[PATCH 2/3] tracing: Make synth_event trace functions endian-correct

From: Tom Zanussi
Date: Thu Feb 13 2020 - 17:16:59 EST


synth_event_trace(), synth_event_trace_array() and
__synth_event_add_val() write directly into the trace buffer and need
to take endianness into account, like trace_event_raw_event_synth()
does.

Signed-off-by: Tom Zanussi <zanussi@xxxxxxxxxx>
---
kernel/trace/trace_events_hist.c | 62 +++++++++++++++++++++++++++++++++++++---
1 file changed, 58 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 483b3fd1094f..913760d2d505 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1898,7 +1898,25 @@ int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
strscpy(str_field, str_val, STR_VAR_LEN_MAX);
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
} else {
- state.entry->fields[n_u64] = val;
+ struct synth_field *field = state.event->fields[i];
+
+ switch (field->size) {
+ case 1:
+ *(u8 *)&state.entry->fields[n_u64] = (u8)val;
+ break;
+
+ case 2:
+ *(u16 *)&state.entry->fields[n_u64] = (u16)val;
+ break;
+
+ case 4:
+ *(u32 *)&state.entry->fields[n_u64] = (u32)val;
+ break;
+
+ default:
+ state.entry->fields[n_u64] = val;
+ break;
+ }
n_u64++;
}
}
@@ -1950,7 +1968,26 @@ int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
strscpy(str_field, str_val, STR_VAR_LEN_MAX);
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
} else {
- state.entry->fields[n_u64] = vals[i];
+ struct synth_field *field = state.event->fields[i];
+ u64 val = vals[i];
+
+ switch (field->size) {
+ case 1:
+ *(u8 *)&state.entry->fields[n_u64] = (u8)val;
+ break;
+
+ case 2:
+ *(u16 *)&state.entry->fields[n_u64] = (u16)val;
+ break;
+
+ case 4:
+ *(u32 *)&state.entry->fields[n_u64] = (u32)val;
+ break;
+
+ default:
+ state.entry->fields[n_u64] = val;
+ break;
+ }
n_u64++;
}
}
@@ -2069,8 +2106,25 @@ static int __synth_event_add_val(const char *field_name, u64 val,

str_field = (char *)&entry->fields[field->offset];
strscpy(str_field, str_val, STR_VAR_LEN_MAX);
- } else
- entry->fields[field->offset] = val;
+ } else {
+ switch (field->size) {
+ case 1:
+ *(u8 *)&trace_state->entry->fields[field->offset] = (u8)val;
+ break;
+
+ case 2:
+ *(u16 *)&trace_state->entry->fields[field->offset] = (u16)val;
+ break;
+
+ case 4:
+ *(u32 *)&trace_state->entry->fields[field->offset] = (u32)val;
+ break;
+
+ default:
+ trace_state->entry->fields[field->offset] = val;
+ break;
+ }
+ }
out:
return ret;
}
--
2.14.1