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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/pwc.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/pwc.h')
-rw-r--r--include/trace/events/pwc.h65
1 files changed, 65 insertions, 0 deletions
diff --git a/include/trace/events/pwc.h b/include/trace/events/pwc.h
new file mode 100644
index 000000000..054370254
--- /dev/null
+++ b/include/trace/events/pwc.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#if !defined(_TRACE_PWC_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_PWC_H
+
+#include <linux/usb.h>
+#include <linux/tracepoint.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM pwc
+
+TRACE_EVENT(pwc_handler_enter,
+ TP_PROTO(struct urb *urb, struct pwc_device *pdev),
+ TP_ARGS(urb, pdev),
+ TP_STRUCT__entry(
+ __field(struct urb*, urb)
+ __field(struct pwc_frame_buf*, fbuf)
+ __field(int, urb__status)
+ __field(u32, urb__actual_length)
+ __field(int, fbuf__filled)
+ __string(name, pdev->v4l2_dev.name)
+ ),
+ TP_fast_assign(
+ __entry->urb = urb;
+ __entry->fbuf = pdev->fill_buf;
+ __entry->urb__status = urb->status;
+ __entry->urb__actual_length = urb->actual_length;
+ __entry->fbuf__filled = (pdev->fill_buf
+ ? pdev->fill_buf->filled : 0);
+ __assign_str(name);
+ ),
+ TP_printk("dev=%s (fbuf=%p filled=%d) urb=%p (status=%d actual_length=%u)",
+ __get_str(name),
+ __entry->fbuf,
+ __entry->fbuf__filled,
+ __entry->urb,
+ __entry->urb__status,
+ __entry->urb__actual_length)
+);
+
+TRACE_EVENT(pwc_handler_exit,
+ TP_PROTO(struct urb *urb, struct pwc_device *pdev),
+ TP_ARGS(urb, pdev),
+ TP_STRUCT__entry(
+ __field(struct urb*, urb)
+ __field(struct pwc_frame_buf*, fbuf)
+ __field(int, fbuf__filled)
+ __string(name, pdev->v4l2_dev.name)
+ ),
+ TP_fast_assign(
+ __entry->urb = urb;
+ __entry->fbuf = pdev->fill_buf;
+ __entry->fbuf__filled = pdev->fill_buf->filled;
+ __assign_str(name);
+ ),
+ TP_printk(" dev=%s (fbuf=%p filled=%d) urb=%p",
+ __get_str(name),
+ __entry->fbuf,
+ __entry->fbuf__filled,
+ __entry->urb)
+);
+
+#endif /* _TRACE_PWC_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>