Merge branch 'master' into kconfig

5 files changed, 185 insertions, 0 deletions

diff --git a/kernel-devel/kexec-and-crash-kernel/Makefile b/kernel-devel/kexec-and-crash-kernel/Makefile
new file mode 100644
index 0000000..d641258
--- /dev/null
+++ b/kernel-devel/kexec-and-crash-kernel/Makefile
@@ -0,0 +1,9 @@
+all:
+	for pdf in `ls -1 *.tex` ; do \
+		TEXINPUTS=`pwd`/../..:.:..:$(TEXINPUTS) pdflatex $$pdf; \
+		TEXINPUTS=`pwd`/../..:.:..:$(TEXINPUTS) pdflatex $$pdf; \
+	done
+
+clean:
+	rm -f *.aux *.log *.pdf *.log *.snm *.toc *.vrb *.nav *.out
+
diff --git a/kernel-devel/kexec-and-crash-kernel/crashkernel_patches/crashkernel.diff b/kernel-devel/kexec-and-crash-kernel/crashkernel_patches/crashkernel.diff
new file mode 100644
index 0000000..1d3e082
--- /dev/null
+++ b/kernel-devel/kexec-and-crash-kernel/crashkernel_patches/crashkernel.diff
@@ -0,0 +1,65 @@
+From: Magnus Damm <damm at opensource.se>
+
+Update the copy_oldmem_page() function to ioremap() only
+when accessing memory that is outside the regular range
+of system memory that is managed by the kernel.
+
+Without this patch a warning is triggered in the ARM-specific
+ioremap implementation, see WARN_ON(pfn_valid()) in ioremap.c
+
+The copy_oldmem_page() function is used by the secondary crash
+kernel to access memory using the /proc/vmcore code implemented
+in fs/proc/vmcore.c. To pass information from the first kernel
+to the secondary crash kernel a kernel command line option is
+used to point out where the elf core hdr is located.
+
+The crash kernel is loaded through kexec-tools which also contains
+code that reserves memory for the elfcorehdr= option. This memory
+block is reserved _inside_ the main system memory of the secondary
+kernel. The /proc/vmcore code in the secondary kernel is however
+using copy_oldmem_page() to access both this elfcorehdr area and
+the rest of the memory used by the the first kernel.
+
+So the copy_oldmem_page() function is used to access data that
+may be located in system memory, or it may be outside. Always
+using ioremap will not work, so this patch makes it conditional
+based on pfn_valid().
+
+For more details please look at the sh7372-based example here:
+http://permalink.gmane.org/gmane.linux.ports.sh.devel/11502
+
+Signed-off-by: Magnus Damm <damm at opensource.se>
+---
+
+ arch/arm/kernel/crash_dump.c |   14 ++++++++++----
+ 1 file changed, 10 insertions(+), 4 deletions(-)
+
+--- 0001/arch/arm/kernel/crash_dump.c
++++ work/arch/arm/kernel/crash_dump.c	2011-06-18 20:59:49.000000000 +0900
+@@ -39,9 +39,13 @@ ssize_t copy_oldmem_page(unsigned long p
+ 	if (!csize)
+ 		return 0;
+ 
+-	vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);
+-	if (!vaddr)
+-		return -ENOMEM;
++	if (pfn_valid(pfn)) {
++		vaddr = phys_to_virt(pfn << PAGE_SHIFT);
++	} else {
++		vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);
++		if (!vaddr)
++			return -ENOMEM;
++	}
+ 
+ 	if (userbuf) {
+ 		if (copy_to_user(buf, vaddr + offset, csize)) {
+@@ -52,6 +56,8 @@ ssize_t copy_oldmem_page(unsigned long p
+ 		memcpy(buf, vaddr + offset, csize);
+ 	}
+ 
+-	iounmap(vaddr);
++	if (!pfn_valid(pfn))
++		iounmap(vaddr);
++
+ 	return csize;
+ }
diff --git a/kernel-devel/kexec-and-crash-kernel/crashkernel_patches/kexec_fix_arm_braindamage.diff b/kernel-devel/kexec-and-crash-kernel/crashkernel_patches/kexec_fix_arm_braindamage.diff
new file mode 100644
index 0000000..877f5ea
--- /dev/null
+++ b/kernel-devel/kexec-and-crash-kernel/crashkernel_patches/kexec_fix_arm_braindamage.diff
@@ -0,0 +1,28 @@
+Index: kexec-tools-2.0.3/kexec/arch/arm/crashdump-arm.c
+===================================================================
+--- kexec-tools-2.0.3.orig/kexec/arch/arm/crashdump-arm.c	2011-10-03 00:56:38.000000000 +0200
++++ kexec-tools-2.0.3/kexec/arch/arm/crashdump-arm.c	2013-07-06 17:26:13.410309437 +0200
+@@ -204,12 +204,12 @@
+  * @cmdline. Note that @cmdline must be at least %COMMAND_LINE_SIZE bytes long
+  * (including %NUL).
