4bb3219837
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
29 lines
557 B
C
29 lines
557 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_POWERPC_BOOK3S_64_KEXEC_H_
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#define _ASM_POWERPC_BOOK3S_64_KEXEC_H_
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#include <asm/plpar_wrappers.h>
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#define reset_sprs reset_sprs
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static inline void reset_sprs(void)
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{
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if (cpu_has_feature(CPU_FTR_ARCH_206)) {
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mtspr(SPRN_AMR, 0);
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mtspr(SPRN_UAMOR, 0);
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}
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if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
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mtspr(SPRN_IAMR, 0);
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if (cpu_has_feature(CPU_FTR_HVMODE))
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mtspr(SPRN_CIABR, 0);
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else
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plpar_set_ciabr(0);
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}
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/* Do we need isync()? We are going via a kexec reset */
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isync();
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}
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#endif
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