13 a.m. UTC | #1 
On Sat, 2014-08-09 at 11:15 +0530, Vasant Hegde wrote:

> Ben,
>   - This patchset applies cleanly on powerpc next branch.
>   - Andrew Morton suggested to include this patch in powerpc tree.
>     (https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-August/119802.html)
> 

Ok, Andrew, can I have an Ack ?

Cheers,
Ben.

>  include/linux/printk.h |    3 +++
>  kernel/printk/printk.c |   12 ++++++++++++
>  2 files changed, 15 insertions(+)
> 
> diff --git a/include/linux/printk.h b/include/linux/printk.h
> index 319ff7e..b8c0316 100644
> --- a/include/linux/printk.h
> +++ b/include/linux/printk.h
> @@ -10,6 +10,9 @@
>  extern const char linux_banner[];
>  extern const char linux_proc_banner[];
>  
> +extern char *log_buf_addr_get(void);
> +extern u32 log_buf_len_get(void);
> +
>  static inline int printk_get_level(const char *buffer)
>  {
>  	if (buffer[0] == KERN_SOH_ASCII && buffer[1]) {
> diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
> index ea2d5f6..d6a984c 100644
> --- a/kernel/printk/printk.c
> +++ b/kernel/printk/printk.c
> @@ -270,6 +270,18 @@ static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
>  static char *log_buf = __log_buf;
>  static u32 log_buf_len = __LOG_BUF_LEN;
>  
> +/* Return log buffer address */
> +char *log_buf_addr_get(void)
> +{
> +	return log_buf;
> +}
> +
> +/* Return log buffer size */
> +u32 log_buf_len_get(void)
> +{
> +	return log_buf_len;
> +}
> +
>  /* human readable text of the record */
>  static char *log_text(const struct printk_log *msg)
>  {
Andrew Morton Aug. 12, 2014, 9:47 p.m. UTC | #2 
On Mon, 11 Aug 2014 11:13:32 +1000 Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:

> On Sat, 2014-08-09 at 11:15 +0530, Vasant Hegde wrote:
> 
> > Ben,
> >   - This patchset applies cleanly on powerpc next branch.
> >   - Andrew Morton suggested to include this patch in powerpc tree.
> >     (https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-August/119802.html)
> > 
> 
> Ok, Andrew, can I have an Ack ?

Acked-by: Andrew Morton <akpm@linux-foundation.org>
diff mbox

Patch

diff --git a/include/linux/printk.h b/include/linux/printk.h
index 319ff7e..b8c0316 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -10,6 +10,9 @@ 
 extern const char linux_banner[];
 extern const char linux_proc_banner[];
 
+extern char *log_buf_addr_get(void);
+extern u32 log_buf_len_get(void);
+
 static inline int printk_get_level(const char *buffer)
 {
 	if (buffer[0] == KERN_SOH_ASCII && buffer[1]) {
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index ea2d5f6..d6a984c 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -270,6 +270,18 @@  static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
 static char *log_buf = __log_buf;
 static u32 log_buf_len = __LOG_BUF_LEN;
 
+/* Return log buffer address */
+char *log_buf_addr_get(void)
+{
+	return log_buf;
+}
+
+/* Return log buffer size */
+u32 log_buf_len_get(void)
+{
+	return log_buf_len;
+}
+
 /* human readable text of the record */
 static char *log_text(const struct printk_log *msg)
 {