diff options
| author | Jordan Niethe <jniethe5@gmail.com> | 2020-12-07 12:05:18 +1100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-12-07 23:26:01 +1100 |
| commit | 4bb3219837a3dcf58bce96c27db6e0cd48f3d9b2 (patch) | |
| tree | e92fd13de51d907e3e89be4ab83ccbf03c7eee18 /arch/powerpc | |
| parent | 8817aabb1bdd5811130f94ff6442bb19c9158a3a (diff) | |
powerpc/book3s64/kexec: Clear CIABR on kexec
The value in CIABR persists across kexec which can lead to unintended
results when the new kernel hits the old kernel's breakpoint. For
example:
0:mon> bi $loadavg_proc_show
0:mon> b
type address
1 inst c000000000519060 loadavg_proc_show+0x0/0x130
0:mon> x
$ kexec -l /mnt/vmlinux --initrd=/mnt/rootfs.cpio.gz --append='xmon=off'
$ kexec -e
$ cat /proc/loadavg
Trace/breakpoint trap
Make sure CIABR is cleared so this does not happen.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207010519.15597-1-jniethe5@gmail.com
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/kexec.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/kexec.h b/arch/powerpc/include/asm/book3s/64/kexec.h index 6b5c3a248ba2..d4b9d476ecba 100644 --- a/arch/powerpc/include/asm/book3s/64/kexec.h +++ b/arch/powerpc/include/asm/book3s/64/kexec.h @@ -3,6 +3,7 @@ #ifndef _ASM_POWERPC_BOOK3S_64_KEXEC_H_ #define _ASM_POWERPC_BOOK3S_64_KEXEC_H_ +#include <asm/plpar_wrappers.h> #define reset_sprs reset_sprs static inline void reset_sprs(void) @@ -14,6 +15,10 @@ static inline void reset_sprs(void) if (cpu_has_feature(CPU_FTR_ARCH_207S)) { mtspr(SPRN_IAMR, 0); + if (cpu_has_feature(CPU_FTR_HVMODE)) + mtspr(SPRN_CIABR, 0); + else + plpar_set_ciabr(0); } /* Do we need isync()? We are going via a kexec reset */ |