The patch titled
kexec jump: fix for ftrace
has been added to the -mm tree. Its filename is
kexec-jump-fix-for-ftrace.patch
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See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: kexec jump: fix for ftrace
From: Huang Ying <ying.huang@xxxxxxxxx>
Ftrace depends on some processor state that we destroyed during kexec and
restored by restore_processor_state(). So save_processor_state() and
restore_processor_state() are moved into machine_kexec() and ftrace is
restored after restore_processor_state().
Signed-off-by: Huang Ying <ying.huang@xxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/machine_kexec_32.c | 16 +++++++++++++++-
kernel/kexec.c | 2 --
2 files changed, 15 insertions(+), 3 deletions(-)
diff -puN arch/x86/kernel/machine_kexec_32.c~kexec-jump-fix-for-ftrace arch/x86/kernel/machine_kexec_32.c
--- a/arch/x86/kernel/machine_kexec_32.c~kexec-jump-fix-for-ftrace
+++ a/arch/x86/kernel/machine_kexec_32.c
@@ -12,6 +12,7 @@
#include <linux/init.h>
#include <linux/numa.h>
#include <linux/ftrace.h>
+#include <linux/suspend.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -113,6 +114,7 @@ void machine_kexec(struct kimage *image)
{
unsigned long page_list[PAGES_NR];
void *control_page;
+ int save_ftrace_enabled;
asmlinkage unsigned long
(*relocate_kernel_ptr)(unsigned long indirection_page,
unsigned long control_page,
@@ -120,7 +122,12 @@ void machine_kexec(struct kimage *image)
unsigned int has_pae,
unsigned int preserve_context);
- tracer_disable();
+#ifdef CONFIG_KEXEC_JUMP
+ if (kexec_image->preserve_context)
+ save_processor_state();
+#endif
+
+ save_ftrace_enabled = __ftrace_enabled_save();
/* Interrupts aren't acceptable while we reboot */
local_irq_disable();
@@ -178,6 +185,13 @@ void machine_kexec(struct kimage *image)
(unsigned long)page_list,
image->start, cpu_has_pae,
image->preserve_context);
+
+#ifdef CONFIG_KEXEC_JUMP
+ if (kexec_image->preserve_context)
+ restore_processor_state();
+#endif
+
+ __ftrace_enabled_restore(save_ftrace_enabled);
}
void arch_crash_save_vmcoreinfo(void)
diff -puN kernel/kexec.c~kexec-jump-fix-for-ftrace kernel/kexec.c
--- a/kernel/kexec.c~kexec-jump-fix-for-ftrace
+++ a/kernel/kexec.c
@@ -1469,7 +1469,6 @@ int kernel_kexec(void)
error = device_power_down(PMSG_FREEZE);
if (error)
goto Enable_irqs;
- save_processor_state();
} else
#endif
{
@@ -1482,7 +1481,6 @@ int kernel_kexec(void)
#ifdef CONFIG_KEXEC_JUMP
if (kexec_image->preserve_context) {
- restore_processor_state();
device_power_up(PMSG_RESTORE);
Enable_irqs:
local_irq_enable();
_
Patches currently in -mm which might be from ying.huang@xxxxxxxxx are
origin.patch
kexec-jump-clean-up-ifdef-and-comments.patch
kexec-jump-rename-kexec_control_code_size-to-kexec_control_page_size.patch
kexec-jump-check-code-size-in-control-page.patch
kexec-jump-remove-duplication-of-kexec_restart_prepare.patch
kexec-jump-in-sync-with-hibernation-implementation.patch
kexec-jump-__ftrace_enabled_save-restore.patch
kexec-jump-fix-for-ftrace.patch
--
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