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authorFuad Tabba <fuad.tabba@linux.dev>2026-09-22 19:14:30 +0100
committerWill Deacon <will@kernel.org>2026-09-23 12:34:30 +0000
commit2bc6b218717b9d08f466f88209251d54bc09b207 (patch)
treecb91c941eccb15f94cbec4e96aa3a9c8736b5d66 /include/trace/events/printk.h
downloadlinux-stable-2bc6b218717b9d08f466f88209251d54bc09b207.tar.gz
linux-stable-2bc6b218717b9d08f466f88209251d54bc09b207.zip
arm64/boot: Disable trapping of PMZR_EL0 writes to EL2grafted
__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2. PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a write from EL0 reaches the trap and takes the host down without a panic message. Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9 bits. Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9") Cc: stable@vger.kernel.org Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Oliver Upton <oupton@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'include/trace/events/printk.h')
-rw-r--r--include/trace/events/printk.h37
1 files changed, 37 insertions, 0 deletions
diff --git a/include/trace/events/printk.h b/include/trace/events/printk.h
new file mode 100644
index 000000000..13d405b2f
--- /dev/null
+++ b/include/trace/events/printk.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM printk
+
+#if !defined(_TRACE_PRINTK_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_PRINTK_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(console,
+ TP_PROTO(const char *text, size_t len),
+
+ TP_ARGS(text, len),
+
+ TP_STRUCT__entry(
+ __dynamic_array(char, msg, len + 1)
+ ),
+
+ TP_fast_assign(
+ /*
+ * Each trace entry is printed in a new line.
+ * If the msg finishes with '\n', cut it off
+ * to avoid blank lines in the trace.
+ */
+ if ((len > 0) && (text[len-1] == '\n'))
+ len -= 1;
+
+ memcpy(__get_str(msg), text, len);
+ __get_str(msg)[len] = 0;
+ ),
+
+ TP_printk("%s", __get_str(msg))
+);
+#endif /* _TRACE_PRINTK_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>