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authorGanesh Goudar <ganeshgr@linux.ibm.com>2020-10-09 12:10:04 +0530
committerMichael Ellerman <mpe@ellerman.id.au>2020-10-16 20:13:55 +1100
commit8d0e2101274358d9b6b1f27232b40253ca48bab5 (patch)
treee505cbd8c1d48319bd0e1e9a41697201ec1aa37c
parentd4263b12a1a0e8816e021450be0765a1ad8bb53c (diff)
powerpc/mce: Avoid nmi_enter/exit in real mode on pseries hash
Use of nmi_enter/exit in real mode handler causes the kernel to panic and reboot on injecting SLB mutihit on pseries machine running in hash MMU mode, because these calls try to accesses memory outside RMO region in real mode handler where translation is disabled. Add check to not to use these calls on pseries machine running in hash MMU mode. Fixes: 116ac378bb3f ("powerpc/64s: machine check interrupt update NMI accounting") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201009064005.19777-2-ganeshgr@linux.ibm.com
-rw-r--r--arch/powerpc/kernel/mce.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
index ada59f6c4298..63702c0badb9 100644
--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -591,12 +591,11 @@ EXPORT_SYMBOL_GPL(machine_check_print_event_info);
long notrace machine_check_early(struct pt_regs *regs)
{
long handled = 0;
- bool nested = in_nmi();
u8 ftrace_enabled = this_cpu_get_ftrace_enabled();
this_cpu_set_ftrace_enabled(0);
-
- if (!nested)
+ /* Do not use nmi_enter/exit for pseries hpte guest */
+ if (radix_enabled() || !firmware_has_feature(FW_FEATURE_LPAR))
nmi_enter();
hv_nmi_check_nonrecoverable(regs);
@@ -607,7 +606,7 @@ long notrace machine_check_early(struct pt_regs *regs)
if (ppc_md.machine_check_early)
handled = ppc_md.machine_check_early(regs);
- if (!nested)
+ if (radix_enabled() || !firmware_has_feature(FW_FEATURE_LPAR))
nmi_exit();
this_cpu_set_ftrace_enabled(ftrace_enabled);