Re: [PATCH] gpu: host1x: trace: fix string fields in host1x traces
From: Steven Rostedt
Date: Tue May 19 2026 - 14:11:16 EST
On Tue, 19 May 2026 12:16:43 +0200
Artur Kowalski <arturkow2000@xxxxxxxxx> wrote:
> Use __assign_str and __get_str as required by tracing subsystem. Fixes
> string fields being rejected by the verifier and unreadable from
> userspace.
Does anyone use these tracepoints? The fact that they have been broken
for 5 years and nobody noticed makes me think they are useless.
I rather remove them than fix them, but if someone thinks that these
are still useful then by all means apply this patch.
Acked-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
-- Steve
>
> Tested on v6.18.21.
>
> Signed-off-by: Artur Kowalski <arturkow2000@xxxxxxxxx>
> ---
> include/trace/events/host1x.h | 50 ++++++++++++++++++++++---------------------
> 1 file changed, 26 insertions(+), 24 deletions(-)
>
> diff --git a/include/trace/events/host1x.h b/include/trace/events/host1x.h
> index 1ba84b738e46..1b6aeb7b177b 100644
> --- a/include/trace/events/host1x.h
> +++ b/include/trace/events/host1x.h
> @@ -21,9 +21,11 @@ struct host1x_bo;
> DECLARE_EVENT_CLASS(host1x,
> TP_PROTO(const char *name),
> TP_ARGS(name),
> - TP_STRUCT__entry(__field(const char *, name)),
> - TP_fast_assign(__entry->name = name;),
> - TP_printk("name=%s", __entry->name)
> + TP_STRUCT__entry(__string(name, name)),
> + TP_fast_assign(
> + __assign_str(name);
> + ),
> + TP_printk("name=%s", __get_str(name))
> );
>
> DEFINE_EVENT(host1x, host1x_channel_open,
> @@ -52,19 +54,19 @@ TRACE_EVENT(host1x_cdma_push,
> TP_ARGS(name, op1, op2),
>
> TP_STRUCT__entry(
> - __field(const char *, name)
> + __string(name, name)
> __field(u32, op1)
> __field(u32, op2)
> ),
>
> TP_fast_assign(
> - __entry->name = name;
> + __assign_str(name);
> __entry->op1 = op1;
> __entry->op2 = op2;
> ),
>
> TP_printk("name=%s, op1=%08x, op2=%08x",
> - __entry->name, __entry->op1, __entry->op2)
> + __get_str(name), __entry->op1, __entry->op2)
> );
>
> TRACE_EVENT(host1x_cdma_push_wide,
> @@ -73,7 +75,7 @@ TRACE_EVENT(host1x_cdma_push_wide,
> TP_ARGS(name, op1, op2, op3, op4),
>
> TP_STRUCT__entry(
> - __field(const char *, name)
> + __string(name, name)
> __field(u32, op1)
> __field(u32, op2)
> __field(u32, op3)
> @@ -81,7 +83,7 @@ TRACE_EVENT(host1x_cdma_push_wide,
> ),
>
> TP_fast_assign(
> - __entry->name = name;
> + __assign_str(name);
> __entry->op1 = op1;
> __entry->op2 = op2;
> __entry->op3 = op3;
> @@ -89,7 +91,7 @@ TRACE_EVENT(host1x_cdma_push_wide,
> ),
>
> TP_printk("name=%s, op1=%08x, op2=%08x, op3=%08x op4=%08x",
> - __entry->name, __entry->op1, __entry->op2, __entry->op3,
> + __get_str(name), __entry->op1, __entry->op2, __entry->op3,
> __entry->op4)
> );
>
> @@ -100,7 +102,7 @@ TRACE_EVENT(host1x_cdma_push_gather,
> TP_ARGS(name, bo, words, offset, cmdbuf),
>
> TP_STRUCT__entry(
> - __field(const char *, name)
> + __string(name, name)
> __field(struct host1x_bo *, bo)
> __field(u32, words)
> __field(u32, offset)
> @@ -114,14 +116,14 @@ TRACE_EVENT(host1x_cdma_push_gather,
