If function_graph tracer is enabled during kexec, we see the below
exception in the simulator:
root@(none):/# kexec -e
kvm: exiting hardware virtualization
kexec_core: Starting new kernel
[ 19.262020070,5] OPAL: Switch to big-endian OS
kexec: Starting switchover sequence.
Interrupt to 0xC000000000004380 from 0xC000000000004380
** Execution stopped: Continuous Interrupt, Instruction caused
exception, **
Now that we have a more effective way to disable ftrace, let's use that
before switching to a new kernel during kexec.
Signed-off-by: Naveen N. Rao <naveen.n....@linux.vnet.ibm.com>
---
arch/powerpc/kernel/machine_kexec.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/machine_kexec.c
b/arch/powerpc/kernel/machine_kexec.c
index 2694d078741d..4a1b24a9dd61 100644
--- a/arch/powerpc/kernel/machine_kexec.c
+++ b/arch/powerpc/kernel/machine_kexec.c
@@ -95,16 +95,14 @@ void arch_crash_save_vmcoreinfo(void)
*/
void machine_kexec(struct kimage *image)
{
- int save_ftrace_enabled;
-
- save_ftrace_enabled = __ftrace_enabled_save();
+ get_paca()->ftrace_disabled = 1;
if (ppc_md.machine_kexec)
ppc_md.machine_kexec(image);
else
default_machine_kexec(image);
- __ftrace_enabled_restore(save_ftrace_enabled);
+ get_paca()->ftrace_disabled = 0;
/* Fall back to normal restart if we're still alive. */
machine_restart(NULL);
--
2.16.2
