From 8c42fcfa92998da170ee84cd24c2377db2e90f33 Mon Sep 17 00:00:00 2001
From: Tao Liu <ltao@redhat.com>
Date: Tue, 12 Jul 2022 19:41:25 +0800
Subject: [PATCH 2/2] Fix data type error in perf_handle_mm_page_alloc

For systems as s390, unsigned long and unsigned int are different in
size. After expanding the macro, the code will be:

unsigned int order = *((unsigned long*)
		       (((const unsigned char*)(&raw->data)) +
		        ((struct __perf_event_field_table_mm_page_alloc*)(perf_event_mm_page_alloc.fields))->order_info.offset));

or simply:

unsigned int order = *((unsigned long*)
                       (((const unsigned char*)(&raw->data)) + 16));

If we have the following data array:

Raw data[16]: 0x0
Raw data[17]: 0x0
Raw data[18]: 0x0
Raw data[19]: 0x2
Raw data[20]: 0x0
Raw data[21]: 0x0
Raw data[22]: 0xc
Raw data[23]: 0xc0

The order will be: 0x0cc0, instead of 0x2.

This patch will fix the error data type.

Signed-off-by: Tao Liu <ltao@redhat.com>
---
 src/backend/perf-events.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/perf-events.c b/src/backend/perf-events.c
index 0252991..67f1dad 100644
--- a/src/backend/perf-events.c
+++ b/src/backend/perf-events.c
@@ -156,7 +156,7 @@ static int perf_handle_mm_page_alloc(const unsigned char* header) {
 			sizeof(callchain->ips) * callchain->nr);
 
 	unsigned long pfn = read_data_from_perf_raw(mm_page_alloc, pfn, unsigned long, raw);
-	unsigned int order = read_data_from_perf_raw(mm_page_alloc, order, unsigned long, raw);
+	unsigned int order = read_data_from_perf_raw(mm_page_alloc, order, unsigned int, raw);
 	int pid = read_data_from_perf_raw(mm_page_alloc, common_pid, int, raw);
 
 	// TODO: pfn == -1?
-- 
2.33.1