> words * sizeof(u32));
> }
> __entry->cmdbuf = cmdbuf;
> - __entry->name = name;
> + __assign_str(name);
> __entry->bo = bo;
> __entry->words = words;
> __entry->offset = offset;
> ),
>
> TP_printk("name=%s, bo=%p, words=%u, offset=%d, contents=[%s]",
> - __entry->name, __entry->bo,
> + __get_str(name), __entry->bo,
> __entry->words, __entry->offset,
> __print_hex(__get_dynamic_array(cmdbuf),
> __entry->cmdbuf ? __entry->words * 4 : 0))
> @@ -134,7 +136,7 @@ TRACE_EVENT(host1x_channel_submit,
> TP_ARGS(name, cmdbufs, relocs, syncpt_id, syncpt_incrs),
>
> TP_STRUCT__entry(
> - __field(const char *, name)
> + __string(name, name)
> __field(u32, cmdbufs)
> __field(u32, relocs)
> __field(u32, syncpt_id)
> @@ -142,7 +144,7 @@ TRACE_EVENT(host1x_channel_submit,
> ),
>
> TP_fast_assign(
> - __entry->name = name;
> + __assign_str(name);
> __entry->cmdbufs = cmdbufs;
> __entry->relocs = relocs;
> __entry->syncpt_id = syncpt_id;
> @@ -151,7 +153,7 @@ TRACE_EVENT(host1x_channel_submit,
>
> TP_printk("name=%s, cmdbufs=%u, relocs=%u, syncpt_id=%u, "
> "syncpt_incrs=%u",
> - __entry->name, __entry->cmdbufs, __entry->relocs,
> + __get_str(name), __entry->cmdbufs, __entry->relocs,
> __entry->syncpt_id, __entry->syncpt_incrs)
> );
>
> @@ -161,19 +163,19 @@ TRACE_EVENT(host1x_channel_submitted,
> TP_ARGS(name, syncpt_base, syncpt_max),
>
> TP_STRUCT__entry(
> - __field(const char *, name)
> + __string(name, name)
> __field(u32, syncpt_base)
> __field(u32, syncpt_max)
> ),
>
> TP_fast_assign(
> - __entry->name = name;
> + __assign_str(name);
> __entry->syncpt_base = syncpt_base;
> __entry->syncpt_max = syncpt_max;
> ),
>
> TP_printk("name=%s, syncpt_base=%d, syncpt_max=%d",
> - __entry->name, __entry->syncpt_base, __entry->syncpt_max)
> + __get_str(name), __entry->syncpt_base, __entry->syncpt_max)
> );
>
> TRACE_EVENT(host1x_channel_submit_complete,
> @@ -182,19 +184,19 @@ TRACE_EVENT(host1x_channel_submit_complete,
> TP_ARGS(name, count, thresh),
>
> TP_STRUCT__entry(
> - __field(const char *, name)
> + __string(name, name)
> __field(int, count)
> __field(u32, thresh)
> ),
>
> TP_fast_assign(
> - __entry->name = name;
> + __assign_str(name);
> __entry->count = count;
> __entry->thresh = thresh;
> ),
>
> TP_printk("name=%s, count=%d, thresh=%d",
> - __entry->name, __entry->count, __entry->thresh)
> + __get_str(name), __entry->count, __entry->thresh)
> );
>
> TRACE_EVENT(host1x_wait_cdma,
> @@ -203,16 +205,16 @@ TRACE_EVENT(host1x_wait_cdma,
> TP_ARGS(name, eventid),
>
> TP_STRUCT__entry(
> - __field(const char *, name)
> + __string(name, name)
> __field(u32, eventid)
> ),
>
> TP_fast_assign(
> - __entry->name = name;
> + __assign_str(name);
> __entry->eventid = eventid;
> ),
>
> - TP_printk("name=%s, event=%d", __entry->name, __entry->eventid)
> + TP_printk("name=%s, event=%d", __get_str(name), __entry->eventid)
> );
>
> TRACE_EVENT(host1x_syncpt_load_min,
>
> ---
> base-commit: ab5fce87a778cb780a05984a2ca448f2b41aafbf
> change-id: 20260519-host1x-tracing-e2d608ec5e37
>
> Best regards,
> --
> Artur Kowalski <arturkow2000@xxxxxxxxx>