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| author |   Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2018-04-19 12:34:06 +0530 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2018-05-03 22:32:27 +1000 |
| commit | 88b1a8547f4c00e55d54e081fc15e3980debf5c1 (patch) | |
| tree | ef2bec6859a6a8b10db4517ec9d919a119ac7c74 /arch/powerpc/kernel/machine_kexec.c | |
| parent | powerpc64/ftrace: Disable ftrace during kvm entry/exit (diff) | |
| download | linux-dev-88b1a8547f4c00e55d54e081fc15e3980debf5c1.tar.xz linux-dev-88b1a8547f4c00e55d54e081fc15e3980debf5c1.zip | |
powerpc64/kexec: Hard disable ftrace before switching to the new kernel
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 completely disable ftrace on
ppc64, let's also use that before switching to a new kernel during
kexec.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/machine_kexec.c')
| -rw-r--r-- | arch/powerpc/kernel/machine_kexec.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c index 2694d078741d..936c7e2d421e 100644 --- a/arch/powerpc/kernel/machine_kexec.c +++ b/arch/powerpc/kernel/machine_kexec.c @@ -98,12 +98,14 @@ void machine_kexec(struct kimage *image) int save_ftrace_enabled; save_ftrace_enabled = __ftrace_enabled_save(); + this_cpu_disable_ftrace(); if (ppc_md.machine_kexec) ppc_md.machine_kexec(image); else default_machine_kexec(image); + this_cpu_enable_ftrace(); __ftrace_enabled_restore(save_ftrace_enabled); /* Fall back to normal restart if we're still alive. */ |