+  */
+-static void cmdline_add_mem(char *cmdline, unsigned long size)
++static void cmdline_add_mem(char *cmdline, unsigned long size, unsigned long offset)
+ {
+ 	char buf[COMMAND_LINE_SIZE];
+ 	int buflen;
+ 
+-	buflen = snprintf(buf, sizeof(buf), "%s mem=%ldK", cmdline, size >> 10);
++	buflen = snprintf(buf, sizeof(buf), "%s mem=%ldK@0x%X", cmdline, size >> 10, offset);
+ 	if (buflen < 0)
+ 		die("Failed to construct mem= command line parameter\n");
+ 	if (buflen >= sizeof(buf))
+@@ -301,7 +301,7 @@
+ 	 * prevents the dump capture kernel from using any other memory regions
+ 	 * which belong to the primary kernel.
+ 	 */
+-	cmdline_add_mem(mod_cmdline, elfcorehdr - crash_reserved_mem.start);
++	cmdline_add_mem(mod_cmdline, elfcorehdr - crash_reserved_mem.start, crash_reserved_mem.start);
+ 
+ 	dump_memory_ranges();
+ 	dbgprintf("kernel command line: \"%s\"\n", mod_cmdline);
diff --git a/kernel-devel/kexec-and-crash-kernel/crashkernel_patches/zreladdr.diff b/kernel-devel/kexec-and-crash-kernel/crashkernel_patches/zreladdr.diff
new file mode 100644
index 0000000..867e13a
--- /dev/null
+++ b/kernel-devel/kexec-and-crash-kernel/crashkernel_patches/zreladdr.diff
@@ -0,0 +1,13 @@
+Index: linux-3.2/arch/arm/mach-omap2/Makefile.boot
+===================================================================
+--- linux-3.2.orig/arch/arm/mach-omap2/Makefile.boot	2012-01-05 00:55:44.000000000 +0100
++++ linux-3.2/arch/arm/mach-omap2/Makefile.boot	2013-07-06 17:00:18.718516198 +0200
+@@ -1,3 +1,8 @@
++ifeq ($(CONFIG_CRASH_DUMP),y)
++  zreladdr-y		+= 0x84008000
++params_phys-y		:= 0x84000100
++else
+   zreladdr-y		+= 0x80008000
+ params_phys-y		:= 0x80000100
++endif
+ initrd_phys-y		:= 0x80800000
diff --git a/kernel-devel/kexec-and-crash-kernel/pres_kexec_and_crashkernel_en.tex b/kernel-devel/kexec-and-crash-kernel/pres_kexec_and_crashkernel_en.tex
new file mode 100644
index 0000000..1791267
--- /dev/null
+++ b/kernel-devel/kexec-and-crash-kernel/pres_kexec_and_crashkernel_en.tex
@@ -0,0 +1,70 @@
+\input{configpres}
+
+\title{Kexec and Crashkernels}
+\maketitle
+\begin{frame}
+\frametitle{What is kexec?}
+Kexec is a mechanism to boot Linux from within Linux,
+without going through the BIOS / the Bootloader.
+\end{frame}
+
+\begin{frame}
+\frametitle{kexec-tools}
+http://horms.net/projects/kexec/
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Using kexec: Kernel configuration}
+\begin{verbatim}
+Boot options -->
+[*] Kexec system call
+\end{verbatim}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Using kexec: Booting the new kernel}
+\begin{verbatim}
+# Load the kernel image and set the commandline
+$ kexec -l uImage --append=$(cat /proc/cmdline)
+# Start the new kernel
+$ kexec -e
+\end{verbatim}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Using kexec: Crashkernel}
+\begin{itemize}
+\item Build production kernel (enable kexec system call!)
+\item Build ''crash kernel'' (enable kexec system call and crash dump kernel):
+\begin{verbatim}
+Boot options -->
+[*] Kexec system call
+[*] Build kdump crash kernel
+\end{verbatim}
+\item The crash kernel option should automatically select /proc/vmcore
+\end{itemize}
+\end{frame}
+
+
+\begin{frame}[fragile]
+\frametitle{Using kexec: Crashkernel}
+\begin{itemize}
+\item Boot production kernel (Commandline: crashkernel=256M@0x84000000)
+\item Check if crashkernel memory was reserved: 
+\begin{verbatim}
+cat /proc/iomem | grep Crash
+   84000000-93ffffff : Crash kernel
+\end{verbatim}
+\item Load crash kernel and let the system crash ;-)
+\begin{verbatim}
+kexec -p uImage-crash \
+  --append="$(cat /proc/cmdline | \
+    sed 's/crashkernel/bla/')"
+echo c > /proc/sysrq-trigger
+\end{verbatim}
+\item After crashing the crash kernel should boot up!
+\item Within the crashkernel the core file for the production kernel is available in /proc/vmcore
+\end{itemize}
+\end{frame}
+
+\input{tailpres}